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Sample records for acorn barnacle semibalanus

  1. Fouling acorn barnacles in China—a review

    NASA Astrophysics Data System (ADS)

    Cao, Wenhao; Yan, Tao; Li, Zufu; Li, Jing; Cheng, Zhiqiang

    2013-07-01

    We review the species composition, distribution, and seasonal variation of fouling acorn barnacles in Chinese waters—from Bohai Sea and Yellow Sea to East and South China Seas. Thirty-two species of acorn barnacles were found, of which, the dominant species are Amphibalanus amphitrite, A. reticulatus, A. variegates, Balanus trigonus, Fistulobalanus kondakovi, Megabalanus tintinnabulum, Striatobalanus amaryllis, and Eurapha withersi in the fouling communities. A. amphitrite is the dominant species in the coastal waters of Bohai Sea and Yellow Sea and A. reticulatus is dominant in the East and South China Seas. The settlement period of fouling acorn barnacles is usually in summer and autumn. From north to south with the decrease of latitude, their settlement period obviously extends, even to the whole year, and the species number also increases. Other environmental factors, such as salinity and distance from shore, also play an important role in the distribution of fouling acorn barnacles.

  2. Experimental tests of sex allocation theory with two species of simultaneously hermaphroditic acorn barnacles.

    PubMed

    Hoch, Jeffrey Matthew; Levinton, Jeffrey S

    2012-05-01

    Sex allocation theory for simultaneous hermaphrodites predicts increases in relative allocation to male-specific function as competition for fertilizations increases. Theoretical models developed specifically for competing acorn barnacles predict that the proportional allocation to male function increases toward an asymptote of 50% as the number of competitors for fertilizations increases. Experimental manipulations were used to investigate how mate competition affected both relative and absolute allocation to the sex functions for two species of acorn barnacle: Semibalanus balanoides and Balanus glandula. The ratio of male to female allocation did not increase with the number of competitors for either species. However, both species showed increased allocation to male function (estimated as total mass of sex-specific tissues) with increased crowding. Allocation to female function seemed to be limited by other factors and did not vary with mating group size as predicted. Allocation to male and female function were both positively related to body size, but a trade-off between male and female function, a key assumption of prior models, was not observed.

  3. Recruitment density can determine adult morphology and fecundity in the barnacle, Semibalanus balanoides.

    PubMed

    Hills, Jeremy M; Thomason, Jeremy C

    2003-06-01

    Although consequences of the settlement preference of larvae have been well documented, the consequence of these settlement choices on subsequent mortality, morphology and fecundity has been little studied. The aim of this study was to determine the relationship between recruit and adult density and to determine the effect of recruitment on adult morphology and egg tissue mass. This study follows 48,718 barnacles (Semibalanus balanoides) from recruitment at the end of the settling season to reproductively mature adults at a field site in the Clyde Sea (UK). Overall survivorship of the recruits to adulthood was 8.5%, although survivorship was up to 42% on low density settlement panels. In low density colonies (< 10 recruits cm-2), recruitment density was related to adult density (P < 0.001), whereas no relationship was found for higher density colonies. A shell morphology index measured at adulthood was related to recruitment density for low density recruited colonies (P < 0.001) but not high density colonies. Using ANCOVA, variations between the colonies in shell and egg tissue mass were not explained by mass of somatic tissue. However, egg mass was explained by recruitment density (P < 0.01). These results show that adult density is not a reliable indicator of the previous population density of the colony. Moreover, there are marked differences in population development between colonies with high and low recruit densities in terms of impact upon shell morphology and egg production. The dynamics that operate between recruits at the end of the settlement season and sexually mature adults to create the patterns elucidated in this paper, and other literature, remain unclear.

  4. Can ocean acidification affect population dynamics of the barnacle Semibalanus balanoides at its southern range edge?

    PubMed

    Findlay, Helen S; Burrows, Michael T; Kendall, Michael A; Spicer, John I; Widdicombe, Stephen

    2010-10-01

    The global ocean and atmosphere are warming. There is increasing evidence suggesting that, in addition to other environmental factors, climate change is affecting species distributions and local population dynamics. Additionally, as a consequence of the growing levels of atmospheric carbon dioxide (CO2), the oceans are taking up increasing amounts of this CO2, causing ocean pH to decrease (ocean acidification). The relative impacts of ocean acidification on population dynamics have yet to be investigated, despite many studies indicating that there will be at least a sublethal impact on many marine organisms, particularly key calcifying organisms. Using empirical data, we forced a barnacle (Semibalanus balanoides) population model to investigate the relative influence of sea surface temperature (SST) and ocean acidification on a population nearing the southern limit of its geographic distribution. Hindcast models were compared to observational data from Cellar Beach (southwestern United Kingdom). Results indicate that a declining pH trend (-0.0017 unit/yr), indicative of ocean acidification over the past 50 years, does not cause an observable impact on the population abundance relative to changes caused by fluctuations in temperature. Below the critical temperature (here T(crit) = 13.1 degrees C), pH has a more significant affect on population dynamics at this southern range edge. However, above this value, SST has the overriding influence. At lower SST, a decrease in pH (according to the National Bureau of Standards, pHNBs) from 8.2 to 7.8 can significantly decrease the population abundance. The lethal impacts of ocean acidification observed in experiments on early life stages reduce cumulative survival by approximately 25%, which again will significantly alter the population level at this southern limit. Furthermore, forecast predictions from this model suggest that combined acidification and warming cause this local population to die out 10 years earlier than

  5. Multidecadal signals within co-occurring intertidal barnacles Semibalanus balanoides and Chthamalus spp. linked to the Atlantic Multidecadal Oscillation

    NASA Astrophysics Data System (ADS)

    Mieszkowska, N.; Burrows, M. T.; Pannacciulli, F. G.; Hawkins, S. J.

    2014-05-01

    Few links have been established between the Atlantic Multidecadal Oscillation and long-term dynamics of marine systems due to the scarcity of sustained biological time-series with sufficient multi-decadal coverage. The abundances of co-occurring boreal and Lusitanian species of barnacle have been recorded annually at a rocky shore in Devon, southwest England since 1953. Multidecadal cycles in relative abundances of the cold-water Semibalanus balanoides and warm-water Chthamalus spp. are strongly correlated with both local sea surface temperatures, and a ‘Warm Index' of barnacle abundance shows strong links to the basin-scale Atlantic Multidecadal Oscillation. In contrast there are weak or no observed relationships with the North Atlantic Oscillation for either species. The shorter lifecycle of S. balanoides compared to the chthamalids and the increase in spring and summer temperatures to which newly settled S. balanoides recruits have been exposed during the last decade are likely mechanisms by which barnacle densities are responding to low-frequency temperature variability expressed in the Atlantic Multidecadal Oscillation.

  6. Adhesive proteins of stalked and acorn barnacles display homology with low sequence similarities.

    PubMed

    Jonker, Jaimie-Leigh; Abram, Florence; Pires, Elisabete; Varela Coelho, Ana; Grunwald, Ingo; Power, Anne Marie

    2014-01-01

    Barnacle adhesion underwater is an important phenomenon to understand for the prevention of biofouling and potential biotechnological innovations, yet so far, identifying what makes barnacle glue proteins 'sticky' has proved elusive. Examination of a broad range of species within the barnacles may be instructive to identify conserved adhesive domains. We add to extensive information from the acorn barnacles (order Sessilia) by providing the first protein analysis of a stalked barnacle adhesive, Lepas anatifera (order Lepadiformes). It was possible to separate the L. anatifera adhesive into at least 10 protein bands using SDS-PAGE. Intense bands were present at approximately 30, 70, 90 and 110 kilodaltons (kDa). Mass spectrometry for protein identification was followed by de novo sequencing which detected 52 peptides of 7-16 amino acids in length. None of the peptides matched published or unpublished transcriptome sequences, but some amino acid sequence similarity was apparent between L. anatifera and closely-related Dosima fascicularis. Antibodies against two acorn barnacle proteins (ab-cp-52k and ab-cp-68k) showed cross-reactivity in the adhesive glands of L. anatifera. We also analysed the similarity of adhesive proteins across several barnacle taxa, including Pollicipes pollicipes (a stalked barnacle in the order Scalpelliformes). Sequence alignment of published expressed sequence tags clearly indicated that P. pollicipes possesses homologues for the 19 kDa and 100 kDa proteins in acorn barnacles. Homology aside, sequence similarity in amino acid and gene sequences tended to decline as taxonomic distance increased, with minimum similarities of 18-26%, depending on the gene. The results indicate that some adhesive proteins (e.g. 100 kDa) are more conserved within barnacles than others (20 kDa).

  7. Adhesive Proteins of Stalked and Acorn Barnacles Display Homology with Low Sequence Similarities

    PubMed Central

    Jonker, Jaimie-Leigh; Abram, Florence; Pires, Elisabete; Varela Coelho, Ana; Grunwald, Ingo; Power, Anne Marie

    2014-01-01

    Barnacle adhesion underwater is an important phenomenon to understand for the prevention of biofouling and potential biotechnological innovations, yet so far, identifying what makes barnacle glue proteins ‘sticky’ has proved elusive. Examination of a broad range of species within the barnacles may be instructive to identify conserved adhesive domains. We add to extensive information from the acorn barnacles (order Sessilia) by providing the first protein analysis of a stalked barnacle adhesive, Lepas anatifera (order Lepadiformes). It was possible to separate the L. anatifera adhesive into at least 10 protein bands using SDS-PAGE. Intense bands were present at approximately 30, 70, 90 and 110 kilodaltons (kDa). Mass spectrometry for protein identification was followed by de novo sequencing which detected 52 peptides of 7–16 amino acids in length. None of the peptides matched published or unpublished transcriptome sequences, but some amino acid sequence similarity was apparent between L. anatifera and closely-related Dosima fascicularis. Antibodies against two acorn barnacle proteins (ab-cp-52k and ab-cp-68k) showed cross-reactivity in the adhesive glands of L. anatifera. We also analysed the similarity of adhesive proteins across several barnacle taxa, including Pollicipes pollicipes (a stalked barnacle in the order Scalpelliformes). Sequence alignment of published expressed sequence tags clearly indicated that P. pollicipes possesses homologues for the 19 kDa and 100 kDa proteins in acorn barnacles. Homology aside, sequence similarity in amino acid and gene sequences tended to decline as taxonomic distance increased, with minimum similarities of 18–26%, depending on the gene. The results indicate that some adhesive proteins (e.g. 100 kDa) are more conserved within barnacles than others (20 kDa). PMID:25295513

  8. Genetic variation in the acorn barnacle from allozymes to population genomics.

    PubMed

    Flight, Patrick A; Rand, David M

    2012-09-01

    Understanding the patterns of genetic variation within and among populations is a central problem in population and evolutionary genetics. We examine this question in the acorn barnacle, Semibalanus balanoides, in which the allozyme loci Mpi and Gpi have been implicated in balancing selection due to varying selective pressures at different spatial scales. We review the patterns of genetic variation at the Mpi locus, compare this to levels of population differentiation at mtDNA and microsatellites, and place these data in the context of genome-wide variation from high-throughput sequencing of population samples spanning the North Atlantic. Despite considerable geographic variation in the patterns of selection at the Mpi allozyme, this locus shows rather low levels of population differentiation at ecological and trans-oceanic scales (F(ST) ~ 5%). Pooled population sequencing was performed on samples from Rhode Island (RI), Maine (ME), and Southwold, England (UK). Analysis of more than 650 million reads identified approximately 335,000 high-quality SNPs in 19 million base pairs of the S. balanoides genome. Much variation is shared across the Atlantic, but there are significant examples of strong population differentiation among samples from RI, ME, and UK. An F(ST) outlier screen of more than 22,000 contigs provided a genome-wide context for interpretation of earlier studies on allozymes, mtDNA, and microsatellites. F(ST) values for allozymes, mtDNA and microsatellites are close to the genome-wide average for random SNPs, with the exception of the trans-Atlantic F(ST) for mtDNA. The majority of F(ST) outliers were unique between individual pairs of populations, but some genes show shared patterns of excess differentiation. These data indicate that gene flow is high, that selection is strong on a subset of genes, and that a variety of genes are experiencing diversifying selection at large spatial scales. This survey of polymorphism in S. balanoides provides a number of

  9. Isolation and characterization of agglutinins from the hemolymph of an acorn barnacle, Megabalanus volcano.

    PubMed

    Kamiya, H; Muramoto, K; Goto, R

    1987-01-01

    Two agglutinins, MVA-1 and MVA-2, were isolated from the hemolymph of the acorn barnacle, Megabalanus volcano. They agglutinated human erythrocytes irrespective of the ABO blood group and also rabbit and sheep blood cells. Lactose and fetuin strongly inhibited the hemagglutinating activity. D-galactose, D-arabinose and N-acetylneuraminic acid were also moderate inhibitors. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, both MVA-1 and MVA-2 gave a single band corresponding to 38,000 daltons. It split into one major band with a molecular weight of 23,000 in the presence of 2-mercaptoethanol. The two agglutinins showed the same apparent molecular weight of 116,000 by gel filtration. In isoelectric focusing MVA-1 showed one band at pH 4.8, whereas MVA-2 gave a main band at pH 4.4 with few faint ones in the range between pH 4.0 and 4.8. The agglutinins were glycoproteins containing D-mannose and L-fucose as carbohydrate components. No precipitation reaction was observed in Ouchterlony immuno-diffusion tests using rabbit antisera against the agglutinins from the phylogenetically related Megabalanus rosa.

  10. Genetic differentiation, hybridization and adaptive divergence in two subspecies of the acorn barnacle Tetraclita japonica in the northwestern Pacific.

    PubMed

    Tsang, Ling Ming; Chan, Benny K K; Ma, Ka Yan; Chu, Ka Hou

    2008-09-01

    Two acorn barnacles, Tetraclita japonica japonica and Tetraclita japonica formosana, have been recently reclassified as two subspecies, because they are morphologically similar and genetically indistinguishable in mitochondrial DNA sequences. The two barnacles are distinguishable by parietes colour and exhibit parapatric distributions, coexisting in Japan, where T. j. formosana is very low in abundance. Here we investigated the genetic differentiation between the subspecies using 209 polymorphic amplified fragment length polymorphism markers and 341 individuals from 12 locations. The subspecies are genetically highly differentiated (phi(CT) = 0.267). Bayesian analysis and principal component analysis indicate the presence of hybrids in T. j.formosana samples from Japan. Strong differentiation between the northern and southern populations of T. j. japonica was revealed, and a break between Taiwan and Okinawa was also found in T. j. formosana. The differentiation between the two taxa at individual loci does not deviate from neutral expectation, suggesting that the oceanographic pattern which restricts larval dispersal is a more important factor than divergent selection in maintaining genetic and phenotypic differentiation. The T. j. formosana in Japan are probably recent migrants from Okinawa, and their presence in Japan may represent a poleward range shift driven by global warming. This promotes hybridization and might lead to a breakdown of the boundary between the subspecies. However, both local adaptation and larval dispersal are crucial in determining the population structure within each subspecies. Our study provides new insights into the interplay of local adaptation and dispersal in determining the distribution and genetic structure of intertidal biota and the biogeography of the northwestern Pacific.

  11. Complete mitochondrial genome of the acorn barnacle Striatobalanus amaryllis (Crustacea: Maxillopoda): the first representative from Archaeobalanidae.

    PubMed

    Tsang, Ling Ming; Shen, Xin; Chu, Ka Hou; Chan, Benny Kwok Kan

    2015-01-01

    The mitochondrial genome of the barnacle Striatobalanus amaryllis (Sessilia: family Archaeobalanidae) is 15,063 bp in length. All the 13 protein-coding genes (PCGs) initiate with ATD codon (ATG, ATA or ATT). Four PCGs (COX3, ND3, ND4 and ND4L) end with incomplete stop codon (T- -). Four PCGs (ND1, ND4, ND4L and ND5) are encoded on the light strand (underlined below). Refer to the pancrustacean ground pattern, there are not less than seven tRNAs rearranged in the S. amaryllis mitochondrial genome, including tRNA(Ala), tRNA(Glu)/tRNA(Ser)((AGY)), tRNA(Pro)/tRNA(Thr), tRNA(Pro)/tRNA(Thr), tRNA(Tyr), tRNA(Lys), tRNA(Gln) and tRNA(Cys). Three tRNAs (tRNA(Lys), tRNA(Gln) and tRNA(Cys)) are rearranged between S. amaryllis and Tetraclita japonica (Sessilia: Tetraclitidae), meanwhile one tRNA (tRNA(Cys)) inverted from one strand to another. Compared with Megabalanus volcano (Sessilia: Balanidae), an inversion of one large gene block is identified (including three PCGs and three tRNAs) in S. amaryllis mitochondrial genome: tRNA(Phe)-ND5-tRNA(His)-ND4-ND4L-tRNA(Pro).

  12. Complete mitochondrial genome of the acorn barnacle Striatobalanus amaryllis (Crustacea: Maxillopoda): the first representative from Archaeobalanidae.

    PubMed

    Tsang, Ling Ming; Shen, Xin; Chu, Ka Hou; Chan, Benny Kwok Kan

    2015-01-01

    The mitochondrial genome of the barnacle Striatobalanus amaryllis (Sessilia: family Archaeobalanidae) is 15,063 bp in length. All the 13 protein-coding genes (PCGs) initiate with ATD codon (ATG, ATA or ATT). Four PCGs (COX3, ND3, ND4 and ND4L) end with incomplete stop codon (T- -). Four PCGs (ND1, ND4, ND4L and ND5) are encoded on the light strand (underlined below). Refer to the pancrustacean ground pattern, there are not less than seven tRNAs rearranged in the S. amaryllis mitochondrial genome, including tRNA(Ala), tRNA(Glu)/tRNA(Ser)((AGY)), tRNA(Pro)/tRNA(Thr), tRNA(Pro)/tRNA(Thr), tRNA(Tyr), tRNA(Lys), tRNA(Gln) and tRNA(Cys). Three tRNAs (tRNA(Lys), tRNA(Gln) and tRNA(Cys)) are rearranged between S. amaryllis and Tetraclita japonica (Sessilia: Tetraclitidae), meanwhile one tRNA (tRNA(Cys)) inverted from one strand to another. Compared with Megabalanus volcano (Sessilia: Balanidae), an inversion of one large gene block is identified (including three PCGs and three tRNAs) in S. amaryllis mitochondrial genome: tRNA(Phe)-ND5-tRNA(His)-ND4-ND4L-tRNA(Pro). PMID:24397766

  13. Molecular phylogeny, systematics and morphological evolution of the acorn barnacles (Thoracica: Sessilia: Balanomorpha).

    PubMed

    Pérez-Losada, Marcos; Høeg, Jens T; Simon-Blecher, Noa; Achituv, Yair; Jones, Diana; Crandall, Keith A

    2014-12-01

    The Balanomorpha are the largest group of barnacles and rank among the most diverse, commonly encountered and ecologically important marine crustaceans in the world. Paradoxically, despite their relevance and extensive study for over 150years, their evolutionary relationships are still unresolved. Classical morphological systematics was often based on non-cladistic approaches, while modern phylogenetic studies suffer from severe undersampling of taxa and characters (both molecular and morphological). Here we present a phylogenetic analysis of the familial relationships within the Balanomorpha. We estimate divergence times and examine morphological diversity based on five genes, 156 specimens, 10 fossil calibrations, and six key morphological characters. Two balanomorphan superfamilies, eight families and twelve genera were identified as polyphyletic. Chthamaloids, chionelasmatoid and pachylasmatoids split first from the pedunculated ancestors followed by a clade of tetraclitoids and coronuloids, and most of the balanoids. The Balanomorpha split from the Verrucidae (outgroup) in the Lower Cretaceous (139.6 Mya) with all the main lineages, except Pachylasmatoidea, having emerged by the Paleocene (60.9 Mya). Various degrees of convergence were observed in all the assessed morphological characters except the maxillipeds, which suggests that classical interpretations of balanomorphan morphological evolution need to be revised and reinterpreted.

  14. Molecular phylogeny, systematics and morphological evolution of the acorn barnacles (Thoracica: Sessilia: Balanomorpha).

    PubMed

    Pérez-Losada, Marcos; Høeg, Jens T; Simon-Blecher, Noa; Achituv, Yair; Jones, Diana; Crandall, Keith A

    2014-12-01

    The Balanomorpha are the largest group of barnacles and rank among the most diverse, commonly encountered and ecologically important marine crustaceans in the world. Paradoxically, despite their relevance and extensive study for over 150years, their evolutionary relationships are still unresolved. Classical morphological systematics was often based on non-cladistic approaches, while modern phylogenetic studies suffer from severe undersampling of taxa and characters (both molecular and morphological). Here we present a phylogenetic analysis of the familial relationships within the Balanomorpha. We estimate divergence times and examine morphological diversity based on five genes, 156 specimens, 10 fossil calibrations, and six key morphological characters. Two balanomorphan superfamilies, eight families and twelve genera were identified as polyphyletic. Chthamaloids, chionelasmatoid and pachylasmatoids split first from the pedunculated ancestors followed by a clade of tetraclitoids and coronuloids, and most of the balanoids. The Balanomorpha split from the Verrucidae (outgroup) in the Lower Cretaceous (139.6 Mya) with all the main lineages, except Pachylasmatoidea, having emerged by the Paleocene (60.9 Mya). Various degrees of convergence were observed in all the assessed morphological characters except the maxillipeds, which suggests that classical interpretations of balanomorphan morphological evolution need to be revised and reinterpreted. PMID:25261121

  15. Molecular phylogeny of the acorn barnacle family Tetraclitidae (Cirripedia: Balanomorpha: Tetraclitoidea): validity of shell morphology and arthropodal characteristics in the systematics of Tetraclitid barnacles.

    PubMed

    Tsang, Ling Ming; Chu, Ka Hou; Achituv, Yair; Chan, Benny Kwok Kan

    2015-01-01

    Shell structure is a crucial aspect of barnacle systematics. Within Tetraclitidae, the diametric and monometric growth patterns and number of rows of parietal tubes in the shells are key characteristics used to infer evolutionary trends. We used molecular analysis based on seven genes (mitochondrial COI, 16S and 12S rRNA, and nuclear EF1, RPII, H3, and 18S rRNA) to test two traditional phylogenetic hypothesis: (1) Tetraclitid barnacles are divided into two major lineages, which are distinguished according to monometric and diametric shell growth patterns, and (2) the evolutionary trend in shell parietal development began with a solid shell, which developed into a single tubiferous shell, which then developed into multitubiferous shells. The results indicated that Tetraclitinae and Newmanellinae are not monophyletic, but that Austrobalaninae and Tetraclitellinae are. The phylogram based on the genetic data suggested that Bathylasmatidae is nested within the Tetraclitidae, forming a sister relationship with the Austrobalaninae and Tetraclitinae/Newmanellinae clade. Within the Tetraclitinae/Newmanellinae clade, the genera Tetraclita (multitubiferous shell), Tesseropora (single tubiferous shell), and Yamaguchiella (multitubiferous shell) are polyphyletic. The results suggested that shell morphology and growth patterns do not reflect the evolutionary history of Tetraclitidae, whereas the arthropodal characteristics are informative. PMID:25263422

  16. Molecular phylogeny of the acorn barnacle family Tetraclitidae (Cirripedia: Balanomorpha: Tetraclitoidea): validity of shell morphology and arthropodal characteristics in the systematics of Tetraclitid barnacles.

    PubMed

    Tsang, Ling Ming; Chu, Ka Hou; Achituv, Yair; Chan, Benny Kwok Kan

    2015-01-01

    Shell structure is a crucial aspect of barnacle systematics. Within Tetraclitidae, the diametric and monometric growth patterns and number of rows of parietal tubes in the shells are key characteristics used to infer evolutionary trends. We used molecular analysis based on seven genes (mitochondrial COI, 16S and 12S rRNA, and nuclear EF1, RPII, H3, and 18S rRNA) to test two traditional phylogenetic hypothesis: (1) Tetraclitid barnacles are divided into two major lineages, which are distinguished according to monometric and diametric shell growth patterns, and (2) the evolutionary trend in shell parietal development began with a solid shell, which developed into a single tubiferous shell, which then developed into multitubiferous shells. The results indicated that Tetraclitinae and Newmanellinae are not monophyletic, but that Austrobalaninae and Tetraclitellinae are. The phylogram based on the genetic data suggested that Bathylasmatidae is nested within the Tetraclitidae, forming a sister relationship with the Austrobalaninae and Tetraclitinae/Newmanellinae clade. Within the Tetraclitinae/Newmanellinae clade, the genera Tetraclita (multitubiferous shell), Tesseropora (single tubiferous shell), and Yamaguchiella (multitubiferous shell) are polyphyletic. The results suggested that shell morphology and growth patterns do not reflect the evolutionary history of Tetraclitidae, whereas the arthropodal characteristics are informative.

  17. Acorns Alive.

    ERIC Educational Resources Information Center

    Matthews, Catherine; Vickers, Valerie; Patrick, Patricia

    2002-01-01

    Introduces a lesson plan on the role of the acorn and its complex community of biotic relationships between animal and fungal organisms. Introduces students to ecological concepts through acorn investigations including dissection of acorns and exploring the organisms' interaction web. (YDS)

  18. Mitochondrial genome of the intertidal acorn barnacle Tetraclita serrata Darwin, 1854 (Crustacea: Sessilia): Gene order comparison and phylogenetic consideration within Sessilia.

    PubMed

    Shen, Xin; Tsang, Ling Ming; Chu, Ka Hou; Achituv, Yair; Chan, Benny Kwok Kan

    2015-08-01

    The complete mitochondrial genome of the intertidal barnacle Tetraclita serrata Darwin, 1854 (Crustacea: Maxillopoda: Sessilia) is presented. The genome is a circular molecule of 15,200 bp, which encodes 13 PCGs, 2 ribosomal RNA genes, and 22 transfer RNA genes. All non-coding regions are 591 bp in length, with the longest one speculated as the control region (389 bp), which is located between srRNA and trnK. The overall A+T content of the mitochondrial genome of T. serrata is 65.4%, which is lowest among all the eight mitochondrial genomes reported from sessile barnacles. There are variations of initiation and stop codons in the reported sessile barnacle mitochondrial genomes. Large-scale gene rearrangements are found in these genomes as compared to the pancrustacean ground pattern. ML and Bayesian analyses of all 15 complete mitochondrial genomes available from Maxillopoda lead to identical phylogenies. The phylogenetic tree based on mitochondrial PCGs shows that Argulus americanus (Branchiura) cluster with Armillifer armillatus (Pentastomida), distinct from all ten species from Cirripedia. Within the order Sessilia, Amphibalanus amphitrite (Balanidae) clusters with Striatobalanus amaryllis (Archaeobalanidae), and Nobia grandis (Pyrgomatidae). However, the two Megabalanus (Balanidae) are separated from the above grouping, resulting in non-monophyly of the family Balanidae. Moreover, the two Megabalanus have large-scale rearrangements as compared to the gene order shared by former three species. Therefore, both phylogenetic analysis using PCG sequences and gene order comparison suggest that Balanidae is not a monophyletic group. Given the limited taxa and moderate support values of the internal branches, the non-monophyly of the family Balanidae requires further verification. PMID:25907711

  19. Mitochondrial genome of the intertidal acorn barnacle Tetraclita serrata Darwin, 1854 (Crustacea: Sessilia): Gene order comparison and phylogenetic consideration within Sessilia.

    PubMed

    Shen, Xin; Tsang, Ling Ming; Chu, Ka Hou; Achituv, Yair; Chan, Benny Kwok Kan

    2015-08-01

    The complete mitochondrial genome of the intertidal barnacle Tetraclita serrata Darwin, 1854 (Crustacea: Maxillopoda: Sessilia) is presented. The genome is a circular molecule of 15,200 bp, which encodes 13 PCGs, 2 ribosomal RNA genes, and 22 transfer RNA genes. All non-coding regions are 591 bp in length, with the longest one speculated as the control region (389 bp), which is located between srRNA and trnK. The overall A+T content of the mitochondrial genome of T. serrata is 65.4%, which is lowest among all the eight mitochondrial genomes reported from sessile barnacles. There are variations of initiation and stop codons in the reported sessile barnacle mitochondrial genomes. Large-scale gene rearrangements are found in these genomes as compared to the pancrustacean ground pattern. ML and Bayesian analyses of all 15 complete mitochondrial genomes available from Maxillopoda lead to identical phylogenies. The phylogenetic tree based on mitochondrial PCGs shows that Argulus americanus (Branchiura) cluster with Armillifer armillatus (Pentastomida), distinct from all ten species from Cirripedia. Within the order Sessilia, Amphibalanus amphitrite (Balanidae) clusters with Striatobalanus amaryllis (Archaeobalanidae), and Nobia grandis (Pyrgomatidae). However, the two Megabalanus (Balanidae) are separated from the above grouping, resulting in non-monophyly of the family Balanidae. Moreover, the two Megabalanus have large-scale rearrangements as compared to the gene order shared by former three species. Therefore, both phylogenetic analysis using PCG sequences and gene order comparison suggest that Balanidae is not a monophyletic group. Given the limited taxa and moderate support values of the internal branches, the non-monophyly of the family Balanidae requires further verification.

  20. Barnacle-induced corrosion of high-alloyed steels

    SciTech Connect

    Koryakova, M.D.; Filonenko, N.Yu.; Kaplin, Yu.M.

    1995-03-01

    Local corrosion of two sorts of high-alloyed steels under the action of acorn barnacles (Balanuses) has been studied. It has been shown that in natural seawater at anaerobic conditions beneath living and dead barnacles, metabolic activity of bacteria may be considered as a primary cause for local surface depassivation.

  1. The invasive barnacle species, Austrominius modestus: Its status and competition with indigenous barnacles on the Isle of Cumbrae, Scotland

    NASA Astrophysics Data System (ADS)

    Gallagher, Mary Catherine; Davenport, John; Gregory, Susan; McAllen, Rob; O'Riordan, Ruth

    2015-01-01

    The invasive barnacle Austrominius (= Elminius) modestus has been present in Europe since the 1940s, and has recently been recorded to outnumber native barnacle species at some locations, including an Irish marine nature reserve. It has been suggested that these increases in abundance following a lag phase since establishment, represent the awakening of an 'ecological sleeper', due to changes in environmental conditions. Austrominius modestus was first recorded on the Isle of Cumbrae, Scotland in 1955, and was reported to be well established on the island by 2007. Since this location is close to the northern limit of the invaded range of A. modestus, it has been chosen as a site for the long term monitoring of this species. Quantitative and semi-quantitative surveys of the abundance of A. modestus, together with the native barnacle species Chthamalus montagui and Semibalanus balanoides, have been made on the island on a biannual basis since 2009. This study examined changes in the abundances of these three species from 2009 to 2013, and reports on the present status of this invasive species on the island. Austrominius modestus was found at all sites surveyed, but did not outnumber native barnacle species at any site. Semibalanus balanoides, a cold water boreal species, was the most abundant barnacle species at most sites from 2009 to 2013. All three barnacle species underwent a decline in 2011, but had increased in abundance by 2013. Despite undergoing the smallest increase in abundance between 2011 and 2013, S. balanoides remains the dominant barnacle species on the Isle of Cumbrae. Nearly sixty years after its initial discovery on the island, A. modestus is widespread, however it has not outnumbered native species, which continue to recruit at high densities. This competitive pressure makes it unlikely that A. modestus will outnumber native barnacle species at this location, close to its northern limit, in the near future.

  2. Temporal changes in the strength of density-dependent mortality and growth in intertidal barnacles.

    PubMed

    Jenkins, Stuart R; Murua, Jefferson; Burrows, Michael T

    2008-05-01

    1. In demographically open marine systems, the extent to which density-dependent processes in the benthic adult phase are required for population persistence is unclear. At one extreme, represented by the recruitment limitation hypothesis, larval supply may be insufficient for the total population size to reach a carrying capacity and density-independent mortality predominates. At the opposite extreme, populations are saturated and density-dependent mortality is sufficiently strong to reshape patterns established at settlement. 2. We examined temporal variation in the way density-independent and density-dependent mortality interact in a typical sessile marine benthic invertebrate, the acorn barnacle Semibalanus balanoides (L.), over a 2-year period. 3. Recruitment was manipulated at two high recruitment sites in north Wales, UK to produce recruit densities covering the range naturally found in this species. Following manipulation, fixed quadrats were monitored using digital photography and temporal changes in mortality and growth rate were examined. 4. Over a 2-year period there was a clear, spatially consistent, over-compensatory relationship between the density of recruits and adult abundance indicating strong density-dependent mortality. The strength of density dependence intensified with increasing recruitment. 5. Density-dependent mortality did not operate consistently over the study period. It only operated in the early part of the benthic phase, but the pattern of adult abundance generated was maintained throughout the whole 2-year period. Thus, early life-history processes dictated adult population abundance and dynamics. 6. Examination of the natural recruitment regime in the area of study indicated that both positive and negative effects of recruitment will occur over scales varying from kilometres to metres.

  3. Comparative analysis of barnacle tropomyosin: divergence from decapod tropomyosins and role as a potential allergen.

    PubMed

    Suma, Yota; Ishizaki, Shoichiro; Nagashima, Yuji; Lu, Ying; Ushio, Hideki; Shiomi, Kazuo

    2007-06-01

    Tropomyosin, a myofibrillar protein of 35-38 kDa, represents a major and cross-reactive allergen in decapod crustaceans. This study was initiated to clarify whether decapod-allergic patients also recognize tropomyosins of barnacles, crustaceans phylogenetically remote from decapods, which are locally consumed as a delicacy. On SDS-PAGE, a 37 kDa protein was observed in all the heated extracts prepared from two species of decapods (American lobster Homarus americanus and black tiger prawn Penaeus monodon) and two species of barnacles (acorn barnacle Balanus rostratus and goose barnacle Capitulum mitella). In immunoblotting, the 37 kDa protein was found to react with monoclonal antibodies against American lobster tropomyosin and hence identified as tropomyosin. The patient sera reacted to tropomyosins from both decapods and barnacles and the reactivity was abolished by preincubation with American lobster tropomyosin, demonstrating that barnacle tropomyosins are allergens cross-reactive with decapod tropomyosins. However, the amino acid sequence of acorn barnacle tropomyosin, deduced by cDNA cloning experiments, shares higher sequence identity with abalone tropomyosins than with decapod tropomyosins. In accordance with this, the phylogenetic tree made for tropomyosins from various animals showed that the acorn barnacle tropomyosin is evolutionally classified not into the decapod tropomyosin family but into the molluscan tropomyosin family.

  4. Barnacles resist removal by crack trapping.

    PubMed

    Hui, Chung-Yuen; Long, Rong; Wahl, Kathryn J; Everett, Richard K

    2011-06-01

    We study the mechanics of pull-off of a barnacle adhering to a thin elastic layer which is bonded to a rigid substrate. We address the case of barnacles having acorn shell geometry and hard, calcarious base plates. Pull-off is initiated by the propagation of an interface edge crack between the base plate and the layer. We compute the energy release rate of this crack as it grows along the interface using a finite element method. We also develop an approximate analytical model to interpret our numerical results and to give a closed-form expression for the energy release rate. Our result shows that the resistance of barnacles to interfacial failure arises from a crack-trapping mechanism.

  5. Barnacles resist removal by crack trapping

    PubMed Central

    Hui, Chung-Yuen; Long, Rong; Wahl, Kathryn J.; Everett, Richard K.

    2011-01-01

    We study the mechanics of pull-off of a barnacle adhering to a thin elastic layer which is bonded to a rigid substrate. We address the case of barnacles having acorn shell geometry and hard, calcarious base plates. Pull-off is initiated by the propagation of an interface edge crack between the base plate and the layer. We compute the energy release rate of this crack as it grows along the interface using a finite element method. We also develop an approximate analytical model to interpret our numerical results and to give a closed-form expression for the energy release rate. Our result shows that the resistance of barnacles to interfacial failure arises from a crack-trapping mechanism. PMID:21208968

  6. Modeling variation in interaction strength between barnacles and fucoids.

    PubMed

    Kordas, Rebecca L; Dudgeon, Steve

    2009-01-01

    The strength by which species interact can vary throughout their ontogeny, as environments vary in space and time, and with the density of their populations. Characterizing strengths of interaction in situ for even a small number of species is logistically difficult and may apply only to those conditions under which the estimates were derived. We sought to combine data from field experiments estimating interaction strength of life stages of the barnacle, Semibalanus balanoides, on germlings of Ascophyllum nodosum, with a model that explored the consequences of variability at per capita and per population levels to the abundance of year-old algal recruits. We further simulated how this interaction affected fucoid germling abundance as the timing of their respective settlements varied relative to one another, as occurs regionally across the Gulf of Maine, USA. Juvenile S. balanoides have a weak estimated per capita effect on germlings. Germling populations are sensitive to variation in per capita effects of juvenile barnacles because of the typically large population sizes of the latter. However, high mortality of juvenile barnacles weakens the population interaction strength over time. Adult barnacles probably weakly facilitate fucoid germlings, but greater survival of adults sustains the strength of that interaction at the population level. Germling abundance is positively associated with densities of adult barnacles and negatively associated with that of juvenile barnacles. Metamorphosing cyprid larvae have the strongest per capita effect on germling abundance, but the interaction between the two stages is so short-lived that germling abundance is altered little. Variation in the timing of barnacle and A. nodosum settlement relative to one another had very little influence on the abundance of yearling germlings. Interactions between barnacles and germlings may influence the demographic structure of A. nodosum populations and the persistence of fucoid

  7. Modeling variation in interaction strength between barnacles and fucoids

    PubMed Central

    Dudgeon, Steve

    2009-01-01

    The strength by which species interact can vary throughout their ontogeny, as environments vary in space and time, and with the density of their populations. Characterizing strengths of interaction in situ for even a small number of species is logistically difficult and may apply only to those conditions under which the estimates were derived. We sought to combine data from field experiments estimating interaction strength of life stages of the barnacle, Semibalanus balanoides, on germlings of Ascophyllum nodosum, with a model that explored the consequences of variability at per capita and per population levels to the abundance of year-old algal recruits. We further simulated how this interaction affected fucoid germling abundance as the timing of their respective settlements varied relative to one another, as occurs regionally across the Gulf of Maine, USA. Juvenile S. balanoides have a weak estimated per capita effect on germlings. Germling populations are sensitive to variation in per capita effects of juvenile barnacles because of the typically large population sizes of the latter. However, high mortality of juvenile barnacles weakens the population interaction strength over time. Adult barnacles probably weakly facilitate fucoid germlings, but greater survival of adults sustains the strength of that interaction at the population level. Germling abundance is positively associated with densities of adult barnacles and negatively associated with that of juvenile barnacles. Metamorphosing cyprid larvae have the strongest per capita effect on germling abundance, but the interaction between the two stages is so short-lived that germling abundance is altered little. Variation in the timing of barnacle and A. nodosum settlement relative to one another had very little influence on the abundance of yearling germlings. Interactions between barnacles and germlings may influence the demographic structure of A. nodosum populations and the persistence of fucoid

  8. Predation on barnacles of intertidal and subtidal mussel beds in the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Buschbaum, Christian

    2002-04-01

    Balanids are the numerically dominant epibionts on mussel beds in the Wadden Sea. Near the island of Sylt (German Bight, North Sea), Semibalanus balanoides dominated intertidally and Balanus crenatus subtidally. Field experiments were conducted to test the effects of predation on the density of barnacle recruits. Subtidally, predator exclusion resulted in significantly increased abundances of B. crenatus, while predator exclusion had no significant effects on the density of S. balanoides intertidally. It is suggested that recruitment of B. crenatus to subtidal mussel beds is strongly affected by adult shore crabs ( Carcinus maenas) and juvenile starfish ( Asterias rubens), whereas recruits of S. balanoides in the intertidal zone are mainly influenced by grazing and bulldozing of the very abundant periwinkle Littorina littorea, which is rare subtidally. Thus, not only do the barnacle species differ between intertidal and subtidal mussel beds, but the biotic control factors do so as well.

  9. Growth and development of the barnacle Amphibalanus amphitrite: time and spatially resolved structure and chemistry of the base plate.

    PubMed

    Burden, Daniel K; Spillmann, Christopher M; Everett, Richard K; Barlow, Daniel E; Orihuela, Beatriz; Deschamps, Jeffrey R; Fears, Kenan P; Rittschof, Daniel; Wahl, Kathryn J

    2014-01-01

    The radial growth and advancement of the adhesive interface to the substratum of many species of acorn barnacles occurs underwater and beneath an opaque, calcified shell. Here, the time-dependent growth processes involving various autofluorescent materials within the interface of live barnacles are imaged for the first time using 3D time-lapse confocal microscopy. Key features of the interface development in the striped barnacle, Amphibalanus (= Balanus) amphitrite were resolved in situ and include advancement of the barnacle/substratum interface, epicuticle membrane development, protein secretion, and calcification. Microscopic and spectroscopic techniques provide ex situ material identification of regions imaged by confocal microscopy. In situ and ex situ analysis of the interface support the hypothesis that barnacle interface development is a complex process coupling sequential, timed secretory events and morphological changes. This results in a multi-layered interface that concomitantly fulfills the roles of strongly adhering to a substratum while permitting continuous molting and radial growth at the periphery.

  10. Some biological consequences of environmental change: a study using barnacles (Cirripedia: Balanomorpha) and gum trees (Angiospermae: Myrtaceae).

    PubMed

    Buckeridge, John S

    2010-06-01

    Uniformitarianism permits understanding of the past on the basis of the present, and modeling the future through consideration of the fossil record. The present paper addresses the impact environmental (climatic) change has had on acorn barnacles and eucalyptus trees. Acorn barnacles (Balanomorpha) are first recorded after the K/T mass-extinction event. In the Paleogene, rapid radiation resulted in their occupying most marine environments. That balanomorphs survived both the Paleocene-Eocene thermal maximum and the Pleistocene glaciation is testament to their ability to adapt to opportunities; they are known from the littoral (Chamaesipho) to depths of 3600 m (Tetrachaelasma) and within this from diverse substrates: rock, wood and miscellaneous flotsam, plus in symbiosis or commensalism with most larger marine organisms. Darwin's (1854) view of the late Tertiary as the age of barnacles is reflected in their diversity, distribution and biomass. Barnacles are contrasted with the Australian Myrtaceae: plants ranging from woody shrubs to tall trees. The most significant is Eucalyptus sensu lato, which typifies Australia's flora, and is characterized by aromatic leaves that produce eucalyptol. Eucalyptus has evolved strategies that result in its domination of Australian open woodlands: these include production of highly flammable eucalyptol oil (with a flashpoint of 49 °C) and an unprecedented ability to regenerate following forest fires. Gum trees and barnacles first appear in the Paleogene, their earliest records are Australasian, and they both demonstrate extraordinary resilience when environmental conditions are optimal. PMID:21392330

  11. Some biological consequences of environmental change: a study using barnacles (Cirripedia: Balanomorpha) and gum trees (Angiospermae: Myrtaceae).

    PubMed

    Buckeridge, John S

    2010-06-01

    Uniformitarianism permits understanding of the past on the basis of the present, and modeling the future through consideration of the fossil record. The present paper addresses the impact environmental (climatic) change has had on acorn barnacles and eucalyptus trees. Acorn barnacles (Balanomorpha) are first recorded after the K/T mass-extinction event. In the Paleogene, rapid radiation resulted in their occupying most marine environments. That balanomorphs survived both the Paleocene-Eocene thermal maximum and the Pleistocene glaciation is testament to their ability to adapt to opportunities; they are known from the littoral (Chamaesipho) to depths of 3600 m (Tetrachaelasma) and within this from diverse substrates: rock, wood and miscellaneous flotsam, plus in symbiosis or commensalism with most larger marine organisms. Darwin's (1854) view of the late Tertiary as the age of barnacles is reflected in their diversity, distribution and biomass. Barnacles are contrasted with the Australian Myrtaceae: plants ranging from woody shrubs to tall trees. The most significant is Eucalyptus sensu lato, which typifies Australia's flora, and is characterized by aromatic leaves that produce eucalyptol. Eucalyptus has evolved strategies that result in its domination of Australian open woodlands: these include production of highly flammable eucalyptol oil (with a flashpoint of 49 °C) and an unprecedented ability to regenerate following forest fires. Gum trees and barnacles first appear in the Paleogene, their earliest records are Australasian, and they both demonstrate extraordinary resilience when environmental conditions are optimal.

  12. Biogeography, Competition, and Microclimate: The Barnacle Chthamalus fragilis in New England.

    PubMed

    Wethey, David S

    2002-08-01

    Geographic limits of species are commonly associated with climatic or physical boundaries, but the mechanisms of exclusion at the limits of distribution are poorly understood. In some intertidal populations, the strengths of interactions with natural enemies are mediated by microclimate, and determine geographic limits. The northern limit of the barnacle Chthamalus fragilis in New England is the south side of Cape Cod, Massachusetts. South of the cape, Chthamalus has a refuge from competition in the high intertidal, which is too hot for survival of its superior competitor Semibalanus balanoides. North of the cape, the high intertidal is cooler, and Semibalanus survives, so Chthamalus has no refuge. Thus, geographic variation in the strength of competition may determine the geographic limit of Chthamalus. Intolerance of cold by Chthamalus cannot account for the geographic limit: transplants of Chthamalus 80 km beyond its northern limit survived up to 8 yr in the absence of competition with Semibalanus. At the geographic limit of Chthamalus in the Cape Cod Canal there are two bridges, 5 km apart. On the southern bridge, Chthamalus is abundant and occupies a refuge above Semibalanus. On the northern bridge in 2001, only 7 individual Chthamalus were present. Despite the proximity of the bridges, their microclimates are very different. The southern bridge, where Chthamalus is abundant, is up to 8°C hotter than the northern bridge. This higher temperature creates a refuge in the high intertidal for Chthamalus. On the cooler northern bridge, there is no refuge for Chthamalus. Because of the difference in temperatures of the water masses that meet in the canal, heat storage in the rock of the bridge piers causes the temperatures to differ between the bridges. Thus, geographic change in microclimate alters the strength of competition, and determines the geographic limit."When we travel from south to north, or from a damp region to a dry, we invariably see some species

  13. Biogeography, Competition, and Microclimate: The Barnacle Chthamalus fragilis in New England.

    PubMed

    Wethey, David S

    2002-08-01

    Geographic limits of species are commonly associated with climatic or physical boundaries, but the mechanisms of exclusion at the limits of distribution are poorly understood. In some intertidal populations, the strengths of interactions with natural enemies are mediated by microclimate, and determine geographic limits. The northern limit of the barnacle Chthamalus fragilis in New England is the south side of Cape Cod, Massachusetts. South of the cape, Chthamalus has a refuge from competition in the high intertidal, which is too hot for survival of its superior competitor Semibalanus balanoides. North of the cape, the high intertidal is cooler, and Semibalanus survives, so Chthamalus has no refuge. Thus, geographic variation in the strength of competition may determine the geographic limit of Chthamalus. Intolerance of cold by Chthamalus cannot account for the geographic limit: transplants of Chthamalus 80 km beyond its northern limit survived up to 8 yr in the absence of competition with Semibalanus. At the geographic limit of Chthamalus in the Cape Cod Canal there are two bridges, 5 km apart. On the southern bridge, Chthamalus is abundant and occupies a refuge above Semibalanus. On the northern bridge in 2001, only 7 individual Chthamalus were present. Despite the proximity of the bridges, their microclimates are very different. The southern bridge, where Chthamalus is abundant, is up to 8°C hotter than the northern bridge. This higher temperature creates a refuge in the high intertidal for Chthamalus. On the cooler northern bridge, there is no refuge for Chthamalus. Because of the difference in temperatures of the water masses that meet in the canal, heat storage in the rock of the bridge piers causes the temperatures to differ between the bridges. Thus, geographic change in microclimate alters the strength of competition, and determines the geographic limit."When we travel from south to north, or from a damp region to a dry, we invariably see some species

  14. The coexistence of acorns with different maturation patterns explains acorn production variability in cork oak.

    PubMed

    Pons, Josep; Pausas, Juli G

    2012-07-01

    In dry areas such as Mediterranean ecosystems, fluctuations in seed production are typically explained by resource (water) availability. However, acorn production in cork oak (Quercus suber) populations shows a very low relationship to weather. Because cork oak trees produce acorns with different maturation patterns (annual and biennial), we hypothesized that acorn production in coexisting individuals with a different dominant acorn maturation type should respond differently to climatic factors and that disaggregating the trees according to their acorn-maturation pattern should provide a more proximal relation to weather factors. We assessed acorn production variability in fragmented cork oak populations of the eastern Iberian Peninsula by counting the total number of acorns in 155 trees during an 8-year period. An initial assessment of acorn production variability in relation to weather parameters yielded very low explained variance (7%). However, after the trees were grouped according to their dominant acorn maturation pattern, weather parameters were found to account for 44% of the variability in acorn crops, with trees with annual acorns exhibiting mast fruiting in years with reduced spring frost and shorter summer droughts and trees with biennial acorns showing the opposite pattern. Thus, conditions that negatively affect annual production could be beneficial for biennial production (and vice versa). The results highlight the importance of the resource-matching hypothesis for explaining acorn production in Quercus suber and suggest that different seed maturation types within a population may allow the species to deal with highly variable weather conditions. They also emphasize the importance of understanding acorn maturation patterns for interpreting masting cycles.

  15. Sojourner, Barnacle Bill, & Yogi

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This view taken by the Imager for Mars Pathfinder (IMP) was taken on Sol 3. Barnacle Bill, the small rock at left, and Yogi, the large rock at upper right, have been examined by Sojourner's Alpha Proton X-Ray Spectrometer (APXS) instrument and the rover's cameras. Barnacle Bill has the chemical composition of an andesitic volcanic rock, but may have been produced by sedimentation processes or meteorite impact. The lander's rear ramp which Sojourner used to descend to the Martian surface is at lower left, and a portion of deflated airbag is at lower right.

    Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  16. Regional decoupling between NW Atlantic barnacle recruit and adult density is related to changes in pelagic food supply and benthic disturbance

    NASA Astrophysics Data System (ADS)

    Cole, Stephen W. B.; Scrosati, Ricardo A.; Tam, Jamie C.; Sussmann, Andrea V.

    2011-01-01

    We investigated the regional variation in barnacle ( Semibalanus balanoides) recruit and adult abundance on the NW Atlantic coast. At the end of the recruitment season (June-July), we sampled wave-exposed rocky intertidal sites in two regions on the open Atlantic coast (Maine, AM, and Nova Scotia, AN) and in two regions on the Gulf of St. Lawrence coast (Northumberland Strait, GN, and Cape Breton Island, GC). Recruit density was highest in the southernmost region (AM), followed by GN and, then, by AN and GC. Regional values of nearshore primary productivity (satellite data of chlorophyll- a concentration, a surrogate for phytoplankton abundance) were highest for AM and GN, suggesting that food supply (barnacles are filter feeders) is an important factor determining regional recruitment patterns. Adult barnacle density was regionally decoupled from recruit density. Adults occurred in very low abundances on the Gulf of St. Lawrence coast (GN and GC) and were relatively abundant on the Atlantic coast (AM and AN), although always in much lower abundances than recruits. The low adult densities on the Gulf of St. Lawrence coast seem to result mainly from intense ice scour, as this coast freezes extensively every winter, as opposed to the ice-free Atlantic coast. Ice scour thus appears to override regional recruitment differences in determining adult density. Therefore, our data suggest that both pelagic food supply and benthic disturbance contribute to setting regional patterns in barnacle population structure on the NW Atlantic coast.

  17. Barnacle removal process and product

    SciTech Connect

    Richmond, T.L.

    1984-07-24

    Barnacles from marine vessels are removed by spraying the surfaces thereof with a mixture the active ingredients of which are a hydrocarbon liquid oil; a surfactant; alcohol; a metal hypochlorite; and an alkyl, dialkyl benzyl ammonium salt. After the solution has been applied to the surfaces for about 20 minutes, the barnacles are removed by power spraying the surfaces with water.

  18. Barnacles and biofouling.

    PubMed

    Holm, Eric R

    2012-09-01

    Biofouling, the attachment and growth of organisms on submerged, man-made surfaces, has plagued ship operators for at least 2500 years. Accumulation of biofouling, including barnacles and other sessile marine invertebrates, increases the frictional resistance of ships' hulls, resulting in an increase in power and in fuel consumption required to make speed. Scientists and engineers recognized over 100 years ago that in order to solve the biofouling problem, a deeper understanding of the biology of the organisms involved, particularly with regard to larval settlement and metamorphosis and adhesives and adhesion, would be required. Barnacles have served as an important tool in pursuing this research. Over the past 20 years, the pace of these studies has accelerated, likely driven by the introduction of environmental regulations banning the most effective biofouling control products from the market. Research has largely focused on larval settlement and metamorphosis, the development of new biocides, and materials/surface science. Increased research has so far, however, failed to result in commercial applications. Two recent successes (medetomidine/Selektope(®), surface-bound noradrenaline) build on our improving understanding of the role of the larval nervous system in mediating settlement and metamorphosis. New findings with regard to the curing of barnacle adhesives may pave the way to additional successes. Although the development of most current biofouling control technologies remains largely uninfluenced by basic research on, for example, the ability of settling larvae to perceive surface cues, or the nature of the interaction between organismal adhesives and the substrate, newly-developed materials can serve as useful probes to further our understanding of these processes.

  19. Growth and development of the barnacle Amphibalanus amphitrite: time and spatially resolved structure and chemistry of the base plate

    PubMed Central

    Burden, Daniel K.; Spillmann, Christopher M.; Everett, Richard K.; Barlow, Daniel E.; Orihuela, Beatriz; Deschamps, Jeffrey R.; Fears, Kenan P.; Rittschof, Daniel; Wahl, Kathryn J.

    2014-01-01

    The radial growth and advancement of the adhesive interface to the substratum of many species of acorn barnacles occurs underwater and beneath an opaque, calcified shell. Here, the time-dependent growth processes involving various autofluorescent materials within the interface of live barnacles are imaged for the first time using 3D time-lapse confocal microscopy. Key features of the interface development in the striped barnacle, Amphibalanus (= Balanus) amphitrite were resolved in situ and include advancement of the barnacle/substratum interface, epicuticle membrane development, protein secretion, and calcification. Microscopic and spectroscopic techniques provide ex situ material identification of regions imaged by confocal microscopy. In situ and ex situ analysis of the interface support the hypothesis that barnacle interface development is a complex process coupling sequential, timed secretory events and morphological changes. This results in a multi-layered interface that concomitantly fulfills the roles of strongly adhering to a substratum while permitting continuous molting and radial growth at the periphery. PMID:25115515

  20. The complete mitochondrial genome of common fouling barnacle Amphibalanus amphitrite (Darwin, 1854) (Sessilia: Balanidae) reveals gene rearrangements compared to pancrustacean ground pattern.

    PubMed

    Shen, Xin; Chan, Benny Kwok Kan; Tsang, Ling Ming

    2015-01-01

    Here we present the complete mitochondrial genome of the common fouling barnacle, Amphibalanus amphitrite (Sessilia: Balanidae). Refer to pancrustacean mitochondrial ground pattern, seven conserved genes blocks are found in A. amphitrite mitochondrial genome. On the other hand, translocations of at least six tRNAs (trnA, trnE/trnS2, trnP/trnT, trnK, trnQ and trnC) are identified and translocation and inversion occurred simultaneously in one tRNAs (trnY). Comparison among the acorn barnacle mitogenomes reveals inversion of a six-gene block (trnP-nd4L-nd4-trnH-nd5-trnF) between A. amphitrite and Megabalanus. Volcano (Balanidae), suggesting non-conserved gene order even at intrafamilial level. The three species share three conserved genes blocks, of which the two are derived from the pancrustacean ground pattern and represent synapomorphies of acorn barnacles. In sum, large-scale gene rearrangements are observed in A. amphitrite mitochondrial genome as compared to the pancrustacean ground pattern and other barnacle species.

  1. Darwin and barnacles.

    PubMed

    Deutsch, Jean

    2010-02-01

    In this essay, I discuss the origin of Charles Darwin's interest in cirripedes (barnacles). Indeed, he worked intensively on cirripedes during the years in which he was developing the theory that eventually led to the publication of The Origin of Species. In the light of our present knowledge, I present Darwin's achievements in the morphology, systematics and biology of these small marine invertebrates, and also his mistakes. I suggest that the word that sheds the most light here is homology, and that his mistakes were due to following Richard Owen's method of determining homologies by reference to an ideal archetype. I discuss the ways in which his studies on cirripedes influenced the writing of The Origin. PMID:20338525

  2. Darwin and barnacles.

    PubMed

    Deutsch, Jean

    2010-02-01

    In this essay, I discuss the origin of Charles Darwin's interest in cirripedes (barnacles). Indeed, he worked intensively on cirripedes during the years in which he was developing the theory that eventually led to the publication of The Origin of Species. In the light of our present knowledge, I present Darwin's achievements in the morphology, systematics and biology of these small marine invertebrates, and also his mistakes. I suggest that the word that sheds the most light here is homology, and that his mistakes were due to following Richard Owen's method of determining homologies by reference to an ideal archetype. I discuss the ways in which his studies on cirripedes influenced the writing of The Origin.

  3. Sojourner near Barnacle Bill

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Sojourner is visible in this image, one of the first taken by the deployed Imager for Mars Pathfinder (IMP) on Sol 3. The rover has moved from this position into one that later facilitated its using the Alpha Proton X-Ray Spectrometer (APXS) instrument on Barnacle Bill. The APXS, located at the rear of the rover, is not visible in this image.

    The image was taken by the Imager for Mars Pathfinder (IMP) after its deployment on Sol 3. Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  4. A 12-year record of intertidal barnacle recruitment in Atlantic Canada (2005–2016): relationships with sea surface temperature and phytoplankton abundance

    PubMed Central

    2016-01-01

    On the Gulf of St. Lawrence coast of Nova Scotia (Canada), recruitment of the barnacle Semibalanus balanoides occurs in May and June. Every year in June between 2005 and 2016, we recorded recruit density for this barnacle at the same wave-exposed rocky intertidal location on this coast. During these 12 years, mean recruit density was lowest in 2015 (198 recruits dm−2) and highest in 2007 (969 recruits dm−2). The highest recruit density observed in a single quadrat was 1,457 recruits dm−2 (in 2011) and the lowest was 34 recruits dm−2 (in 2015). Most barnacle recruits appear during May, which suggests that most pelagic larvae (which develop over 5–6 weeks before benthic settlement) are in the water column in April. An AICc-based model selection approach identified sea surface temperature (SST) in April and the abundance of phytoplankton (food for barnacle larvae, measured as chlorophyll-a concentration –Chl-a–) in April as good explanatory variables. Together, April SST and April Chl-a explained 51% of the observed interannual variation in recruit density, with an overall positive influence. April SST was positively related to March–April air temperature (AT). April Chl-a was negatively related to the April ratio between the number of days with onshore winds (which blow from phytoplankton-limited offshore waters) and the number of days with alongshore winds (phytoplankton is more abundant on coastal waters). Therefore, this study suggests that climatic processes affecting April SST and April Chl-a indirectly influence intertidal barnacle recruitment by influencing larval performance. PMID:27812421

  5. Barnacle distribution in Lough Hyne Marine Nature Reserve: a new baseline and an account of invasion by the introduced Australasian species Elminius modestus Darwin

    NASA Astrophysics Data System (ADS)

    Lawson, Jennifer; Davenport, John; Whitaker, Alan

    2004-08-01

    The distribution and abundances of the following species of barnacles were established in autumn 2001 within the Lough Hyne Marine Nature Reserve: Cthamalus stellatus, Cthamalus montagui, Semibalanus balanoides, Elminius modestus, Balanus crenatus and Verruca stroemia. The results of the survey showed a clear distinction between the vertical distribution and the abundance of barnacle species inside Lough Hyne, and those sites sampled in the Rapids and outside the Lough. The Lough is now dominated by the introduced Australasian species E. modestus. This species was first recorded outside Lough Hyne in 1956. By 1988 it was found occasionally throughout the Lough, and appreciable numbers were recorded in 1990-1991. It has now replaced all other species in some parts of the North Basin. At sites subject to freshwater influence it is totally dominant, including in the highly sheltered Goleen site where intertidal barnacles have not previously been recorded. It is suggested that, once established in the North Basin, the sheltered nature of the Lough, combined with high summer temperatures and limited circulation, fostered retention of larvae and heavy spatfall of E. modestus.

  6. Survival of northern red oak acorns after fall burning. Forest Service research paper (Final)

    SciTech Connect

    Auchmoody, L.R.; Smith, H.C.

    1993-01-01

    The survival of recently fallen northern red oak acorns after exposure to a cool fall burn was evaluated in northwestern Pennsylvania. Although no acorns were consumed by the fire, some were charred. Between 40 and 49 percent of the acorns in the litter were destroyed. The fire was not hot enough to kill Curculio larvae within the acorns. Burned acorns infested with Curculio that survived the fire had 20 percent lower germination rates than unburned acorns.

  7. Mini-review: barnacle adhesives and adhesion.

    PubMed

    Kamino, Kei

    2013-01-01

    Barnacles are intriguing, not only with respect to their importance as fouling organisms, but also in terms of the mechanism of underwater adhesion, which provides a platform for biomimetic and bioinspired research. These aspects have prompted questions regarding how adult barnacles attach to surfaces under water. The multidisciplinary and interdisciplinary nature of the studies makes an overview covering all aspects challenging. This mini-review, therefore, attempts to bring together aspects of the adhesion of adult barnacles by looking at the achievements of research focused on both fouling and adhesion. Biological and biochemical studies, which have been motivated mainly by understanding the nature of the adhesion, indicate that the molecular characteristics of barnacle adhesive are unique. However, it is apparent from recent advances in molecular techniques that much remains undiscovered regarding the complex event of underwater attachment. Barnacles attached to silicone-based elastomeric coatings have been studied widely, particularly with respect to fouling-release technology. The fact that barnacles fail to attach tenaciously to silicone coatings, combined with the fact that the mode of attachment to these substrata is different to that for most other materials, indicates that knowledge about the natural mechanism of barnacle attachment is still incomplete. Further research on barnacles will enable a more comprehensive understanding of both the process of attachment and the adhesives used. Results from such studies will have a strong impact on technology aimed at fouling prevention as well as adhesion science and engineering.

  8. Opportunism and the resilience of barnacles (Cirripedia: Thoracica) to environmental change.

    PubMed

    Buckeridge, John S

    2012-06-01

    Cirripede-like organisms have their origins in the Palaeozoic, but until the Cainozoic, were represented primarily by pedunculated forms, such as the Scalpelliformes. Acorn barnacles (Balanomorpha) are first recorded after the Cretaceous-Tertiary extinction event. During the late Palaeogene, rapid radiation of cirripedes resulted in sufficient diversification for them to occupy most marine environments. That they survived both the Palaeocene-Eocene Thermal Maximum and the Pleistocene glaciation is testament to their ability to rapidly adapt to opportunities. The wide habitat distribution of balanomorphs in particular is unparalleled; they are known from the upper littoral (Chthamalus) to depths of 3600 m (Tetrachaelasma) and within this attached to rock, wood and miscellaneous flotsam, plus in symbiosis or commensalism with larger marine organisms. Darwin's (1854) view of the Tertiary as the age of barnacles is reflected in this diversity, distribution and biomass. All cirripedes are, nonetheless, at risk, from rapid habitat change, competition, pollution and, especially in light of their sessile habit, from predation. This paper assesses the viability of a number of cirripedes and concludes that the Lepadiformes, Scalpelliformes and Balanomorpha are the most resilient, and will most quickly adapt to occupy new niches when opportunities arise.

  9. Opportunism and the resilience of barnacles (Cirripedia: Thoracica) to environmental change.

    PubMed

    Buckeridge, John S

    2012-06-01

    Cirripede-like organisms have their origins in the Palaeozoic, but until the Cainozoic, were represented primarily by pedunculated forms, such as the Scalpelliformes. Acorn barnacles (Balanomorpha) are first recorded after the Cretaceous-Tertiary extinction event. During the late Palaeogene, rapid radiation of cirripedes resulted in sufficient diversification for them to occupy most marine environments. That they survived both the Palaeocene-Eocene Thermal Maximum and the Pleistocene glaciation is testament to their ability to rapidly adapt to opportunities. The wide habitat distribution of balanomorphs in particular is unparalleled; they are known from the upper littoral (Chthamalus) to depths of 3600 m (Tetrachaelasma) and within this attached to rock, wood and miscellaneous flotsam, plus in symbiosis or commensalism with larger marine organisms. Darwin's (1854) view of the Tertiary as the age of barnacles is reflected in this diversity, distribution and biomass. All cirripedes are, nonetheless, at risk, from rapid habitat change, competition, pollution and, especially in light of their sessile habit, from predation. This paper assesses the viability of a number of cirripedes and concludes that the Lepadiformes, Scalpelliformes and Balanomorpha are the most resilient, and will most quickly adapt to occupy new niches when opportunities arise. PMID:22691197

  10. APXS on Barnacle Bill - color

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The image was taken by a camera aboard the Sojourner rover on Sol 4. Portions of the rover's Alpha Proton X-Ray Spectrometer (APXS) instrument are visible studying Barnacle Bill.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech).

  11. aCORN Electrostatic mirror upgrade, design and operation

    NASA Astrophysics Data System (ADS)

    Hassan, Md; aCORN Collaboration

    2015-10-01

    The electron-antineutrino angular correlation (a) in the neutron beta decay is being measured by the aCORN experiment. aCORN is aiming to measure a to a relative accuracy of 1 % using a novel technique where electrons and protons from the neutron decay are detected in coincidence. The momenta of the particles are selected in such a way that two groups of protons are formed based on the proton time-of-flight. An electrostatic mirror reflects all protons towards the proton detector and preaccelerates them for collimation. In the last aCORN run the largest source of systematic correction was due to transverse electric fields in the mirror. For the next phase of aCORN, we upgraded the electrostatic mirror. The design and operation of the upgraded electrostatic mirror will be presented. This work is supported by NSF, NIST and DOE Office of Science.

  12. Detail view of bronze door. Note oak branches with acorns ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of bronze door. Note oak branches with acorns in the left panels and olive branches with olives in right. - Flanders Field American Cemetery & Memorial, Chapel, Wortegemseweg 117, Waregem, West Flanders (Belgium)

  13. Sojourner near Barnacle Bill - color

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Sojourner is visible in this color image, one of the first taken by the deployed Imager for Mars Pathfinder (IMP) on Sol 3. The rover has moved from this position into one that later facilitated its using the Alpha Proton X-Ray Spectrometer (APXS) instrument on Barnacle Bill. The APXS, located at the rear of the rover, is not visible in this image.

    The image was taken by the Imager for Mars Pathfinder (IMP) after its deployment on Sol 3. Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  14. [Larvae of barnacles (Cirripedia: Thoracica) in the White sea plankton].

    PubMed

    Poltarukha, O P

    2003-01-01

    The barnacle fauna in the White Sea is briefly described. The morphology of barnacle larvae in this water body is comparatively analyzed. The characters important for the larvae identification are given particular attention. A classification key was developed for the nauplius and cyprid larvae of barnacles in the White Sea.

  15. Reproductive skew in the polygynandrous acorn woodpecker.

    PubMed

    Haydock, Joseph; Koenig, Walter D

    2002-05-14

    Reproductive skew models, which focus on the degree to which reproduction is shared equally (low skew) or monopolized by a single individual (high skew) within groups, have been heralded as providing a general unifying framework for understanding the factors determining social evolution. Here, we test the ability of optimal skew, or "transactional," models, which predict the level of skew necessary to promote stable associations of dominants and subordinates, rather than independent breeding, to predict reproductive partitioning in the acorn woodpecker (Melanerpes formicivorus). This species provides a key test case because only a few vertebrates exhibit polygynandry (multiple breeders of both sexes within a group). Contrary to the predictions of the models, joint-nesting females share reproduction more equitably than expected, apparently because egg destruction and the inability of females to defend their eggs from cobreeders eliminate any possibility for one female to control reproduction. For males, however, reproductive skew is high, with the most successful male siring over three times as many young as the next most successful male. Although this result is consistent with optimal skew models, other aspects of male behavior are not; in particular, the reproductively most successful male frequently switches between nests produced by the same set of cobreeders, and we were unable to detect any phenotypic correlate of success. These results are consistent with an alternative null model in which cobreeder males have equal chance of paternity, but paternity of offspring within broods is nonindependent as a consequence of female, rather than male, control.

  16. Sojourner, Barnacle Bill, Yogi, & Couch

    NASA Technical Reports Server (NTRS)

    1997-01-01

    At center, Sojourner has traveled off the lander's rear ramp and onto the surface of Mars. 3D glasses are necessary to identify surface detail. The rock Barnacle Bill is to the left of Sojourner, and the large rock Yogi is at upper right. On the horizon sits the rock dubbed 'Couch.' A deflated airbag sits at lower right.

    The image was taken by the Imager for Mars Pathfinder (IMP) on Sol 3. The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  17. Sojourner's APXS studies Barnacle Bill

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Sojourner's first analysis of a rock on Mars began on Sol 3 with the study of Barnacle Bill, a nearby rock named for its rough surface. The Alpha Proton X-Ray Spectrometer (APXS) will be used to determine the elements that make up the rocks and soil on Mars. A full study using the APXS takes approximately ten hours, and can measure all elements except hydrogen at any time of the Martian day or night. The APXS will conduct its studies by bombarding rocks and soil samples with alpha particle radiation -- charged particles equivalent to the nucleus of a helium atom, consisting of two protons and two neutrons.

    The image was taken by the Imager for Mars Pathfinder (IMP) after its deployment on Sol 3. Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  18. [Formation peculiarities of Quercus robur L. acorn mycobiota under conditions of Kyiv Polissya].

    PubMed

    Voloshchuk, N M; Bilous, V M

    2013-01-01

    The structure of mycobiota (epiphytic and from inner tissues) of Q. robur acorns (580 samples) under conditions of Kyiv Polissya was studied. Acorn samples were collected from oak trees during vegetation period. The epiphytes and mycobiota isolated from inner tissues of acorns was represented by 38 and 20 species, respectively. The majority of fungi were isolated in July. Cosmopolitan and non-specific species Acremonium sp., Alternaria alternata, Cladosporium cladosporioides, Trichoderma harzianum, T. viride and specific ones - Phoma sp. and Phomopsis sp. were isolated from inner acorn tissues. It was established that potential seed and seedling pathogens infect acorns during the process of their formation. The paper is presented in Ukrainian. PMID:24006787

  19. Triterpene Galloyl Esters from Edible Acorn of Castanopsis cuspidata.

    PubMed

    Ogata, Misaki; Saito, Yoshinori; Matsuo, Yosuke; Maeda, Hajime; Tanaka, Takashi

    2016-02-01

    Polyphenols of edible acorns of Castanopsis cuspidata were examined and two triterpene galloyl esters were isolated. Based on two-dimensional NMR spectroscopic evidence the structures were determined to be 3,24-di-O-galloyl-2α,3β-23,24-tetrahydroxyolean-12-en-28-oic acid (1) and 3,24-di-O-galloyl- 2α,3β-23,24-tetrahydroxyurs-12-en-28-oic acid (2). The triterpene hexahydroxydiphenoyl esters, which had been found in the leaves, were not detected in the acorns.

  20. Relative influences of ocean acidification and temperature on intertidal barnacle post-larvae at the northern edge of their geographic distribution

    NASA Astrophysics Data System (ADS)

    Findlay, Helen S.; Kendall, Michael A.; Spicer, John I.; Widdicombe, Stephen

    2010-03-01

    The Arctic Ocean and its associated ecosystems face numerous challenges over the coming century. Increasing atmospheric CO 2 is causing increasing warming and ice melting as well as a concomitant change in ocean chemistry ("ocean acidification"). As temperature increases it is expected that many temperate species will expand their geographic distribution northwards to follow this thermal shift; however with the addition of ocean acidification this transition may not be so straightforward. Here we investigate the potential impacts of ocean acidification and climate change on populations of an intertidal species, in this case the barnacle Semibalanus balanoides, at the northern edge of its range. Growth and development of metamorphosing post-larvae were negatively impacted at lower pH (pH 7.7) compared to the control (pH 8.1) but were not affected by elevated temperature (+4 °C). The mineral composition of the shells did not alter under any of the treatments. The combination of reduced growth and maintained mineral content suggests that there may have been a change in the energetic balance of the exposed animals. In undersaturated conditions more mineral is expected to dissolve from the shell and hence more energy would be required to maintain the mineral integrity. Any energy that would normally be invested into growth could be reallocated and hence organisms growing in lowered pH grow slower and end up smaller than individuals grown in higher pH conditions. The idea of reallocation of resources under different conditions of pH requires further investigation. However, there could be long-term implications on the fitness of these barnacles, which in turn may prevent them from successfully colonising new areas.

  1. The tempo and mode of barnacle evolution.

    PubMed

    Pérez-Losada, Marcos; Harp, Margaret; Høeg, Jens T; Achituv, Yair; Jones, Diana; Watanabe, Hiromi; Crandall, Keith A

    2008-01-01

    Previous phylogenetic attempts at resolving barnacle evolutionary relationships are few and have relied on limited taxon sampling. Here we combine DNA sequences from three nuclear genes (18S, 28S and H3) and 44 morphological characters collected from 76 thoracican (ingroup) and 15 rhizocephalan (outgroup) species representing almost all the Thoracica families to assess the tempo and mode of barnacle evolution. Using phylogenetic methods of maximum parsimony, maximum likelihood, and Bayesian inference and 14 fossil calibrations, we found that: (1) Iblomorpha form a monophyletic group; (2) pedunculated barnacles without shell plates (Heteralepadomorpha) are not ancestral, but have evolved, at least twice, from plated forms; (3) the ontogenetic pattern with 5-->6-->8-->12+ plates does not reflect Thoracica shell evolution; (4) the traditional asymmetric barnacles (Verrucidae) and the Balanomorpha are each monophyletic and together they form a monophyletic group; (5) asymmetry and loss of a peduncle have evolved twice in the Thoracica, resulting in neither the Verrucomorpha nor the Sessilia forming monophyletic groups in their present definitions; (6) the Scalpellomorpha are not monophyletic; (7) the Thoracica suborders evolved since the Early Carboniferous (340mya) with the final radiation of the Sessilia in the Upper Jurassic (147mya). These results, therefore, reject many of the underlying hypotheses about character evolution in the Cirripedia Thoracica, stimulate a variety of new thoughts on thoracican radiation, and suggest the need for a major rearrangement in thoracican classification based on estimated phylogenetic relationships.

  2. For the Classroom: Filter Feeding in Barnacles.

    ERIC Educational Resources Information Center

    Joseph, Lois

    1983-01-01

    Provided is a high school activity in which students observe the filter feeding of barnacles and the effects of a variety of changing parameters upon their feeding process. Includes list of materials needed and procedures necessary to accomplish the activity. (JN)

  3. Super Resolution Anaglyph of Barnacle Bill

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Barnacle Bill is a small rock immediately west-northwest of the Mars Pathfinder lander and was the first rock visited by the Sojourner Rover's alpha proton X-ray spectrometer (APXS) instrument. This image and [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  4. Preventing Growth Of Barnacles On Propellers

    NASA Technical Reports Server (NTRS)

    Parrish, Kemp L.

    1993-01-01

    Possible to prevent barnacles and other marine life from obtaining firm bonds on propellers and other metal parts by coating parts with NEDOX (or equivalent) cavitation-resistant material. Available in several forms; one that works best is mold-release coating. Also provides improved surface hardness, protection against electrolysis, better resistance to abrasion, and less friction between propellers and water.

  5. Predaceous Feeding in Two Common Gooseneck Barnacles.

    PubMed

    Howard, G K; Scott, H C

    1959-03-13

    Lepas anatifera and Mitella polymerus, while relatively unselective omnivores, behave at times like predatory macrophagous carnivores. Observations suggest a greater range of food size for gooseneck barnacles than is generally suspected and clearly indicate that large organisms, when available, are effectively captured and handled.

  6. Oaks, Acorns, Climate and Squirrels, An Environmental Investigation.

    ERIC Educational Resources Information Center

    National Wildlife Federation, Washington, DC.

    This environmental unit is one of a series designed for integration within an existing curriculum. The unit is self-contained and requires minimal teacher preparation. The philosophy of the units is based on an experience-oriented process that encourages self-paced independent student work. In this particular unit, oaks and acorns are the vehicle…

  7. Studies, Sit-Ins Earn ACORN's Activists Voice in Education

    ERIC Educational Resources Information Center

    Gehring, John

    2004-01-01

    In Baltimore, Chicago, New York, Oakland, California and Philadelphia, to name a few cities where it has been active, Association of Community Organizations for Reform Now (ACORN) has emerged as a major player in K-12 in education issues. Its army of organizers has tackled everything from a lack of stop signs to such vexing issues as teacher…

  8. ACORN's Accelerated Income Redistribution Project: A Program Evaluation

    ERIC Educational Resources Information Center

    Brooks, Fred; Russell, Daniel; Fisher, Robert

    2006-01-01

    Objective: This study evaluated the Association of Community Organizations for Reform Now's (ACORN) efforts to increase the uptake of families claiming the earned income tax credit through door-to-door canvassing and managing free tax preparation clinics in three pilot cities. Method: The mixed-method program evaluation included administrative…

  9. Matrix algebra routines for the Acorn Archimedes microcomputer: example applications.

    PubMed

    Fielding, A

    1988-08-01

    A set of matrix algebra routines have been written, as BASICV procedures, for the Acorn Archimedes microcomputer. It is shown that these procedures are executed so quickly that programs, which require matrix algebra computations, can be written in interpreted BASIC. Two example applications, reciprocal averaging and principal components analysis, are demonstrated.

  10. Acorn cotyledons are larger than their seedlings' need: evidence from artificial cutting experiments.

    PubMed

    Yi, Xianfeng; Wang, Zhenyu; Liu, Changqu; Liu, Guoqiang; Zhang, Mingming

    2015-01-29

    Although the consequences of cotyledon removal have been widely studied in oaks producing large acorns, we have little knowledge of at what level cotyledons can be removed without affecting acorn survival and seedling development. In this study, we aimed to test the hypothesis that the amount of energy reserves in cotyledons is more than the demands of seedlings and that large acorns can tolerate seed predation and/or attract seed predators for seed dispersal. Acorn germination rates were not affected even when 60% of cotyledons were cut off at the basal end, suggesting that the energy reserves contained in cotyledons are not essential for acorn survival. Post-cut acorn mass, more than initial acorn mass, appear to be a better predictor of seedling performance, indicating that the energy reserves in cotyledons are sufficient for seedlings. Acorns with large masses sustained cotyledon damage better than small ones with respect to seedling performance. Large acorns were more likely to be dispersed and cached by animals, implying that producing large acorns is more important for oaks to manipulate seed predators and dispersers rather than provide a seedling with cotyledonary reserves.

  11. Acorn cotyledons are larger than their seedlings' need: evidence from artificial cutting experiments

    PubMed Central

    Yi, Xianfeng; Wang, Zhenyu; Liu, Changqu; Liu, Guoqiang; Zhang, Mingming

    2015-01-01

    Although the consequences of cotyledon removal have been widely studied in oaks producing large acorns, we have little knowledge of at what level cotyledons can be removed without affecting acorn survival and seedling development. In this study, we aimed to test the hypothesis that the amount of energy reserves in cotyledons is more than the demands of seedlings and that large acorns can tolerate seed predation and/or attract seed predators for seed dispersal. Acorn germination rates were not affected even when 60% of cotyledons were cut off at the basal end, suggesting that the energy reserves contained in cotyledons are not essential for acorn survival. Post-cut acorn mass, more than initial acorn mass, appear to be a better predictor of seedling performance, indicating that the energy reserves in cotyledons are sufficient for seedlings. Acorns with large masses sustained cotyledon damage better than small ones with respect to seedling performance. Large acorns were more likely to be dispersed and cached by animals, implying that producing large acorns is more important for oaks to manipulate seed predators and dispersers rather than provide a seedling with cotyledonary reserves. PMID:25630843

  12. Incorporating Cache Management Behavior into Seed Dispersal: The Effect of Pericarp Removal on Acorn Germination

    PubMed Central

    Yi, Xianfeng; Zhang, Mingming; Bartlow, Andrew W.; Dong, Zhong

    2014-01-01

    Selecting seeds for long-term storage is a key factor for food hoarding animals. Siberian chipmunks (Tamias sibiricus) remove the pericarp and scatter hoard sound acorns of Quercus mongolica over those that are insect-infested to maximize returns from caches. We have no knowledge of whether these chipmunks remove the pericarp from acorns of other species of oaks and if this behavior benefits seedling establishment. In this study, we tested whether Siberian chipmunks engage in this behavior with acorns of three other Chinese oak species, Q. variabilis, Q. aliena and Q. serrata var. brevipetiolata, and how the dispersal and germination of these acorns are affected. Our results show that when chipmunks were provided with sound and infested acorns of Quercus variabilis, Q. aliena and Q. serrata var. brevipetiolata, the two types were equally harvested and dispersed. This preference suggests that Siberian chipmunks are incapable of distinguishing between sound and insect-infested acorns. However, Siberian chipmunks removed the pericarp from acorns of these three oak species prior to dispersing and caching them. Consequently, significantly more sound acorns were scatter hoarded and more infested acorns were immediately consumed. Additionally, indoor germination experiments showed that pericarp removal by chipmunks promoted acorn germination while artificial removal showed no significant effect. Our results show that pericarp removal allows Siberian chipmunks to effectively discriminate against insect-infested acorns and may represent an adaptive behavior for cache management. Because of the germination patterns of pericarp-removed acorns, we argue that the foraging behavior of Siberian chipmunks could have potential impacts on the dispersal and germination of acorns from various oak species. PMID:24647670

  13. Molecular phylogeny and character evolution of the chthamaloid barnacles (Cirripedia: Thoracica).

    PubMed

    Pérez-Losada, Marcos; Høeg, Jens T; Crandall, Keith A; Achituv, Yair

    2012-10-01

    The Chthamaloidea (Balanomorpha) present the most plesiomorphic characters in shell plates and cirri, mouthparts, and oral cone within the acorn barnacles (Thoracica: Sessilia). Due to their importance in understanding both the origin and diversification of the Balanomorpha, the evolution of the Chthamaloidea has been debated since Darwin's seminal monographs. Theories of morphological and ontogenetic evolution suggest that the group could have evolved multiple times from pedunculated relatives and that shell plate number diminished gradually (8→6→4) from an ancestral state with eight wall plates surrounded by whorls of small imbricating plates; but this hypothesis has never been subjected to a rigorous phylogenetic test. Here we used multilocus sequence data and extensive taxon sampling to build a comprehensive phylogeny of the Chthamaloidea as a basis for understanding their morphological evolution. Our maximum likelihood and Bayesian analyses separate the Catophragmidae (eight shell plates and imbricating plates) from the Chthamalidae (8-4 shell plates and no imbricating plates), but do no support a gradual reduction in shell plates (8→6→4). This suggests that evolution at the base of the Balanomorpha involved a considerable amount of homoplasy.

  14. Some insights into how barnacles survive as sessile organisms.

    PubMed

    Buckeridge, John S; Reeves, Jessica M

    2009-12-01

    During routine chemical analyses of the stalked ibliform barnacle Chaetolepas calcitergum Buckeridge & Newman 2006, peaks of more than 7% (by dry mass) of bromine were detected. Although bromine ions occur in seawater (up to 66 ppm), this level of accumulation, in the soft tissue of the barnacle, is extraordinary. Organic concentration of bromine compounds occurs in a number of invertebrates, such as algae and sponges, but this is the first record of elevated bromine in goose barnacles. The high accumulation of bromine compound(s) is most likely a defense mechanism. The present paper includes a review of the mechanisms deployed by barnacles to repel predators.

  15. Biomineral Structure and Strength of Barnacle Exoskeletons

    NASA Astrophysics Data System (ADS)

    Swift, Nathan

    2011-03-01

    Studying the construction of organic-inorganic compound structures through biomineralization is potentially very useful. During biomineral formation, organisms restructure naturally occurring minerals in conjunction with their own organically produced minerals to create new structures. While there is extensive knowledge about material properties and structure of the raw minerals themselves, insight into how specific biomineral structures and compounds contribute to an object's mechanical properties is lacking. In this study, the exoskeletons of barnacles from the genus Balanus were examined, both for their physical structure (how they're put together) and for their mechanical properties (strength, hardness, and elasticity). Scanning electron microscopy produced close-up, detailed images of the inner shell structure to determine what type of structure barnacles build during exoskeleton formation. Energy dispersive x-ray spectroscopy was used to map the elemental components of the shells. Nanoindentation tested the mechanical properties of these mapped structures to determine how certain characteristics of the exoskeleton contribute to its mechanical properties.

  16. Darwin's "beloved barnacles": tough lessons in variation.

    PubMed

    Mannouris, Costas

    2011-01-01

    In 1846, burdened by insecurity and self-doubt, and having been convinced that he needed to study some group of organisms closely, Darwin embarked on an eight-year odyssey in the protean and perplexing world of barnacles. At the time, he was searching for evidence in support of his theory of evolution by natural selection. In the course of his long study of barnacles, however, he was not just validating his preexisting theoretical system, but was also modifying his views on such fundamental aspects as the universality of individual variation, which is the focus of this paper. According to this notion, the members of any population of living things are expected to exhibit sufficient differences from one another for natural selection to operate. By emphasizing the theoretical value of the barnacle project, my analysis contributes to the historiographic tradition which highlights the significance of the period between the first comprehensive formulation of the theory of evolution by natural selection in 1844 and its urgent publication in the late 1850s. In the course of these years, Darwin's theory was not just accumulating empirical laurels, but was also expected to adapt to a changing conceptual landscape. PMID:21789955

  17. Darwin's "beloved barnacles": tough lessons in variation.

    PubMed

    Mannouris, Costas

    2011-01-01

    In 1846, burdened by insecurity and self-doubt, and having been convinced that he needed to study some group of organisms closely, Darwin embarked on an eight-year odyssey in the protean and perplexing world of barnacles. At the time, he was searching for evidence in support of his theory of evolution by natural selection. In the course of his long study of barnacles, however, he was not just validating his preexisting theoretical system, but was also modifying his views on such fundamental aspects as the universality of individual variation, which is the focus of this paper. According to this notion, the members of any population of living things are expected to exhibit sufficient differences from one another for natural selection to operate. By emphasizing the theoretical value of the barnacle project, my analysis contributes to the historiographic tradition which highlights the significance of the period between the first comprehensive formulation of the theory of evolution by natural selection in 1844 and its urgent publication in the late 1850s. In the course of these years, Darwin's theory was not just accumulating empirical laurels, but was also expected to adapt to a changing conceptual landscape.

  18. Planting northern red oak acorns: Is size and planting depth important. Forest Service research paper (Final)

    SciTech Connect

    Auchmoody, L.R.; Smith, H.C.; Walters, R.S.

    1994-10-27

    A study was conducted in northern Pennsylvania to determine whether predation by small mammals and insects is related to the size of red oak acorns. Three sizes of acorns were used along with two planting techniques and three levels of overstory shading. Three-year results indicated that acorn size is not a factor in mammal and insect predation. Acorn size did not affect 3-year survival. Although 3-year total height growth was statistically different after 3 years, the differences were too small for practical use.

  19. The Design and Implementation of the aCORN Magnet

    NASA Astrophysics Data System (ADS)

    Collett, Brian; aCORN Collaboration

    2015-10-01

    The aCORN experiment confines the neutron decay products close to an axis using a set of collimators. The electron-antineutrino angular correlation leads to an asymmetry in the number of decay protons emerging parallel to the electron versus the number emerging anti-parallel. A measurement of the asymmetry leads to a measurement of the coefficient, ``a.'' aCORN employs a highly uniform magnetic field aligned to within 10-4 radians of the collimator axis to limit the maximum transverse momentum of the protons. Errors in uniformity or alignment of the field lead to differences in the phase space for the two proton populations and thus to systematic errors in the value of ``a.'' The design of the magnet system, its power supplies, and the field mapping systems will be presented.

  20. Acoustic detection of UHE neutrinos - the ACORNE project

    NASA Astrophysics Data System (ADS)

    Thompson, L. F.; Perkin, J. D.; ACORNE Collaboration

    2008-11-01

    An interesting new possibility of detection of ultra-high energy (UHE) neutrinos is that of acoustic detection whereby the acoustic pressure pulse generated as a UHE neutrino interacts in a suitable medium such as water or ice is detected by an array of acoustic sensors. Recent years have seen something of a renaissance of this field and there are currently a number of activities worldwide to assess the potential of this technique. The UK-based ACORNE collaboration is one of these activities; ACORNE has access to the QinetiQ underwater acoustic range off Rona, an island off the North-West coast of Scotland. The poster will summarise ACORNE's R&D work, including simulation of the thermoacoustic emission of neutrino-induced particle cascades, reconstruction of event vertices and the effects of refraction, potential neutrino flux sensitivities from large area hydrophone arrays, a study transducer based calibration techniques and an analysis of the first acoustic data recorded by the Rona hydrophone array.

  1. Trace metals in barnacles: the significance of trophic transfer.

    PubMed

    Rainbow, Philip S; Wang, Wen-Xiong

    2005-05-01

    Barnacles have very high accumulated trace metal body concentrations that vary with local trace metal bioavailabilities and represent integrated measures of the supply of bioavailable metals. Pioneering work in Chinese waters in Hong Kong highlighted the potential value of barnacles (particularly Balanus amphitrite) as trace metal biomonitors in coastal waters, identifying differences in local trace metal bioavailabilities over space and time. Work in Hong Kong has also shown that although barnacles have very high rates of trace metal uptake from solution, they also have very high trace metal assimilation efficiencies from the diet. High assimilation efficiencies coupled with high ingestion rates ensure that trophic uptake is by far the dominant trace metal uptake route in barnacles, as verified for cadmium and zinc. Kinetic modelling has shown that low efflux rate constants and high uptake rates from the diet combine to bring about accumulated trace metal concentrations in barnacles that are amongst the highest known in marine invertebrates.

  2. Flow over Barnacles-Characterization of Barnacle Geometry and Some Initial Flow Characteristics

    NASA Astrophysics Data System (ADS)

    Sadique, Jasim; Yang, Xiang; Meneveau, Charles; Schultz, Michael; Mittal, Rajat

    2013-11-01

    Macrobiofouling is a serious concern for the marine industry, costing billions in preventive and control measures. Accurate modelling of flows over surfaces with such complex geometry and wide range of length scales is still a huge challenge. Such simulations are required in predicting the effects of fouling, like surface drag and also forces experienced by individual barnacles. DNS or wall resolved LES are impractical due to constraints imposed by the nature of the geometry. We aim to develop and test a computational tool for accurate simulation of such flows. The method being proposed incorporates generalized dynamic wall models along with sharp-interface Immersed Boundary Methods. The results from these simulations will help us understand the effects on surface drag caused by variations in parameters like roughness density, roughness heights, spatial heterogeneity etc. Along with this, detailed studies on a single barnacle will help us in understanding flow structures in the presence of boundary layers. In this talk we will give a brief overview of the problem and some results from our investigation on the characterization of Barnacle geometries and on the characteristics of flow over a single barnacle. This research is supported by a grant from the Office of Naval Research.

  3. Does multiple seed loading in Blue Jays result in selective dispersal of smaller acorns?

    PubMed

    Bartlow, Andrew W; Kachmar, Michael; Lichti, Nathanael; Swihart, Robert K; Stratford, Jeffrey A; Steele, Michael A

    2011-09-01

    Studies from both tropical and temperate systems show that scatter-hoarding rodents selectively disperse larger seeds farther from their source than smaller seeds, potentially increasing seedling establishment in larger-seeded plants. Size-biased dispersal is evident in many oaks (Quercus) and is true both across and within species. Here, we predict that intraspecifc variation in seed size also influences acorn dispersal by the Blue Jay (Cyanocitta cristata Linnaeus), but in an opposite manner. Blue Jays are gape-limited and selectively disperse smaller acorn species (e.g. pin oaks [Quercus palustris Münchh]), but often carry several acorns in their crop during a single dispersal event. We predict that jays foraging on smaller acorns will load more seeds per trip and disperse seeds to greater distances than when single acorns are carried in the bill. To test this, we presented free-ranging Blue Jays with pin oak acorns of different sizes over a 2-year period. In each of 16 experimental trials, we monitored the birds at a feeding station with remote cameras and determined the number of acorns removed and the distance acorns were dispersed when cached. Jays were significantly more likely to engage in multiple seed loading with smaller seeds in both years of the study. During the second year, these smaller acorns were dispersed farther than larger acorns, and during the first year, larger acorns were dispersed farther, revealing an inconsistent response to seed size during our study. We suggest that in some circumstances, multiple seed loading by Blue Jays may favor dispersal in some plant species.

  4. Sojourner near Barnacle Bill - 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    At right, Sojourner has traveled off the lander's rear ramp and onto the surface of Mars. 3D glasses are necessary to identify surface detail. The rock Barnacle Bill and the rear ramp is to the left of Sojourner.

    The image was taken by the Imager for Mars Pathfinder (IMP) on Sol 3. The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  5. Imaging Active Surface Processes in Barnacle Adhesive Interfaces.

    PubMed

    Golden, Joel P; Burden, Daniel K; Fears, Kenan P; Barlow, Daniel E; So, Christopher R; Burns, Justin; Miltenberg, Benjamin; Orihuela, Beatriz; Rittshof, Daniel; Spillmann, Christopher M; Wahl, Kathryn J; Tender, Leonard M

    2016-01-19

    Surface plasmon resonance imaging (SPRI) and voltammetry were used simultaneously to monitor Amphibalanus (=Balanus) amphitrite barnacles reattached and grown on gold-coated glass slides in artificial seawater. Upon reattachment, SPRI revealed rapid surface adsorption of material with a higher refractive index than seawater at the barnacle/gold interface. Over longer time periods, SPRI also revealed secretory activity around the perimeter of the barnacle along the seawater/gold interface extending many millimeters beyond the barnacle and varying in shape and region with time. Ex situ experiments using attenuated total reflectance infrared (ATR-IR) spectroscopy confirmed that reattachment of barnacles was accompanied by adsorption of protein to surfaces on similar time scales as those in the SPRI experiments. Barnacles were grown through multiple molting cycles. While the initial reattachment region remained largely unchanged, SPRI revealed the formation of sets of paired concentric rings having alternately darker/lighter appearance (corresponding to lower and higher refractive indices, respectively) at the barnacle/gold interface beneath the region of new growth. Ex situ experiments coupling the SPRI imaging with optical and FTIR microscopy revealed that the paired rings coincide with molt cycles, with the brighter rings associated with regions enriched in amide moieties. The brighter rings were located just beyond orifices of cement ducts, consistent with delivery of amide-rich chemistry from the ducts. The darker rings were associated with newly expanded cuticle. In situ voltammetry using the SPRI gold substrate as the working electrode revealed presence of redox active compounds (oxidation potential approx 0.2 V vs Ag/AgCl) after barnacles were reattached on surfaces. Redox activity persisted during the reattachment period. The results reveal surface adsorption processes coupled to the complex secretory and chemical activity under barnacles as they construct

  6. Imaging Active Surface Processes in Barnacle Adhesive Interfaces.

    PubMed

    Golden, Joel P; Burden, Daniel K; Fears, Kenan P; Barlow, Daniel E; So, Christopher R; Burns, Justin; Miltenberg, Benjamin; Orihuela, Beatriz; Rittshof, Daniel; Spillmann, Christopher M; Wahl, Kathryn J; Tender, Leonard M

    2016-01-19

    Surface plasmon resonance imaging (SPRI) and voltammetry were used simultaneously to monitor Amphibalanus (=Balanus) amphitrite barnacles reattached and grown on gold-coated glass slides in artificial seawater. Upon reattachment, SPRI revealed rapid surface adsorption of material with a higher refractive index than seawater at the barnacle/gold interface. Over longer time periods, SPRI also revealed secretory activity around the perimeter of the barnacle along the seawater/gold interface extending many millimeters beyond the barnacle and varying in shape and region with time. Ex situ experiments using attenuated total reflectance infrared (ATR-IR) spectroscopy confirmed that reattachment of barnacles was accompanied by adsorption of protein to surfaces on similar time scales as those in the SPRI experiments. Barnacles were grown through multiple molting cycles. While the initial reattachment region remained largely unchanged, SPRI revealed the formation of sets of paired concentric rings having alternately darker/lighter appearance (corresponding to lower and higher refractive indices, respectively) at the barnacle/gold interface beneath the region of new growth. Ex situ experiments coupling the SPRI imaging with optical and FTIR microscopy revealed that the paired rings coincide with molt cycles, with the brighter rings associated with regions enriched in amide moieties. The brighter rings were located just beyond orifices of cement ducts, consistent with delivery of amide-rich chemistry from the ducts. The darker rings were associated with newly expanded cuticle. In situ voltammetry using the SPRI gold substrate as the working electrode revealed presence of redox active compounds (oxidation potential approx 0.2 V vs Ag/AgCl) after barnacles were reattached on surfaces. Redox activity persisted during the reattachment period. The results reveal surface adsorption processes coupled to the complex secretory and chemical activity under barnacles as they construct

  7. True metabolizable energy for wood ducks from acorns compared to other waterfowl foods

    USGS Publications Warehouse

    Kaminski, R.M.; Davis, J.B.; Essig, H.W.; Gerard, P.D.; Reinecke, K.J.

    2003-01-01

    Acorns of bottomland red oaks (Quercus spp.) are an important food of North American wood ducks (Aix sponsa). Barras et al. (1996) demonstrated that female wood ducks selected willow oak ( Q. phetlos) acorns over other species. We measured true metabolizable energy (TME) derived by captive, wild-strain, adult female wood ducks from acorns of willow oak, water oak (Q. nigra), cherrybark oak (Q. pagoda), and pin oak (Q. patustris) to determine whether female wood ducks' preference for willow oak acorns was related to TME. Estimates of TME within acorn species were relatively precise, yet we did not detect variation in TME among acorn species (P= 0.31 ); hence, we estimated TME across species (2.76 + 0.033 [SE] kcal/g dry mass; n = 34). We concluded that TME apparently did not explain female wood ducks' preference for willow oak acorns and hypothesized that morphological characteristics of willow oak acorns may be proximate cues related to selection by wood ducks. We also summarized known TME estimates for acorns fed to wood ducks and mallards (Anas platyrhynchos), and natural and agricultural foods fed to mallards, northern pintails (A. acura), blue-winged teal (A. discors), and Canada geese (Branta canadensis). We found that acorns and moist-soil plant seeds and tubers provided, on average, about 76% of the TME in agricultural seeds. Thus, bottomland-hardwood and moist-soil habitats have potential to provide significant amounts of dietary energy, as well as greater diversity of foods and nutrients than croplands. Researchers should continue to determine TME of common foods (plant and animal) of waterfowl, and use TME in estimating waterfowl habitat carrying capacity (e.g., Reinecke et al. 1989). Additionally, large-scale, reliable estimates of plant and animal food availability in bottomland-hardwood and moist-soil habitats are needed to evaluate carrying capacity of landscapes important to waterfowl, such as the Mississippi Alluvial Valley (MAV).

  8. Ion and neuropharmacological studies of barnacle settlement

    NASA Astrophysics Data System (ADS)

    Rittschof, Dan; Maki, James; Mitchell, Ralph; Costlow, John D.

    Experiments tested effects of altering ion concentrations and the effects of additions of biologically active substances in the media surrounding settling stage barnacle larvae. Alteration of ionic concentrations did not result in induction of metamorphosis. Excess potassium ion, magnesium ion and calcium ion inhibited settlement. Potassium ion affected young cyprids while other cations had more pronounced effects on older cyprids. Replacement of one cation by another reduced the inhibitory effects of all but calcium. Excess magnesium was routinely inhibitory while lowered magnesium had little effect. Calcium ion could be increased 50% by lowering magnesium concentrations without affecting settlement. However, low calcium ion concentrations inhibited settlement. Of the biologically active substances tested, only soluble barnacle settlement factor and dibuteryl cAMP induced metamorphosis. SITS, a calcium channel blocker, inhibited settlement and negated the effects SF +. Most of the other compounds inhibited settlement at millimolar concentrations and had no effect when tested at lower concentrations. Picrotoxin, a compound that interferes with chloride ion movement (and membrane depolarization) strongly inhibited metamorphosis with an EC 50 of 10 -6 mol.

  9. ACORNS: Analysis of Correlations Used in Neutron Spectrometry

    1988-05-01

    The program ACORNS performs the complete analysis of the input covariance and/or relative covariance and/or correlation matrices, first of all used in the activation neutron spectrometry. These matrices have to be positive definite. To check the fulfillment of this requirement, the program calculates the eigenvalues and eigenvectors of those. If all the eigenvalues are positive, the program optionally performs the factor analysis. The user's input can be either made manually, or the cross section librariesmore » generated by the code X333.« less

  10. Genetic and Morphological Differentiation of the Indo-West Pacific Intertidal Barnacle Chthamalus malayensis

    PubMed Central

    Tsang, Ling Ming; Wu, Tsz Huen; Shih, Hsi-Te; Williams, Gray A.; Chu, Ka Hou; Chan, Benny K.K.

    2012-01-01

    Chthamalus malayensis is a common intertidal acorn barnacle widely distributed in the Indo-West Pacific. Analysis of sequences of mitochondrial cytochrome c oxidase subunit I reveals four genetically differentiated clades with almost allopatric distribution in this region. The four clades exhibit morphological differences in arthropodal characters, including the number of conical spines and number of setules of the basal guard setae on the cirri. These characters are, however, highly variable within each clade; such that the absolute range of the number of conical spines and setules overlaps between clades, and therefore, these are not diagnostic characters for taxonomic identification. The geographic distribution of the four clades displays a strong relationship between surface temperatures of the sea and ocean-current realms. The Indo-Malay (IM) clade is widespread in the tropical, equatorial region, including the Indian Ocean, Malay Peninsula, and North Borneo. The South China (SC) and Taiwan (TW) clades are found in tropical to subtropical regions, with the former distributed along the coasts of southern China, Vietnam, Thailand, and the western Philippines under the influence of the South China Warm Current. The TW clade is endemic to Taiwan, while the Christmas Island (CI) clade is confined to CI. There was weak or no population subdivision observed within these clades, suggesting high gene flow within the range of the clades. The clades demonstrate clear signatures of recent demographic expansion that predated the Last Glacial Maximum (LGM), but they have maintained a relatively stable effective population in the past 100,000 years. The persistence of intertidal fauna through the LGM may, therefore, be a common biogeographic pattern. The lack of genetic subdivision in the IM clade across the Indian and Pacific Oceans may be attributed to recent expansion of ranges and the fact that a mutation-drift equilibrium has not been reached, or the relaxed habitat

  11. Genetic and morphological differentiation of the Indo-West Pacific intertidal barnacle Chthamalus malayensis.

    PubMed

    Tsang, Ling Ming; Wu, Tsz Huen; Shih, Hsi-Te; Williams, Gray A; Chu, Ka Hou; Chan, Benny K K

    2012-09-01

    Chthamalus malayensis is a common intertidal acorn barnacle widely distributed in the Indo-West Pacific. Analysis of sequences of mitochondrial cytochrome c oxidase subunit I reveals four genetically differentiated clades with almost allopatric distribution in this region. The four clades exhibit morphological differences in arthropodal characters, including the number of conical spines and number of setules of the basal guard setae on the cirri. These characters are, however, highly variable within each clade; such that the absolute range of the number of conical spines and setules overlaps between clades, and therefore, these are not diagnostic characters for taxonomic identification. The geographic distribution of the four clades displays a strong relationship between surface temperatures of the sea and ocean-current realms. The Indo-Malay (IM) clade is widespread in the tropical, equatorial region, including the Indian Ocean, Malay Peninsula, and North Borneo. The South China (SC) and Taiwan (TW) clades are found in tropical to subtropical regions, with the former distributed along the coasts of southern China, Vietnam, Thailand, and the western Philippines under the influence of the South China Warm Current. The TW clade is endemic to Taiwan, while the Christmas Island (CI) clade is confined to CI. There was weak or no population subdivision observed within these clades, suggesting high gene flow within the range of the clades. The clades demonstrate clear signatures of recent demographic expansion that predated the Last Glacial Maximum (LGM), but they have maintained a relatively stable effective population in the past 100,000 years. The persistence of intertidal fauna through the LGM may, therefore, be a common biogeographic pattern. The lack of genetic subdivision in the IM clade across the Indian and Pacific Oceans may be attributed to recent expansion of ranges and the fact that a mutation-drift equilibrium has not been reached, or the relaxed habitat

  12. Biochemical biomarkers in barnacles Balanus improvisus: pollution and seasonal effects.

    PubMed

    Zanette, Juliano; Monserrat, José Maria; Bianchini, Adalto

    2015-02-01

    Biochemical biomarkers were evaluated in the barnacle Balanus improvisus (Crustacea: Cirripedia) sampled from both polluted and reference sites in the Patos Lagoon Estuary, Southern Brazil. During winter, higher glutathione S-transferase (GST) activity was recorded in the barnacles from the polluted sites, indicating environmental exposure to contaminants. Relatively low lipid peroxide levels (LPO) were also observed in barnacles from polluted sites, indicating that oxidative stress by lipid peroxidation was not a major threat in barnacles from those sites. Seasonal differences in the GST and total oxyradical scavenging capacity (TOSC) could have contributed to the low LPO levels in the summer relative to the levels in the winter. Catalase activity and metallothionein levels were not affected by contamination or seasonality. The seasonal changes observed in biomarker responses were paralleled by the differences in temperature, which could have affected physiological responses, including the balance between pro-oxidants and antioxidants. PMID:25460064

  13. Biochemical biomarkers in barnacles Balanus improvisus: pollution and seasonal effects.

    PubMed

    Zanette, Juliano; Monserrat, José Maria; Bianchini, Adalto

    2015-02-01

    Biochemical biomarkers were evaluated in the barnacle Balanus improvisus (Crustacea: Cirripedia) sampled from both polluted and reference sites in the Patos Lagoon Estuary, Southern Brazil. During winter, higher glutathione S-transferase (GST) activity was recorded in the barnacles from the polluted sites, indicating environmental exposure to contaminants. Relatively low lipid peroxide levels (LPO) were also observed in barnacles from polluted sites, indicating that oxidative stress by lipid peroxidation was not a major threat in barnacles from those sites. Seasonal differences in the GST and total oxyradical scavenging capacity (TOSC) could have contributed to the low LPO levels in the summer relative to the levels in the winter. Catalase activity and metallothionein levels were not affected by contamination or seasonality. The seasonal changes observed in biomarker responses were paralleled by the differences in temperature, which could have affected physiological responses, including the balance between pro-oxidants and antioxidants.

  14. Localization of Phosphoproteins within the Barnacle Adhesive Interface.

    PubMed

    Dickinson, Gary H; Yang, Xu; Wu, Fanghui; Orihuela, Beatriz; Rittschof, Dan; Beniash, Elia

    2016-06-01

    Barnacles permanently adhere to nearly any inert substrate using proteinaceous glue. The glue consists of at least ten major proteins, some of which have been isolated and sequenced. Questions still remain about the chemical mechanisms involved in adhesion and the potential of the glue to serve as a platform for mineralization of the calcified base plate. We tested the hypothesis that barnacle glue contains phosphoproteins, which have the potential to play a role in both adhesion and mineralization. Using a combination of phosphoprotein-specific gel staining and Western blotting with anti-phosphoserine antibody, we identified multiple phosphorylated proteins in uncured glue secretions from the barnacle Amphibalanus amphitrite The protein composition of the glue and the quantity and abundance of phosphoproteins varied distinctly among individual barnacles, possibly due to cyclical changes in the glue secretion over time. We assessed the location of the phosphoproteins within the barnacle glue layer using decalcified barnacle base plates and residual glue deposited by reattached barnacles. Phosphoproteins were found throughout the organic matrix of the base plate and within the residual glue. Staining within the residual glue appeared most intensely in regions where capillary glue ducts, which are involved in cyclical release of glue, had been laid down. Lastly, mineralization studies of glue proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated that proteins identified as phosphorylated possibly induce mineralization of calcium carbonate (CaCO3). These results contribute to our understanding of the protein composition of barnacle glue, and provide new insights into the potential roles of phosphoproteins in underwater bioadhesives. PMID:27365418

  15. Ability of chestnut oak to tolerate acorn pruning by rodents. The role of the cotyledonary petiole

    NASA Astrophysics Data System (ADS)

    Yi, Xianfeng; Curtis, Rachel; Bartlow, Andrew W.; Agosta, Salvatore J.; Steele, Michael A.

    2013-01-01

    Acorns of many white oak species germinate soon after autumn seed fall, a characteristic widely interpreted as a general adaptation to escape predation by small rodents. However, the mechanism by which early, rapid germination allows escape and/or tolerance of seed damage remains unclear. Here we reported how specific germination traits of chestnut oak ( Quercus montana) acorns, and those of other white oak species, allow successful escape from acorn pruning by rodents. During germination, chestnut oak acorns develop elongated cotyledonary petioles, which extend beyond the distal end of the acorn (1-2 cm) to the point at which the epicotyl and radicle diverge. However, granivorous rodents often prune the taproots above or below the plumule when eating or caching these germinated acorns in autumn. Hence, we hypothesized elongation of cotyledonary petioles allows chestnut oaks to escape acorn pruning by rodents. We simulated pruning by rodents by cutting the taproot at different stages of germination (radicle length) to evaluate the regeneration capacity of four resulting seedling remnants following taproot pruning: acorns with the plumule (remnant I), acorns without the plumule (remnant II), and pruned taproots with (remnant III) or without the plumule (remnant IV). Our results showed that remnant I germinated into seedlings regardless of the length of the taproot previously pruned and removed. Remnant III successfully germinated and survived provided that taproots were ≥6 cm in length, whereas remnant IV was unable to produce seedlings. Remnant II only developed adventitious roots near the severed ends of the cotyledonary petioles. Field experiments also showed that pruned taproots with the plumule successfully regenerated into seedlings. We suggest that the elongated cotyledonary petioles, typical of most white oak species in North America, represent a key adaptation that allows frequent escape from rodent damage and predation. The ability of pruned taproots to

  16. Predicting Free-Space Occupancy on Novel Artificial Structures by an Invasive Intertidal Barnacle Using a Removal Experiment

    PubMed Central

    Bracewell, Sally A.; Robinson, Leonie A.; Firth, Louise B.; Knights, Antony M.

    2013-01-01

    Artificial structures can create novel habitat in the marine environment that has been associated with the spread of invasive species. They are often located in areas of high disturbance and can vary significantly in the area of free space provided for settlement of marine organisms. Whilst correlation between the amount of free space available and recruitment success has been shown in populations of several marine benthic organisms, there has been relatively little focus on invasive species, a group with the potential to reproduce in vast numbers and colonise habitats rapidly. Invasion success following different scales of disturbance was examined in the invasive acorn barnacle, Austrominiusmodestus, on a unique art installation located in Liverpool Bay. Population growth and recruitment success were examined by comparing recruitment rates within disturbance clearings of 4 different sizes and by contrasting population development with early recruitment rates over a 10 week period. Disturbed areas were rapidly recolonised and monocultures of A. modestus formed within 6 weeks. The size of patch created during disturbance had no effect on the rate of recruitment, while a linear relationship between recruit density and patch size was observed. Density-dependent processes mediated initial high recruitment resulting in population stability after 8-10 weeks, but densities continued to greatly exceed those reported in natural habitats. Given that artificial structures are likely to continue to proliferate in light of climate change projections, free-space is likely to become more available more frequently in the future supporting the expansion of fast-colonising species. PMID:24023944

  17. Removal of water turbidity by natural coagulants obtained from chestnut and acorn.

    PubMed

    Sćiban, Marina; Klasnja, Mile; Antov, Mirjana; Skrbić, Biljana

    2009-12-01

    The ability of seed extracts of several species of chestnut and acorn to act as natural coagulants was tested using a synthetic turbid water. Active components were extracted from ground seeds of Horse chestnut and acorns of some species of family Fagaceae: Common oak, Turkey oak, Northern red oak and European chestnut. All investigated extracts had coagulation capabilities and their amounts depended on pH values and initial turbidities. The seed extracts from European chestnut and Common oak acorn were the most efficient expressing the highest coagulation activities, about 80% and 70%, respectively, in both low and medium investigated water turbidities at the lowest coagulant dose 0.5 ml/L.

  18. Barnacles as biomonitors of metal contamination in coastal waters

    NASA Astrophysics Data System (ADS)

    Reis, Pedro A.; Salgado, Maria Antónia; Vasconcelos, Vitor

    2011-07-01

    The use of barnacles as biomonitors of metal contamination in coastal waters worldwide is reviewed as a critique compilation of the reported studies and presents resume-tables of available data for future reference. The barnacle body reflects both short and long-term metal level environmental variations and the metal bioaccumulation occurs mainly in their granules (relatively inactive pools). The barnacle body is considered as good biomonitoring material and different barnacle species could bioaccumulate metal concentration ranges of 40-153,000 μg/g of Zn, 20-22,230 μg/g de Fe, 1.5-21,800 μg/g of Cu, 5.9-4742 μg/g of Mn, 0.1-1000 μg/g of Pb, 0.7-330 μg/g of Cd, 0.4-99 μg/g of Ni and 0.2-49 μg/g of Cr. However, as the plates ('shells') of barnacle exoskeletons can be affected by metal levels in coastal waters, mainly in their composition and morphology, they are not considered good biomonitoring material. Despite this, the use of a specific barnacle species or group of species in a specific region must firstly be carefully validated and the interpretation of the contaminant bioaccumulation levels should involve specific environmental variations of the region, physiological parameters of the barnacle species and the relationship between the potential toxicity of the contaminant for the environment and their significance for the barnacle species. Barnacles, particularly a widespread cosmopolitan species such as Amphibalanus amphitrite, have a great potential as biomonitors of anthropogenic contamination in coastal waters and have been used worldwide, including Europe (United Kingdom, Turkey, Poland, Croatia, Spain and Portugal), Asia (India and China), Oceania (Australia), North America (Florida, Massachusetts and Mexico) and South America (Brazil). The use of barnacle species as biomonitors of metal contamination in coastal waters is considered an important and valuable tool to evaluate and predict the ecological quality of an ecosystem.

  19. A collaborative outcome resource network (ACORN): Tools for increasing the value of psychotherapy.

    PubMed

    Brown, George S Jeb; Simon, Ashley; Cameron, Joanne; Minami, Takuya

    2015-12-01

    The authors describe a collaborative outcomes resource network (ACORN) and the suite of measurement and decision support tools (ACORN Toolkit) that have emerged from this collaboration for the purpose of providing clinical feedback to therapists. The ACORN Toolkit is most accurately described as a comprehensive clinical information system designed to increase the value of mental health services across large systems of care. It was built to integrate large datasets from multiple sources including outcome data, client demographics and diagnostic data, therapist credentialing information, pharmacy data, and service claims data. For the limited purposes of this article, the authors focus on the ACORN Toolkit for measuring and how it has contributed to improving outcomes in psychotherapy. Implications to current practice and future training are provided.

  20. Diverse, continuous, and plastic sexual systems in barnacles.

    PubMed

    Yusa, Yoichi; Takemura, Mayuko; Sawada, Kota; Yamaguchi, Sachi

    2013-10-01

    Barnacles (Crustacea: Thoracica) show diverse sexual systems, including simultaneous hermaphroditism, androdioecy (hermaphrodites + males), and dioecy (females + males). When males occur, they are always much smaller (called dwarf males) than conspecific hermaphrodites or females. Ever since Darwin made this discovery, many scientists have been fascinated by such diversity. In this study, we provide an overview of (1) the diversity of sexual systems in barnacles, (2) the continuity between different sexual systems in some genera or species, and (3) the plasticity in sexual expression in several species. First, although most barnacles are hermaphroditic, both theoretical and empirical studies suggest that females and dwarf males tend to occur in species with small mating groups. Low sperm competition among hermaphrodites and little chance to act as a male are both associated with small group sizes and identified as the forces promoting the evolution of dwarf males and pure females, respectively. Second, in some groups of barnacles, the distinction between hermaphrodites and dwarf males is unclear because of the potential of dwarf males to become hermaphrodites. As many barnacle species tend toward protandric simultaneous hermaphroditism (develop male function first and then add female function without discarding male function), the dwarf males in such cases are best described as potential hermaphrodites that arrest growth and emphasize male function much earlier because of attachment to conspecifics. This is presumably advantageous in fertilizing the eggs of the host individuals. The distinction between hermaphrodites and females may also be obscured in some species. Third, sex allocation and penial morphology are plastic in some species. We also report the results of a transplanting experiment on small individuals of the pedunculate barnacle Octolasmis angulata, which suggests that individuals transplanted onto conspecifics developed longer and broader penises than

  1. aCORN Beta Spectrometer and Electrostatic Mirror

    NASA Astrophysics Data System (ADS)

    Hassan, Md; aCORN Collaboration

    2013-10-01

    aCORN uses a high efficiency backscatter suppressed beta spectrometer to measure the electron-antineutrino correlation in neutron beta decay. We measure the correlation by counting protons and beta electrons in coincidence with precisely determined electron energy. There are 19 photomultiplier tubes arranged in a hexagonal array coupled to a single phosphor doped polystyrene scintillator. The magnetic field is shaped so that electrons that backscatter without depositing their full energy strike a tulip-shaped array of scintillator paddles and these events are vetoed. The detailed construction, performance and calibration of this beta spectrometer will be presented. I will also present the simulation, construction, and features of our novel electrostatic mirror. This work was supported by the National Science Foundation and the NIST Center for Neutron Research.

  2. An exploratory study of the nutritional composition of Tanoak (Lithocarpus densiflorus) acorns after potassium phosphonate treatment.

    PubMed

    Meyers, Katherine J; Swiecki, Tedmund J; Mitchell, Alyson E

    2007-07-25

    Native American Pomo communities who live in the Northern Coastal range of California and consume acorns from tanoak trees as part of traditional diets are facing the potential loss of many culturally important trees to sudden oak death. Pomo and other Native American communities are reluctant to use the protective fungicide, potassium phosphonate, on trees used for acorn collection without information on how the treatment affects acorn properties. In this study, select macronutrients and polyphenolics were quantified in tanoak acorns to evaluate the influence of potassium phosphonate treatment on the composition and nutritional value of tanoak acorns. Of the fatty acids tested from C14:0 to C20:1, only C17:0 was significantly lower (p < 0.05) in the nontreated and treated acorns after the first year. There were no differences detected in total phenolic content, gallic acid content, or ellagic acid content. Protein, phosphorus, and potassium levels were not significantly affected by fungicide treatment. Soluble glucose and fructose levels were significantly higher (p < 0.05) in both nontreated and treated groups after the first year; soluble sucrose levels did not change. Total glucose, starch, and total nonstructural carbohydrates increased significantly (p < 0.05) in the nontreated group after the first year but not in the treatment group; however, the treatment group values did not differ significantly from the control group values at baseline. The lack of any negative significant differences between acorns from treated and untreated tanoak trees implies that sodium phosphonate application for the prevention of sudden oak death does not impact the predominant polyphenolics or macronutrient quality of tanoak acorns. PMID:17559226

  3. An exploratory study of the nutritional composition of Tanoak (Lithocarpus densiflorus) acorns after potassium phosphonate treatment.

    PubMed

    Meyers, Katherine J; Swiecki, Tedmund J; Mitchell, Alyson E

    2007-07-25

    Native American Pomo communities who live in the Northern Coastal range of California and consume acorns from tanoak trees as part of traditional diets are facing the potential loss of many culturally important trees to sudden oak death. Pomo and other Native American communities are reluctant to use the protective fungicide, potassium phosphonate, on trees used for acorn collection without information on how the treatment affects acorn properties. In this study, select macronutrients and polyphenolics were quantified in tanoak acorns to evaluate the influence of potassium phosphonate treatment on the composition and nutritional value of tanoak acorns. Of the fatty acids tested from C14:0 to C20:1, only C17:0 was significantly lower (p < 0.05) in the nontreated and treated acorns after the first year. There were no differences detected in total phenolic content, gallic acid content, or ellagic acid content. Protein, phosphorus, and potassium levels were not significantly affected by fungicide treatment. Soluble glucose and fructose levels were significantly higher (p < 0.05) in both nontreated and treated groups after the first year; soluble sucrose levels did not change. Total glucose, starch, and total nonstructural carbohydrates increased significantly (p < 0.05) in the nontreated group after the first year but not in the treatment group; however, the treatment group values did not differ significantly from the control group values at baseline. The lack of any negative significant differences between acorns from treated and untreated tanoak trees implies that sodium phosphonate application for the prevention of sudden oak death does not impact the predominant polyphenolics or macronutrient quality of tanoak acorns.

  4. Nest-site selection in the acorn woodpecker

    USGS Publications Warehouse

    Hooge, P.N.; Stanback, M.T.; Koenig, W.D.

    1999-01-01

    Acorn Woodpeckers (Melanerpes formicivorus) at Hastings Reservation in central California prefer to nest in dead limbs in large, dead valley oaks (Quercus lobata) and California sycamores (Platanus racemosa) that are also frequently used as acorn storage trees. Based on 232 nest cavities used over an 18-year period, we tested whether preferred or modal nest-site characters were associated with increased reproductive success (the 'nest-site quality' hypothesis). We also examined whether more successful nests were likely to experience more favorable microclimatic conditions or to be less accessible to terrestrial predators. We found only equivocal support for the nest-site quality hypothesis: only 1 of 5 preferred characters and 2 of 10 characters exhibiting a clear modality were correlated with higher reproductive success. All three characteristics of nests known or likely to be associated with a more favorable microclimate, and two of five characteristics likely to render nests less accessible to predators, were correlated with higher reproductive success: These results suggest that nest cavities in this population are built in part to take advantage of favorable microclimatic conditions and, to a lesser extent, to reduce access to predators. However, despite benefits of particular nest characteristics, birds frequently nested in apparently suboptimal cavities. We also found a significant relationship between mean group size and the history of occupancy of particular territories and the probability of nest cavities being built in microclimatically favorable live limbs, suggesting that larger groups residing on more stable territories were better able to construct nests with optimal characteristics. This indicates that there may be demographic, as well as ecological, constraints on nest-site selection in this primary cavity nester.

  5. Electron microscopy and composition of raw acorn starch in relation to in vivo starch digestibility.

    PubMed

    Cappai, Maria Grazia; Alesso, Giuseppe Andrea; Nieddu, Giuseppa; Sanna, Marina; Pinna, Walter

    2013-06-01

    The structure and composition of starch play an important role as co-factors affecting raw starch digestibility: such features were investigated in raw acorn starch from the most diffused oak trees in the Mediterranean basin. A total of 620 whole ripe acorns from Holm (Quercus ilex L., n = 198), Downy (Quercus pubescens Willd., n = 207) and Cork (Quercus suber L., n = 215) oaks sampled on the Sardinia Isle (40° 56' 0'' N; 9° 4' 0'' E; 545 m above the mean sea level) in the same geographical area, were analyzed for their chemical composition. The starch contents ranged between 51.2% and 53.5% of dry matter. The starch granules displayed a spheroid/ovoid and cylindrical shape; on scanning electron microscopic (SEM) analyses, a bimodal distribution of starch granule size was observed both for Holm and Cork oak acorns, whereas the starch granules of Downy oak acorns showed diameters between 10.2 and 13.8 μm. The specific amylose to amylopectin ratio of acorn starch was 25.8%, 19.5% and 34.0% in the Holm, Downy and Cork oaks, respectively. The (13)C Nuclear Magnetic Resonance (NMR) signal analysis displayed a pivotal spectrum for the identification of the amylose peaks in raw acorn starch, as a basis for the amylose to amylopectin ratio determination.

  6. Australian barnacles (Cirripedia: Thoracica), distributions and biogeographical affinities.

    PubMed

    Jones, Diana S

    2012-09-01

    Currently, 279 barnacle species are recognized in Australia waters. The barnacle fauna of tropical Australia exhibits high species diversity (221), with a high incidence of tropical species (87 Indo-west Pacific [IWP], 16 West Pacific and 65 Indo-Malayan), a low species endemicity (8), and 44 cosmopolitan and 1 Australasian species. Conversely, that of temperate Australia shows lower species diversity (129), with a lower incidence of tropical species (26 IWP, 10 West Pacific and 25 Indo-Malayan), higher species endemicity (23), 37 cosmopolitan, 6 Australasian species, and 3 Australasian/Antarctic species. Distributions corroborate the general patterns demonstrated by the shallow-water biota of northern tropical and southern temperate Australian biogeographic provinces. Tropical and temperate provinces grade into each other in a broad overlap zone along both the western and eastern Australian coasts. This overlap zone is essentially a transitional region, with the gradual replacement of a tropical barnacle fauna in the north by a predominantly temperate barnacle fauna in the south. Both western and eastern Australian coasts are bounded by major poleward-flowing warm currents that have considerable influence on the marine flora and fauna, distributing tropical species of many taxa much farther south than could be predicted by latitude. Currently, 16 barnacle species introduced into Australian waters are identified, although this number may increase in the future due to new port developments and increased shipping arrivals.

  7. High spectral resolution image of Barnacle Bill

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The rover Sojourner's first target for measurement by the Alpha-Proton-Xray Spectrometer (APXS) was the rock named Barnacle Bill, located close to the ramp down which the rover made its egress from the lander. The full spectral capability of the Imager for Mars Pathfinder (IMP), consisting of 13 wavelength filters, was used to characterize the rock's surface. The measured area is relatively dark, and is shown in blue. Nearby on the rock surface, soil material is trapped in pits (shown in red).

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  8. Biventricular Finite Element Modeling of the Acorn CorCap Cardiac Support Device on a Failing Heart

    PubMed Central

    Wenk, Jonathan F.; Ge, Liang; Zhang, Zhihong; Mojsejenko, Dimitri; Potter, D. Dean; Tseng, Elaine E.; Guccione, Julius M.; Ratcliffe, Mark B.

    2013-01-01

    Background The Acorn CorCap Cardiac Support Device (CSD; Acorn Cardiovascular Inc, St. Paul, MN) is a woven polyester jacket that is placed around the heart and designed to reverse the progressive remodeling associated with dilated cardiomyopathy. However, the effects of the Acorn CSD on myofiber stress and ventricular function remain unknown. We tested the hypothesis that the Acorn CSD reduces end-diastolic (ED) myofiber stress. Methods A previously described weakly coupled biventricular finite element (FE) model and circulatory model based on magnetic resonance images of a dog with dilated cardiomyopathy was used. Virtual applications of the CSD alone (Acorn), CSD with rotated fabric fiber orientation (rotated), CSD with 5% prestretch (tight), and CSD wrapped only around the left ventricle (LV; LV-only) were performed, and the effect on myofiber stress at ED and pump function was calculated. Results The Acorn CSD has a large effect on ED myofiber stress in the LV free wall, with reductions of 55%, 79%, 92%, and 40% in the Acorn, rotated, tight, and LV-only cases, respectively. However, there is a tradeoff in which the Acorn CSD reduces stroke volume at LV end-diastolic pressure of 8 mm Hg by 23%, 25%, 30%, and 7%, respectively, in the Acorn, rotated, tight, and LV-only cases. Conclusions The Acorn CSD significantly reduces ED myofiber stress. However, CSD wrapped only around the LV was the only case with minimal negative effect on pump function. Findings suggest that LV-only CSD and Acorn fabric orientation should be optimized to allow maximal myofiber stress reduction with minimal reduction in pump function. PMID:23643546

  9. Calcium Efflux from Barnacle Muscle Fibers

    PubMed Central

    Russell, J. M.; Blaustein, M. P.

    1974-01-01

    Calcium-45 was injected into single giant barnacle muscle fibers, and the rate of efflux was measured under a variety of conditions. The rate constant (k) for 45Ca efflux into standard seawater averaged 17 x 10–4 min–1 which corresponds to an efflux of about 1–2 pmol/cm2·s. Removal of external Ca (Cao) reduced the efflux by 50%. In most fibers about 40% of the 45Ca efflux into Ca-free seawater was dependent on external Na (Nao); treatment with 3.5 mM caffeine increased the magnitude of the Nao-dependent efflux. In a few fibers removal of Nao, in the absence of Cao, either had no effect or increased k; caffeine (2–3.5 mM) unmasked an Nao-dependent efflux in these fibers. The Nao-dependent Ca efflux had a Q10 of about 3.7. The data are consistent with the idea that a large fraction of the Ca efflux may be carrier-mediated, and may involve both Ca-Ca and Na-Ca counterflow. The relation between the Nao-dependent Ca efflux and the external Na concentration is sigmoid, and suggests that two, or more likely three, external Na+ ions may activate the efflux of one Ca+2. With a three-for-one Na-Ca exchange, the Na electrochemical gradient may be able to supply sufficient energy to maintain the Ca gradient in these fibers. Other, more complex models are not excluded, however, and may be required to explain some puzzling features of the Ca efflux such as the variable Nao-dependence. PMID:4812633

  10. Dung beetles eat acorns to increase their ovarian development and thermal tolerance.

    PubMed

    Verdú, José R; Casas, José L; Lobo, Jorge M; Numa, Catherine

    2010-01-01

    Animals eat different foods in proportions that yield a more favorable balance of nutrients. Despite known examples of these behaviors across different taxa, their ecological and physiological benefits remain unclear. We identified a surprising dietary shift that confers ecophysiological advantages in a dung beetle species. Thorectes lusitanicus, a Mediterranean ecosystem species adapted to eat semi-dry and dry dung (dung-fiber consumers) is also actively attracted to oak acorns, consuming and burying them. Acorn consumption appears to confer potential advantages over beetles that do not eat acorns: acorn-fed beetles showed important improvements in the fat body mass, hemolymph composition, and ovary development. During the reproductive period (October-December) beetles incorporating acorns into their diets should have greatly improved resistance to low-temperature conditions and improved ovarian development. In addition to enhancing the understanding of the relevance of dietary plasticity to the evolutionary biology of dung beetles, these results open the way to a more general understanding of the ecophysiological implications of differential dietary selection on the ecology and biogeography of these insects.

  11. Dung beetles eat acorns to increase their ovarian development and thermal tolerance.

    PubMed

    Verdú, José R; Casas, José L; Lobo, Jorge M; Numa, Catherine

    2010-01-01

    Animals eat different foods in proportions that yield a more favorable balance of nutrients. Despite known examples of these behaviors across different taxa, their ecological and physiological benefits remain unclear. We identified a surprising dietary shift that confers ecophysiological advantages in a dung beetle species. Thorectes lusitanicus, a Mediterranean ecosystem species adapted to eat semi-dry and dry dung (dung-fiber consumers) is also actively attracted to oak acorns, consuming and burying them. Acorn consumption appears to confer potential advantages over beetles that do not eat acorns: acorn-fed beetles showed important improvements in the fat body mass, hemolymph composition, and ovary development. During the reproductive period (October-December) beetles incorporating acorns into their diets should have greatly improved resistance to low-temperature conditions and improved ovarian development. In addition to enhancing the understanding of the relevance of dietary plasticity to the evolutionary biology of dung beetles, these results open the way to a more general understanding of the ecophysiological implications of differential dietary selection on the ecology and biogeography of these insects. PMID:20404931

  12. Dung Beetles Eat Acorns to Increase Their Ovarian Development and Thermal Tolerance

    PubMed Central

    Verdú, José R.; Casas, José L.; Lobo, Jorge M.; Numa, Catherine

    2010-01-01

    Animals eat different foods in proportions that yield a more favorable balance of nutrients. Despite known examples of these behaviors across different taxa, their ecological and physiological benefits remain unclear. We identified a surprising dietary shift that confers ecophysiological advantages in a dung beetle species. Thorectes lusitanicus, a Mediterranean ecosystem species adapted to eat semi-dry and dry dung (dung-fiber consumers) is also actively attracted to oak acorns, consuming and burying them. Acorn consumption appears to confer potential advantages over beetles that do not eat acorns: acorn-fed beetles showed important improvements in the fat body mass, hemolymph composition, and ovary development. During the reproductive period (October-December) beetles incorporating acorns into their diets should have greatly improved resistance to low-temperature conditions and improved ovarian development. In addition to enhancing the understanding of the relevance of dietary plasticity to the evolutionary biology of dung beetles, these results open the way to a more general understanding of the ecophysiological implications of differential dietary selection on the ecology and biogeography of these insects. PMID:20404931

  13. Acorn selection by the wood mouse Apodemus sylvaticus: a semi-controlled experiment in a Mediterranean environment.

    PubMed

    Rosalino, Luís Miguel; Nóbrega, Filomena; Santos-Reis, Margarida; Teixeira, Generosa; Rebelo, Rui

    2013-09-01

    Fruits are highly important food resources for mammals in Mediterranean Europe, and due to the dominance of oaks (Quercus sp.), acorns are among those used by a vast array of species, including rodents. The metabolic yield of acorn intake may determine a selection pattern: preference for fat, carbohydrate, and consequently energy-rich fruits; or avoidance of fruits containing high concentrations of secondary chemical compounds (e.g., tannic acid). We studied the acorn feeding selection pattern of wood mice (Apodemus sylvaticus) inhabiting a mixed oak woodland, southwest Portugal, using an experiment conducted in an open-air enclosure. We tested which variables associated with the wood mouse (e.g., sex) and acorns (e.g., size and nutrient content) from three oak species (holm Q. rotundifolia, Portuguese Q. faginea and cork Q. suber oak) could be constraining acorn consumption. Our results indicate that wood mice are selecting acorns of the most common oak species (Q. suber), probably due to their previous familiarization with the fruit due to its dominance in the ecosystem but probably also because its chemical characteristics (sugar contents). Rodent gender and acorn morphology (width) are also influential, with females more prone to consume acorns with smaller width, probably due to handling limitation. This selective behaviour may have consequences for dispersion and natural regeneration of the different oak species.

  14. Sexual systems and life history of barnacles: a theoretical perspective.

    PubMed

    Yamaguchi, Sachi; Charnov, Eric L; Sawada, Kota; Yusa, Yoichi

    2012-09-01

    Thoracican barnacles show one of the most diverse sexual systems in animals: hermaphroditism, dioecy (males and females), and androdioecy (males and hermaphrodites). In addition, when present, male barnacles are very small and are called "dwarf males". The diverse sexual systems and male dwarfism in this taxon have attracted both theoretical and empirical biologists. In this article, we review the theoretical studies on barnacles' sexual systems in the context of sex allocation and life history theories. We first introduce the sex allocation models by Charnov, especially in relation to the mating group size, and a new expansion of his models is also proposed. We then explain three studies by Yamaguchi et al., who have studied the interaction between sex allocation and life history in barnacles. These studies consistently showed that limited mating opportunity favors androdioecy and dioecy over hermaphroditism. In addition, other factors, such as rates of survival and availability of food, are also important. We discuss the importance of empirical studies testing these predictions and how empirical studies interact with theoretical constructs.

  15. Modelling boundary layer flow over barnacle-fouled surfaces

    NASA Astrophysics Data System (ADS)

    Sadique, Jasim; Yang, Xiang; Meneveau, Charles; Mittal, Rajat

    2014-11-01

    Macro-biofouling is a critical concern for the marine industry. However, there is little data on flow and drag over such surfaces. Accurate modelling of such multi-scale flows remains a big challenge. Such simulations are vital in providing insights into the fundamental flow physics, and they can be used to estimate the timing, need and effectiveness of measures used to counteract bio-fouling. This talk focuses on the use of a sharp-interface immersed boundary method coupled with a wall model and large-eddy simulations to carry out accurate simulations of a turbulent boundary layer flow over macro-fouled surfaces. For the current study, high resolution scans of barnacles were used to create simple geometrical representations. Simulations were then carried out to test how well these simpler geometric models mimic the flow over actual barnacles. Simulations of array of modeled barnacles, with different barnacle densities have also been carried out and we present results on the effect distribution density on the flow physics and drag on the surfaces. This work is funded by ONR Grant N00014-12-1-0582.

  16. Austromegabalanus psittacus barnacle shell structure and proteoglycan localization and functionality.

    PubMed

    Fernández, M S; Arias, J I; Neira-Carrillo, A; Arias, J L

    2015-09-01

    Comparative analyzes of biomineralization models have being crucial for the understanding of the functional properties of biominerals and the elucidation of the processes through which biomacromolecules control the synthesis and structural organization of inorganic mineral-based biomaterials. Among calcium carbonate-containing bioceramics, egg, mollusk and echinoderm shells, and crustacean carapaces, have being fairly well characterized. However, Thoraceca barnacles, although being crustacea, showing molting cycle, build a quite stable and heavily mineralized shell that completely surround the animal, which is for life firmly cemented to the substratum. This makes barnacles an interesting model for studying processes of biomineralization. Here we studied the main microstructural and ultrastructural features of Austromegabalanus psittacus barnacle shell, characterize the occurrence of specific proteoglycans (keratan-, dermatan- and chondroitin-6-sulfate proteoglycans) in different soluble and insoluble organic fractions extracted from the shell, and tested them for their ability to crystallize calcium carbonate in vitro. Our results indicate that, in the barnacle model, proteoglycans are good candidates for the modification of the calcite crystal morphology, although the cooperative effect of some additional proteins in the shell could not be excluded.

  17. Effects of barnacle epibionts on the periwinkle Littorina littorea (L.)

    NASA Astrophysics Data System (ADS)

    Buschbaum, C.; Reise, K.

    1999-08-01

    In a sandy bay with mussel beds in the Wadden Sea (Island of Sylt, eastern North Sea), periwinkles Littorina littorea (L.) were often strongly overgrown with the barnacle Balanus crenatus Bruguière in the lower intertidal zone. Consequences of this epibiosis on mobility, reproduction and mortalityof the snail were examined. B. crenatus growing on L. littorea increased snail volume up to 4-fold and weight up to 3.5-fold and crawling speed of fouled L. littorea was significantly slowed down. The epibiotic structure also caused a decrease in reproductive output. In laboratory experiments, egg production of fouled L. littorea was significantly lower than in snails free of barnacles. Presumably, copulation of the periwinkles is hampered by the voluminous and prickly cover of barnacles. Field studies demonstrated an increased mortality of overgrown L. littorea. A decrease in reproductive output and a lower survival of snails with a cover of barnacles suggest that B. crenatus epibionts may have a significant impact on the population of L. littorea.

  18. Austromegabalanus psittacus barnacle shell structure and proteoglycan localization and functionality.

    PubMed

    Fernández, M S; Arias, J I; Neira-Carrillo, A; Arias, J L

    2015-09-01

    Comparative analyzes of biomineralization models have being crucial for the understanding of the functional properties of biominerals and the elucidation of the processes through which biomacromolecules control the synthesis and structural organization of inorganic mineral-based biomaterials. Among calcium carbonate-containing bioceramics, egg, mollusk and echinoderm shells, and crustacean carapaces, have being fairly well characterized. However, Thoraceca barnacles, although being crustacea, showing molting cycle, build a quite stable and heavily mineralized shell that completely surround the animal, which is for life firmly cemented to the substratum. This makes barnacles an interesting model for studying processes of biomineralization. Here we studied the main microstructural and ultrastructural features of Austromegabalanus psittacus barnacle shell, characterize the occurrence of specific proteoglycans (keratan-, dermatan- and chondroitin-6-sulfate proteoglycans) in different soluble and insoluble organic fractions extracted from the shell, and tested them for their ability to crystallize calcium carbonate in vitro. Our results indicate that, in the barnacle model, proteoglycans are good candidates for the modification of the calcite crystal morphology, although the cooperative effect of some additional proteins in the shell could not be excluded. PMID:26276577

  19. The chemistry of stalked barnacle adhesive (Lepas anatifera)

    PubMed Central

    Jonker, Jaimie-Leigh; Morrison, Liam; Lynch, Edward P.; Grunwald, Ingo; von Byern, Janek; Power, Anne Marie

    2015-01-01

    The results of the first chemical analysis of the adhesive of Lepas anatifera, a stalked barnacle, are presented. A variety of elements were identified in scanning electron microscopy with energy dispersive spectrometry (SEM-EDS) of the adhesive, including Na, Mg, Ca, Cl, S, Al, Si, K and Fe; however, protein–metal interactions were not detected in Raman spectra of the adhesive. Elemental signatures from SEM-EDS of L. anatifera adhesive glands were less varied. Phosphorous was mostly absent in adhesive samples; supporting previous studies showing that phosphoserines do not play a significant role in adult barnacle adhesion. Disulfide bridges arising from Cys dimers were also investigated; Raman analysis showed weak evidence for S–S bonds in L. anatifera. In addition, there was no calcium carbonate signal in the attenuated total reflectance Fourier transform infrared spectra of L. anatifera adhesive, unlike several previous studies in other barnacle species. Significant differences were observed between the Raman spectra of L. anatifera and Balanus crenatus; these and a range of Raman peaks in the L. anatifera adhesive are discussed. Polysaccharide was detected in L. anatifera adhesive but the significance of this awaits further experiments. The results demonstrate some of the diversity within barnacle species in the chemistry of their adhesives. PMID:25657841

  20. Distribution, abundance and trail characteristics of acorn worms at Australian continental margins

    NASA Astrophysics Data System (ADS)

    Anderson, T. J.; Przeslawski, R.; Tran, M.

    2011-04-01

    Acorn worms (Enteropneusta), which were previously thought to be a missing link in understanding the evolution of chordates, are an unusual and potentially important component of many deep-sea benthic environments, particularly for nutrient cycling. Very little is known about their distribution, abundance, or behaviour in deep-sea environments around the world, and almost nothing is known about their distribution within Australian waters. In this study, we take advantage of two large-scale deep-sea mapping surveys along the eastern (northern Lord Howe Rise) and western continental margins of Australia to quantify the distribution, abundance and trail-forming behaviour of this highly unusual taxon. This is the first study to quantify the abundance and trail behaviour of acorn worms within Australian waters and provides the first evidence of strong depth-related distributions. Acorn worm densities and trail activity were concentrated between transect-averaged depths of 1600 and 3000 m in both eastern and western continental margins. The shallow limit of their depth distribution was 1600 m. The deeper limit was less well-defined, as individuals were found in small numbers below 3000 down to 4225 m. This distributional pattern may reflect a preference for these depths, possibly due to higher availability of nutrients, rather than a physiological constraint to greater depths. Sediment characteristics alone were poor predictors of acorn worm densities and trail activity. High densities of acorn worms and trails were associated with sandy-mud sediments, but similar sediment characteristics in either shallower or deeper areas did not support similar densities of acorn worms or trails. Trail shapes varied between eastern and western margins, with proportionally more meandering trails recorded in the east, while spiral and meandering trails were both common in the west. Trail shape varied by depth, with spiral-shaped trails dominant in areas of high acorn worm densities

  1. Temporal variability and cooperative breeding: testing the bet-hedging hypothesis in the acorn woodpecker.

    PubMed

    Koenig, Walter D; Walters, Eric L

    2015-10-01

    Cooperative breeding is generally considered an adaptation to ecological constraints on dispersal and independent breeding, usually due to limited breeding opportunities. Although benefits of cooperative breeding are typically thought of in terms of increased mean reproductive success, it has recently been proposed that this phenomenon may be a bet-hedging strategy that reduces variance in reproductive success (fecundity variance) in populations living in highly variable environments. We tested this hypothesis using long-term data on the polygynandrous acorn woodpecker (Melanerpes formicivorus). In general, fecundity variance decreased with increasing sociality, at least when controlling for annual variation in ecological conditions. Nonetheless, decreased fecundity variance was insufficient to compensate for reduced per capita reproductive success of larger, more social groups, which typically suffered lower estimated mean fitness. We did, however, find evidence that sociality in the form of larger group size resulted in increased fitness in years following a small acorn crop due to reduced fecundity variance. Bet-hedging, although not the factor driving sociality in general, may play a role in driving acorn woodpecker group living when acorns are scarce and ecological conditions are poor.

  2. Reasoning about Natural Selection: Diagnosing Contextual Competency Using the ACORNS Instrument

    ERIC Educational Resources Information Center

    Nehm, Ross H.; Beggrow, Elizabeth P.; Opfer, John E.; Ha, Minsu

    2012-01-01

    Studies of students' thinking about natural selection have revealed that the scenarios in which students reason evoke different types, magnitudes, and arrangements of knowledge elements and misconceptions. Diagnostic tests are needed that probe students' thinking across a representative array of evolutionary contexts. The ACORNS is a diagnostic…

  3. Temporal variability and cooperative breeding: testing the bet-hedging hypothesis in the acorn woodpecker.

    PubMed

    Koenig, Walter D; Walters, Eric L

    2015-10-01

    Cooperative breeding is generally considered an adaptation to ecological constraints on dispersal and independent breeding, usually due to limited breeding opportunities. Although benefits of cooperative breeding are typically thought of in terms of increased mean reproductive success, it has recently been proposed that this phenomenon may be a bet-hedging strategy that reduces variance in reproductive success (fecundity variance) in populations living in highly variable environments. We tested this hypothesis using long-term data on the polygynandrous acorn woodpecker (Melanerpes formicivorus). In general, fecundity variance decreased with increasing sociality, at least when controlling for annual variation in ecological conditions. Nonetheless, decreased fecundity variance was insufficient to compensate for reduced per capita reproductive success of larger, more social groups, which typically suffered lower estimated mean fitness. We did, however, find evidence that sociality in the form of larger group size resulted in increased fitness in years following a small acorn crop due to reduced fecundity variance. Bet-hedging, although not the factor driving sociality in general, may play a role in driving acorn woodpecker group living when acorns are scarce and ecological conditions are poor. PMID:26400744

  4. Acorn Caching in Tree Squirrels: Teaching Hypothesis Testing in the Park

    ERIC Educational Resources Information Center

    McEuen, Amy B.; Steele, Michael A.

    2012-01-01

    We developed an exercise for a university-level ecology class that teaches hypothesis testing by examining acorn preferences and caching behavior of tree squirrels (Sciurus spp.). This exercise is easily modified to teach concepts of behavioral ecology for earlier grades, particularly high school, and provides students with a theoretical basis for…

  5. Temporal variability and cooperative breeding: testing the bet-hedging hypothesis in the acorn woodpecker

    PubMed Central

    Koenig, Walter D.; Walters, Eric L.

    2015-01-01

    Cooperative breeding is generally considered an adaptation to ecological constraints on dispersal and independent breeding, usually due to limited breeding opportunities. Although benefits of cooperative breeding are typically thought of in terms of increased mean reproductive success, it has recently been proposed that this phenomenon may be a bet-hedging strategy that reduces variance in reproductive success (fecundity variance) in populations living in highly variable environments. We tested this hypothesis using long-term data on the polygynandrous acorn woodpecker (Melanerpes formicivorus). In general, fecundity variance decreased with increasing sociality, at least when controlling for annual variation in ecological conditions. Nonetheless, decreased fecundity variance was insufficient to compensate for reduced per capita reproductive success of larger, more social groups, which typically suffered lower estimated mean fitness. We did, however, find evidence that sociality in the form of larger group size resulted in increased fitness in years following a small acorn crop due to reduced fecundity variance. Bet-hedging, although not the factor driving sociality in general, may play a role in driving acorn woodpecker group living when acorns are scarce and ecological conditions are poor. PMID:26400744

  6. Memristive Model of the Barnacle Giant Muscle Fibers

    NASA Astrophysics Data System (ADS)

    Sah, Maheshwar Pd.; Kim, Hyongsuk; Eroglu, Abdullah; Chua, Leon

    The generation of action potentials (oscillations) in biological systems is a complex, yet poorly understood nonlinear dynamical phenomenon involving ions. This paper reveals that the time-varying calcium ion and the time-varying potassium ion, which are essential for generating action potentials in Barnacle giant muscle fibers are in fact generic memristors in the perspective of electrical circuit theory. We will show that these two ions exhibit all the fingerprints of memristors from the equations of the Morris-Lecar model of the Barnacle giant muscle fibers. This paper also gives a textbook reference to understand the difference between memristor and nonlinear resistor via analysis of the potassium ion-channel memristor and calcium ion-channel nonlinear resistor. We will also present a comprehensive in-depth analysis of the generation of action potentials (oscillations) in memristive Morris-Lecar model using small-signal circuit model and the Hopf bifurcation theorem.

  7. Adaptive evolution of sexual systems in pedunculate barnacles.

    PubMed

    Yusa, Yoichi; Yoshikawa, Mai; Kitaura, Jun; Kawane, Masako; Ozaki, Yuki; Yamato, Shigeyuki; Høeg, Jens T

    2012-03-01

    How and why diverse sexual systems evolve are fascinating evolutionary questions, but few empirical studies have dealt with these questions in animals. Pedunculate (gooseneck) barnacles show such diversity, including simultaneous hermaphroditism, coexistence of dwarf males and hermaphrodites (androdioecy), and coexistence of dwarf males and females (dioecy). Here, we report the first phylogenetically controlled test of the hypothesis that the ultimate cause of the diverse sexual systems and presence of dwarf males in this group is limited mating opportunities for non-dwarf individuals, owing to mating in small groups. Within the pedunculate barnacle phylogeny, dwarf males and females have evolved repeatedly. Females are more likely to evolve in androdioecious than hermaphroditic populations, suggesting that evolution of dwarf males has preceded that of females in pedunculates. Both dwarf males and females are associated with a higher proportion of solitary individuals in the population, corroborating the hypothesis that limited mating opportunities have favoured evolution of these diverse sexual systems, which have puzzled biologists since Darwin.

  8. Can incubators work in Africa? Acorn Technologies and the entrepreneur-centric model

    PubMed Central

    2010-01-01

    Background Incubators are organizations that support the growth of new and typically technology-based enterprises, by providing business support services that bring together human and financial capital. Although the traditional role of incubators has been for economic development, they may also be a useful policy lever to tackle global health, by fostering the development and delivery of local health innovation. Given its high disease burden, life sciences incubators hold particular potential for Africa. As the most industrially advanced African nation, South Africa serves as a litmus test for identifying effective incubator policies. The case study method was used to illustrate how one such publicly funded incubator founded in 2002, Acorn Technologies, helped to catalyze local health product innovation. Discussion Acorn helped to support twelve biomedical device firms. One of them, Real World Diagnostics, was founded by a trainee from Acorn’s innovative internship program (Hellfire). It developed rapid strip diagnostic tests for locally prevalent diseases including schistosomiasis and HIV, and reported $2 million (USD) in revenue in 2009. Acorn achieved this success by operating as a non-profit virtual incubator with little physical infrastructure. Employing a virtual model in combination with stringent selection criteria of capital efficiency for clients proved to be effective in reducing its own fixed costs. Acorn focused on entrepreneurship training and networking, both critical at an early stage in an environment dominated by multinational biomedical device companies. Acorn and its clients learned that employing a cross-subsidy business model allowed one to generate royalty revenue through imports to subsidize R&D for local diseases. However, funding constraints and government expectations for rapid self-sustainability forced Acorn to merge with its sister biotechnology incubator in 2009. Summary A key to Acorn’s achievements was identifying entrepreneurs

  9. Effect of ultrasound on cyprids and juvenile barnacles.

    PubMed

    Guo, Shi Feng; Lee, Heow Pueh; Chaw, Kuan Chun; Miklas, Jason; Teo, Serena Lay Ming; Dickinson, Gary H; Birch, William R; Khoo, Boo Cheong

    2011-02-01

    Settlement inhibition of barnacle (Amphibalanus amphitrite) cypris larvae resulting from exposure to ultrasound was measured at three frequencies (23, 63, and 102 kHz), applied at three acoustic pressure levels (9, 15, and 22 kPa) for exposure times of 30, 150, and 300 s. The lowest settlement was observed for 23 kHz, which also induced the highest cyprid mortality. Cyprid settlement following exposure to 23 kHz at 22 kPa for 30 s was reduced by a factor of two. Observing surface exploration by the cyprids revealed an altered behaviour following exposure to ultrasound: step length was increased, while step duration, walking pace, and the fraction of cyprids exploring the surface were significantly reduced with respect to control cyprids. The basal area of juvenile barnacles, metamorphosed from ultrasound-treated cyprids was initially smaller than unexposed individuals, but normalised over two weeks' growth. Thus, ultrasound exposure effectively reduced cyprid settlement, yet metamorphosed barnacles grew normally.

  10. Heavy metal concentrations in edible barnacles exposed to natural contamination.

    PubMed

    Dionísio, M; Costa, A; Rodrigues, A

    2013-04-01

    The giant barnacle Megabalanus azoricus is a popular seafood in the Azores. It is mainly caught in coastal environments and sold for domestic human consumption. This species is a filter feeder and can be used as a biomonitor of trace metal bioavailabilities. To investigate consumption safety, the concentrations of 10 trace metals - As, Cd, Cr, Cu, Mn, Pb, Rb, Se, Sr and Zn - were evaluated in 3 body tissues of M. azoricus from 3 sites on 2 islands. There were no significant differences between the metal loads of the barnacles from the different sites. However, the concentrations of the total trace metal loads revealed significant differences among the tissues (cirrus, muscles and ovaries). The concentrations of some metals in the body were not within the safety levels for consumers, based on the allowable standard levels for crustaceans issued by the European Union and of legislations in several countries. Alarming levels of As and Cd were found. Considering the absence of heavy industry in the region, a non-anthropogenic volcanic source was assumed to be the reason for the observed metal levels. Barnacles, in particular M. azoricus, seem to be useful as bioindicators in this peculiar environment.

  11. Precise tuning of barnacle leg length to coastal wave action.

    PubMed Central

    Arsenault, D. J.; Marchinko, K. B.; Palmer, A. R.

    2001-01-01

    Both spatial and temporal variation in environmental conditions can favour intraspecific plasticity in animal form. But how precise is such environmental modulation? Individual Balanus glandula Darwin, a common northeastern Pacific barnacle, produce longer feeding legs in still water than in moving water. We report here that, on the west coast of Vancouver Island, Canada, the magnitude and the precision of this phenotypic variation is impressive. First, the feeding legs of barnacles from protected bays were nearly twice as long (for the same body mass) as those from open ocean shores. Second, leg length varied surprisingly precisely with wave exposure: the average maximum velocities of breaking waves recorded in situ explained 95.6-99.5% of the variation in average leg length observed over a threefold range of wave exposure. The decline in leg length with increasing wave action was less than predicted due to simple scaling, perhaps due to changes in leg shape or material properties. Nonetheless, the precision of this relationship reveals a remarkably close coupling between growth environment and adult form, and suggests that between-population differences in barnacle leg length may be used for estimating differences in average wave exposure easily and accurately in studies of coastal ecology. PMID:11600079

  12. The effect of cavitation bubbles on the removal of juvenile barnacles.

    PubMed

    Guo, Shifeng; Khoo, Boo Cheong; Teo, Serena Lay Ming; Lee, Heow Pueh

    2013-09-01

    The effect of cavitation bubbles on the removal of juvenile barnacles was documented using high speed photography. Using spark generated bubbles, the interaction between barnacle and cavitation bubble was examined in detail. The liquid jet generated by the bubble collapse was observed to be directed towards barnacle at different impact intensities, which is related to the dimensionless distance H' (H'=H/Rm), where H is the distance between bubble formation point and the top of barnacle, and Rm is the maximum bubble radius. At lower values of H', higher speed liquid jet was produced; consequently a larger impact pressure was generated. In general, barnacles are more easily removed at a younger stage. In older barnacles, the liquid jet impact was only able to remove the barnacle shells, leaving the base plate attached to the surface. This study indicates that cavitation can be used to remove attached barnacles, and it would be more efficient if it is applied during early stages of fouling, before the formation of hard calcareous structures.

  13. ESR dating pleistocene barnacles from BC and Maine: a new method for tracking sea level change.

    PubMed

    Blackwell, Bonnie A B; Gong, J J J; Skinner, Anne R; Blais-Stevens, Andrée; Nelson, Robert E; Blickstein, Joel I B

    2010-02-01

    Barnacles have never been successfully dated by electron spin resonance (ESR). Living mainly in the intertidal zone, barnacles die when sea level changes cause their permanent exposure. Thus, dating the barnacles dates past sea level changes. From this, we can measure apparent sea level changes that occur due to ocean volume changes, crustal isostasy, and tectonics. ESR can date aragonitic mollusc shells ranging in age from 5 ka to at least 500 ka. By modifying the standard ESR method for molluscs to chemically dissolve 20 microm from off the shells, six barnacle samples from Norridgewock, Maine, and Khyex River, British Columbia, were tested for suitability for ESR dating. Due to Mn2+ interference peaks, the four Maine barnacle samples were not datable by ESR. Two barnacles from BC, which lacked Mn2+ interference, yielded a mean ESR age of 15.1 +/- 1.0 ka. These ages agree well with 14C dates on the barnacles themselves and wood in the overlying glaciomarine sediment. Although stability tests to calculate the mean dating signal lifetime and more ESR calibration tests against other barnacles of known age are needed to ensure the method's accuracy, ESR can indeed date Balanus, and thus, sea level changes.

  14. Loggerhead turtle movements reconstructed from 18O and 13C profiles from commensal barnacle shells

    NASA Astrophysics Data System (ADS)

    Killingley, John S.; Lutcavage, Molly

    1983-03-01

    Commensal barnacles, Chelonibia testudinaria, from logger-head turtles have 18O and 13C variations in their calcitic shells that record the environments in which the turtles live. Isotopic profiles from the barnacle shells can thus be interpreted to reconstruct movements of the host turtle between open ocean and brackish-water regimes.

  15. PCR-cloning of cadmium-inducible peptides in the barnacle, Megabalanus volcano.

    PubMed

    Togi, Akiko; Kamino, Kei; Shizuri, Yoshikazu

    2002-04-01

    A 340 bp DNA fragment was amplified from barnacle (Megabalanus volcano) cDNA by polymerase chain reaction using primers designed based on the amino acid sequences of barnacle cadmium-inducible peptides CdlP1 and CdlP2. The whole sequence was determined by rapid amplification of cDNA ends method. The cDNA contained an open reading frame encoding 71 amino acid residues and the sequences for CdlP1 and CdlP2 were found to be located in the center of this coding region. Although CdlP1 and CdlP2 had been detected only in the cadmium-exposed barnacles, their mRNA was present both in cadmium-exposed barnacles and in unexposed barnacles. These results suggest that posttranslational proteolytic processing may be induced in the presence of cadmium.

  16. Barnacle Bill and Surrounding from Super-Pan

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is an image from the super-pan sequence. Of importance are some of the features around the rock nicknamed Barnacle Bill in the left foreground. The rock shows a 'streamlined tail' composed of particles deposited by wind on the leeward (downwind) side of the rock. Also seen is a 'moat' around the opposite (windward) side of the rock where either erosion (or non-deposition) of fine sediment has occurred. Mars Pathfinder scientist believe that the wind blowing over and around rocks like Barnacle Bill creates an airflow pattern wherein a buffer zone is formed immediately upwind of the rock and airflow patterns keep sediment from being deposited directly upwind of Barnacle Bill. On the downwind side, however, the airflow is complex and a small wake and tapered 'dead air zone' form. Sediment can be deposited within this region, the shape of the formed deposit corresponds to the airflow patterns that exist behind the rock. Similar features have been observed at the Viking landing sites, and are thought to form under high wind conditions during the autumn and winter seasons in the northern hemisphere. This image mosaic was processed by the U.S. Geological Survey in support of the NASA/JPL Mars Pathfinder Mars Mission.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  17. Mitochondrial evolution across lineages of the vampire barnacle Notochthamalus scabrosus.

    PubMed

    Wares, John P

    2015-02-01

    Eight whole mitochondrial genomes from the barnacle Notochthamalus scabrosus, with one from the northern lineage and seven from the divergent southern lineage, are presented. The annotated and aligned data were analyzed for signals of non-neutral evolution. Overall, these data are consistent with purifying selection operating on the protein-coding regions of the mitochondrion. However, a notable region of nonsynonymous substitution at the 3' end of the ND2 gene region, along with unusual site frequency spectra in two other gene regions, was identified.

  18. Antifouling Block Copolymer Surfaces that Resist Settlement of Barnacle Larvae

    SciTech Connect

    Weinman,C.; Krishnan, S.; Park, D.; Paik, M.; Wong, K.; Fischer, D.; Handlin, D.; Kowalke, G.; Wendt, D.; et al

    2007-01-01

    Marine biofouling is a serious problem caused by the accumulation and settlement of barnacles, macroalgae, and microbial slimes on the hulls of seafaring vessels. Biofouling can significantly increase drag, leading to startling consequences with regards to fuel consumption. Environmentally compatible solutions to biofouling are being sought as traditional metal-based systems of fouling control are being phased out due to their inherent toxicity. Further exasperating the problem of biofouling is the vast range of fouling organisms and environmental conditions experienced throughout the world. This renders the development of a universal biofouling coating a significant challenge.

  19. Effect of drying temperatures on starch-related functional and thermal properties of acorn flours.

    PubMed

    Correia, P R; Beirão-da-Costa, M L

    2011-03-01

    The application of starchy flours from different origins in food systems depends greatly on information about the chemical and functional properties of such food materials. Acorns are important forestry resources in the central and southern regions of Portugal. To preserve these fruits and to optimize their use, techniques like drying are needed. The effects of different drying temperatures on starch-related functional properties of acorn flours obtained from dried fruits of Quercus rotundifolia (QR) and Quercus suber (QS) were evaluated. Flours were characterized for amylose and resistant starch (RS) contents, swelling ability, and gelatinization properties. Drying temperature mainly affected amylose content and viscoamylographic properties. Amylograms of flours from fruits dried at 60 °C displayed higher consistency (2102 B.U. and 1560 B.U., respectively, for QR and QS). The transition temperatures and enthalpy were less affected by drying temperature, suggesting few modifications in starch structure during drying. QR flours presented different functional properties to those obtained from QS acorn flours. The effect of drying temperatures were more evident in QR.

  20. Climate, Deer, Rodents, and Acorns as Determinants of Variation in Lyme-Disease Risk

    PubMed Central

    Canham, Charles D; Oggenfuss, Kelly; Winchcombe, Raymond J; Keesing, Felicia

    2006-01-01

    Risk of human exposure to vector-borne zoonotic pathogens is a function of the abundance and infection prevalence of vectors. We assessed the determinants of Lyme-disease risk (density and Borrelia burgdorferi-infection prevalence of nymphal Ixodes scapularis ticks) over 13 y on several field plots within eastern deciduous forests in the epicenter of US Lyme disease (Dutchess County, New York). We used a model comparison approach to simultaneously test the importance of ambient growing-season temperature, precipitation, two indices of deer (Odocoileus virginianus) abundance, and densities of white-footed mice (Peromyscus leucopus), eastern chipmunks (Tamias striatus), and acorns ( Quercus spp.), in both simple and multiple regression models, in predicting entomological risk. Indices of deer abundance had no predictive power, and precipitation in the current year and temperature in the prior year had only weak effects on entomological risk. The strongest predictors of a current year's risk were the prior year's abundance of mice and chipmunks and abundance of acorns 2 y previously. In no case did inclusion of deer or climate variables improve the predictive power of models based on rodents, acorns, or both. We conclude that interannual variation in entomological risk of exposure to Lyme disease is correlated positively with prior abundance of key hosts for the immature stages of the tick vector and with critical food resources for those hosts. PMID:16669698

  1. Climate, deer, rodents, and acorns as determinants of variation in lyme-disease risk.

    PubMed

    Ostfeld, Richard S; Canham, Charles D; Oggenfuss, Kelly; Winchcombe, Raymond J; Keesing, Felicia

    2006-06-01

    Risk of human exposure to vector-borne zoonotic pathogens is a function of the abundance and infection prevalence of vectors. We assessed the determinants of Lyme-disease risk (density and Borrelia burgdorferi-infection prevalence of nymphal Ixodes scapularis ticks) over 13 y on several field plots within eastern deciduous forests in the epicenter of US Lyme disease (Dutchess County, New York). We used a model comparison approach to simultaneously test the importance of ambient growing-season temperature, precipitation, two indices of deer (Odocoileus virginianus) abundance, and densities of white-footed mice (Peromyscus leucopus), eastern chipmunks (Tamias striatus), and acorns (Quercus spp.), in both simple and multiple regression models, in predicting entomological risk. Indices of deer abundance had no predictive power, and precipitation in the current year and temperature in the prior year had only weak effects on entomological risk. The strongest predictors of a current year's risk were the prior year's abundance of mice and chipmunks and abundance of acorns 2 y previously. In no case did inclusion of deer or climate variables improve the predictive power of models based on rodents, acorns, or both. We conclude that interannual variation in entomological risk of exposure to Lyme disease is correlated positively with prior abundance of key hosts for the immature stages of the tick vector and with critical food resources for those hosts.

  2. The impact of desiccation on the adhesion of barnacles attached to non-stick coatings.

    PubMed

    Wiegemann, Maja; Watermann, Burkard

    2004-06-01

    Fouling-release coatings prevent fouling of ships' hulls through hydrodynamic forces generated as the ship moves through the water. The effectiveness of such coatings may be evaluated by measuring the adhesion strength of settled organisms, e.g. barnacles. The influence of desiccation of the barnacle adhesive on such measurements was investigated. Shear forces required to remove barnacles of the genus Balanus increased during the course of desiccation up to the point when the barnacles suddenly self-detached. The increase was thought to be due to the rising cohesive strength of the adhesive. Growing tensile forces within the weakly cross-linked adhesive, however, are suggested to have led to self-detachment. The shear forces required to remove barnacles of the genus Elminius were generally low and did not differ significantly during the course of desiccation. The different results may be attributed to specific base morphologies. It was concluded that measuring the adhesion strength of members of the Balanidae on non-stick surfaces in air could produce flawed results due to the influence of desiccation of the barnacle adhesive. The investigations have also provided new insights into the characteristics of barnacle adhesive.

  3. Introduction to the symposium--barnacle biology: essential aspects and contemporary approaches.

    PubMed

    Zardus, John D

    2012-09-01

    Barnacles have evolved a number of specialized features peculiar for crustaceans: they produce a calcified, external shell; they exhibit sexual strategies involving dioecy and androdioecy; and some have become internal parasites of other Crustacea. The thoroughly sessile habit of adults also belies the highly mobile and complex nature of their larval stages. Given these and other remarkable innovations in their natural history, it is perhaps not surprising that barnacles present a spectrum of opportunities for study. This symposium integrates research on barnacles in the areas of larval biology, biofouling, reproduction, biogeography, speciation, population genetics, ecological genomics, and phylogenetics. Pioneering comparisons are presented of metamorphosis among barnacles from three major lineages. Biofouling is investigated from the perspectives of biochemical and biomechanical mechanisms. Tradeoffs in reproductive specializations are scrutinized through theoretical modeling and empirical validation. Patterns of endemism and diversity are delineated in Australia and intricate species boundaries in the genus Chthamalus are elucidated for the Indo-Pacific. General methodological concerns with population expansion studies in crustaceans are highlighted using barnacle models. Data from the first, draft barnacle genome are employed to examine location-specific selection. Lastly, barnacle evolution is framed in a deep phylogenetic context and hypothetical origins of defined characters are outlined and tested.

  4. Effect of ultrasound on cyprid footprint and juvenile barnacle adhesion on a fouling release material.

    PubMed

    Guo, Shifeng; Khoo, Boo Cheong; Teo, Serena Lay Ming; Zhong, Shaoping; Lim, Chwee Teck; Lee, Heow Pueh

    2014-03-01

    In our earlier studies, we have demonstrated that low and high intensity ultrasound can prevent barnacle cyprid settlement. In this study, we found that ultrasound treatment reduced the adhesion of newly metamorphosed barnacles up to 2 days' old. This was observed in the reduction of adhesion strength of the newly settled barnacles from ultrasound treated cyprids on silicone substrate compared to the adhesion strength of barnacles metamorphosed from cyprids not exposed to ultrasound. Atomic force microscopy (AFM) was used to analyze the effect of ultrasound on barnacle cyprid footprints (FPs), which are protein adhesives secreted when the larvae explore surfaces. The ultrasound treated cyprids were found to secrete less FPs, which appeared to spread a larger area than those generated by untreated cyprids. The evidence from this study suggests that ultrasound treatment results in a reduced cyprid settlement and footprint secretion, and may affect the subsequent recruitment of barnacles onto fouling release surfaces by reducing the ability of early settlement stage of barnacles (up to 2 days' old) from firmly adhering to the substrates. Ultrasound therefore can be used in combination with fouling release coatings to offer a more efficient antifouling strategy.

  5. On the origin of a novel parasitic-feeding mode within suspension-feeding barnacles.

    PubMed

    Rees, David John; Noever, Christoph; Høeg, Jens Thorvald; Ommundsen, Anders; Glenner, Henrik

    2014-06-16

    In his monograph on Cirripedia from 1851, Darwin pointed to a highly unusual, plateless, and most likely parasitic barnacle of uncertain phylogenetic affinity. Darwin's barnacle was Anelasma squalicola, found on deep-water sharks of the family Etmopteridae, or lantern sharks. The barnacle is uncommon and is therefore rarely studied. Recent observations by us have shown that they occur at an unusually high prevalence on the velvet belly lantern shark, Etmopterus spinax, in restricted fjord areas of western Norway. A phylogenetic analysis based on ribosomal DNA data (16S, 18S, and 28S) from 99 selected barnacle species, including all available pedunculate barnacle sequences from GenBank, shows that A. squalicola is most closely related (sister taxon) to the pedunculate barnacle Capitulum mitella. Both C. mitella and species of Pollicipes, situated one node higher in the tree, are conventional suspension feeders from the rocky intertidal. Our phylogenetic analysis now makes it possible to establish morphological homologies between A. squalicola and its sister taxon and provides the evolutionary framework to explain the unprecedented transition from a filter-feeding barnacle to a parasitic mode of life.

  6. Incorporation of silicone oil into elastomers enhances barnacle detachment by active surface strain.

    PubMed

    Shivapooja, Phanindhar; Cao, Changyong; Orihuela, Beatriz; Levering, Vrad; Zhao, Xuanhe; Rittschof, Daniel; López, Gabriel P

    2016-10-01

    Silicone-oil additives are often used in fouling-release silicone coatings to reduce the adhesion strength of barnacles and other biofouling organisms. This study follows on from a recently reported active approach to detach barnacles, which was based on the surface strain of elastomeric materials, by investigating a new, dual-action approach to barnacle detachment using Ecoflex®-based elastomers incorporated with poly(dimethylsiloxane)-based oil additives. The experimental results support the hypothesis that silicone-oil additives reduce the amount of substratum strain required to detach barnacles. The study also de-coupled the two effects of silicone oils (ie surface-activity and alteration of the bulk modulus) and examined their contributions in reducing barnacle adhesion strength. Further, a finite element model based on fracture mechanics was employed to qualitatively understand the effects of surface strain and substratum modulus on barnacle adhesion strength. The study demonstrates that dynamic substratum deformation of elastomers with silicone-oil additives provides a bifunctional approach towards management of biofouling by barnacles. PMID:27560712

  7. Raw hulled shredded acorns from Downy Oak (Quercus pubescens) in the diet of pigs: effects on digestibility and faeces characteristics.

    PubMed

    Cappai, M G; Wolf, P; Rust, P; Pinna, W; Kamphues, J

    2013-05-01

    Faeces quality and composition are both of interest to veterinary practitioners dealing with pigs' health and disturbances in the alimentary tract, especially in free-range situations. In the Mediterranean basin, acorns are used as a starch source for fattening pigs, yet little information is available on how that affects faecal quality and digestibility. Therefore, a combined diet containing ripe hulled shredded acorns vs. a pelleted complete diet for finishers was evaluated for the digestibility and faecal consistency. The trial involved eight crossbred pigs, and a matched-pair approach was used to divide animals into two groups, which were fed with two different diets: acorns group (A): n = 4, 70% ripe hulled shredded acorns + 30% pelleted complete diet combined, as fed; control group (C): n = 4, 100% pelleted complete feed. The pigs were housed individually and fed the experimental diets for 8 days; daily feed intake and faeces amounts were recorded and faeces quality assessed. The digestibility of organic matter (OM) and starch of the two diets, as well as of pure acorns, were calculated and compared. Daily feed consumption was significantly higher in group A, but the mean dry matter intake (DMI) per pig was similar in both groups. Dark, firm and consistent faeces were reported for each pig from group A in comparison with group B, whose faeces were paler and softer. Digestibility of OM and starch were lower in group A than in group B (67.8 ± 3.4 vs. 83.9 ± 1.1 and 82.5 ± 3.4 vs. 92.3 ± 2.1 respectively): total tract digestibility of native starch from pure acorns was calculated at 77%. The peculiar consistency of faeces was related to macroscopic acorn hulls, constantly detected in the faeces of all animals sampled in group A.

  8. Antifouling properties of tough gels against barnacles in a long-term marine environment experiment.

    PubMed

    Murosaki, T; Noguchi, T; Hashimoto, K; Kakugo, A; Kurokawa, T; Saito, J; Chen, Y M; Furukawa, H; Gong, J P

    2009-10-01

    In the marine environment, the antifouling (AF) properties of various kinds of hydrogels against sessile marine organisms (algae, sea squirts, barnacles) were tested in a long-term experiment. The results demonstrate that most hydrogels can endure at least 2 months in the marine environment. In particular, mechanically tough PAMPS/PAAm DN and PVA gels exhibited AF activity against marine sessile organisms, especially barnacles, for as long as 330 days. The AF ability of hydrogels toward barnacles is explained in terms of an 'easy-release' mechanism in which the high water content and the elastic modulus of the gel are two important parameters.

  9. How do coral barnacles start their life in their hosts?

    PubMed

    Liu, Jennie Chien Wen; Høeg, Jens Thorvald; Chan, Benny K K

    2016-06-01

    Coral-associated invertebrates are the most significant contributors to the diversity of reef ecosystems, but no studies have examined how larvae manage to settle and grow in their coral hosts. Video recordings were used to document this process in the coral barnacle Darwiniella angularis associated with the coral Cyphastrea chalcidicum Settlement and metamorphosis in feeding juveniles lasted 8-11 days and comprised six phases. The settling cyprid starts by poking its antennules into the tissue of the prospective host (I: probing stage). The coral releases digestive filaments for defence, but tolerating such attack the cyprid penetrates further (II: battling stage). Ecdysis is completed 2 days after settlement (III: carapace detachment). The barnacle becomes embedded deep in the coral tissue while completing metamorphosis between 4 and 6 days (IV: embedding stage), but reappears as a feeding juvenile 8-11 days after settlement (V: emerging stage; VI: feeding stage). Cyprids preferably settle in areas between the coral polyps, where they have a much higher survival rate than on the polyp surfaces.

  10. Accumulation of Zn, Cu and Cd by crabs and barnacles

    NASA Astrophysics Data System (ADS)

    Rainbow, P. S.

    1985-11-01

    The crab Carcinus maenas (L.) and the barnacle Elminius modestus Darwin were exposed to a range of dissolved concentrations of Zn, Cu and Cd for 21 days in artificial seawater. Accumulation of Zn and Cu by crabs has been interpreted in terms of the presence of a regulation mechanism to maintain constant body concentrations (83·2 ± 19·4 μg Zn g -1 dry wt.; 39·8 ± 9·8 μg Cu g -1 dry wt.) under varying external dissolved metal levels, until a threshold dissolved metal concentration ( c. 400 μg Zn l -1; c. 170 μg Cu l -1) beyond which net accumulation of metal begins. Cadium appears to be accumulated by C. maenas at all exposures with no evidence for regulation of body cadmium concentrations. Exposure of E. modestus to Zn, Cu or Cd caused net accumulation of the respective metal in the bodies of the barnacles, with no evidence for regulation of body metal concentrations.

  11. How do coral barnacles start their life in their hosts?

    PubMed

    Liu, Jennie Chien Wen; Høeg, Jens Thorvald; Chan, Benny K K

    2016-06-01

    Coral-associated invertebrates are the most significant contributors to the diversity of reef ecosystems, but no studies have examined how larvae manage to settle and grow in their coral hosts. Video recordings were used to document this process in the coral barnacle Darwiniella angularis associated with the coral Cyphastrea chalcidicum Settlement and metamorphosis in feeding juveniles lasted 8-11 days and comprised six phases. The settling cyprid starts by poking its antennules into the tissue of the prospective host (I: probing stage). The coral releases digestive filaments for defence, but tolerating such attack the cyprid penetrates further (II: battling stage). Ecdysis is completed 2 days after settlement (III: carapace detachment). The barnacle becomes embedded deep in the coral tissue while completing metamorphosis between 4 and 6 days (IV: embedding stage), but reappears as a feeding juvenile 8-11 days after settlement (V: emerging stage; VI: feeding stage). Cyprids preferably settle in areas between the coral polyps, where they have a much higher survival rate than on the polyp surfaces. PMID:27330170

  12. Barnacle reproductive hotspots linked to nearshore ocean conditions.

    PubMed

    Leslie, Heather M; Breck, Erin N; Chan, Francis; Lubchenco, Jane; Menge, Bruce A

    2005-07-26

    Coastal marine ecosystems provide important ecosystem services to human populations worldwide. Understanding the contexts in which a species has markedly higher reproductive output is vital for effective management and conservation of these valuable and highly impacted systems. We documented reproductive hotspots along the Oregon coast for an ecologically significant marine invertebrate, the intertidal barnacle Balanus glandula. Greater larval production in both natural and experimental populations was associated with higher primary productivity in the adjacent nearshore ocean, providing strong evidence for bottom-up forcing. Mean cumulative larval production per 100 cm2 in natural barnacle populations in the region of higher primary productivity was almost 5x that of populations in the less productive region. Mean estimated larval production per individual in experimental populations in the region of higher primary productivity was >2x that of populations in the region of lower productivity, and mean larval production per 100 cm2 was >120x greater in the region of higher productivity. Our results highlight the importance of spatial heterogeneity in reproduction and other ecological processes in the marine environment and provide a mechanistic basis for evaluating the relative contributions of different sites when designing marine reserves and other protected areas. Our findings also advance the understanding of the role of bottom-up influences on population and community dynamics and contribute data for the next generation of models of marine community dynamics.

  13. Adaptive evolution of sexual systems in pedunculate barnacles

    PubMed Central

    Yusa, Yoichi; Yoshikawa, Mai; Kitaura, Jun; Kawane, Masako; Ozaki, Yuki; Yamato, Shigeyuki; Høeg, Jens T.

    2012-01-01

    How and why diverse sexual systems evolve are fascinating evolutionary questions, but few empirical studies have dealt with these questions in animals. Pedunculate (gooseneck) barnacles show such diversity, including simultaneous hermaphroditism, coexistence of dwarf males and hermaphrodites (androdioecy), and coexistence of dwarf males and females (dioecy). Here, we report the first phylogenetically controlled test of the hypothesis that the ultimate cause of the diverse sexual systems and presence of dwarf males in this group is limited mating opportunities for non-dwarf individuals, owing to mating in small groups. Within the pedunculate barnacle phylogeny, dwarf males and females have evolved repeatedly. Females are more likely to evolve in androdioecious than hermaphroditic populations, suggesting that evolution of dwarf males has preceded that of females in pedunculates. Both dwarf males and females are associated with a higher proportion of solitary individuals in the population, corroborating the hypothesis that limited mating opportunities have favoured evolution of these diverse sexual systems, which have puzzled biologists since Darwin. PMID:21881138

  14. A new copepod with transformed body plan and unique phylogenetic position parasitic in the acorn worm Ptychodera flava.

    PubMed

    Tung, Che-Huang; Cheng, Yu-Rong; Lin, Ching-Yi; Ho, Ju-Shey; Kuo, Chih-Horng; Yu, Jr-Kai; Su, Yi-Hsien

    2014-02-01

    Symbiotic copepods compose one-third of the known copepod species and are associated with a wide range of animal groups. Two parasitic copepods endoparasitic in acorn worms (Hemichordata), Ive balanoglossi and Ubius hilli, collected in the Mediterranean Sea and Australian waters, respectively, were described a century ago. Here we report a new parasitic copepod species, Ive ptychoderae sp. nov., found in Ptychodera flava, a widespread acorn worm in the Indo-Pacific Ocean and an emerging organism for developmental and evolutionary studies. The female of I. ptychoderae is characterized by having a reduced maxilliped and five pairs of annular swellings along the body that are morphologically similar but distinguishable from those in the two previously described parasitic copepods in acorn worms. Phylogenetic analysis based on the 18S rDNA sequence shows that I. ptychoderae may belong to Poecilostomatoida but represent a new family, which we name Iveidae fam. nov. Ive ptychoderae is commonly found in the acorn worm population with an average prevalence of 42% during the collecting period. The infection of the parasite induces the formation of cysts and causes localized lesions of the host tissues, suggesting that it may have negative effects on its host. Interestingly, most cysts contain a single female with one or multiple male copepods, suggesting that their sex determination may be controlled by environmental conditions. The relationships between the parasitic copepods and acorn worms thus provide a platform for understanding physiological and ecological influences and coevolution between parasites and hosts. PMID:24648208

  15. A new copepod with transformed body plan and unique phylogenetic position parasitic in the acorn worm Ptychodera flava.

    PubMed

    Tung, Che-Huang; Cheng, Yu-Rong; Lin, Ching-Yi; Ho, Ju-Shey; Kuo, Chih-Horng; Yu, Jr-Kai; Su, Yi-Hsien

    2014-02-01

    Symbiotic copepods compose one-third of the known copepod species and are associated with a wide range of animal groups. Two parasitic copepods endoparasitic in acorn worms (Hemichordata), Ive balanoglossi and Ubius hilli, collected in the Mediterranean Sea and Australian waters, respectively, were described a century ago. Here we report a new parasitic copepod species, Ive ptychoderae sp. nov., found in Ptychodera flava, a widespread acorn worm in the Indo-Pacific Ocean and an emerging organism for developmental and evolutionary studies. The female of I. ptychoderae is characterized by having a reduced maxilliped and five pairs of annular swellings along the body that are morphologically similar but distinguishable from those in the two previously described parasitic copepods in acorn worms. Phylogenetic analysis based on the 18S rDNA sequence shows that I. ptychoderae may belong to Poecilostomatoida but represent a new family, which we name Iveidae fam. nov. Ive ptychoderae is commonly found in the acorn worm population with an average prevalence of 42% during the collecting period. The infection of the parasite induces the formation of cysts and causes localized lesions of the host tissues, suggesting that it may have negative effects on its host. Interestingly, most cysts contain a single female with one or multiple male copepods, suggesting that their sex determination may be controlled by environmental conditions. The relationships between the parasitic copepods and acorn worms thus provide a platform for understanding physiological and ecological influences and coevolution between parasites and hosts.

  16. In vivo and in situ synchrotron radiation-based μ-XRF reveals elemental distributions during the early attachment phase of barnacle larvae and juvenile barnacles.

    PubMed

    Senkbeil, Tobias; Mohamed, Tawheed; Simon, Rolf; Batchelor, David; Di Fino, Alessio; Aldred, Nick; Clare, Anthony S; Rosenhahn, Axel

    2016-02-01

    Barnacles are able to establish stable surface contacts and adhere underwater. While the composition of adult barnacle cement has been intensively studied, far less is known about the composition of the cement of the settlement-stage cypris larva. The main challenge in studying the adhesives used by these larvae is the small quantity of material available for analysis, being on the order of nanograms. In this work, we applied, for the first time, synchrotron radiation-based μ-X-ray fluorescence analysis (SR-μ-XRF) for in vivo and in situ analysis of young barnacles and barnacle cyprids. To obtain biologically relevant information relating to the body tissues, adhesives, and shell of the organisms, an in situ sample environment was developed to allow direct microprobe investigation of hydrated specimens without pretreatment of the samples. In 8-day-old juvenile barnacles (Balanus improvisus), the junctions between the six plates forming the shell wall showed elevated concentrations of calcium, potassium, bromine, strontium, and manganese. Confocal measurements allowed elemental characterization of the adhesive interface of recently attached cyprids (Balanus amphitrite), and substantiated the accumulation of bromine both at the point of initial attachment as well as within the cyprid carapace. In situ measurements of the cyprid cement established the presence of bromine, chlorine, iodine, sulfur, copper, iron, zinc, selenium, and nickel for both species. The previously unrecognized presence of bromine, iron, and selenium in the cyprid permanent adhesive will hopefully inspire further biochemical investigations of the function of these substances.

  17. In vivo and in situ synchrotron radiation-based μ-XRF reveals elemental distributions during the early attachment phase of barnacle larvae and juvenile barnacles.

    PubMed

    Senkbeil, Tobias; Mohamed, Tawheed; Simon, Rolf; Batchelor, David; Di Fino, Alessio; Aldred, Nick; Clare, Anthony S; Rosenhahn, Axel

    2016-02-01

    Barnacles are able to establish stable surface contacts and adhere underwater. While the composition of adult barnacle cement has been intensively studied, far less is known about the composition of the cement of the settlement-stage cypris larva. The main challenge in studying the adhesives used by these larvae is the small quantity of material available for analysis, being on the order of nanograms. In this work, we applied, for the first time, synchrotron radiation-based μ-X-ray fluorescence analysis (SR-μ-XRF) for in vivo and in situ analysis of young barnacles and barnacle cyprids. To obtain biologically relevant information relating to the body tissues, adhesives, and shell of the organisms, an in situ sample environment was developed to allow direct microprobe investigation of hydrated specimens without pretreatment of the samples. In 8-day-old juvenile barnacles (Balanus improvisus), the junctions between the six plates forming the shell wall showed elevated concentrations of calcium, potassium, bromine, strontium, and manganese. Confocal measurements allowed elemental characterization of the adhesive interface of recently attached cyprids (Balanus amphitrite), and substantiated the accumulation of bromine both at the point of initial attachment as well as within the cyprid carapace. In situ measurements of the cyprid cement established the presence of bromine, chlorine, iodine, sulfur, copper, iron, zinc, selenium, and nickel for both species. The previously unrecognized presence of bromine, iron, and selenium in the cyprid permanent adhesive will hopefully inspire further biochemical investigations of the function of these substances. PMID:26715248

  18. Release characteristics of reattached barnacles to non-toxic silicone coatings.

    PubMed

    Kim, Jongsoo; Nyren-Erickson, Erin; Stafslien, Shane; Daniels, Justin; Bahr, James; Chisholm, Bret J

    2008-01-01

    Release mechanisms of barnacles (Amphibalanus amphitrite or Balanus amphitrite) reattached to platinum-cured silicone coatings were studied as a function of coating thickness (210-770 microm), elastic modulus (0.08-1.3 MPa), and shear rate (2-22 microm s(-1)). It was found that the shear stress of the reattached, live barnacles necessary to remove from the silicone coatings was controlled by the combined term (E/t)(0.5) of the elastic modulus (E) and thickness (t). As the ratio of the elastic modulus to coating thickness decreased, the barnacles were more readily removed from the silicone coatings, showing a similar release behavior to pseudobarnacles (epoxy glue). The barnacle mean shear stress ranged from 0.017 to 0.055 MPa whereas the pseudobarnacle mean shear stress ranged from 0.022 to 0.095 MPa.

  19. Oceanic barnacles act as foundation species on plastic debris: implications for marine dispersal.

    PubMed

    Gil, Michael A; Pfaller, Joseph B

    2016-01-01

    Plastic has emerged as an abundant, stable substratum for oceanic dispersal of organisms via rafting. However, the ecological mechanisms underlying community diversity on plastic debris remain poorly understood. On a cruise from California to Hawai'i, we surveyed plastic debris, some likely originating from the 2011 Tōhoku tsunami, to examine the relationship between rafting community diversity and both habitat area and stalked barnacle (Lepas spp.) abundance. For sessile taxa richness, we observed an interaction in which the positive effect of debris area weakened the negative effect of barnacle cover. In contrast, for mobile taxa richness, including cohabiting species from opposite sides of the Pacific Ocean, barnacle abundance had a positive effect that was strongest at smaller debris sizes. These findings suggest that barnacles, through interactions with habitat area, have trait-dependent effects on other species, serving as both foundation species and competitors, mediating the diversity and dispersal potential of marine organisms on plastic debris. PMID:26813348

  20. Oceanic barnacles act as foundation species on plastic debris: implications for marine dispersal.

    PubMed

    Gil, Michael A; Pfaller, Joseph B

    2016-01-27

    Plastic has emerged as an abundant, stable substratum for oceanic dispersal of organisms via rafting. However, the ecological mechanisms underlying community diversity on plastic debris remain poorly understood. On a cruise from California to Hawai'i, we surveyed plastic debris, some likely originating from the 2011 Tōhoku tsunami, to examine the relationship between rafting community diversity and both habitat area and stalked barnacle (Lepas spp.) abundance. For sessile taxa richness, we observed an interaction in which the positive effect of debris area weakened the negative effect of barnacle cover. In contrast, for mobile taxa richness, including cohabiting species from opposite sides of the Pacific Ocean, barnacle abundance had a positive effect that was strongest at smaller debris sizes. These findings suggest that barnacles, through interactions with habitat area, have trait-dependent effects on other species, serving as both foundation species and competitors, mediating the diversity and dispersal potential of marine organisms on plastic debris.

  1. Mechanical properties of the cement of the stalked barnacle Dosima fascicularis (Cirripedia, Crustacea).

    PubMed

    Zheden, Vanessa; Klepal, Waltraud; Gorb, Stanislav N; Kovalev, Alexander

    2015-02-01

    The stalked barnacle Dosima fascicularis secretes foam-like cement, the amount of which usually exceeds that produced by other barnacles. When Dosima settles on small objects, this adhesive is additionally used as a float which gives buoyancy to the animal. The dual use of the cement by D. fascicularis requires mechanical properties different from those of other barnacle species. In the float, two regions with different morphological structure and mechanical properties can be distinguished. The outer compact zone with small gas-filled bubbles (cells) is harder than the interior one and forms a protective rind presumably against mechanical damage. The inner region with large, gas-filled cells is soft. This study demonstrates that D. fascicularis cement is soft and visco-elastic. We show that the values of the elastic modulus, hardness and tensile stress are considerably lower than in the rigid cement of other barnacles. PMID:25657833

  2. Mechanical properties of the cement of the stalked barnacle Dosima fascicularis (Cirripedia, Crustacea)

    PubMed Central

    Zheden, Vanessa; Klepal, Waltraud; Gorb, Stanislav N.; Kovalev, Alexander

    2015-01-01

    The stalked barnacle Dosima fascicularis secretes foam-like cement, the amount of which usually exceeds that produced by other barnacles. When Dosima settles on small objects, this adhesive is additionally used as a float which gives buoyancy to the animal. The dual use of the cement by D. fascicularis requires mechanical properties different from those of other barnacle species. In the float, two regions with different morphological structure and mechanical properties can be distinguished. The outer compact zone with small gas-filled bubbles (cells) is harder than the interior one and forms a protective rind presumably against mechanical damage. The inner region with large, gas-filled cells is soft. This study demonstrates that D. fascicularis cement is soft and visco-elastic. We show that the values of the elastic modulus, hardness and tensile stress are considerably lower than in the rigid cement of other barnacles. PMID:25657833

  3. Oceanic barnacles act as foundation species on plastic debris: implications for marine dispersal

    PubMed Central

    Gil, Michael A.; Pfaller, Joseph B.

    2016-01-01

    Plastic has emerged as an abundant, stable substratum for oceanic dispersal of organisms via rafting. However, the ecological mechanisms underlying community diversity on plastic debris remain poorly understood. On a cruise from California to Hawai’i, we surveyed plastic debris, some likely originating from the 2011 Tōhoku tsunami, to examine the relationship between rafting community diversity and both habitat area and stalked barnacle (Lepas spp.) abundance. For sessile taxa richness, we observed an interaction in which the positive effect of debris area weakened the negative effect of barnacle cover. In contrast, for mobile taxa richness, including cohabiting species from opposite sides of the Pacific Ocean, barnacle abundance had a positive effect that was strongest at smaller debris sizes. These findings suggest that barnacles, through interactions with habitat area, have trait-dependent effects on other species, serving as both foundation species and competitors, mediating the diversity and dispersal potential of marine organisms on plastic debris. PMID:26813348

  4. Migrations of california gray whales tracked by oxygen-18 variations in their epizoic barnacles.

    PubMed

    Killingley, J S

    1980-02-15

    Barnacles attached to the California gray whale have oxygen isotope compositions that serve as a record of changing ocean temperatures as the whale migrates between arctic and subtropical waters. The isotopic values for the barnacles can be used to track whale migrations and to reconstruct the recent movements of beached whales. The method may be useful for tracing the movements of other animals, living or fossil, and for reconstructing the voyages of ancient ships. PMID:17796007

  5. Migrations of California gray whales tracked by oxygen-18 variations in their epizoic barnacles

    SciTech Connect

    Killingley, J.S.

    1980-02-15

    Barnacles attached to the California gray whale have oxygen isotope compositions that serve as a record of changing ocean temperatures as the whale migrates between arctic and subtropical waters. The isotopic values for the barnacles can be used to track whale migrations and to reconstruct the recent movements of beached whales. The method may be useful for tracing the movements of other animals, living or fossil, and for reconstructing the voyages of ancient ships.

  6. Barnacle Bill in Super Resolution from Insurance Panorama

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Barnacle Bill is a small rock immediately west-northwest of the Mars Pathfinder lander and was the first rock visited by the Sojourner Rover's alpha proton X-ray spectrometer (APXS) instrument. This image shows super resolution techniques applied to the first APXS target rock, which was never imaged with the rover's forward cameras. Super resolution was applied to help to address questions about the texture of this rock and what it might tell us about its mode of origin.

    This view of Barnacle Bill was produced by combining the 'Insurance Pan' frames taken while the IMP camera was still in its stowed position on sol2. The composite color frames that make up this anaglyph were produced for both the right and left eye of the IMP. The right eye composite consists of 5 frames, taken with different color filters, the left eye consists of only 1 frame. The resultant image from each eye was enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be. These panchromatic frames were then colorized with the red, green, and blue filtered images from the same sequence. The color balance was adjusted to approximate the true color of Mars.

    The anaglyph view was produced by combining the left with the right eye color composite frames by assigning the left eye composite view to the red color plane and the right eye composite view to the green and blue color planes (cyan), to produce a stereo anaglyph mosaic. This mosaic can be viewed in 3-D on your computer monitor or in color print form by wearing red-blue 3-D glasses.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. Barnacle Bill is a small rock immediately west-northwest of the Mars Pathfinder lander and was the first rock visited by the Sojourner Rover's alpha proton X-ray spectrometer (APXS) instrument.

  7. Prawns, barnacles, and nonsteroidal anti-inflammatory drugs: effect modifiers or diagnostic confounders [corrected].

    PubMed

    Vidal, C; Bartolomé, B; González-Quintela, A; Rodríguez, V; Armisén, M

    2007-01-01

    A 42-year-old woman with no history of atopy reported several episodes of generalized urticaria and shortness of breath after eating shellfish (prawns and barnacles) but with good tolerance of the same foods between episodes. Skin prick tests (SPTs), serum enzyme allergosorbent tests (EAST) for specific immunoglobulin (Ig) E, Western blot and inhibition assays, and oral challenge tests with prawns, barnacles, nonsteroidal anti-inflammatory drugs (NSAIDs), and alcohol as potential effect modifiers were performed. Specific IgE to both barnacle and prawn were detected by SPTs and EAST. Results from a Western blot of raw prawn revealed an IgE binding band of 37 kDa and IgE binding bands of 143, 83, 38, 32, and 20 kDa appeared in the raw barnacle assay. Oral challenge tests were positive with prawns and prawn extract only if preceded by NSAIDs. Oral challenges with NSAIDs alone, prawns alone, barnacles with or without NSAIDs and alcohol led to no reaction. A synergistic effect of NSAIDs in inducing anaphylaxis after prawn intake was confirmed. No similar effect was achieved with barnacles despite the presence of specific IgE. Additional factors needed to elicit a clinical reaction in food allergy may not be obvious and several oral challenge protocols are mandatory in such cases.

  8. The identification and role of a novel eicosanoid in the reproductive behaviour of barnacles (Balanus balanus).

    PubMed

    Maskrey, Ben H; Taylor, Graham W; Rowley, Andrew F

    2006-02-01

    Post-copulatory behaviour in barnacles involves a violent rocking movement of the opercular valves, which is thought to contribute to the expulsion of oocytes through the oviduct into the mantle cavity where they are fertilised. We demonstrate in this study that the seminal vesicles/testis of the subtidal barnacle Balanus balanus produce a biologically active factor, barnacle muscle stimulatory factor (BMSF), which causes a significant increase in cirral and body muscular activity. BMSF was identified using a combination of high performance liquid chromatography and mass spectrometry as a novel eicosanoid/oxylipin, 8,13-dihydroxyeicosapentaenoic acid. This is rapidly inactivated under mild acid conditions to form a complex range of triene and pentaene chromophore-containing products that have only been partially identified. Injection of purified BMSF into the mantle cavity of barnacles caused the rocking movements of the opercular valves as reported following fertilisation. In excised barnacles, it also caused muscular contractions of the whole body mass. The breakdown products of BMSF, however, were without such activities. The function of BMSF in facilitating fertilisation in barnacles is comparable to the role of other eicosanoids in human reproduction, reinforcing the view that these compounds have conserved activities in both invertebrates and vertebrates.

  9. Prolonged morphometric study of barnacles grown on soft substrata of hydrogels and elastomers.

    PubMed

    Ahmed, Nafees; Murosaki, Takayuki; Kurokawa, Takayuki; Kakugo, Akira; Yashima, Shintaro; Nogata, Yasuyuki; Gong, Jian Ping

    2014-01-01

    A long-term investigation of the shell shape and the basal morphology of barnacles grown on tough, double-network (DN) hydrogels and polydimethylsiloxane (PDMS) elastomer was conducted in a laboratory environment. The elastic modulus of these soft substrata varied between 0.01 and 0.47 MPa. Polystyrene (PS) (elastic modulus, 3 GPa) was used as a hard substratum control. It was found that the shell shape and the basal plate morphology of barnacles were different on the rigid PS substratum compared to the soft substrata of PDMS and DN hydrogels. Barnacles on the PS substratum had a truncated cone shape with a flat basal plate while on soft PDMS and DN gels, barnacles had a pseudo-cylindrical shape and their basal plates showed curvature. In addition, a large adhesive layer was observed under barnacles on PDMS, but not on DN gels. The effect of substratum stiffness is discussed in terms of barnacle muscle contraction, whereby the relative stiffness of the substratum compared to that of the muscle is considered as the key parameter.

  10. 'Flying barnacles': implications for the spread of non-indigenous species.

    PubMed

    Tøttrup, Anders P; Chan, Benny K K; Koskinen, Hannu; Høeg, Jens T

    2010-07-01

    The presence of adult barnacles of Fistulobalanus pallidus (Darwin) and Fistulobalanus albicostatus (Pilsbry) attached to field-readable plastic leg rings on the Lesser Black-backed Gull Larus fuscus in Northern Europe is reported. L. fuscus is a long-distance palaearctic migrant, breeding in temperate areas spreading widely over inland and marine habitats outside the breeding season. The species is known to perform long-distance migration to Africa and the Middle East. Combining present knowledge on the birds' migratory pattern and the home range of the barnacle species, it is concluded that the cypris larvae of F. pallidus must have settled in African waters, whereas the area where F. albicostatus settled on the bird leg rings is less certain. The barnacles were of adult size and must thus have been attached for a period of no less than 2 months. More than 30 individual barnacles could occur together on a single field-readable plastic leg ring. The barnacles could therefore, if ported alive to a new area, reproduce successfully and thus either introduce the species or genetically affect other native populations. This may pose a new and wholly unexpected transportation pathway for barnacles as invasive species.

  11. Larval vision contributes to gregarious settlement in barnacles: adult red fluorescence as a possible visual signal.

    PubMed

    Matsumura, Kiyotaka; Qian, Pei-Yuan

    2014-03-01

    Gregarious settlement, an essential behavior for many barnacle species that can only reproduce by mating with a nearby barnacle, has long been thought to rely on larval ability to recognize chemical signals from conspecifics during settlement. However, the cyprid, the settlement stage larva in barnacles, has one pair of compound eyes that appear only at the late nauplius VI and cyprid stages, but the function(s) of these eyes remains unknown. Here we show that cyprids of the intertidal barnacle Balanus (=Amphibalanus) amphitrite can locate adult barnacles even in the absence of chemical cues, and prefer to settle around them probably via larval sense of vision. We also show that the cyprids can discriminate color and preferred to settle on red surfaces. Moreover, we found that shells of adult B. amphitrite emit red auto-fluorescence and the adult extracts with the fluorescence as a visual signal attracted cyprid larvae to settle around it. We propose that the perception of specific visual signals can be involved in behavior of zooplankton including marine invertebrate larvae, and that barnacle auto-fluorescence may be a specific signal involved in gregarious larval settlement.

  12. Increased algal fouling on mussels with barnacle epibionts: a fouling cascade

    NASA Astrophysics Data System (ADS)

    Gutiérrez, Jorge L.; Palomo, M. Gabriela

    2016-06-01

    If the external surfaces of epibionts are more suitable to other fouling species than those of their basibionts, a 'fouling cascade' might occur where epibionts facilitate secondary colonization by other epibionts. Here we evaluate whether the presence of epibiotic barnalces (Balanus glandula) influences the probability of mussel (Brachidontes rodriguezii) fouling by ephemeral red algae (Porphyra sp.) in a Southwestern Atlantic rocky shore. Mussels with barnacle epibionts showed a higher prevalence of Porphyra sp. fouling (32-40% depending on sampling date) than mussels without them (3-7%). Two lines of evidence indicate that barnacles facilitate Porphyra sp. fouling. First, most Porphyra sp. thalli in mussels with barnacle epibionts were attached to barnacle shells (75-92% of cases). Secondly, Porphyra sp. associated with mussels with barnacle epibionts in a proportion that significantly exceeded that expected under random co-occurrence. These results suggest the occurrence of a fouling cascade where barnacle epibiosis on mussels facilitates subsequent algal fouling. Recognizing the occurrence of such fouling cascades is important because they might explain the non-random aggregation of multiple epibiotic species onto a proportionally few individuals of the host species.

  13. Phylogeny and evolution of life history strategies of the parasitic barnacles (Crustacea, Cirripedia, Rhizocephala).

    PubMed

    Glenner, Henrik; Hebsgaard, Martin Bay

    2006-12-01

    The barnacles (Crustacea, Cirripedia) consist of three well-defined orders: the conventional filter-feeding barnacles (Thoracica), the burrowing barnacles (Acrothoracica), and the parasitic barnacles (Rhizocephala). Thoracica and Acrothoracica feed by catching food particles from the surrounding seawater using their thoracic appendages while members of Rhizocephala are exclusively parasitic. The parasite consists of a sac-shaped, external reproductive organ situated on the abdomen of its crustacean host and a nutrient-absorbing root system embedded into the heamolymph of the host. In order to resolve the phylogenetic relationship of the order Rhizocephala and elucidate the evolution of the different life history strategies found within the Rhizocephala, we have performed the first comprehensive phylogenetic analysis of the group. Our results indicate that Rhizocephala is monophyletic with a filter-feeding barnacle-like ancestor. The host-infective stage, the kentrogon larva, inserted in the lifecycle of the rhizocephalan suborder, Kentrogonida, is shown to be ancestral and most likely a homologue of the juvenile stage of a conventional thoracican barnacle. The mode of host inoculation found in the suborder Akentrogonida, where the last pelagic larval stage directly injects the parasitic material into the heamolymph of the host is derived, and has evolved only once within the Rhizocephala. Lastly, our results show that the ancestral host for extant rhizocephalans appears to be the anomuran crustaceans (Anomura), which includes hermit crabs and squat lobsters.

  14. Significance of trophic transfer in predicting the high concentration of zinc in barnacles

    SciTech Connect

    Wang, W.X.; Qui, J.W.; Qian, P.Y.

    1999-09-01

    Barnacles are known to accumulate Zn to a phenomenal concentration, but physiological processes governing Zn accumulation are poorly defined. The authors determined the assimilation efficiency and efflux rate constant of Zn in barnacles (Balanus amphitrite) using radiotracer technique. Assimilation efficiency of Zn from ingested food ranged between 76 and 87% for the diatom diets and between 86 and 98% for the zooplankton preys. These AEs were the highest measured among aquatic invertebrates. Varying distribution in the soft tissues of zooplankton did not account for the variability of Zn AE observed among different zooplankton preys. Most Zn was distributed in the guts of the animals, presumably associated with the numerous granules beneath the gut epithelium. The efflux rate constant was 0.003 d{sup {minus}1}, and the calculated biological retention half-time was about 230 days. Using a simple bioenergetic-based kinetic model, the authors demonstrated that trophic transfer can account for such a high Zn concentration in barnacles. The predicted Zn concentrations in barnacles were directly comparable to the concentrations measured in Hong Kong coastal waters {micro}g. The high Zn concentration is related to its very efficient assimilation in barnacles coupled with a very low efflux rate. Biological variability must be fully appreciated before barnacles can be designated as an appropriate biomonitor of Zn contamination in coastal waters. The authors study suggests that metal concentration in aquatic animals can be predicted only when both physiological and geochemical processes are considered.

  15. The Geographic Distribution of a Tropical Montane Bird Is Limited by a Tree: Acorn Woodpeckers (Melanerpes formicivorus) and Colombian Oaks (Quercus humboldtii) in the Northern Andes

    PubMed Central

    2015-01-01

    Species distributions are limited by a complex array of abiotic and biotic factors. In general, abiotic (climatic) factors are thought to explain species’ broad geographic distributions, while biotic factors regulate species’ abundance patterns at local scales. We used species distribution models to test the hypothesis that a biotic interaction with a tree, the Colombian oak (Quercus humboldtii), limits the broad-scale distribution of the Acorn Woodpecker (Melanerpes formicivorus) in the Northern Andes of South America. North American populations of Acorn Woodpeckers consume acorns from Quercus oaks and are limited by the presence of Quercus oaks. However, Acorn Woodpeckers in the Northern Andes seldom consume Colombian oak acorns (though may regularly drink sap from oak trees) and have been observed at sites without Colombian oaks, the sole species of Quercus found in South America. We found that climate-only models overpredicted Acorn Woodpecker distribution, suggesting that suitable abiotic conditions (e.g. in northern Ecuador) exist beyond the woodpecker’s southern range margin. In contrast, models that incorporate Colombian oak presence outperformed climate-only models and more accurately predicted the location of the Acorn Woodpecker’s southern range margin in southern Colombia. These findings support the hypothesis that a biotic interaction with Colombian oaks sets Acorn Woodpecker’s broad-scale geographic limit in South America, probably because Acorn Woodpeckers rely on Colombian oaks as a food resource (possibly for the oak’s sap rather than for acorns). Although empirical examples of particular plants limiting tropical birds’ distributions are scarce, we predict that similar biotic interactions may play an important role in structuring the geographic distributions of many species of tropical montane birds with specialized foraging behavior. PMID:26083262

  16. The Geographic Distribution of a Tropical Montane Bird Is Limited by a Tree: Acorn Woodpeckers (Melanerpes formicivorus) and Colombian Oaks (Quercus humboldtii) in the Northern Andes.

    PubMed

    Freeman, Benjamin G; Mason, Nicholas A

    2015-01-01

    Species distributions are limited by a complex array of abiotic and biotic factors. In general, abiotic (climatic) factors are thought to explain species' broad geographic distributions, while biotic factors regulate species' abundance patterns at local scales. We used species distribution models to test the hypothesis that a biotic interaction with a tree, the Colombian oak (Quercus humboldtii), limits the broad-scale distribution of the Acorn Woodpecker (Melanerpes formicivorus) in the Northern Andes of South America. North American populations of Acorn Woodpeckers consume acorns from Quercus oaks and are limited by the presence of Quercus oaks. However, Acorn Woodpeckers in the Northern Andes seldom consume Colombian oak acorns (though may regularly drink sap from oak trees) and have been observed at sites without Colombian oaks, the sole species of Quercus found in South America. We found that climate-only models overpredicted Acorn Woodpecker distribution, suggesting that suitable abiotic conditions (e.g. in northern Ecuador) exist beyond the woodpecker's southern range margin. In contrast, models that incorporate Colombian oak presence outperformed climate-only models and more accurately predicted the location of the Acorn Woodpecker's southern range margin in southern Colombia. These findings support the hypothesis that a biotic interaction with Colombian oaks sets Acorn Woodpecker's broad-scale geographic limit in South America, probably because Acorn Woodpeckers rely on Colombian oaks as a food resource (possibly for the oak's sap rather than for acorns). Although empirical examples of particular plants limiting tropical birds' distributions are scarce, we predict that similar biotic interactions may play an important role in structuring the geographic distributions of many species of tropical montane birds with specialized foraging behavior. PMID:26083262

  17. Classification of the pre-settlement behaviour of barnacle cyprids

    PubMed Central

    Maleschlijski, Stojan; Bauer, Stella; Aldred, Nick; Clare, Anthony S.; Rosenhahn, Axel

    2015-01-01

    Barnacle cyprids exhibit a complex swimming and exploratory behaviour on surfaces and settlement is a consequence of extensive surface probing and selection of suitable settlement sites. In this work, the behaviour of cyprids in their pre-settlement phase was studied by three-dimensional video stereoscopy. With this technique, three-dimensional trajectories were obtained that were quantitatively analysed. The velocity during vertical sinking of cyprids of Balanus amphitrite was used with a modified form of Stokes' law to calculate their mean body density. Furthermore, a classification of the swimming patterns allowed the extension of existing models describing cyprid locomotion and swimming behaviour. The patterns were characterized with respect to their occurrence, transition between patterns and their velocity distribution, and motions were identified that led to surface contacts. This analysis provides a classification framework, which can assist future attempts to identify behavioural responses of cyprids to specific settlement cues. PMID:25551141

  18. Barnacle geese achieve significant energetic savings by changing posture.

    PubMed

    Tickle, Peter G; Nudds, Robert L; Codd, Jonathan R

    2012-01-01

    Here we report the resting metabolic rate in barnacle geese (Branta leucopsis) and provide evidence for the significant energetic effect of posture. Under laboratory conditions flow-through respirometry together with synchronous recording of behaviour enabled a calculation of how metabolic rate varies with posture. Our principal finding is that standing bipedally incurs a 25% increase in metabolic rate compared to birds sitting on the ground. In addition to the expected decrease in energy consumption of hindlimb postural muscles when sitting, we hypothesise that a change in breathing mechanics represents one potential mechanism for at least part of the observed difference in energetic cost. Due to the significant effect of posture, future studies of resting metabolic rates need to take into account and/or report differences in posture.

  19. Colour-Based Binary Discrimination of Scarified Quercus robur Acorns under Varying Illumination

    PubMed Central

    Jabłoński, Mirosław; Tylek, Paweł; Walczyk, Józef; Tadeusiewicz, Ryszard; Piłat, Adam

    2016-01-01

    Efforts to predict the germination ability of acorns using their shape, length, diameter and density are reported in the literature. These methods, however, are not efficient enough. As such, a visual assessment of the viability of seeds based on the appearance of cross-sections of seeds following their scarification is used. This procedure is more robust but demands significant effort from experienced employees over a short period of time. In this article an automated method of acorn scarification and assessment has been announced. This type of automation requires the specific setup of a machine vision system and application of image processing algorithms for evaluation of sections of seeds in order to predict their viability. In the stage of the analysis of pathological changes, it is important to point out image features that enable efficient classification of seeds in respect of viability. The article shows the results of the binary separation of seeds into two fractions (healthy or spoiled) using average components of regular red-green-blue and perception-based hue-saturation-value colour space. Analysis of accuracy of discrimination was performed on sections of 400 scarified acorns acquired using two various setups: machine vision camera under uncontrolled varying illumination and commodity high-resolution camera under controlled illumination. The accuracy of automatic classification has been compared with predictions completed by experienced professionals. It has been shown that both automatic and manual methods reach an accuracy level of 84%, assuming that the images of the sections are properly normalised. The achieved recognition ratio was higher when referenced to predictions provided by professionals. Results of discrimination by means of Bayes classifier have been also presented as a reference. PMID:27548173

  20. Indirect effects of tending ants on holm oak volatiles and acorn quality

    PubMed Central

    Llusia, Joan; Peñuelas, Josep

    2011-01-01

    The indirect effect of ants on plants through their mutualism with honeydew-producing insects has been extensively investigated. Honeydew-producing insects that are tended by ants impose a cost on plant fitness and health by reducing seed production and/or plant growth. This cost is associated with sap intake and virus transmissions but may be overcompesated by tending ants if they deter or prey on hebivorous insects. The balance between cost and benefits depends on the tending ant species. In this study we report other indirect effects on plants of the mutualism between aphids and ants. We have found that two Lasius ant species, one native and the other invasive, may change the composition of volatile organic compounds (VOCs) of the holm oak (Quercus ilex) blend when they tend the aphid Lachnus roboris. The aphid regulation of its feeding and honeydew production according to the ant demands was proposed as a plausible mechanism that triggers changes in VOCs. Additionally, we now report here that aphid feeding, which is located most of the time on acorns cap or petiole, significantly increased the relative content of linolenic acid in acorns from holm oak colonized by the invasive ant. This acid is involved in the response of plants to insect herbivory as a precursor or jasmonic acid. No effect was found on acorn production, germination or seedlings quality. These results suggest that tending-ants may trigger the physiological response of holm oaks involved in plant resistance toward aphid herbivory and this response is ant species-dependent. PMID:21494087

  1. Colour-Based Binary Discrimination of Scarified Quercus robur Acorns under Varying Illumination.

    PubMed

    Jabłoński, Mirosław; Tylek, Paweł; Walczyk, Józef; Tadeusiewicz, Ryszard; Piłat, Adam

    2016-01-01

    Efforts to predict the germination ability of acorns using their shape, length, diameter and density are reported in the literature. These methods, however, are not efficient enough. As such, a visual assessment of the viability of seeds based on the appearance of cross-sections of seeds following their scarification is used. This procedure is more robust but demands significant effort from experienced employees over a short period of time. In this article an automated method of acorn scarification and assessment has been announced. This type of automation requires the specific setup of a machine vision system and application of image processing algorithms for evaluation of sections of seeds in order to predict their viability. In the stage of the analysis of pathological changes, it is important to point out image features that enable efficient classification of seeds in respect of viability. The article shows the results of the binary separation of seeds into two fractions (healthy or spoiled) using average components of regular red-green-blue and perception-based hue-saturation-value colour space. Analysis of accuracy of discrimination was performed on sections of 400 scarified acorns acquired using two various setups: machine vision camera under uncontrolled varying illumination and commodity high-resolution camera under controlled illumination. The accuracy of automatic classification has been compared with predictions completed by experienced professionals. It has been shown that both automatic and manual methods reach an accuracy level of 84%, assuming that the images of the sections are properly normalised. The achieved recognition ratio was higher when referenced to predictions provided by professionals. Results of discrimination by means of Bayes classifier have been also presented as a reference. PMID:27548173

  2. Antifouling activity of synthetic alkylpyridinium polymers using the barnacle model.

    PubMed

    Piazza, Veronica; Dragić, Ivanka; Sepčić, Kristina; Faimali, Marco; Garaventa, Francesca; Turk, Tom; Berne, Sabina

    2014-04-01

    Polymeric alkylpyridinium salts (poly-APS) isolated from the Mediterranean marine sponge, Haliclona (Rhizoniera) sarai, effectively inhibit barnacle larva settlement and natural marine biofilm formation through a non-toxic and reversible mechanism. Potential use of poly-APS-like compounds as antifouling agents led to the chemical synthesis of monomeric and oligomeric 3-alkylpyridinium analogues. However, these are less efficient in settlement assays and have greater toxicity than the natural polymers. Recently, a new chemical synthesis method enabled the production of poly-APS analogues with antibacterial, antifungal and anti-acetylcholinesterase activities. The present study examines the antifouling properties and toxicity of six of these synthetic poly-APS using the barnacle (Amphibalanus amphitrite) as a model (cyprids and II stage nauplii larvae) in settlement, acute and sub-acute toxicity assays. Two compounds, APS8 and APS12-3, show antifouling effects very similar to natural poly-APS, with an anti-settlement effective concentration that inhibits 50% of the cyprid population settlement (EC₅₀) after 24 h of 0.32 mg/L and 0.89 mg/L, respectively. The toxicity of APS8 is negligible, while APS12-3 is three-fold more toxic (24-h LC₅₀: nauplii, 11.60 mg/L; cyprids, 61.13 mg/L) than natural poly-APS. This toxicity of APS12-3 towards nauplii is, however, 60-fold and 1200-fold lower than that of the common co-biocides, Zn- and Cu-pyrithione, respectively. Additionally, exposure to APS12-3 for 24 and 48 h inhibits the naupliar swimming ability with respective IC₅₀ of 4.83 and 1.86 mg/L. PMID:24699112

  3. Application of Vegetation Indices to Estimate Acorn Production at Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Escribano, Juan A.; Díaz-Ambrona, Carlos G. H.; Recuero, Laura; Huesca, Margarita; Cicuendez, Victor; Palacios, Alicia; Tarquis, Ana M.

    2014-05-01

    The Iberian pig valued natural resources of the pasture when fattened in mountain. The variability of acorn production is not contained in any line of Spanish agricultural insurance. However, the production of arable pasture is covered by line insurance number 133 for loss of pasture compensation. This scenario is only contemplated for breeding cows and brave bulls, sheep, goats and horses, although pigs are not included. This insurance is established by monitoring ten-day composites Normalized Difference Vegetation Index (NDVI) measured by satellite over treeless pastures, using MODIS TERRA satellite. The aim of this work is to check if we can use a satellite vegetation index to estimate the production of acorns. In order to do so, two Spanish grassland locations have been analyzed: regions of Olivenza (Jerez-Oliva) and Merida (Badajoz). The acorns production was evaluated through 2002-2005 gauging conducted by the Grupo Habitat de la Orden (Badajoz). Medium resolution (500x500 m2) MODIS images were used during the same time period to estimate the ten-day composites NDVI at these locations. Finally, meteorological data was obtained from SIAR and MAGRAMA network stations, calculating the ten-day averaged temperature and ten day accumulated precipitation. Considering two accumulated factors, NDVI and temperature, three phenological stages were well defined being the second one which pointed differences among campaigns. Then, accumulated precipitation versus accumulated NDVI was plot for this second phenological stage obtaining maximum differences at 300 mm of cumulative rainfall. Analyzing acorn production with accumulated NDVI in that moment a production function was obtained with a correlation coefficient of 0.71. These results will be discussed in detail. References J.A. Escribano, C.G.H. Diaz-Ambrona, L. Recuero, M. Huesca, V. Cicuendez, A. Palacios-Orueta y A.M. Tarquis. Aplicacion de Indices de Vegetacion para evaluar la falta de produccion de pastos y

  4. Isolation of bioactive polysaccharide from acorn and evaluation of its functional properties.

    PubMed

    Tadayoni, Mehrnoosh; Sheikh-Zeinoddin, Mahmoud; Soleimanian-Zad, Sabihe

    2015-01-01

    The aim of this study was to evaluate the prebiotic potential and some functional properties of polysaccharides isolated from acorn fruit. The FTIR spectrum of isolated acorn polysaccharide (IAP) showed the typical bands corresponding to sugars and polysaccharides. The IAP was resistant to simulated acidic and enzymatic digestion even more than Inulin (In). The prebiotic activity, which was tested using IAP as a carbon source, showed significant increase in the growth and viability of Lactobacillus plantarum A7 (probiotic). Viability of Lactobacillus plantarum A7 in IAP and In supplemented media was stable even after 72 h, whereas in glucose supplemented medium, bacterial growth showed a notable decrease after 24h. Lipid absorption capacity (LAC) and water holding capacity (WHC) of IAP were 5.44 ± 0.02 (g oil/g DM) and 4.33 ± 0.03 (g water/g DM), respectively, which were comparable to some dietary fibers and were more than In. IAP scavenged DPPH radicals by 82.24%. IAP was found to have a high scavenging ability compared to the reference prebiotic (In), giving a scavenging ability of about 20%. Therefore, due to prebiotic capability, high WHC, LAC and good antioxidant activity, IAP can be a suitable candidate for technological applications and health improving effects in functional food. PMID:25159883

  5. New Techniques for High-Contrast Imaging with ADI: The ACORNS-ADI SEEDS Data Reduction Pipeline

    NASA Technical Reports Server (NTRS)

    Brandt, Timothy D.; McElwain, Michael W.; Turner, Edwin L.; Abe, L.; Brandner, W.; Carson, J.; Egner, S.; Feldt, M.; Golota, T.; Grady, C. A.; Guyon, O.; Hashimoto, J.; Hayano, Y.; Hayashi, M.; Hayashi, S.; Henning, T.; Hodapp, K. W.; Ishil, M.; Lye, M.; Janson, M.; Kandori, R.; Knapp, G. R.; Kudo, T.; Kusakabe, N.; Kuzuhara, M.

    2012-01-01

    We describe Algorithms for Calibration, Optimized Registration, and Nulling the Star in Angular Differential Imaging (ACORNS-ADI), a new, parallelized software package to reduce high-contrast imaging data, and its application to data from the Strategic Exploration of Exoplanets and Disks (SEEDS) survey. We implement seyeral new algorithms, includbg a method to centroid saturated images, a trimmed mean for combining an image sequence that reduces noise by up to approx 20%, and a robust and computationally fast method to compute the sensitivitv of a high-contrast obsen-ation everywhere on the field-of-view without introducing artificial sources. We also include a description of image processing steps to remove electronic artifacts specific to Hawaii2-RG detectors like the one used for SEEDS, and a detailed analysis of the Locally Optimized Combination of Images (LOCI) algorithm commonly used to reduce high-contrast imaging data. ACORNS-ADI is efficient and open-source, and includes several optional features which may improve performance on data from other instruments. ACORNS-ADI is freely available for download at www.github.com/t-brandt/acorns_-adi under a BSD license

  6. New Techniques for High-contrast Imaging with ADI: The ACORNS-ADI SEEDS Data Reduction Pipeline

    NASA Astrophysics Data System (ADS)

    Brandt, Timothy D.; McElwain, Michael W.; Turner, Edwin L.; Abe, L.; Brandner, W.; Carson, J.; Egner, S.; Feldt, M.; Golota, T.; Goto, M.; Grady, C. A.; Guyon, O.; Hashimoto, J.; Hayano, Y.; Hayashi, M.; Hayashi, S.; Henning, T.; Hodapp, K. W.; Ishii, M.; Iye, M.; Janson, M.; Kandori, R.; Knapp, G. R.; Kudo, T.; Kusakabe, N.; Kuzuhara, M.; Kwon, J.; Matsuo, T.; Miyama, S.; Morino, J.-I.; Moro-Martín, A.; Nishimura, T.; Pyo, T.-S.; Serabyn, E.; Suto, H.; Suzuki, R.; Takami, M.; Takato, N.; Terada, H.; Thalmann, C.; Tomono, D.; Watanabe, M.; Wisniewski, J. P.; Yamada, T.; Takami, H.; Usuda, T.; Tamura, M.

    2013-02-01

    We describe Algorithms for Calibration, Optimized Registration, and Nulling the Star in Angular Differential Imaging (ACORNS-ADI), a new, parallelized software package to reduce high-contrast imaging data, and its application to data from the SEEDS survey. We implement several new algorithms, including a method to register saturated images, a trimmed mean for combining an image sequence that reduces noise by up to ~20%, and a robust and computationally fast method to compute the sensitivity of a high-contrast observation everywhere on the field of view without introducing artificial sources. We also include a description of image processing steps to remove electronic artifacts specific to Hawaii2-RG detectors like the one used for SEEDS, and a detailed analysis of the Locally Optimized Combination of Images (LOCI) algorithm commonly used to reduce high-contrast imaging data. ACORNS-ADI is written in python. It is efficient and open-source, and includes several optional features which may improve performance on data from other instruments. ACORNS-ADI requires minimal modification to reduce data from instruments other than HiCIAO. It is freely available for download at www.github.com/t-brandt/acorns-adi under a Berkeley Software Distribution (BSD) license. Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  7. NEW TECHNIQUES FOR HIGH-CONTRAST IMAGING WITH ADI: THE ACORNS-ADI SEEDS DATA REDUCTION PIPELINE

    SciTech Connect

    Brandt, Timothy D.; Turner, Edwin L.; McElwain, Michael W.; Grady, C. A.; Abe, L.; Brandner, W.; Feldt, M.; Henning, T.; Carson, J.; Egner, S.; Golota, T.; Guyon, O.; Hayano, Y.; Hayashi, S.; Ishii, M.; Goto, M.; Hashimoto, J.; Hayashi, M.; Iye, M.; Hodapp, K. W.; and others

    2013-02-20

    We describe Algorithms for Calibration, Optimized Registration, and Nulling the Star in Angular Differential Imaging (ACORNS-ADI), a new, parallelized software package to reduce high-contrast imaging data, and its application to data from the SEEDS survey. We implement several new algorithms, including a method to register saturated images, a trimmed mean for combining an image sequence that reduces noise by up to {approx}20%, and a robust and computationally fast method to compute the sensitivity of a high-contrast observation everywhere on the field of view without introducing artificial sources. We also include a description of image processing steps to remove electronic artifacts specific to Hawaii2-RG detectors like the one used for SEEDS, and a detailed analysis of the Locally Optimized Combination of Images (LOCI) algorithm commonly used to reduce high-contrast imaging data. ACORNS-ADI is written in python. It is efficient and open-source, and includes several optional features which may improve performance on data from other instruments. ACORNS-ADI requires minimal modification to reduce data from instruments other than HiCIAO. It is freely available for download at www.github.com/t-brandt/acorns-adi under a Berkeley Software Distribution (BSD) license.

  8. Reconstructing Holocene conditions under the McMurdo Ice Shelf using Antarctic barnacle shells

    NASA Astrophysics Data System (ADS)

    Burgess, S. N.; Henderson, G. M.; Hall, B. L.

    2010-10-01

    This study evaluates the potential of barnacles for paleoceanographic reconstruction and, in particular, of the Antarctic species Bathylasma corolliforme to reconstruct past conditions under ice shelves. Like other barnacle species, this Antarctic barnacle secretes a robust low-Mg calcite shell with distinct growth increments on the external surface indicating growth over a number of years (30-50 in samples studied here). The Bathylasma samples used in this study grew in the Ross Sea and became entrained at the grounding line of a coastal ice shelf in McMurdo Sound, offering potential as an archive of changing conditions in this difficult to access environment under the McMurdo ice shelf. Nine barnacle shells were subsampled at high resolution (60 μm) for δ 18O and δ 13C analysis. These samples were dated with 14C and U-Th techniques, although the later did not yield useful age information due to open-system behaviour of barnacle calcite. Measured δ 18O values indicate that Bathylasma calcifies close to equilibrium with ambient seawater. One older sample (≈ 200 ka) has similar δ 18O and δ 13C values as the eight Holocene samples, suggesting that barnacle calcite is not prone to significant diagenesis in this setting. Apparent isotope equilibrium and lack of diagenesis make barnacles a promising archive for reconstruction of past ocean conditions. Cycles of δ 18O observed within each sample sometimes correlate with the external growth ridges, but not always, and have amplitudes of typically 0.6‰. This magnitude of variation suggests shell growth during a significant portion of the year, although it remains unclear whether growth continues throughout the year. However, the prominent growth bands suggest at least a signficant seasonal slowing in growth rate. Variations in barnacle δ 18O within each plate and between plates are too large to be caused by temperature, and instead reflect changes in δ 18O of the seawater, allowing some assessment of seawater

  9. Morphological and host specificity evolution in coral symbiont barnacles (Balanomorpha: Pyrgomatidae) inferred from a multi-locus phylogeny.

    PubMed

    Tsang, Ling Ming; Chu, Ka Hou; Nozawa, Yoko; Chan, Benny Kwok Kan

    2014-08-01

    Coral-inhabiting barnacles (Thoracica: Pyrgomatidae) are obligatory symbionts of scleractinian and fire corals. We attempted to reconstruct the phylogeny of coral-inhabiting barnacles using a multi-locus approach (mitochondrial 12S and 16S rRNA, and nuclear EF1, H3 and RP gene sequences, total 3532bp), which recovered a paraphyletic pattern. The fire-coral inhabiting barnacle Wanella milleporae occupied a basal position with respect to the other coral inhabiting barnacles. Pyrgomatids along with the coral-inhabiting archaeobalanid Armatobalanus nested within the same clade and this clade was subdivided into two major lineages: Armatobalanus+Cantellius with species proposed to be the ancestral stock of extant coral barnacles, and the other comprising the remaining genera studied. Ancestral state reconstruction (ASR) suggested multiple independent fusions and separations of shell plates and opercular valves in coral barnacle evolution, which counters the traditional hypothesis founded on a scheme of morphological similarities. Most of the coral barnacles are restricted to one or two coral host families only, suggesting a trend toward narrow host range and more specific adaptation. Furthermore, there is a close linkage between coral host usage and phylogenetic relationships with sister taxa usually being found on the same coral host family. This suggests that symbiotic relationships in coral-inhabiting barnacles are phylogenetically conserved and that host associated specialization plays an important role in their diversification. PMID:24636895

  10. Morphological and host specificity evolution in coral symbiont barnacles (Balanomorpha: Pyrgomatidae) inferred from a multi-locus phylogeny.

    PubMed

    Tsang, Ling Ming; Chu, Ka Hou; Nozawa, Yoko; Chan, Benny Kwok Kan

    2014-08-01

    Coral-inhabiting barnacles (Thoracica: Pyrgomatidae) are obligatory symbionts of scleractinian and fire corals. We attempted to reconstruct the phylogeny of coral-inhabiting barnacles using a multi-locus approach (mitochondrial 12S and 16S rRNA, and nuclear EF1, H3 and RP gene sequences, total 3532bp), which recovered a paraphyletic pattern. The fire-coral inhabiting barnacle Wanella milleporae occupied a basal position with respect to the other coral inhabiting barnacles. Pyrgomatids along with the coral-inhabiting archaeobalanid Armatobalanus nested within the same clade and this clade was subdivided into two major lineages: Armatobalanus+Cantellius with species proposed to be the ancestral stock of extant coral barnacles, and the other comprising the remaining genera studied. Ancestral state reconstruction (ASR) suggested multiple independent fusions and separations of shell plates and opercular valves in coral barnacle evolution, which counters the traditional hypothesis founded on a scheme of morphological similarities. Most of the coral barnacles are restricted to one or two coral host families only, suggesting a trend toward narrow host range and more specific adaptation. Furthermore, there is a close linkage between coral host usage and phylogenetic relationships with sister taxa usually being found on the same coral host family. This suggests that symbiotic relationships in coral-inhabiting barnacles are phylogenetically conserved and that host associated specialization plays an important role in their diversification.

  11. Something Darwin didn't know about barnacles: spermcast mating in a common stalked species.

    PubMed

    Barazandeh, Marjan; Davis, Corey S; Neufeld, Christopher J; Coltman, David W; Palmer, A Richard

    2013-03-01

    Most free-living barnacles are hermaphroditic, and eggs are presumed to be fertilized either by pseudo-copulation or self-fertilization. Although the common northeast Pacific intertidal gooseneck barnacle, Pollicipes polymerus, is believed only to cross-fertilize, some isolated individuals well outside penis range nonetheless bear fertilized eggs. They must therefore either self-fertilize or-contrary to all prior expectations about barnacle mating-obtain sperm from the water. To test these alternative hypotheses, we collected isolated individuals bearing egg masses, as well as isolated pairs where at least one parent carried egg masses. Using 16 single nucleotide polymorphism markers, we confirmed that a high percentage of eggs were fertilized with sperm captured from the water. Sperm capture occurred in 100 per cent of isolated individuals and, remarkably, even in 24 per cent of individuals that had an adjacent partner. Replicate subsamples of individual egg masses confirmed that eggs fertilized by captured sperm occurred throughout the egg mass. Sperm capture may therefore be a common supplement to pseudo-copulation in this species. These observations (i) overturn over a century of beliefs about what barnacles can (or cannot) do in terms of sperm transfer, (ii) raise doubts about prior claims of self-fertilization in barnacles, (iii) raise interesting questions about the capacity for sperm capture in other species (particularly those with short penises), and (iv) show, we believe for the first time, that spermcast mating can occur in an aquatic arthropod.

  12. Precisely proportioned: intertidal barnacles alter penis form to suit coastal wave action.

    PubMed

    Neufeld, Christopher J; Palmer, A Richard

    2008-05-01

    For their size, barnacles possess the longest penis of any animal (up to eight times their body length). However, as one of few sessile animals to copulate, they face a trade-off between reaching more mates and controlling ever-longer penises in turbulent flow. We observed that penises of an intertidal barnacle (Balanus glandula) from wave-exposed shores were shorter than, stouter than, and more than twice as massive for their length as, those from nearby protected bays. In addition, penis shape variation was tightly correlated with maximum velocity of breaking waves, and, on all shores, larger barnacles had disproportionately stouter penises. Finally, field experiments confirmed that most of this variation was due to phenotypic plasticity: barnacles transplanted to a wave-exposed outer coast produced dramatically shorter and wider penises than counterparts moved to a protected harbour. Owing to the probable trade-off between penis length and ability to function in flow, and owing to the ever-changing wave conditions on rocky shores, intertidal barnacles appear to have acquired the capacity to change the size and shape of their penises to suit local hydrodynamic conditions. This dramatic plasticity in genital form is a valuable reminder that factors other than the usual drivers of genital diversification--female choice, sexual conflict and male-male competition--can influence genital form.

  13. Mating group size and evolutionarily stable pattern of sexuality in barnacles.

    PubMed

    Yamaguchi, Sachi; Yusa, Yoichi; Yamato, Shigeyuki; Urano, Satoru; Takahashi, Satoshi

    2008-07-01

    Barnacles, marine crustaceans, have various patterns of sexuality depending on species including simultaneous hermaphroditism, androdioecy (hermaphrodites and dwarf males), and dioecy (females and dwarf males). We develop a model that predicts the pattern of sexuality in barnacles by two key environmental factors: (i) food availability and (ii) the fraction of larvae that settle on the sea floor. Populations in the model consist of small individuals and large ones. We calculate the optimal resource allocation toward male function, female function and growth for small and large barnacles that maximizes each barnacle's lifetime reproductive success using dynamic programming. The pattern of sexuality is defined by the combination of the optimal resource allocations. In our model, the mating group size is a dependent variable and we found that sexuality pattern changes with the food availability through the mating group size: simultaneous hermaphroditism appears in food-rich environments, where the mating group size is large, protandric simultaneous hermaphroditism appears in intermediate food environments, where the mating group size also takes intermediate value, the other sexuality patterns, androdioecy, dioecy, and sex change are observed in food-poor environments, where the mating group size is small. Our model is the first one where small males can control their growth to large individuals, and hence has ability to explain a rich spectrum of sexual patterns found in barnacles.

  14. Evaluation of a fully automated method to measure the critical removal stress of adult barnacles.

    PubMed

    Conlan, Sheelagh L; Mutton, Robert J; Aldred, Nick; Clare, Anthony S

    2008-01-01

    A computer-controlled force gauge designed to measure the adhesive strength of barnacles on test substrata is described. The instrument was evaluated with adult barnacles grown in situ on Silastic T2(R)-coated microscope slides and epoxy replicas adhered to the same substratum with synthetic adhesive. The force per unit area required to detach the barnacles (critical removal stress) using the new automated system was comparable to that obtained with ASTM D5618 (1994) (0.19 and 0.28 MPa compared with 0.18 and 0.27 MPa for two batches of barnacles). The automated method showed a faster rate of force development compared with the manual spring force gauge used for ASTM D5618 (1994). The new instrument was as accurate and precise at determining surface area as manual delineation used with ASTM D5618 (1994). The method provided significant advantages such as higher throughput speed, the ability to test smaller barnacles (which took less time to grow) and to control the force application angle and speed. The variability in measurements was lower than previously reported, suggesting an improved ability to compare the results obtained by different researchers.

  15. The unexpected mating system of the androdioecious barnacle Chelonibia testudinaria (Linnaeus 1758).

    PubMed

    Ewers-Saucedo, Christine; Hope, Neva B; Wares, John P

    2016-05-01

    Androdioecy was first described by Darwin in his seminal work on barnacle diversity; he identified males and hermaphrodites in the same reproductive population. Today, we realize that many androdioecious plants and animals share astonishing similarities, particularly with regard to their evolutionary history and mating system. Notably, these species were ancestrally dioecious, and their mating system has the following characteristics: hermaphrodites self-fertilize frequently, males are more successful in large mating groups, and males have a mating advantage. A male mating advantage makes androdioecy more likely to persist over evolutionary times. Androdioecious barnacles, however, appear to persist as an outlier with a different evolutionary trajectory: they originate from hermaphroditic species. Although sexual systems of androdioecious barnacles are known, no information on the mating system of androdioecious barnacles is available. This study assessed the mating system of the androdioecious barnacle Chelonibia testudinaria. In contrast to other androdioecious species, C. testudinaria does not self-fertilize, males do not have a mating advantage over hermaphrodites, and the average mating group is quite small, averaging only three individuals. Mating success is increased by proximity to the mate and penis length. Taken together, the mating system of C. testudinaria is unusual in comparison with other androdioecious plants and animals, and the lack of a male mating advantage suggests that the mating system alone does not provide an explanation for the maintenance of androdioecy in this species. Instead, we propose that sex-specific life history equalizes male and hermaphroditic overall fitness. PMID:26923636

  16. Chloride Fluxes in Isolated Dialyzed Barnacle Muscle Fibers

    PubMed Central

    DiPolo, R.

    1972-01-01

    Chloride outflux and influx has been studied in single isolated muscle fibers from the giant barnacle under constant internal composition by means of a dialysis perfusion technique. Membrane potential was continually recorded. The chloride outfluxes and influxes were 143 and 144 pmoles/cm2-sec (mean resting potential: 58 mv, temperature: 22°–24°C) with internal and external chloride concentrations of 30 and 541 mM, respectively. The chloride conductance calculated from tracer measurements using constant field assumptions is about fourfold greater than that calculated from published electrical data. Replacing 97% of the external chloride ions by propionate reduces the chloride efflux by 51%. Nitrate ions applied either to the internal or external surface of the membrane slows the chloride efflux. The external pH dependence of the chloride efflux follows the external pH dependence of the membrane conductance, in the range pH 3.9–4.7, increasing with decreasing pH. In the range pH 5–9, the chloride efflux increased with increasing pH, in a manner similar to that observed in frog muscle fibers. The titration curve for internal pH changes in the range 4.0–7.0 was quantitatively much different from that for external pH change, indicating significant asymmetry in the internal and external pH dependence of the chloride efflux. PMID:5074810

  17. Genetic diversity of hydrothermal-vent barnacles in Manus Basin

    NASA Astrophysics Data System (ADS)

    Plouviez, Sophie; Schultz, Thomas F.; McGinnis, Gwendolyn; Minshall, Halle; Rudder, Meghan; Van Dover, Cindy L.

    2013-12-01

    We evaluated mitochondrial cytochrome oxidase I genetic diversity of two barnacle species (Eochionelasmus ohtai manusensis, Vulcanolepas cf. parensis) at three sites in Manus Basin (Solwara 1, South Su, Solwara 8). There was no evidence for within-site or between-site genetic differentiation for either species. While E. ohtai manusensis showed limited genetic variation, V. cf. parensis showed greater variation, with sequences distributed between two divergent groups. Assuming the cytochrome oxidase I gene is not under selection, significantly negative Tajima's D in E. ohtai manusensis is consistent with a recent population expansion due to a bottleneck or founder effect, whereas V. cf. parensis (combined groups) did not depart from a stable effective population size. Considering the groups separately, V. cf. parensis Group 1 (but not Group 2) showed a negative Tajima's D, indicating these groups may have encountered different historical demographic conditions. Data reported here are part of a baseline study against which recovery of genetic diversity following mineral extraction at Solwara 1 can be measured.

  18. A potassium contribution to the response of the barnacle photoreceptor.

    PubMed Central

    Hanani, M; Shaw, C

    1977-01-01

    1. Intracellular recording from photoreceptors in the lateral eye of the barnacle show a brief negative-going 'dip' shortly after the onset of the late receptor potential. This phase can sometimes result in a hyperpolarization relative to the resting membrane potential. 2. The dip is prominent in light-adapted cells and is reduced by dark-adaptation. Low extracellular Ca2+ also reduces it. 3. The amplitude of the dip changes inversely with the K+ concentration in the saline. 4. The amplitude of the dip depends on the membrane potential, with a reversal potential near - 80 mV. 5. K+ blocking agents such as quinine and quinidine reduce or abolish the dip. 6. These observations indicate that the dip is due to a brief increase in K+ conductance which may be dependent on an influx of Ca ions. The fast decay of this phase may be brought about by a rapid uptake of Ca2+ by an intracellular mechanism. PMID:915767

  19. Sodium and Potassium Fluxes in Isolated Barnacle Muscle Fibers

    PubMed Central

    Brinley, F. J.

    1968-01-01

    Sodium and potassium influxes and outfluxes have been studied in single isolated muscle fibers from the giant barnacle both by microinjection and by external loading. The sodium influxes and outfluxes were 49 and 39 pmoles /cm2-sec (temperature = 15–16°C) respectively. The potassium influxes and outfluxes were 28 and 60 pmoles/cm2-sec (temperature = 13–16°C) respectively. Replacement of external sodium by lithium reduced sodium outflux by 67% but had no effect on potassium outflux. Removal of external potassum reduced the sodium outflux by 51% but had no effect on potassium outflux. External strophanthidin (10–30 µM) reduced sodium outflux by 80–90% and increased potassium outflux by 40% in normal fibers. The time constant for sodium exchange increased linearly with internal sodium concentration, as did the fraction of sodium outflux insensitive to a maximally inhibitory concentration of external strophanthidin in the range of 10 tO 80 mM internal sodium. The strophanthidin-sensitive component of sodium outflux could be related to the internal sodium concentration by the following empirical formula: See PDF for Equation PMID:5651768

  20. Reconstructing Holocene conditions under ice in the Ross Sea and in the Southern Ocean using barnacles

    NASA Astrophysics Data System (ADS)

    Burgess, S. N.; Henderson, G. M.; Hall, B. L.

    2009-12-01

    Paleoclimate archives that capture annual and subannual resolution marine conditions outside the tropics are not common but would be highly desirable. This study demonstrates the potential of barnacles for such purposes and applies them to paleoceanographic reconstruction under the McMurdo ice shelf and in the Southern Ocean. Most of the Bathylasma samples used in this study grew in the Ross Sea and range in age between modern samples (used for calibration) and Holocene samples which were collected on the surface of the McMurdo Ice Shelf, having been entrained at the grounding line and moved through the ice by surface ablation and further basal freezing. Like other barnacles, this species secretes a robust low-Mg calcite shell with distinct growth increments on the external surface indicating growth durations of several decades. Barnacle shells were subsampled at high resolution (60 μm) for δ18O and δ13C analysis and dated by 14C. Measured δ18O values indicate that Bathylasma calcifies close to equilibrium with ambient seawater and those of old (>200kyr) samples suggest little or no diagenesis. These features make barnacles a promising archive for reconstruction of past ocean conditions. Variations in barnacle δ18O within each plate and between plates reflect changes in δ18O of the seawater, and allow some assessment of the salinity under the ice shelf. Salinities are lowered by addition of meltwaters, but the barnacle data suggest this lowering does not go below 33‰. Salinity near the grounding line shows both temporal and spatial variability. These data indicate that Bathylasma can provide valuable paleoclimate information at subannual resolution for shallow/intermediate water depths and regions such as Antarctica that play an important role in the climate system. We are now exploring this potential to investigate intermediate water conditions in the South Pacific during the last glacial using samples from seamounts on the Macquarie Ridge and south of

  1. Mg/Ca and isotopic high resolution record of deep-sea hydrothermal barnacles

    NASA Astrophysics Data System (ADS)

    Bojar, A.-V.; Bojar, H.-P.; Tufar, W.

    2012-04-01

    Barnacles are crustaceans adapted to a sessile existence and cemented to a substrate by a protein complex. Most of the known species inhabit shallow marine environment, less than 2% of the species are found at depths between 100 and 2500 m. The shell of barnacles has a great adaptive significance, the shell of some barnacle species have been already investigated for microstructure. In this study we investigated the shell microstructure as well as the Mg/Ca and stable isotope distribution of barnacles found at a depth of around 2500m at a black smoker from the Manus Spreading centre, north-east of Papua New Guinea. The shell consists of three substructures: an outer layer with pores and aragonite crystals, a massive interior mass and an inner layer with pores. The shell shows grown lines and the outer layer exhibits longitudinal striation from base to apex. The pores have a medium size of 0.8 microns. The size of the calcitic microcrystals are in the range of 0.2 to 0.5 microns, beside, larger aragonite crystals, with size of c. 10 microns are present. The massive interior mass has a compact structure, no pores or channels could be observed. Oxygen stable isotope data of barnacle shell were performed from the centre to the border of the calcitic shells, along profiles. Within one shell, the isotope values show variations of max. 0.6 ‰. The calculated temperatures from the stable isotope data consistently indicate that the barnacles populate sites with low temperature values, up to a few °C. The calculated temperatures from the isotope data are also in agreement with the reported habitat from the North Fiji and Lau Basins, where temperatures of max. 6°C were measured at sites populated by barnacles. Both calculated and measured temperatures of a few degrees indicate that at the sites where barnacles live, hydrothermal fluid input is present, as ambient temperature is around 1.5°C. Electron-microbeam analyses were done along the interior layer of the shell. The

  2. Reversible antifouling effect of the cyclotide cycloviolacin O2 against barnacles.

    PubMed

    Göransson, Ulf; Sjögren, Martin; Svangård, Erika; Claeson, Per; Bohlin, Lars

    2004-08-01

    Cycloviolacin O2, a plant peptide of the cyclotide family, is shown to have potent effects against fouling barnacles (Balanus improvisus), with complete inhibition of settlement at a concentration of 0.25 microM. The effect of cycloviolacin O2 against barnacles is reversible and nontoxic in the bioassay employed in these studies. Cycloviolacin O2 was isolated from the terrestrial plant Viola odorata by strong cation exchange and reversed-phase HPLC and identified by mass spectrometry following aminoethylation and enzymatic cleavage.

  3. Comparative analysis of Cucurbita pepo metabolism throughout fruit development in acorn squash and oilseed pumpkin

    PubMed Central

    Wyatt, Lindsay E; Strickler, Susan R; Mueller, Lukas A; Mazourek, Michael

    2016-01-01

    Both the fruit mesocarp and the seeds of winter squash can be used for consumption, although the focus of breeding efforts varies by cultivar. Cultivars bred for fruit consumption are selected for fruit mesocarp quality traits such as carotenoid content, percent dry matter, and percent soluble solids, while these traits are essentially ignored in oilseed pumpkins. To compare fruit development in these two types of squash, we sequenced the fruit transcriptome of two cultivars bred for different purposes: an acorn squash, ‘Sweet REBA’, and an oilseed pumpkin, ‘Lady Godiva’. Putative metabolic pathways were developed for carotenoid, starch, and sucrose synthesis in winter squash fruit and squash homologs were identified for each of the structural genes in the pathways. Gene expression, especially of known rate-limiting and branch point genes, corresponded with metabolite accumulation both across development and between the two cultivars. Thus, developmental regulation of metabolite genes is an important factor in winter squash fruit quality.

  4. Comparative analysis of Cucurbita pepo metabolism throughout fruit development in acorn squash and oilseed pumpkin.

    PubMed

    Wyatt, Lindsay E; Strickler, Susan R; Mueller, Lukas A; Mazourek, Michael

    2016-01-01

    Both the fruit mesocarp and the seeds of winter squash can be used for consumption, although the focus of breeding efforts varies by cultivar. Cultivars bred for fruit consumption are selected for fruit mesocarp quality traits such as carotenoid content, percent dry matter, and percent soluble solids, while these traits are essentially ignored in oilseed pumpkins. To compare fruit development in these two types of squash, we sequenced the fruit transcriptome of two cultivars bred for different purposes: an acorn squash, 'Sweet REBA', and an oilseed pumpkin, 'Lady Godiva'. Putative metabolic pathways were developed for carotenoid, starch, and sucrose synthesis in winter squash fruit and squash homologs were identified for each of the structural genes in the pathways. Gene expression, especially of known rate-limiting and branch point genes, corresponded with metabolite accumulation both across development and between the two cultivars. Thus, developmental regulation of metabolite genes is an important factor in winter squash fruit quality. PMID:27688889

  5. Comparative analysis of Cucurbita pepo metabolism throughout fruit development in acorn squash and oilseed pumpkin.

    PubMed

    Wyatt, Lindsay E; Strickler, Susan R; Mueller, Lukas A; Mazourek, Michael

    2016-01-01

    Both the fruit mesocarp and the seeds of winter squash can be used for consumption, although the focus of breeding efforts varies by cultivar. Cultivars bred for fruit consumption are selected for fruit mesocarp quality traits such as carotenoid content, percent dry matter, and percent soluble solids, while these traits are essentially ignored in oilseed pumpkins. To compare fruit development in these two types of squash, we sequenced the fruit transcriptome of two cultivars bred for different purposes: an acorn squash, 'Sweet REBA', and an oilseed pumpkin, 'Lady Godiva'. Putative metabolic pathways were developed for carotenoid, starch, and sucrose synthesis in winter squash fruit and squash homologs were identified for each of the structural genes in the pathways. Gene expression, especially of known rate-limiting and branch point genes, corresponded with metabolite accumulation both across development and between the two cultivars. Thus, developmental regulation of metabolite genes is an important factor in winter squash fruit quality.

  6. Comparative analysis of Cucurbita pepo metabolism throughout fruit development in acorn squash and oilseed pumpkin

    PubMed Central

    Wyatt, Lindsay E; Strickler, Susan R; Mueller, Lukas A; Mazourek, Michael

    2016-01-01

    Both the fruit mesocarp and the seeds of winter squash can be used for consumption, although the focus of breeding efforts varies by cultivar. Cultivars bred for fruit consumption are selected for fruit mesocarp quality traits such as carotenoid content, percent dry matter, and percent soluble solids, while these traits are essentially ignored in oilseed pumpkins. To compare fruit development in these two types of squash, we sequenced the fruit transcriptome of two cultivars bred for different purposes: an acorn squash, ‘Sweet REBA’, and an oilseed pumpkin, ‘Lady Godiva’. Putative metabolic pathways were developed for carotenoid, starch, and sucrose synthesis in winter squash fruit and squash homologs were identified for each of the structural genes in the pathways. Gene expression, especially of known rate-limiting and branch point genes, corresponded with metabolite accumulation both across development and between the two cultivars. Thus, developmental regulation of metabolite genes is an important factor in winter squash fruit quality. PMID:27688889

  7. Morphological characterization of the asexual reproduction in the acorn worm Balanoglossus simodensis.

    PubMed

    Miyamoto, Norio; Saito, Yasunori

    2010-09-01

    The acorn worm Balanoglossus simodensis reproduces asexually by fragmentation and subsequent regeneration from the body fragments. We examined the morphogenesis of its asexual reproduction. At first, we collected asexually reproducing specimens and observed their morphogenesis. Then, we succeeded in inducing the asexual reproduction artificially by cutting the worm at the end of the genital region. The process of morphogenesis is completely the same between naturally collected and artificially induced specimens. The stages during morphogenesis were established on the basis of the external features of the asexually reproducing fragments. The internal features of the fragments were also examined at each stage. In a separate phase of the study, the capacity for regeneration of some body parts was also examined by dividing intact worms into about 10 fragments. Although the capacity for regeneration varied among the different body parts, some fragments regenerated into complete individuals in 1 month. The process of regeneration was the same as that in the asexually produced fragments.

  8. Decremental conduction of the visual signal in barnacle lateral eye

    PubMed Central

    Shaw, Stephen R.

    1972-01-01

    1. There are problems associated with the notion that slow potentials alone are used to transmit information in the early stages of some visual systems. This idea and alternatives have been tested on the barnacle lateral ocellus, a simple eye with only three photoreceptors, each with its own axon about 1 cm long. 2. All of the receptors have very similar properties including spectral sensitivity, and are also electrically coupled together. Impulses cannot be recorded from any of the cell bodies, all of which have been impaled as shown by dye marking. 3. No impulses can be recorded externally from most of the ocellar nerve or intracellularly from the receptor axon terminals. Impulses driven by light, sometimes recorded in the final part of the nerve, are believed to originate in other axons. 4. During illumination of the eye, current enters the receptor soma and leaves via the rest of the axon. This is consistent with the idea that the axon acts as a purely passive cable. The passive behaviour was also demonstrated in a comparison of the relative attenuation down the axon, of hyperpolarizations and depolarizations. 5. Calculations based on the supposed electrical constants of the somas showed that the slow potential itself was unlikely to be the visual signal, since it would be enormously attenuated by passive spread down the long thin axons. To check this, the axon terminals in the supraoesophageal ganglion were penetrated and identified by electrical and dye-marking criteria. In fact, the slow potential was attenuated in the most favourable case only by a factor of about three, indicating an axon membrane resistance in the range of 105 Ω. cm2. 6. This resistance may be substantially higher than that of the soma surface membrane, corrected for increased surface area. The sheath around each axon probably does not influence the electrical properties, judged by its permeability to the small molecule of Procion Yellow. 7. The minimal loss of voltage in the axon and

  9. Analysis of the Behaviours Mediating Barnacle Cyprid Reversible Adhesion

    PubMed Central

    Aldred, Nick; Høeg, Jens T.; Maruzzo, Diego; Clare, Anthony S.

    2013-01-01

    When exploring immersed surfaces the cypris larvae of barnacles employ a tenacious and rapidly reversible adhesion mechanism to facilitate their characteristic ‘walking’ behaviour. Although of direct relevance to the fields of marine biofouling and bio-inspired adhesive development, the mechanism of temporary adhesion in cyprids remains poorly understood. Cyprids secrete deposits of a proteinaceous substance during surface attachment and these are often visible as ‘footprints’ on previously explored surfaces. The attachment structures, the antennular discs, of cyprids also present a complex morphology reminiscent of both the hairy appendages used by some terrestrial invertebrates for temporary adhesion and a classic ‘suction cup’. Despite the numerous analytical approaches so-far employed, it has not been possible to resolve conclusively the respective contributions of viscoelastic adhesion via the proteinaceous ‘temporary adhesive’, ‘dry’ adhesion via the cuticular villi present on the disc and the behavioural contribution by the organism. In this study, high-speed photography was used for the first time to capture the behaviour of cyprids at the instant of temporary attachment and detachment. Attachment is facilitated by a constantly sticky disc surface – presumably due to the presence of the proteinaceous temporary adhesive. The tenacity of the resulting bond, however, is mediated behaviourally. For weak attachment the disc is constantly moved on the surface, whereas for a strong attachment the disc is spread out on the surface. Voluntary detachment is by force, requiring twisting or peeling of the bond – seemingly without any more subtle detachment behaviours. Micro-bubbles were observed at the adhesive interface as the cyprid detached, possibly an adaptation for energy dissipation. These observations will allow future work to focus more specifically on the cyprid temporary adhesive proteins, which appear to be fundamental to adhesion

  10. The impact of coating hardness on the anti-barnacle efficacy of an embedded antifouling biocide.

    PubMed

    Pinori, Emiliano; Elwing, Hans; Berglin, Mattias

    2013-01-01

    The efficacy of antifouling coatings designed to minimise the release of biocide, either by embedded (non-covalent) or tethered (covalently bonded) biocides, relies on sufficient bioavailability of the active compound upon contact between the organism and the coating. This investigation is focused on whether coating hardness affects the efficacy of embedded coating systems. Two experimental, non-eroding and waterborne latex paint formulations composed mainly of polystyrene (PS) or polyvinyl versatate (PV) were chosen for their difference in mechanical properties measured in terms of Buchholz indentation resistance. Ivermectin was added to both formulations to a final concentration of 0.1% (w/v) and the steady state release rate was measured according to ISO 15181 at between 34 and 70 ng cm(-2) day(-1) for both formulations. Field trials conducted over 3 months showed significant differences in anti-barnacle efficacy between the formulations despite their similar release profiles. The softer PV coating showed complete anti-barnacle efficacy, ie no barnacles were detected, while the harder PS coating showed no efficacy against barnacle colonisation during the same time period. The results indicate a new antifouling strategy whereby a route of intoxication is triggered by the organism itself upon interaction with the coating and its embedded biocide. This finding opens new possibilities in controlling macrofouling by low emission antifouling coatings.

  11. Characterization of metalloproteinase-like activities in barnacle (Balanus amphitrite) nauplii.

    PubMed

    Mannello, Ferdinando; Canesi, Laura; Faimali, Marco; Piazza, Veronica; Gallo, Gabriella; Geraci, Sebastiano

    2003-05-01

    The presence of extracellular matrix (ECM) degrading enzymes was investigated in naupliar stages of the barnacle Balanus amphitrite Darwin. The results of substrate gel-zymography and quantitative assays demonstrated that naupliar extracts contain several protease activities that are specific towards gelatin substrates; some caseinolytic activity was also detected. Substrate specificity was observed in all naupliar stages (II-VI). The gelatinolytic activities showed dependence on both Ca(2+) and Zn(2+) and inhibition by EDTA, EGTA, and 1,10-phenanthroline. Also Mg(2+) partially activated the enzymes, whereas Cd(2+), Cu(2+), Hg(2+) and Pb(2+) were inhibitory. The thermal denaturation profile was significantly different in the presence and absence of Ca(2+) and Zn(2+). Overall, the results indicate that the Ca(2+)/Zn(2+)-dependent gelatinase activities in barnacle nauplii belong to the subfamily of matrix metalloproteases. Barnacle larvae MMPs showed biochemical characteristics different from those of vertebrate MMPs but common to other gelatinases from marine invertebrates: they were unaffected by several protease inhibitors and insensitive to specific activators/inhibitors of vertebrate MMPs. The presence of MMP-like activities in different naupliar stages suggests a constitutive role for these enzymes in ECM remodeling during barnacle larvae growth and development. PMID:12781969

  12. Living on the Edge: Settlement Patterns by the Symbiotic Barnacle Xenobalanus globicipitis on Small Cetaceans.

    PubMed

    Carrillo, Juan M; Overstreet, Robin M; Raga, Juan A; Aznar, Francisco J

    2015-01-01

    The highly specialized coronulid barnacle Xenobalanus globicipitis attaches exclusively on cetaceans worldwide, but little is known about the factors that drive the microhabitat patterns on its hosts. We investigate this issue based on data on occurrence, abundance, distribution, orientation, and size of X. globicipitis collected from 242 striped dolphins (Stenella coeruleoalba) that were stranded along the Mediterranean coast of Spain. Barnacles exclusively infested the fins, particularly along the trailing edge. Occurrence, abundance, and density of X. globicipitis were significantly higher, and barnacles were significantly larger, on the caudal fin than on the flippers and dorsal fin. Barnacles were found more frequently and in greater numbers on the dorsal rather than ventral side of the caudal fin and on the central third of dorsal and ventral fluke surfaces. Nearly all examined individuals attached with their cirral fan oriented opposite to the fluke edge. We suggest that X. globicipitis may chemically recognize dolphins as a substratum, but fins, particularly the flukes, are passively selected because of creation of vortices that increase contact of cyprids with skin and early survival of these larvae at the corresponding sites. Cyprids could actively select the trailing edge and orient with the cirri facing the main direction of flow. Attachment on the dorsal side of the flukes is likely associated with asymmetrical oscillation of the caudal fin, and the main presence on the central segment of the flukes could be related to suitable water flow conditions generated by fluke performance for both settlement and nutrient filtration.

  13. Gooseneck barnacles (Lepas spp.) ingest microplastic debris in the North Pacific Subtropical Gyre.

    PubMed

    Goldstein, Miriam C; Goodwin, Deborah S

    2013-01-01

    Substantial quantities of small plastic particles, termed "microplastic," have been found in many areas of the world ocean, and have accumulated in particularly high densities on the surface of the subtropical gyres. While plastic debris has been documented on the surface of the North Pacific Subtropical Gyre (NPSG) since the early 1970s, the ecological implications remain poorly understood. Organisms associated with floating objects, termed the "rafting assemblage," are an important component of the NPSG ecosystem. These objects are often dominated by abundant and fast-growing gooseneck barnacles (Lepas spp.), which predate on plankton and larval fishes at the sea surface. To assess the potential effects of microplastic on the rafting community, we examined the gastrointestinal tracts of 385 barnacles collected from the NPSG for evidence of plastic ingestion. We found that 33.5% of the barnacles had plastic particles present in their gastrointestinal tract, ranging from one plastic particle to a maximum of 30 particles. Particle ingestion was positively correlated to capitulum length, and no blockage of the stomach or intestines was observed. The majority of ingested plastic was polyethylene, with polypropylene and polystyrene also present. Our results suggest that barnacle ingestion of microplastic is relatively common, with unknown trophic impacts on the rafting community and the NPSG ecosystem.

  14. Sexual systems and dwarf males in barnacles: integrating life history and sex allocation theories.

    PubMed

    Yamaguchi, Sachi; Yusa, Yoichi; Sawada, Kota; Takahashi, Satoshi

    2013-03-01

    Barnacles, which are sedentary marine crustaceans, have diverse sexual systems that include simultaneous hermaphroditism, androdioecy (coexistence of hermaphrodites and males) and dioecy (females and males). In dioecious and androdioecious species, the males are very small and are thus called dwarf males. These sexual systems are defined by two factors: sex allocation of non-dwarf individuals and the presence or absence of dwarf males. We constructed an ESS model treating sex allocation and life history simultaneously to explain sexual systems in barnacles. We analyzed the evolutionarily stable size-dependent resource allocation strategy to male reproductive function, female reproductive function and growth in non-dwarf barnacles, and the ESS proportion of dwarf males, under conditions of varying mortality and food availability. Sex allocation in non-dwarf individuals (hermaphrodites or females) is affected by mate availability and the proportion of dwarf males. When hermaphrodites appear, all hermaphrodites become protandric simultaneous hermaphrodites. Furthermore, high mortality and poor resource availability favor dwarf males because of their early maturation and weakened sperm competition. In conclusion, we showed that combining sex allocation and life history theories is a useful way to understand various sexual systems in barnacles and perhaps in other organisms as well.

  15. Living on the Edge: Settlement Patterns by the Symbiotic Barnacle Xenobalanus globicipitis on Small Cetaceans

    PubMed Central

    Overstreet, Robin M.; Raga, Juan A.

    2015-01-01

    The highly specialized coronulid barnacle Xenobalanus globicipitis attaches exclusively on cetaceans worldwide, but little is known about the factors that drive the microhabitat patterns on its hosts. We investigate this issue based on data on occurrence, abundance, distribution, orientation, and size of X. globicipitis collected from 242 striped dolphins (Stenella coeruleoalba) that were stranded along the Mediterranean coast of Spain. Barnacles exclusively infested the fins, particularly along the trailing edge. Occurrence, abundance, and density of X. globicipitis were significantly higher, and barnacles were significantly larger, on the caudal fin than on the flippers and dorsal fin. Barnacles were found more frequently and in greater numbers on the dorsal rather than ventral side of the caudal fin and on the central third of dorsal and ventral fluke surfaces. Nearly all examined individuals attached with their cirral fan oriented opposite to the fluke edge. We suggest that X. globicipitis may chemically recognize dolphins as a substratum, but fins, particularly the flukes, are passively selected because of creation of vortices that increase contact of cyprids with skin and early survival of these larvae at the corresponding sites. Cyprids could actively select the trailing edge and orient with the cirri facing the main direction of flow. Attachment on the dorsal side of the flukes is likely associated with asymmetrical oscillation of the caudal fin, and the main presence on the central segment of the flukes could be related to suitable water flow conditions generated by fluke performance for both settlement and nutrient filtration. PMID:26083019

  16. Gooseneck barnacles (Lepas spp.) ingest microplastic debris in the North Pacific Subtropical Gyre.

    PubMed

    Goldstein, Miriam C; Goodwin, Deborah S

    2013-01-01

    Substantial quantities of small plastic particles, termed "microplastic," have been found in many areas of the world ocean, and have accumulated in particularly high densities on the surface of the subtropical gyres. While plastic debris has been documented on the surface of the North Pacific Subtropical Gyre (NPSG) since the early 1970s, the ecological implications remain poorly understood. Organisms associated with floating objects, termed the "rafting assemblage," are an important component of the NPSG ecosystem. These objects are often dominated by abundant and fast-growing gooseneck barnacles (Lepas spp.), which predate on plankton and larval fishes at the sea surface. To assess the potential effects of microplastic on the rafting community, we examined the gastrointestinal tracts of 385 barnacles collected from the NPSG for evidence of plastic ingestion. We found that 33.5% of the barnacles had plastic particles present in their gastrointestinal tract, ranging from one plastic particle to a maximum of 30 particles. Particle ingestion was positively correlated to capitulum length, and no blockage of the stomach or intestines was observed. The majority of ingested plastic was polyethylene, with polypropylene and polystyrene also present. Our results suggest that barnacle ingestion of microplastic is relatively common, with unknown trophic impacts on the rafting community and the NPSG ecosystem. PMID:24167779

  17. Living on the Edge: Settlement Patterns by the Symbiotic Barnacle Xenobalanus globicipitis on Small Cetaceans.

    PubMed

    Carrillo, Juan M; Overstreet, Robin M; Raga, Juan A; Aznar, Francisco J

    2015-01-01

    The highly specialized coronulid barnacle Xenobalanus globicipitis attaches exclusively on cetaceans worldwide, but little is known about the factors that drive the microhabitat patterns on its hosts. We investigate this issue based on data on occurrence, abundance, distribution, orientation, and size of X. globicipitis collected from 242 striped dolphins (Stenella coeruleoalba) that were stranded along the Mediterranean coast of Spain. Barnacles exclusively infested the fins, particularly along the trailing edge. Occurrence, abundance, and density of X. globicipitis were significantly higher, and barnacles were significantly larger, on the caudal fin than on the flippers and dorsal fin. Barnacles were found more frequently and in greater numbers on the dorsal rather than ventral side of the caudal fin and on the central third of dorsal and ventral fluke surfaces. Nearly all examined individuals attached with their cirral fan oriented opposite to the fluke edge. We suggest that X. globicipitis may chemically recognize dolphins as a substratum, but fins, particularly the flukes, are passively selected because of creation of vortices that increase contact of cyprids with skin and early survival of these larvae at the corresponding sites. Cyprids could actively select the trailing edge and orient with the cirri facing the main direction of flow. Attachment on the dorsal side of the flukes is likely associated with asymmetrical oscillation of the caudal fin, and the main presence on the central segment of the flukes could be related to suitable water flow conditions generated by fluke performance for both settlement and nutrient filtration. PMID:26083019

  18. Gooseneck barnacles (Lepas spp.) ingest microplastic debris in the North Pacific Subtropical Gyre

    PubMed Central

    Goodwin, Deborah S.

    2013-01-01

    Substantial quantities of small plastic particles, termed “microplastic,” have been found in many areas of the world ocean, and have accumulated in particularly high densities on the surface of the subtropical gyres. While plastic debris has been documented on the surface of the North Pacific Subtropical Gyre (NPSG) since the early 1970s, the ecological implications remain poorly understood. Organisms associated with floating objects, termed the “rafting assemblage,” are an important component of the NPSG ecosystem. These objects are often dominated by abundant and fast-growing gooseneck barnacles (Lepas spp.), which predate on plankton and larval fishes at the sea surface. To assess the potential effects of microplastic on the rafting community, we examined the gastrointestinal tracts of 385 barnacles collected from the NPSG for evidence of plastic ingestion. We found that 33.5% of the barnacles had plastic particles present in their gastrointestinal tract, ranging from one plastic particle to a maximum of 30 particles. Particle ingestion was positively correlated to capitulum length, and no blockage of the stomach or intestines was observed. The majority of ingested plastic was polyethylene, with polypropylene and polystyrene also present. Our results suggest that barnacle ingestion of microplastic is relatively common, with unknown trophic impacts on the rafting community and the NPSG ecosystem. PMID:24167779

  19. The effect of within-year variation in acorn crop size on seed harvesting by avian hoarders.

    PubMed

    Pesendorfer, Mario B; Koenig, Walter D

    2016-05-01

    Spatial and temporal variation in resource distribution affect the movement and foraging behavior of many animals. In the case of animal-dispersed trees, numerous studies have addressed masting-the synchronized variation in seed production between years-but the fitness consequences of spatial variation in seed production within a year are unclear. We investigated the effects of variable acorn production in a population of valley oaks (Quercus lobata) on the composition and behavior of the avian-disperser community. We found that western scrub-jays (Aphelocoma californica), high-quality dispersers that store seeds in the ground, were attracted to, and exhibited increased per capita dispersal rates from, trees with large acorn crops. In contrast, acorn woodpeckers (Melanerpes formicivorus), low-quality dispersers that store acorns in trees where they are unlikely to germinate, increased per capita hoarding rates but did not attend trees with large seed crops in higher numbers, suggesting that the two species responded to resources on different spatial scales. Antagonistic interactions within and between species increased with the number of birds attending a tree, resulting in a potential cost for foraging birds, but did not reduce dispersal rates. Using a simulation model, we estimated that trees with large initial crops experienced a greater proportion (77 %) of high-quality seed dispersal events than trees with small crops (62 %). Our findings provide support for a mechanistic link between seed production and foraging behavior of seed dispersers as predicted by the predator dispersal hypothesis for the functional consequences of variable seed production in hoarder-dispersed trees.

  20. Evolutionary and biogeographical patterns of barnacles from deep-sea hydrothermal vents.

    PubMed

    Herrera, Santiago; Watanabe, Hiromi; Shank, Timothy M

    2015-02-01

    The characterization of evolutionary and biogeographical patterns is of fundamental importance to identify factors driving biodiversity. Due to their widespread but discontinuous distribution, deep-sea hydrothermal vent barnacles represent an excellent model for testing biogeographical hypotheses regarding the origin, dispersal and diversity of modern vent fauna. Here, we characterize the global genetic diversity of vent barnacles to infer their time of radiation, place of origin, mode of dispersal and diversification. Our approach was to target a suite of multiple loci in samples representing seven of the eight described genera. We also performed restriction-site associated DNA sequencing on individuals from each species. Phylogenetic inferences and topology hypothesis tests indicate that vent barnacles have colonized deep-sea hydrothermal vents at least twice in history. Consistent with preliminary estimates, we find a likely radiation of barnacles in vent ecosystems during the Cenozoic. Our analyses suggest that the western Pacific was the place of origin of the major vent barnacle lineage, followed by circumglobal colonization eastwards through the Southern Hemisphere during the Neogene. The inferred time of radiation rejects the classic hypotheses of antiquity of vent taxa. The timing and the mode of origin, radiation and dispersal are consistent with recent inferences made for other deep-sea taxa, including nonvent species, and are correlated with the occurrence of major geological events and mass extinctions. Thus, we suggest that the geological processes and dispersal mechanisms discussed here can explain the current distribution patterns of many other marine taxa and have played an important role shaping deep-sea faunal diversity. These results also constitute the critical baseline data with which to assess potential effects of anthropogenic disturbances on deep-sea ecosystems. PMID:25602032

  1. Evolutionary and biogeographical patterns of barnacles from deep-sea hydrothermal vents.

    PubMed

    Herrera, Santiago; Watanabe, Hiromi; Shank, Timothy M

    2015-02-01

    The characterization of evolutionary and biogeographical patterns is of fundamental importance to identify factors driving biodiversity. Due to their widespread but discontinuous distribution, deep-sea hydrothermal vent barnacles represent an excellent model for testing biogeographical hypotheses regarding the origin, dispersal and diversity of modern vent fauna. Here, we characterize the global genetic diversity of vent barnacles to infer their time of radiation, place of origin, mode of dispersal and diversification. Our approach was to target a suite of multiple loci in samples representing seven of the eight described genera. We also performed restriction-site associated DNA sequencing on individuals from each species. Phylogenetic inferences and topology hypothesis tests indicate that vent barnacles have colonized deep-sea hydrothermal vents at least twice in history. Consistent with preliminary estimates, we find a likely radiation of barnacles in vent ecosystems during the Cenozoic. Our analyses suggest that the western Pacific was the place of origin of the major vent barnacle lineage, followed by circumglobal colonization eastwards through the Southern Hemisphere during the Neogene. The inferred time of radiation rejects the classic hypotheses of antiquity of vent taxa. The timing and the mode of origin, radiation and dispersal are consistent with recent inferences made for other deep-sea taxa, including nonvent species, and are correlated with the occurrence of major geological events and mass extinctions. Thus, we suggest that the geological processes and dispersal mechanisms discussed here can explain the current distribution patterns of many other marine taxa and have played an important role shaping deep-sea faunal diversity. These results also constitute the critical baseline data with which to assess potential effects of anthropogenic disturbances on deep-sea ecosystems.

  2. Multiple origins and incursions of the Atlantic barnacle Chthamalus proteus in the Pacific.

    PubMed

    Zardus, John D; Hadfield, Michael G

    2005-10-01

    Chthamalus proteus, a barnacle native to the Caribbean and western Atlantic, was introduced to the Pacific within the last few decades. Using direct sequencing of mitochondrial DNA (COI), we characterized genetic variation in native and introduced populations and searched for genetic matches between regions to determine if there were multiple geographical sources and introduction points for this barnacle. In the native range, we found great genetic differences among populations (max. F(ST) = 0.613) encompassing four lineages: one endemic to Panama, one endemic to Brazil, and two occurring Caribbean-wide. All four lineages were represented in the Pacific, but not equally; the Brazilian lineage was most prevalent and the Panamanian least common. Twenty-one individuals spread among nearly every island from where the barnacle is known in the Pacific, exactly matched six haplotypes scattered among Curaçao, the Netherlands Antilles; St John, US Virgin Islands; Puerto Rico; and Brazil, confirming a multigeographical origin for the Pacific populations. Significant genetic differences were also found in introduced populations from the Hawaiian Islands (F(CT) = 0.043, P < 0.001), indicating introduction events have occurred at more than one locality. However, the sequence, timing and number of arrival events remains unknown. Possible reasons for limited transport of this barnacle through the Panama Canal are discussed. This and a preponderance of Brazilian-type individuals in the Pacific suggest an unexpected route of entry from around Cape Horn, South America. Unification in the Pacific of historically divergent lineages of this barnacle raises the possibility for selection of 'hybrids' with novel ecological adaptations in its new environment. PMID:16202091

  3. An externally brooding acorn worm (Hemichordata, Enteropneusta, Torquaratoridae) from the Russian arctic.

    PubMed

    Osborn, Karen J; Gebruk, Andrey V; Rogacheva, Antonina; Holland, Nicholas D

    2013-10-01

    A single specimen of a previously undescribed acorn worm in the family Torquaratoridae was trawled from a bottom depth of about 350 m in the Kara Sea (Russian Arctic). The new species is the shallowest of the exclusively deep-sea torquaratorids found to date, possibly an example of high-latitude emergence. On the basis of ribosomal DNA sequences and morphology, the worm is described here as the holotype of Coleodesmium karaensis n. gen., n. sp. It is most similar in overall body shape to the previously described enteropneust genus Allapasus, but is uniquely characterized by a tubular component of the proboscis skeleton ensheathing the collar nerve cord. Additionally, within the proboscis, the sparseness of the musculature of C. karaensis clearly distinguishes it from the much more muscular members of Allapasus. The holotype is a female bearing about a dozen embryos on the surface of her pharyngeal region, each recessed within a shallow depression in the dorsal epidermis. The embryos, ranging from late gastrula to an early stage of coelom formation, are a little more than 1 mm in diameter and surrounded by a thin membrane. Each embryo comprises an external ectoderm of monociliated cells (not arranged in obvious ciliated bands) and an internal endo-mesoderm; the blastopore is closed. In the most advanced embryos, the anterior coelom is starting to constrict off from the archenteron. Coleodesmium karaensis is the first enteropneust (and indeed the first hemichordate) found brooding embryos on the surface of the mother's body. PMID:24243964

  4. Shared parentage and incest avoidance in the cooperatively breeding acorn woodpecker.

    PubMed

    Haydock, J; Koenig, W D; Stanback, M T

    2001-06-01

    Social groups of acorn woodpeckers (Melanerpes formicivorus) range in size from unaided pairs to 15 adults. Behavioural indicators of mate guarding, assumed incest avoidance and observations of egg-laying indicate that social organization ranges from monogamous pairs to groups with up to seven male and three female putative cobreeders plus up to 10 nonbreeding helpers. In addition, groups occasionally lack a putative breeder throughout the breeding season. Here we report results from multilocus DNA fingerprinting of 372 nestlings from 123 nests in groups with putative cobreeders of one or both sexes. No extra-group fertilizations were found. Putative cobreeding males within social groups shared paternity. However, the most reproductively successful male was, on average, almost three times as successful as the next most successful and additional males only occasionally sired offspring. In contrast, cobreeding females shared parentage equally. Helpers never bred incestuously when their opposite-sex parent (or another relative, such as their uncle) held breeding status in the group. However, during breeding male vacancies, 14 nestlings were produced when helper males bred incestuously with their mother. Both male and female helpers usually became successful cobreeders with their same-sex parent following replacement of the opposite-sex breeder(s) by unrelated individuals.

  5. An externally brooding acorn worm (Hemichordata, Enteropneusta, Torquaratoridae) from the Russian arctic.

    PubMed

    Osborn, Karen J; Gebruk, Andrey V; Rogacheva, Antonina; Holland, Nicholas D

    2013-10-01

    A single specimen of a previously undescribed acorn worm in the family Torquaratoridae was trawled from a bottom depth of about 350 m in the Kara Sea (Russian Arctic). The new species is the shallowest of the exclusively deep-sea torquaratorids found to date, possibly an example of high-latitude emergence. On the basis of ribosomal DNA sequences and morphology, the worm is described here as the holotype of Coleodesmium karaensis n. gen., n. sp. It is most similar in overall body shape to the previously described enteropneust genus Allapasus, but is uniquely characterized by a tubular component of the proboscis skeleton ensheathing the collar nerve cord. Additionally, within the proboscis, the sparseness of the musculature of C. karaensis clearly distinguishes it from the much more muscular members of Allapasus. The holotype is a female bearing about a dozen embryos on the surface of her pharyngeal region, each recessed within a shallow depression in the dorsal epidermis. The embryos, ranging from late gastrula to an early stage of coelom formation, are a little more than 1 mm in diameter and surrounded by a thin membrane. Each embryo comprises an external ectoderm of monociliated cells (not arranged in obvious ciliated bands) and an internal endo-mesoderm; the blastopore is closed. In the most advanced embryos, the anterior coelom is starting to constrict off from the archenteron. Coleodesmium karaensis is the first enteropneust (and indeed the first hemichordate) found brooding embryos on the surface of the mother's body.

  6. Transformation of signals by interneurones in the barnacle's visual pathway

    PubMed Central

    Oertel, Donata; Stuart, Ann E.

    1981-01-01

    1. The photoreceptors of the median eye of the giant barnacle drive decrementally-conducting neurones in the supraoesophageal ganglion termed `inverting cells' (I-cells) which in turn drive impulse-producing neurones termed `amplifying cells' (A-cells). Using intracellular recording techniques we have studied the role of I-cells in visual processing. 2. Horseradish peroxidase injections show that I-cells are interneurones whose processes are confined to the regions of the photoreceptor terminals on both sides of the bilaterally symmetrical ganglion. 3. In the dark, I-cell membrane potentials (-45 mV) are considerably less negative than those of other ganglion cells (-60 to -70 mV). At the onset of a maintained light, I-cells undergo a transient peak hyperpolarization which declines to a steady-state response. Both response components are graded with light intensity. 4. The reversal potential of the peak of the I-cell light response depends on the external K+ concentration more strongly than does the dark resting potential (3-30 mm-K+). This evidence indicates that the hyperpolarization results from an increase in the cell's permeability to K+ ions. 5. At the offset of light an I-cell undergoes a transient depolarization that overshoots the dark membrane potential. Dimming of a background light can also cause the I-cell membrane potential to overshoot its dark resting value. This overshoot is associated with a large depolarizing synaptic potential in A-cells. 6. An overshoot of the dark resting potential can also be elicited by the break of a hyperpolarizing pulse of current injected into an I-cell. The amplitude of this overshoot increases with pulse duration over a time course of seconds. 7. In the presence of external tetraethylammonium ion (TEA) and tetrodotoxin, (TTX), the break of a hyperpolarizing pulse or the onset of a depolarizing pulse can evoke in an I-cell an action potential whose rate of rise and amplitude depend on the external Ca concentration. This

  7. Synergistic roles for lipids and proteins in the permanent adhesive of barnacle larvae.

    PubMed

    Gohad, Neeraj V; Aldred, Nick; Hartshorn, Christopher M; Jong Lee, Young; Cicerone, Marcus T; Orihuela, Beatriz; Clare, Anthony S; Rittschof, Dan; Mount, Andrew S

    2014-07-11

    Thoracian barnacles rely heavily upon their ability to adhere to surfaces and are environmentally and economically important as biofouling pests. Their adhesives have unique attributes that define them as targets for bio-inspired adhesive development. With the aid of multi-photon and broadband coherent anti-Stokes Raman scattering microscopies, we report that the larval adhesive of barnacle cyprids is a bi-phasic system containing lipids and phosphoproteins, working synergistically to maximize adhesion to diverse surfaces under hostile conditions. Lipids, secreted first, possibly displace water from the surface interface creating a conducive environment for introduction of phosphoproteins while simultaneously modulating the spreading of the protein phase and protecting the nascent adhesive plaque from bacterial biodegradation. The two distinct phases are contained within two different granules in the cyprid cement glands, implying far greater complexity than previously recognized. Knowledge of the lipidic contribution will hopefully inspire development of novel synthetic bioadhesives and environmentally benign antifouling coatings.

  8. New alien barnacles in the Azores and some remarks on the invasive potential of Balanidae

    NASA Astrophysics Data System (ADS)

    Torres, Paulo; Costa, Ana Cristina; Dionísio, Maria Ana

    2012-12-01

    Global homogenization of biota is underway through worldwide introduction and establishment of non-indigenous (exotic) species. Organisms fouling ship hulls are continually in transit and can affect communities through biodiversity loss and serious damage to economy and public health. In the Azores, for the first time, underwater alien species prospection was conducted in marinas and recreational harbours, at São Miguel Island. Populations of three locally previously unknown barnacle species were found: Amphibalanus amphitrite, Amphibalanus eburneus and Perforatus perforatus. These species account for the more than 50% of alien barnacles worldwide that belong to Balanidae family. Hence, some considerations about morphology and life cycle of this family are advanced, discussed and related to their invasive potential.

  9. Role of tannin-binding salivary proteins and tannase-producing bacteria in the acclimation of the Japanese wood mouse to acorn tannins.

    PubMed

    Shimada, Takuya; Saitoh, Takashi; Sasaki, Eiki; Nishitani, Yosuke; Osawa, Ro

    2006-06-01

    We studied the defense mechanisms against the negative effects of tannins in acorns by using the Japanese wood mouse (Apodemus speciosus) and acorns of a Japanese deciduous oak Quercus crispula, which contain 9.9% tannins on a dry weight basis. For the experiment, we allocated 26 wood mice into two groups: acclimated (N = 12) and nonacclimated (N = 14). Mice in the nonacclimated group were fed only acorns for 10 d after 4 wk of receiving a tannin-free diet. In contrast, mice in the acclimated group received ca. 3 g acorns daily in addition to the tannin-free diet for the first 4 wk, then they were fed only acorns for 10 d. Body weight, food intake, and digestibility were monitored. In addition, the amount of salivary proline-rich proteins (PRPs) and abundance of tannase-producing bacteria (TPB) in the feces of mice were measured. Of the 14 mice in the nonacclimated group, 8 died, whereas only 1 of the 12 in the acclimated group died. During the first 5 d of feeding acorns only, mice in the nonacclimated group lost, on average, 17.5% of their body mass, while those in the acclimated group lost only 2.5%. Food intake, dry matter digestibility, and nitrogen digestibility were higher in the acclimated group than in the nonacclimated group. The results indicate that wood mice can mitigate the negative effects of tannins by acclimation. Path analysis revealed that increased secretion of PRPs and abundance of Lactobacillus type of TPB might explain the acclimation to tannins.

  10. The effect of boldness on decision-making in barnacle geese is group-size-dependent.

    PubMed

    Kurvers, Ralf H J M; Adamczyk, Vena M A P; van Wieren, Sipke E; Prins, Herbert H T

    2011-07-01

    In group-living species, decisions made by individuals may result in collective behaviours. A central question in understanding collective behaviours is how individual variation in phenotype affects collective behaviours. However, how the personality of individuals affects collective decisions in groups remains poorly understood. Here, we investigated the role of boldness on the decision-making process in different-sized groups of barnacle geese. Naive barnacle geese, differing in boldness score, were introduced in a labyrinth in groups with either one or three informed demonstrators. The demonstrators possessed information about the route through the labyrinth. In pairs, the probability of choosing a route prior to the informed demonstrator increased with increasing boldness score: bolder individuals decided more often for themselves where to go compared with shyer individuals, whereas shyer individuals waited more often for the demonstrators to decide and followed this information. In groups of four individuals, however, there was no effect of boldness on decision-making, suggesting that individual differences were less important with increasing group size. Our experimental results show that personality is important in collective decisions in pairs of barnacle geese, and suggest that bolder individuals have a greater influence over the outcome of decisions in groups.

  11. The origins and evolution of dwarf males and habitat use in thoracican barnacles.

    PubMed

    Lin, Hsiu-Chin; Høeg, Jens T; Yusa, Yoichi; Chan, Benny K K

    2015-10-01

    Barnacles are exceptional in having various sexual systems (androdioecy, hermaphroditism, dioecy) and with a high morphological diversity of males, though these are always minute (dwarf) compared to their female or hermaphrodite partners. For the first time, we use a multiple DNA marker-based phylogeny to elucidate the ancestral states and evolution of (1) dwarf males, (2) their morphology when present, (3) their attachment site on the partner, and (4) habitat use in thoracican barnacles. Our taxon sampling was especially rich in rare deep-sea Scalpelliformes and comprised species with diverse sexual systems and dwarf male morphologies. Within the thoracican barnacles dwarf male evolution is subject to extensive convergence, but always correlated to similar ecological conditions. Males evolved convergently at least four times from purely hermaphroditic ancestors, in each case correlated with the invasion into habitats with low mating group sizes. The independent evolution of dwarf males in these lineages dovetails with the males having different morphologies and occurring in several different locations on their sexual partner.

  12. Ecology and Evolution of Phenotypic Plasticity in the Penis and Cirri of Barnacles.

    PubMed

    Hoch, J Matthew; Schneck, Daniel T; Neufeld, Christopher J

    2016-10-01

    Most barnacles are sessile, simultaneous hermaphrodites that reproduce by copulation. This is achieved through the extension of a muscular penis, famous for being the proportionally largest in the animal kingdom. The penis is a long cylindrical or conical organ, composed of a series of folded rings, allowing it to stretch to great lengths. The penises are covered with chemosensory setae allowing them to seek out receptive neighbors. For many species, the condition of the penis changes seasonally. In the most extreme circumstances, it degenerates and is shed during the first post-mating molt and is re-grown for the next mating season. Barnacle penises have been shown to exhibit phenotypic plasticity in response to many different challenges. When exposed to heavy waves, diameter is increased by thickening both the cuticle and muscles. When mates are far, length increases by adding ringed annulations. Experiments have shown that these plastic traits are modular, capable of changing independently from each other and that they improve mating ability. Alternate strategies to increase reproductive ability by barnacles include the production of dwarf and complemental males, sperm casting and sperm leakage, and aerial copulation. All of these mating strategies may have important implications for the study of reproductive biology, life history, and sex allocation theory.

  13. Quantitative proteomics study of larval settlement in the Barnacle Balanus amphitrite.

    PubMed

    Chen, Zhang-Fan; Zhang, Huoming; Wang, Hao; Matsumura, Kiyotaka; Wong, Yue Him; Ravasi, Timothy; Qian, Pei-Yuan

    2014-01-01

    Barnacles are major sessile components of the intertidal areas worldwide, and also one of the most dominant fouling organisms in fouling communities. Larval settlement has a crucial ecological effect not only on the distribution of the barnacle population but also intertidal community structures. However, the molecular mechanisms involved in the transition process from the larval to the juvenile stage remain largely unclear. In this study, we carried out comparative proteomic profiles of stage II nauplii, stage VI nauplii, cyprids, and juveniles of the barnacle Balanus amphitrite using label-free quantitative proteomics, followed by the measurement of the gene expression levels of candidate proteins. More than 700 proteins were identified at each stage; 80 were significantly up-regulated in cyprids and 95 in juveniles vs other stages. Specifically, proteins involved in energy and metabolism, the nervous system and signal transduction were significantly up-regulated in cyprids, whereas proteins involved in cytoskeletal remodeling, transcription and translation, cell proliferation and differentiation, and biomineralization were up-regulated in juveniles, consistent with changes associated with larval metamorphosis and tissue remodeling in juveniles. These findings provided molecular evidence for the morphological, physiological and biological changes that occur during the transition process from the larval to the juvenile stages in B. amphitrite.

  14. Bivalve and barnacle larvae distribution driven by water temperature in a Mediterranean lagoon.

    PubMed

    Ziadi, Boutheina; Dhib, Amel; Turki, Souad; Aleya, Lotfi

    2015-05-01

    The objective of this study was to explore the relationships between the distribution of some meroplanktonic species and water temperature. Meroplankton larvae abundance of bivalves, and barnacles and water temperature fluctuations were studied from February 2011 to January 2012 at five stations in Ghar El Melh lagoon (GML) Mediterranean Sea, northern Tunisia). According to redundancy analysis (RDA), a significant difference was found in the distribution of larvae among the seasons (F = 10.28, p < 0.001); summer and autumn appear to be the period of bivalve larvae development, whereas the arrival of barnacle larvae coincided with winter and spring. The generalized additive models (GAMs) show strong correlation of bivalve larvae with high temperature (F = 23.2; p < 0.001) and the affinity of barnacle larvae to low temperature values (F = 8.41; p = 0.004). This environmental parameter accounted for 26 % of the deviance in variability in larvae abundance. The development process of many generations of larvae may therefore have been predetermined by temperature.

  15. Quantitative Proteomics Study of Larval Settlement in the Barnacle Balanus amphitrite

    PubMed Central

    Wang, Hao; Matsumura, Kiyotaka; Wong, Yue Him; Ravasi, Timothy; Qian, Pei-Yuan

    2014-01-01

    Barnacles are major sessile components of the intertidal areas worldwide, and also one of the most dominant fouling organisms in fouling communities. Larval settlement has a crucial ecological effect not only on the distribution of the barnacle population but also intertidal community structures. However, the molecular mechanisms involved in the transition process from the larval to the juvenile stage remain largely unclear. In this study, we carried out comparative proteomic profiles of stage II nauplii, stage VI nauplii, cyprids, and juveniles of the barnacle Balanus amphitrite using label-free quantitative proteomics, followed by the measurement of the gene expression levels of candidate proteins. More than 700 proteins were identified at each stage; 80 were significantly up-regulated in cyprids and 95 in juveniles vs other stages. Specifically, proteins involved in energy and metabolism, the nervous system and signal transduction were significantly up-regulated in cyprids, whereas proteins involved in cytoskeletal remodeling, transcription and translation, cell proliferation and differentiation, and biomineralization were up-regulated in juveniles, consistent with changes associated with larval metamorphosis and tissue remodeling in juveniles. These findings provided molecular evidence for the morphological, physiological and biological changes that occur during the transition process from the larval to the juvenile stages in B. amphitrite. PMID:24551147

  16. The origins and evolution of dwarf males and habitat use in thoracican barnacles.

    PubMed

    Lin, Hsiu-Chin; Høeg, Jens T; Yusa, Yoichi; Chan, Benny K K

    2015-10-01

    Barnacles are exceptional in having various sexual systems (androdioecy, hermaphroditism, dioecy) and with a high morphological diversity of males, though these are always minute (dwarf) compared to their female or hermaphrodite partners. For the first time, we use a multiple DNA marker-based phylogeny to elucidate the ancestral states and evolution of (1) dwarf males, (2) their morphology when present, (3) their attachment site on the partner, and (4) habitat use in thoracican barnacles. Our taxon sampling was especially rich in rare deep-sea Scalpelliformes and comprised species with diverse sexual systems and dwarf male morphologies. Within the thoracican barnacles dwarf male evolution is subject to extensive convergence, but always correlated to similar ecological conditions. Males evolved convergently at least four times from purely hermaphroditic ancestors, in each case correlated with the invasion into habitats with low mating group sizes. The independent evolution of dwarf males in these lineages dovetails with the males having different morphologies and occurring in several different locations on their sexual partner. PMID:25979758

  17. Biochemical analyses of the cement float of the goose barnacle Dosima fascicularis--a preliminary study.

    PubMed

    Zheden, Vanessa; Klepal, Waltraud; von Byern, Janek; Bogner, Fabian Robert; Thiel, Karsten; Kowalik, Thomas; Grunwald, Ingo

    2014-09-01

    The goose barnacle Dosima fascicularis produces an excessive amount of adhesive (cement), which has a double function, being used for attachment to various substrata and also as a float (buoy). This paper focuses on the chemical composition of the cement, which has a water content of 92%. Scanning electron microscopy with EDX was used to measure the organic elements C, O and N in the foam-like cement. Vibrational spectroscopy (FTIR, Raman) provided further information about the overall secondary structure, which tended towards a β-sheet. Disulphide bonds could not be detected by Raman spectroscopy. The cystine, methionine, histidine and tryptophan contents were each below 1% in the cement. Analyses of the cement revealed a protein content of 84% and a total carbohydrate content of 1.5% in the dry cement. The amino acid composition, 1D/2D-PAGE and MS/MS sequence analysis revealed a de novo set of peptides/proteins with low homologies with other proteins such as the barnacle cement proteins, largely with an acidic pI between 3.5 and 6.0. The biochemical composition of the cement of D. fascicularis is similar to that of other barnacles, but it shows interesting variations. PMID:25237772

  18. Harvest locations of goose barnacles can be successfully discriminated using trace elemental signatures.

    PubMed

    Albuquerque, Rui; Queiroga, Henrique; Swearer, Stephen E; Calado, Ricardo; Leandro, Sérgio M

    2016-01-01

    European Union regulations state that consumers must be rightfully informed about the provenance of fishery products to prevent fraudulent practices. However, mislabeling of the geographical origin is a common practice. It is therefore paramount to develop forensic methods that allow all players involved in the supply chain to accurately trace the origin of seafood. In this study, trace elemental signatures (TES) of the goose barnacle Pollicipes pollicipes, collected from ten sites along the Portuguese coast, were employed to discriminate individual's origin. Barium (Ba), boron (B), cadmium (Cd), chromium (Cr), lithium (Li), magnesium (Mg), manganese (Mn), phosphorous (P), lead (Pb), strontium (Sr) and zinc (Zn) - were quantified using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Significant differences were recorded among locations for all elements. A regularized discriminant analysis (RDA) revealed that 83% of all individuals were correctly assigned. This study shows TES can be a reliable tool to confirm the geographic origin of goose barnacles at fine spatial resolution. Although additional studies are required to ascertain the reliability of TES on cooked specimens and the temporal stability of the signature, the approach holds great promise for the management of goose barnacles fisheries, enforcement of conservation policies and assurance in accurate labeling. PMID:27292413

  19. Biochemical analyses of the cement float of the goose barnacle Dosima fascicularis--a preliminary study.

    PubMed

    Zheden, Vanessa; Klepal, Waltraud; von Byern, Janek; Bogner, Fabian Robert; Thiel, Karsten; Kowalik, Thomas; Grunwald, Ingo

    2014-09-01

    The goose barnacle Dosima fascicularis produces an excessive amount of adhesive (cement), which has a double function, being used for attachment to various substrata and also as a float (buoy). This paper focuses on the chemical composition of the cement, which has a water content of 92%. Scanning electron microscopy with EDX was used to measure the organic elements C, O and N in the foam-like cement. Vibrational spectroscopy (FTIR, Raman) provided further information about the overall secondary structure, which tended towards a β-sheet. Disulphide bonds could not be detected by Raman spectroscopy. The cystine, methionine, histidine and tryptophan contents were each below 1% in the cement. Analyses of the cement revealed a protein content of 84% and a total carbohydrate content of 1.5% in the dry cement. The amino acid composition, 1D/2D-PAGE and MS/MS sequence analysis revealed a de novo set of peptides/proteins with low homologies with other proteins such as the barnacle cement proteins, largely with an acidic pI between 3.5 and 6.0. The biochemical composition of the cement of D. fascicularis is similar to that of other barnacles, but it shows interesting variations.

  20. Harvest locations of goose barnacles can be successfully discriminated using trace elemental signatures.

    PubMed

    Albuquerque, Rui; Queiroga, Henrique; Swearer, Stephen E; Calado, Ricardo; Leandro, Sérgio M

    2016-06-13

    European Union regulations state that consumers must be rightfully informed about the provenance of fishery products to prevent fraudulent practices. However, mislabeling of the geographical origin is a common practice. It is therefore paramount to develop forensic methods that allow all players involved in the supply chain to accurately trace the origin of seafood. In this study, trace elemental signatures (TES) of the goose barnacle Pollicipes pollicipes, collected from ten sites along the Portuguese coast, were employed to discriminate individual's origin. Barium (Ba), boron (B), cadmium (Cd), chromium (Cr), lithium (Li), magnesium (Mg), manganese (Mn), phosphorous (P), lead (Pb), strontium (Sr) and zinc (Zn) - were quantified using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Significant differences were recorded among locations for all elements. A regularized discriminant analysis (RDA) revealed that 83% of all individuals were correctly assigned. This study shows TES can be a reliable tool to confirm the geographic origin of goose barnacles at fine spatial resolution. Although additional studies are required to ascertain the reliability of TES on cooked specimens and the temporal stability of the signature, the approach holds great promise for the management of goose barnacles fisheries, enforcement of conservation policies and assurance in accurate labeling.

  1. Harvest locations of goose barnacles can be successfully discriminated using trace elemental signatures

    PubMed Central

    Albuquerque, Rui; Queiroga, Henrique; Swearer, Stephen E.; Calado, Ricardo; Leandro, Sérgio M.

    2016-01-01

    European Union regulations state that consumers must be rightfully informed about the provenance of fishery products to prevent fraudulent practices. However, mislabeling of the geographical origin is a common practice. It is therefore paramount to develop forensic methods that allow all players involved in the supply chain to accurately trace the origin of seafood. In this study, trace elemental signatures (TES) of the goose barnacle Pollicipes pollicipes, collected from ten sites along the Portuguese coast, were employed to discriminate individual’s origin. Barium (Ba), boron (B), cadmium (Cd), chromium (Cr), lithium (Li), magnesium (Mg), manganese (Mn), phosphorous (P), lead (Pb), strontium (Sr) and zinc (Zn) - were quantified using Inductively Coupled Plasma−Mass Spectrometry (ICP-MS). Significant differences were recorded among locations for all elements. A regularized discriminant analysis (RDA) revealed that 83% of all individuals were correctly assigned. This study shows TES can be a reliable tool to confirm the geographic origin of goose barnacles at fine spatial resolution. Although additional studies are required to ascertain the reliability of TES on cooked specimens and the temporal stability of the signature, the approach holds great promise for the management of goose barnacles fisheries, enforcement of conservation policies and assurance in accurate labeling. PMID:27292413

  2. Compounds from Silicones Alter Enzyme Activity in Curing Barnacle Glue and Model Enzymes

    PubMed Central

    Rittschof, Daniel; Orihuela, Beatriz; Harder, Tilmann; Stafslien, Shane; Chisholm, Bret; Dickinson, Gary H.

    2011-01-01

    Background Attachment strength of fouling organisms on silicone coatings is low. We hypothesized that low attachment strength on silicones is, in part, due to the interaction of surface available components with natural glues. Components could alter curing of glues through bulk changes or specifically through altered enzyme activity. Methodology/Principal Findings GC-MS analysis of silicone coatings showed surface-available siloxanes when the coatings were gently rubbed with a cotton swab for 15 seconds or given a 30 second rinse with methanol. Mixtures of compounds were found on 2 commercial and 8 model silicone coatings. The hypothesis that silicone components alter glue curing enzymes was tested with curing barnacle glue and with commercial enzymes. In our model, barnacle glue curing involves trypsin-like serine protease(s), which activate enzymes and structural proteins, and a transglutaminase which cross-links glue proteins. Transglutaminase activity was significantly altered upon exposure of curing glue from individual barnacles to silicone eluates. Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents. Conclusions/Significance Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties. Altered curing of natural glues has potential in fouling management. PMID:21379573

  3. The Interplay among Acorn Abundance and Rodent Behavior Drives the Spatial Pattern of Seedling Recruitment in Mature Mediterranean Oak Forests.

    PubMed

    Sunyer, Pau; Boixadera, Ester; Muñoz, Alberto; Bonal, Raúl; Espelta, Josep Maria

    2015-01-01

    The patterns of seedling recruitment in animal-dispersed plants result from the interactions among environmental and behavioral variables. However, we know little on the contribution and combined effect of both kinds of variables. We designed a field study to assess the interplay between environment (vegetation structure, seed abundance, rodent abundance) and behavior (seed dispersal and predation by rodents, and rooting by wild boars), and their contribution to the spatial patterns of seedling recruitment in a Mediterranean mixed-oak forest. In a spatially explicit design, we monitored intensively all environmental and behavioral variables in fixed points at a small spatial scale from autumn to spring, as well as seedling emergence and survival. Our results revealed that the spatial patterns of seedling emergence were strongly related to acorn availability on the ground, but not by a facilitation effect of vegetation cover. Rodents changed seed shadows generated by mother trees by dispersing most seeds from shrubby to open areas, but the spatial patterns of acorn dispersal/predation had no direct effect on recruitment. By contrast, rodents had a strong impact on recruitment as pilferers of cached seeds. Rooting by wild boars also reduced recruitment by reducing seed abundance, but also by changing rodent's behavior towards higher consumption of acorns in situ. Hence, seed abundance and the foraging behavior of scatter-hoarding rodents and wild boars are driving the spatial patterns of seedling recruitment in this mature oak forest, rather than vegetation features. The contribution of vegetation to seedling recruitment (e.g. facilitation by shrubs) may be context dependent, having a little role in closed forests, or being overridden by directed seed dispersal from shrubby to open areas. We warn about the need of using broad approaches that consider the combined action of environment and behavior to improve our knowledge on the dynamics of natural regeneration in

  4. The Interplay among Acorn Abundance and Rodent Behavior Drives the Spatial Pattern of Seedling Recruitment in Mature Mediterranean Oak Forests

    PubMed Central

    Boixadera, Ester; Bonal, Raúl

    2015-01-01

    The patterns of seedling recruitment in animal-dispersed plants result from the interactions among environmental and behavioral variables. However, we know little on the contribution and combined effect of both kinds of variables. We designed a field study to assess the interplay between environment (vegetation structure, seed abundance, rodent abundance) and behavior (seed dispersal and predation by rodents, and rooting by wild boars), and their contribution to the spatial patterns of seedling recruitment in a Mediterranean mixed-oak forest. In a spatially explicit design, we monitored intensively all environmental and behavioral variables in fixed points at a small spatial scale from autumn to spring, as well as seedling emergence and survival. Our results revealed that the spatial patterns of seedling emergence were strongly related to acorn availability on the ground, but not by a facilitationeffect of vegetation cover. Rodents changed seed shadows generated by mother trees by dispersing most seeds from shrubby to open areas, but the spatial patterns of acorn dispersal/predation had no direct effect on recruitment. By contrast, rodents had a strong impact on recruitment as pilferers of cached seeds. Rooting by wild boars also reduced recruitment by reducing seed abundance, but also by changing rodent’s behavior towards higher consumption of acorns in situ. Hence, seed abundance and the foraging behavior of scatter-hoarding rodents and wild boars are driving the spatial patterns of seedling recruitment in this mature oak forest, rather than vegetation features. The contribution of vegetation to seedling recruitment (e.g. facilitation by shrubs) may be context dependent, having a little role in closed forests, or being overridden by directed seed dispersal from shrubby to open areas. We warn about the need of using broad approaches that consider the combined action of environment and behavior to improve our knowledge on the dynamics of natural regeneration in

  5. Transcriptomic analysis of neuropeptides and peptide hormones in the barnacle Balanus amphitrite: evidence of roles in larval settlement.

    PubMed

    Yan, Xing-Cheng; Chen, Zhang-Fan; Sun, Jin; Matsumura, Kiyotaka; Wu, Rudolf S S; Qian, Pei-Yuan

    2012-01-01

    The barnacle Balanus amphitrite is a globally distributed marine crustacean and has been used as a model species for intertidal ecology and biofouling studies. Its life cycle consists of seven planktonic larval stages followed by a sessile juvenile/adult stage. The transitional processes between larval stages and juveniles are crucial for barnacle development and recruitment. Although some studies have been conducted on the neuroanatomy and neuroactive substances of the barnacle, a comprehensive understanding of neuropeptides and peptide hormones remains lacking. To better characterize barnacle neuropeptidome and its potential roles in larval settlement, an in silico identification of putative transcripts encoding neuropeptides/peptide hormones was performed, based on transcriptome of the barnacle B. amphitrite that has been recently sequenced. Potential cleavage sites andstructure of mature peptides were predicted through homology search of known arthropod peptides. In total, 16 neuropeptide families/subfamilies were predicted from the barnacle transcriptome, and 14 of them were confirmed as genuine neuropeptides by Rapid Amplification of cDNA Ends. Analysis of peptide precursor structures and mature sequences showed that some neuropeptides of B. amphitrite are novel isoforms and shared similar characteristics with their homologs from insects. The expression profiling of predicted neuropeptide genes revealed that pigment dispersing hormone, SIFamide, calcitonin, and B-type allatostatin had the highest expression level in cypris stage, while tachykinin-related peptide was down regulated in both cyprids and juveniles. Furthermore, an inhibitor of proprotein convertase related to peptide maturation effectively delayed larval metamorphosis. Combination of real-time PCR results and bioassay indicated that certain neuropeptides may play an important role in cypris settlement. Overall, new insight into neuropeptides/peptide hormones characterized in this study shall

  6. Transcriptomic Analysis of Neuropeptides and Peptide Hormones in the Barnacle Balanus amphitrite: Evidence of Roles in Larval Settlement

    PubMed Central

    Yan, Xing-Cheng; Chen, Zhang-Fan; Sun, Jin; Matsumura, Kiyotaka; Wu, Rudolf S. S.; Qian, Pei-Yuan

    2012-01-01

    The barnacle Balanus amphitrite is a globally distributed marine crustacean and has been used as a model species for intertidal ecology and biofouling studies. Its life cycle consists of seven planktonic larval stages followed by a sessile juvenile/adult stage. The transitional processes between larval stages and juveniles are crucial for barnacle development and recruitment. Although some studies have been conducted on the neuroanatomy and neuroactive substances of the barnacle, a comprehensive understanding of neuropeptides and peptide hormones remains lacking. To better characterize barnacle neuropeptidome and its potential roles in larval settlement, an in silico identification of putative transcripts encoding neuropeptides/peptide hormones was performed, based on transcriptome of the barnacle B. amphitrite that has been recently sequenced. Potential cleavage sites andstructure of mature peptides were predicted through homology search of known arthropod peptides. In total, 16 neuropeptide families/subfamilies were predicted from the barnacle transcriptome, and 14 of them were confirmed as genuine neuropeptides by Rapid Amplification of cDNA Ends. Analysis of peptide precursor structures and mature sequences showed that some neuropeptides of B. amphitrite are novel isoforms and shared similar characteristics with their homologs from insects. The expression profiling of predicted neuropeptide genes revealed that pigment dispersing hormone, SIFamide, calcitonin, and B-type allatostatin had the highest expression level in cypris stage, while tachykinin-related peptide was down regulated in both cyprids and juveniles. Furthermore, an inhibitor of proprotein convertase related to peptide maturation effectively delayed larval metamorphosis. Combination of real-time PCR results and bioassay indicated that certain neuropeptides may play an important role in cypris settlement. Overall, new insight into neuropeptides/peptide hormones characterized in this study shall

  7. An anatomical description of a miniaturized acorn worm (hemichordata, enteropneusta) with asexual reproduction by paratomy.

    PubMed

    Worsaae, Katrine; Sterrer, Wolfgang; Kaul-Strehlow, Sabrina; Hay-Schmidt, Anders; Giribet, Gonzalo

    2012-01-01

    The interstitial environment of marine sandy bottoms is a nutrient-rich, sheltered habitat whilst at the same time also often a turbulent, space-limited, and ecologically challenging environment dominated by meiofauna. The interstitial fauna is one of the most diverse on earth and accommodates miniaturized representatives from many macrofaunal groups as well as several exclusively meiofaunal phyla. The colonization process of this environment, with the restrictions imposed by limited space and low Reynolds numbers, has selected for great morphological and behavioral changes as well as new life history strategies.Here we describe a new enteropneust species inhabiting the interstices among sand grains in shallow tropical waters of the West Atlantic. With a maximum body length of 0.6 mm, it is the first microscopic adult enteropneust known, a group otherwise ranging from 2 cm to 250 cm in adult size. Asexual reproduction by paratomy has been observed in this new species, a reproductive mode not previously reported among enteropneusts. Morphologically, Meioglossus psammophilus gen. et sp. nov. shows closest resemblance to an early juvenile stage of the acorn worm family Harrimaniidae, a result congruent with its phylogenetic placement based on molecular data. Its position, clearly nested within the larger macrofaunal hemichordates, suggests that this represents an extreme case of miniaturization. The evolutionary pathway to this simple or juvenile appearance, as chiefly demonstrated by its small size, dense ciliation, and single pair of gill pores, may be explained by progenesis. The finding of M. psammophilus gen. et sp. nov. underscores the notion that meiofauna may constitute a rich source of undiscovered metazoan diversity, possibly disguised as juveniles of other species. PMID:23144898

  8. An Anatomical Description of a Miniaturized Acorn Worm (Hemichordata, Enteropneusta) with Asexual Reproduction by Paratomy

    PubMed Central

    Worsaae, Katrine; Sterrer, Wolfgang; Kaul-Strehlow, Sabrina; Hay-Schmidt, Anders; Giribet, Gonzalo

    2012-01-01

    The interstitial environment of marine sandy bottoms is a nutrient-rich, sheltered habitat whilst at the same time also often a turbulent, space-limited, and ecologically challenging environment dominated by meiofauna. The interstitial fauna is one of the most diverse on earth and accommodates miniaturized representatives from many macrofaunal groups as well as several exclusively meiofaunal phyla. The colonization process of this environment, with the restrictions imposed by limited space and low Reynolds numbers, has selected for great morphological and behavioral changes as well as new life history strategies. Here we describe a new enteropneust species inhabiting the interstices among sand grains in shallow tropical waters of the West Atlantic. With a maximum body length of 0.6 mm, it is the first microscopic adult enteropneust known, a group otherwise ranging from 2 cm to 250 cm in adult size. Asexual reproduction by paratomy has been observed in this new species, a reproductive mode not previously reported among enteropneusts. Morphologically, Meioglossus psammophilus gen. et sp. nov. shows closest resemblance to an early juvenile stage of the acorn worm family Harrimaniidae, a result congruent with its phylogenetic placement based on molecular data. Its position, clearly nested within the larger macrofaunal hemichordates, suggests that this represents an extreme case of miniaturization. The evolutionary pathway to this simple or juvenile appearance, as chiefly demonstrated by its small size, dense ciliation, and single pair of gill pores, may be explained by progenesis. The finding of M. psammophilus gen. et sp. nov. underscores the notion that meiofauna may constitute a rich source of undiscovered metazoan diversity, possibly disguised as juveniles of other species. PMID:23144898

  9. An anatomical description of a miniaturized acorn worm (hemichordata, enteropneusta) with asexual reproduction by paratomy.

    PubMed

    Worsaae, Katrine; Sterrer, Wolfgang; Kaul-Strehlow, Sabrina; Hay-Schmidt, Anders; Giribet, Gonzalo

    2012-01-01

    The interstitial environment of marine sandy bottoms is a nutrient-rich, sheltered habitat whilst at the same time also often a turbulent, space-limited, and ecologically challenging environment dominated by meiofauna. The interstitial fauna is one of the most diverse on earth and accommodates miniaturized representatives from many macrofaunal groups as well as several exclusively meiofaunal phyla. The colonization process of this environment, with the restrictions imposed by limited space and low Reynolds numbers, has selected for great morphological and behavioral changes as well as new life history strategies.Here we describe a new enteropneust species inhabiting the interstices among sand grains in shallow tropical waters of the West Atlantic. With a maximum body length of 0.6 mm, it is the first microscopic adult enteropneust known, a group otherwise ranging from 2 cm to 250 cm in adult size. Asexual reproduction by paratomy has been observed in this new species, a reproductive mode not previously reported among enteropneusts. Morphologically, Meioglossus psammophilus gen. et sp. nov. shows closest resemblance to an early juvenile stage of the acorn worm family Harrimaniidae, a result congruent with its phylogenetic placement based on molecular data. Its position, clearly nested within the larger macrofaunal hemichordates, suggests that this represents an extreme case of miniaturization. The evolutionary pathway to this simple or juvenile appearance, as chiefly demonstrated by its small size, dense ciliation, and single pair of gill pores, may be explained by progenesis. The finding of M. psammophilus gen. et sp. nov. underscores the notion that meiofauna may constitute a rich source of undiscovered metazoan diversity, possibly disguised as juveniles of other species.

  10. Hoarding decisions by Edward's long-tailed rats (Leopoldamys edwardsi) and South China field mice (Apodemus draco): the responses to seed size and germination schedule in acorns.

    PubMed

    Chang, Gang; Xiao, Zhishu; Zhang, Zhibin

    2009-09-01

    Co-varying traits in acorns such as seed size and germination schedule are important to influence the behavioural decisions of hoarding rodents. Using acorn pairs from cork oak (Quercus variabilis) (large size and short germination schedules) serrate oak (Q. serrata) (small size and short germination schedule) and qinggang (Cyclobalanopsis glauca) (small size and long germination schedule) with contrasting seed size and germination schedule, we conducted a series of experiments to investigate hoarding preferences in response to seed size and germination schedule by Edward's long-tailed rats (Leopoldamys edwardsi) and South China field mice (Apodemus draco) in semi-natural enclosures. We found that the seed size hypothesis was consistently supported: both rodent species ate more small acorns but hoarded more large ones regardless of germination schedules. However, the germination schedule hypothesis was also supported when similar sized acorns were simultaneously provided, e.g. Q. serrata versus C. glauca or germinating versus non-germinating Q. variabilis. Our results, contrary to the studies from North America, indicate that seed size is more important than germination schedules in determining whether the tested animals eat or hoard a given seed.

  11. Amyloid-like conformation and interaction for the self-assembly in barnacle underwater cement.

    PubMed

    Nakano, Masahiro; Kamino, Kei

    2015-01-27

    Barnacles are unique marine sessile crustaceans and permanently attach to various foreign surfaces during most of their lifespan. The protein complex secreted from their body and used to attach their calcareous shell to almost all surfaces in water has long fascinated us because we have limited technology with which to attach materials in water. Unraveling the mechanism of underwater attachment by barnacles is thus important for interface science, for the understanding of the biology and physiology of barnacles, and for the development of technology to prevent fouling. Previous studies have indicated that the intermolecular interactions optimized by conformations of the adhesive proteins are crucial in the self-assembly and/or curing of the adhesive. This study aimed to identify the possible structural determinants responsible for the self-assembly. Thioflavin T binding screening of peptides designed on the basis of the primary structure of a bulk 52 kDa cement protein indicated the presence of some amyloidogenic motifs in the protein. The conformation of the peptide was transformed to a β-sheet by an increase in either pH or ionic strength, resulting in its self-assembly. Thioflavin T binding was inhibited by small polyphenolic molecules, suggesting the contribution of aromatic interactions during self-assembly. The occurrence of amyloid-like units in the protein implies that the protein conformation is an important factor contributing to the self-assembly of the cement, the first event of the curing, as the adhesive material is secreted into the seawater out of the animal's body.

  12. Instantaneous Flow Structures and Opportunities for Larval Settlement: Barnacle Larvae Swim to Settle

    PubMed Central

    Granhag, Lena M.; Jonsson, Per R.

    2016-01-01

    Water flow affects settlement of marine larvae on several scales. At the smallest scale local flow regime may control the probability of adhesion to the substrate. Our aim was to mechanistically understand the transition from suspended to attached larvae in turbulent flow. Recently it was proposed that opportunities for larval settlement in turbulent boundary layers depend on time windows with suitable instantaneous flow properties. In flume flow we characterized the proportion of suitable time windows in a series of flow velocities with focus on the near-bed flow. The change in the proportion of potential settling windows with increasing free-stream velocities was compared to the proportion of temporary attachment of barnacle cypris larvae at different flow velocities. We found large instantaneous flow variations in the near-bed flow where cyprid attachment took place. The probability of temporary attachment in cyprids declined with local flow speed and this response was compatible with a settling window lasting at least 0.1 s with a maximum local flow speed of 1.9–2.4 cm s-1. Cyprids swam against the near-bed flow (negative rheotaxis) and the swimming speed (1.8 cm s-1) was close to the critical speed that permitted temporary attachment. We conclude that temporary attachment in barnacle cyprids requires upstream swimming to maintain a fixed position relative to the substrate for at least 0.1 s. This behaviour may explain the ability of barnacles to recruit to high-flow environments and give cyprids flexibility in the pre-settlement choice of substrates based on flow regime. PMID:27463968

  13. Instantaneous Flow Structures and Opportunities for Larval Settlement: Barnacle Larvae Swim to Settle.

    PubMed

    Larsson, Ann I; Granhag, Lena M; Jonsson, Per R

    2016-01-01

    Water flow affects settlement of marine larvae on several scales. At the smallest scale local flow regime may control the probability of adhesion to the substrate. Our aim was to mechanistically understand the transition from suspended to attached larvae in turbulent flow. Recently it was proposed that opportunities for larval settlement in turbulent boundary layers depend on time windows with suitable instantaneous flow properties. In flume flow we characterized the proportion of suitable time windows in a series of flow velocities with focus on the near-bed flow. The change in the proportion of potential settling windows with increasing free-stream velocities was compared to the proportion of temporary attachment of barnacle cypris larvae at different flow velocities. We found large instantaneous flow variations in the near-bed flow where cyprid attachment took place. The probability of temporary attachment in cyprids declined with local flow speed and this response was compatible with a settling window lasting at least 0.1 s with a maximum local flow speed of 1.9-2.4 cm s-1. Cyprids swam against the near-bed flow (negative rheotaxis) and the swimming speed (1.8 cm s-1) was close to the critical speed that permitted temporary attachment. We conclude that temporary attachment in barnacle cyprids requires upstream swimming to maintain a fixed position relative to the substrate for at least 0.1 s. This behaviour may explain the ability of barnacles to recruit to high-flow environments and give cyprids flexibility in the pre-settlement choice of substrates based on flow regime. PMID:27463968

  14. Cytoplasmic Solvent Structure of Single Barnacle Muscle Cells Studied by Electron Spin Resonance

    PubMed Central

    Sachs, Fred; Latorre, Ramon

    1974-01-01

    A free radical probe was introduced into single barnacle muscle cells, and its freedom of motion inferred from the spin resonance spectra. The probe reported an average local viscosity of 5-10 cp compared with 1 cp for pure water. From a comparison of the temperature dependence of the probe's tumbling rate in model aqueous systems and in the muscle we concluded that in the muscle the probe was undergoing fast exchange between sites of different mobility. Thus 10 cp must be taken as an upper limit for the viscosity of most cell water. PMID:4364470

  15. Photoreception in a barnacle: electrophysiology of the shadow reflex pathway in Balanus cariosus.

    PubMed

    Millecchia, R; Gwilliam, G F

    1972-08-01

    The photoreceptors in the median ocellus of the rock barnacle depolarize when illuminated. This depolarization spreads passively to the axon terminals in the supraesophageal ganglion. A small number of cells in the supraesophageal ganglion hyperpolarize when the median ocellus is illuminated and depolarize when it is shadowed. Nerve impulses are superimposed on the slow depolarization of the ganglion cells. Impulse activity in response to shadowing the median ocellus is recorded in a few fibers of the circumesophageal connectives. Picrotoxin blocks this shadow-induced activity. A model of the shadow reflex pathway is presented. PMID:4339616

  16. Morphology of the cement apparatus and the cement of the buoy barnacle Dosima fascicularis (Crustacea, Cirripedia, Thoracica, Lepadidae).

    PubMed

    Zheden, Vanessa; Von Byern, Janek; Kerbl, Alexandra; Leisch, Nikolaus; Staedler, Yannick; Grunwald, Ingo; Power, Anne Marie; Klepal, Waltraud

    2012-10-01

    Barnacles produce a proteinaceous adhesive called cement to attach permanently to rocks or to other hard substrata. The stalked barnacle Dosima fascicularis is of special interest as it produces a large amount of foam-like cement that can be used as a float. The morphology of the cement apparatus and of the polymerized cement of this species is almost unknown. The current study aims at filling these gaps in our knowledge using light and electron microscopy as well as x-ray microtomography. The shape of the cement gland cells changes from round to ovoid during barnacle development. The cytoplasm of the gland cells, unlike that of some other barnacles, does not have distinct secretory and storage regions. The cement canals, which transport the cement from the gland cells to the base of the stalk, end at different positions in juvenile and mature animals. With increasing size of the cement float, the exit of the cement canals shift from the centrally positioned attachment disk of the vestigial antennules to more lateral positions on the stalk. The bubbles enclosed in the foam-like float are most likely filled with CO(2) that diffuses from the hemolymph into the cement canal system and from there into the cement.

  17. Intraspecific variation in the turtle barnacle, Cylindrolepas sinica Ren, 1980 (Cirripedia, Thoracica, Coronuloidea), with brief notes on habitat selectivity

    PubMed Central

    Hayashi, Ryota

    2013-01-01

    Abstract Specimens of the turtle barnacle Cylindrolepas sinica Ren, 1980 were collected from sea turtles in Japanese waters. The specimens were hexagonal in shape and were found burrowing into the sea turtle plastron. Specimens were dissected and the hard and soft parts were compared with the original description. PMID:24167420

  18. The dark brown integumentary pigment of a barnacle (Balanus eburneus). A comparative study.

    PubMed

    Barden, H; Koulish, S

    1983-01-01

    A histochemical analysis involving tinctorial and solubility tests was pursued in conjunction with electron microscopy for the purpose of identifying the dark brown epidermal pigment of a barnacle (Balanus eburneus) as melanin and/or ommochrome. Histochemically, comparisons were made with other brown pigments located in the subcarapal epidermis of another crustacean, the fiddler crab (Uca pugilator), the dorsal skin of the red-backed salamander (Plethodon cinereus), the liver and testis of a slider turtle (Chrysemys sp.) and the substantia nigra of human brain. The solubility properties of the pigment of the two crustacean invertebrates were in general similar to one another and markedly different from the pigment of the three vertebrates. Insolubility in appropriate solvents classified the vertebrate pigment as melanin. The invertebrate pigment, however, which was soluble in the ommochrome solvents, concentrated sulfuric and formic acids and 2-chloroethanol, remained insoluble in the ommochrome solvents, dilute aqueous and methanolic hydrochloric acid and dilute sulfuric acid. On the basis of these solubilities, an unequivocal classification of the invertebrate pigment as either melanin or ommochrome did not appear possible. The tinctorial and electron microscopic properties of the barnacle pigment were also equally ambiguous in regard to its specific classification.

  19. Phylogenetic relationships of Darwin's "Mr. Arthrobalanus": The burrowing barnacles (Cirripedia: Acrothoracica).

    PubMed

    Lin, Hsiu-Chin; Kobasov, Gregory A; Chan, Benny K K

    2016-07-01

    The barnacles of the superorder Acrothoracica are small, burrowing, epibiotic, and dioecious (large female with dwarf male) crustaceans largely found in the carbonate sediments and skeletons of marine invertebrates. The acrothoracicans represent the Cirripedia with the most plesiomorphic characters and have prominently featured in phylogenetic speculations concerning these crustaceans. Traditionally, Acrothoracica was divided into two main orders, Pygophora and Apygophora. The Apygophora had uniramus cirri and no anus. The Pygophora had biramus terminal cirri and an anus and was further divided into two families, Lithoglyptidae and Cryptophialidae. Kolbasov (2009) revised the superorder Acrothoracica on the basis of morphological examinations of females, dwarf males, and cyprids and rearranged the acrothoracican species into two new orders, Lithoglyptida and Cryptophialida. The present study is the first attempt to reconstruct the phylogenetic relationships of acrothoracican barnacles by sequencing two mitochondrial (cytochrome C oxidase I and 16S ribosomal DNA) and two nuclear (18S ribosomal DNA and histone H3) markers of 8 of the 11 genera comprising 23 acrothoracican species. All monophylies of the eight acrothoracican genera sampled in this study were strongly supported. The deep interfamilial relationship constructed is consistent with the recent morphological phylogenetic relationship proposed by Kolbasov, Newman, and Høeg (Kolbasov, 2009) that Cryptophialidae (order Cryptophialida) is the sister group to all other acrothoracicans (order Lithoglyptida). According to an ancestral character state reconstruction analysis, the posterior lobes of females; armament of opercular bars, attachment stalk, lateral projections of the body, and aperture slits in dwarf males; and habitat use appear to have phylogenetic importance.

  20. Evolution of sex determination and sexually dimorphic larval sizes in parasitic barnacles.

    PubMed

    Yamaguchi, Sachi; Høeg, Jens T; Iwasa, Yoh

    2014-04-21

    The parasitic (rhizocephalan) barnacles include species of which larval sex is determined by the mother (genetic sex determination, GSD), male larvae are larger than female larvae, and a female accepts only two dwarf males who sire all the eggs laid by her. In contrast, other species of parasitic barnacles exhibit monomorphic larvae that choose to become male or female depending on the condition of the host they settle (environmental sex determination, or ESD), and a female accepts numerous dwarf males. Here, we ask why these set of traits are observed together, by examining the evolution of sex determination and the larval size. ESD has an advantage over GSD because each larva has a higher chance of encountering a suitable host. On the other hand, GSD has two advantages over ESD: the larval size can be chosen differently between sexes, and their larvae can avoid spending time for sex determination on the host. We conclude that, in species whose female accepts only two males, the male larvae engage in intense contest competition for reproductive opportunities, and male's success-size relation is very different from female's. Then, larvae with predetermined sex (GSD) with sexually dimorphic larvae is more advantageous than ESD. In contrast, in species whose females accept many dwarf males, the competition among males is less intense, and producing larvae with undetermined sex should evolve. We also discuss the condition for females to evolve receptacles to limit the number of males she accepts.

  1. Phylogenetic position and evolutionary history of the turtle and whale barnacles (Cirripedia: Balanomorpha: Coronuloidea).

    PubMed

    Hayashi, Ryota; Chan, Benny K K; Simon-Blecher, Noa; Watanabe, Hiromi; Guy-Haim, Tamar; Yonezawa, Takahiro; Levy, Yaniv; Shuto, Takuho; Achituv, Yair

    2013-04-01

    Barnacles of the superfamily Coronuloidea are obligate epibionts of various marine mammals, marine reptiles and large crustaceans. We used five molecular markers: 12S rDNA, 16S rDNA, 18S rDNA, 28S rDNA and Histone 3 to infer phylogenetic relationships among sixteen coronuloids, representing most of the recent genera of barnacles of this superfamily. Our analyses confirm the monophyly of Coronuloidea and that this superfamily and Tetraclitoidea are sister groups. The six-plated Austrobalanus clusters with these two superfamilies. Based on BEAST and ML trees, Austrobalanus is basal and sister to the Coronuloidea, but the NJ tree places Austrobalanus within the Tetraclitoidae, and in the MP tree it is sister to both Coronuloidea and Tetraclitoidae. Hence the position of Austrobalanus remains unresolved. Within the Coronuloidea we identified four clades. Chelonibia occupies a basal position within the Coronuloidea which is in agreement with previous studies. The grouping of the other clades does not conform to previous studies. Divergence time analyses show that some of the time estimates are congruent with the fossil record while some others are older, suggesting the possibility of gaps in the fossil record.

  2. Chemistry-specific surface adsorption of the barnacle settlement-inducing protein complex

    PubMed Central

    Petrone, Luigi; Aldred, Nick; Emami, Kaveh; Enander, Karin; Ederth, Thomas; Clare, Anthony S.

    2015-01-01

    Gregarious settlement in barnacle larvae (cyprids) is induced by a contact pheromone, the settlement-inducing protein complex (SIPC). The SIPC has been identified both in the cuticle of adult barnacles and in the temporary adhesive secretion (footprint) of cyprids. Besides acting as a settlement inducer, the presence of the SIPC in footprints points to its additional involvement in the adhesion process. SIPC adsorption behaviour was therefore investigated on a series of self-assembled monolayers (SAMs) by surface plasmon resonance at the pH of seawater (8.3). Fibrinogen and α2-macroglobulin (A2M) (blood complement protease inhibitors with which the SIPC shares 29% sequence homology) were used in the adsorption experiments as positive and negative standards, respectively. The mass uptake of the SIPC was comparable to that of fibrinogen, with adsorption observed even on the protein-resistant oligo(ethylene glycol) surface. Notably, on the positively charged SAM the SIPC showed a kinetic overshoot, indicating a metastable configuration causing the amount of adsorbed protein to temporarily exceed its equilibrium value. A2M adsorption was low or negligible on all SAMs tested, except for the positively charged surface, indicating that A2M adsorption is mainly driven by electrostatics. Evaluation of SIPC non-specific adsorption kinetics revealed that it adsorbed irreversibly and non-cooperatively on all surfaces tested. PMID:25657832

  3. Barnacle: detecting and characterizing tandem duplications and fusions in transcriptome assemblies

    PubMed Central

    2013-01-01

    Background Chimeric transcripts, including partial and internal tandem duplications (PTDs, ITDs) and gene fusions, are important in the detection, prognosis, and treatment of human cancers. Results We describe Barnacle, a production-grade analysis tool that detects such chimeras in de novo assemblies of RNA-seq data, and supports prioritizing them for review and validation by reporting the relative coverage of co-occurring chimeric and wild-type transcripts. We demonstrate applications in large-scale disease studies, by identifying PTDs in MLL, ITDs in FLT3, and reciprocal fusions between PML and RARA, in two deeply sequenced acute myeloid leukemia (AML) RNA-seq datasets. Conclusions Our analyses of real and simulated data sets show that, with appropriate filter settings, Barnacle makes highly specific predictions for three types of chimeric transcripts that are important in a range of cancers: PTDs, ITDs, and fusions. High specificity makes manual review and validation efficient, which is necessary in large-scale disease studies. Characterizing an extended range of chimera types will help generate insights into progression, treatment, and outcomes for complex diseases. PMID:23941359

  4. Plastic Sexual Expression in the Androdioecious Barnacle Octolasmis warwickii (Cirripedia: Pedunculata).

    PubMed

    Wijayanti, Hendry; Yusa, Yoichi

    2016-02-01

    Most barnacles are simultaneous hermaphrodites, but dwarf males are also found attached to hermaphrodites in several species. This biologically rare phenomenon of the coexistence of males and hermaphrodites is termed androdioecy. To test whether the hermaphrodite and male sexes are fixed or plastic in the androdioecious pedunculate barnacle Octolasmis warwickii, we conducted a series of 22-day-long transplanting experiments to evaluate the effects of a) the original site (attached to the conspecific vs. attached directly to the substrate) and b) the transplanting site (conspecific-attached vs. substrate-attached). Penis length (as an index of male function), the presence or absence of egg mass (female function), and growth rate were investigated. As with natural dwarf males, individuals that were transplanted onto conspecifics developed longer penises than did those that were transplanted onto the substrate. The original site of attachment also affected penis length. However, no significant effects of the original site or the transplanting were detected in egg-laying activities, as only one experimental individual laid eggs. Individuals that were transplanted onto conspecifics grew less than those that were attached to the substrate. These results indicate that individual sexual expression is affected by the environment in O. warwickii. PMID:26896177

  5. Chemistry-specific surface adsorption of the barnacle settlement-inducing protein complex.

    PubMed

    Petrone, Luigi; Aldred, Nick; Emami, Kaveh; Enander, Karin; Ederth, Thomas; Clare, Anthony S

    2015-02-01

    Gregarious settlement in barnacle larvae (cyprids) is induced by a contact pheromone, the settlement-inducing protein complex (SIPC). The SIPC has been identified both in the cuticle of adult barnacles and in the temporary adhesive secretion (footprint) of cyprids. Besides acting as a settlement inducer, the presence of the SIPC in footprints points to its additional involvement in the adhesion process. SIPC adsorption behaviour was therefore investigated on a series of self-assembled monolayers (SAMs) by surface plasmon resonance at the pH of seawater (8.3). Fibrinogen and α2-macroglobulin (A2M) (blood complement protease inhibitors with which the SIPC shares 29% sequence homology) were used in the adsorption experiments as positive and negative standards, respectively. The mass uptake of the SIPC was comparable to that of fibrinogen, with adsorption observed even on the protein-resistant oligo(ethylene glycol) surface. Notably, on the positively charged SAM the SIPC showed a kinetic overshoot, indicating a metastable configuration causing the amount of adsorbed protein to temporarily exceed its equilibrium value. A2M adsorption was low or negligible on all SAMs tested, except for the positively charged surface, indicating that A2M adsorption is mainly driven by electrostatics. Evaluation of SIPC non-specific adsorption kinetics revealed that it adsorbed irreversibly and non-cooperatively on all surfaces tested. PMID:25657832

  6. Characterization of Arginine Kinase in the Barnacle Amphibalanus Amphitrite and Its Role in the Larval Settlement.

    PubMed

    Zhang, Gen; Yan, Guo-Yong; Yang, Xiao-Xue; Wong, Yue-Him; Sun, Jin; Zhang, Yu; He, Li-Sheng; Xu, Ying; Qian, Pei-Yuan

    2016-06-01

    Energy metabolism is a key process in larval settlement of barnacles, but the underlying molecular mechanisms remain ambiguous. Arginine kinase (AK) mainly participates in energy metabolism in invertebrates. So far, its roles in barnacles have not been studied. In the present study, we raised an antibody against AK from Amphibalanus amphitrite Darwin to characterize the roles of AK in the larval settlement process. Among the developmental stages, AK was highly expressed during the cypris stage. Along with the aging process in cyprids, the level of AK decreased. The immunostaining results showed that AK was localized to muscular tissues in cyprids, including antennules, antennular muscles, and thoracic limbs. The larval settlement rate decreased and larval movement was inhibited in response to treatments with high concentrations of AK inhibitors (rutin and quercetin). These results demonstrated that AK was involved in the larval settlement of A. amphitrite through mediating energy supply in muscle tissues. Moreover, further analysis indicated that both the p38 MAPK and NO/cGMP pathways positively mediated the expression of AK in cyprids. PMID:27245369

  7. Significance of the conformation of building blocks in curing of barnacle underwater adhesive.

    PubMed

    Kamino, Kei; Nakano, Masahiro; Kanai, Satoru

    2012-05-01

    Barnacles are a unique sessile crustacean that attach irreversibly and firmly to foreign underwater surfaces. Its biological underwater adhesive is a peculiar extracellular multi-protein complex. Here we characterize one of the two major proteins, a 52 kDa protein found in the barnacle cement complex. Cloning of the cDNA revealed that the protein has no homolog in the nonredundant database. The primary structure consists of four long sequence repeats. The process of dissolving the protein at the adhesive joint of the animal by various treatments was monitored in order to obtain insight into the molecular mechanism involved in curing of the adhesive bulk. Treatments with protein denaturant, reducing agents and/or chemical-specific proteolysis in combination with 2D diagonal PAGE indicated no involvement of the protein in intermolecular cross-linkage/polymerization, including formation of intermolecular disulfide bonds. As solubilization of the proteins required high concentrations of denaturing agents, it appears that both the conformation of the protein as building blocks and non-covalent molecular interactions between the building blocks, possibly hydrophobic interactions and hydrogen bonds, are crucial for curing of the cement. It was also suggested that the protein contributes to surface coupling by an anchoring effect to micro- to nanoscopic roughness of surfaces.

  8. Barnacles, limpets and periwinkles: the effects of direct and indirect interactions on cyprid settlement and success

    NASA Astrophysics Data System (ADS)

    Holmes, Sebastian P.; Walker, Graham; van der Meer, Jaap

    2005-02-01

    Conventionally, direct interactions between species are considered to be the most important biological factors determining community composition, structure and stability. However, it has been suggested that the indirect interactions occurring between species may be as important. One area of ecology where the direct effects of one species on another have been well studied is in the rocky intertidal. Examination of the effect of the presence of P. vulgata (limpets) and L. littorea (periwinkles) on the settlement and development of S. balanoides (cyprids/barnacles), over a cyprid settlement season and some six months later, in four different treatments (limpets only, limpets and periwinkles combined, periwinkles only and control (no animals)) revealed the following: (1) that the presence of limpets increased cyprid settlement and recruitment success above treatments containing no limpets; (2) that cyprid settlement and success were greatest on the limpets-only treatment, followed by the limpets-and-periwinkles treatment, then by the control treatment and then by the periwinkles-only treatment; (3) that the initial effects observed in the treatments were reflected in the long-term community structure; (4) that the effects of the treatments were independent of variations in algal biomass between treatments, i.e. the effects were not indirectly mediated through a second species (host); (5) that cyprid mortality was greatest on the periwinkles-only treatment; (6) that the source of the effect of limpets on cyprid settlement appeared to originate indirectly through the action of their residual pedal mucus trails. It is concluded that periwinkles can affect the settlement and success of barnacles directly through biological disturbance (i.e. surface ablation). However, although limpets may have a direct negative effect on barnacle settlement and success, at low to medium densities, limpets can positively indirectly influence the cyprid settlement and success. This effect

  9. Asymmetric coexistence: bidirectional abiotic and biotic effects between goose barnacles and mussels.

    PubMed

    Kawai, Takashi; Tokeshi, Mutsunori

    2006-07-01

    1. Species coexistence depends on the net effect of interacting species, representing the sum of multiple interaction components that may act simultaneously and vary independently depending on ambient environmental conditions. Consequently, for a comprehensive understanding of the compound nature of species interactions and coexistence, a mechanistic approach that allows a separate evaluation of each interaction component is required. 2. Two sessile filter-feeders, the goose barnacle Capitulum mitella and the mussel Septifer virgatus, coexist on moderately wave-exposed rocky shores in south-western Japan. In the upper intertidal, Capitulum positively influenced Septifer survivorship and growth through amelioration of thermal stress and of physical disturbance. On the other hand, these species are potential competitors as they have similar body sizes and modes of resource utilization. These opposite processes, facilitation and competition, are based on abiotic characteristics and biotic functions of the two species, respectively. 3. In order to quantify the bidirectional abiotic, biotic and net effects, a series of experimental manipulations was conducted involving the use of living neighbours with both abiotic and biotic effects, and artificial mimics to simulate abiotic effects without biotic effects. 4. Capitulum had strong positive abiotic effects on the mussel survivorship in most experimental periods, while the biotic effect was negligible or weakly negative, suggesting that the net effect of Capitulum on mussel survival was largely attributable to the abiotic effect. In contrast, a significantly negative biotic effect on the mussel growth rate was always present, though this was cancelled out by the larger, positive abiotic effect. In the case of Septifer, its abiotic and biotic effects on the survivorship of goose barnacles were negligible, while those on the growth rate showed temporal variation. 5. With respect to the relationship between species

  10. An acorn squash (Cucurbita pepo ssp. ovifera) fruit and seed transcriptome as a resource for the study of fruit traits in Cucurbita

    PubMed Central

    Wyatt, Lindsay E; Strickler, Susan R; Mueller, Lukas A; Mazourek, Michael

    2015-01-01

    Acorn squash (Cucurbita pepo) is an iconic fall vegetable in the United States, known for its unique fruit shape and also prized for its culinary properties. Little is known about the metabolism that underlies the development of fruit quality attributes such as color, sweetness, texture and nutritional qualities in acorn squash, or any other winter squash grown worldwide. To provide insight into winter squash fruit and seed development and add to the genomic resources in the Cucurbita genus, RNA sequencing was used to generate an acorn squash fruit and seed transcriptome from the cultivar Sweet REBA at critical points throughout fruit development. 141 838 600 high-quality paired-end Illumina reads were assembled into 55 949 unigenes. 85% of unigenes with predicted open reading frames had homology with previously identified genes and over 62% could be functionally annotated. Comparison with the watermelon and cucumber genomes provided confirmation that the unigenes are full-length and comprehensive, covering an average of 90% of the coding sequence of their homologs and 72% of the cucumber and watermelon exomes. Key candidate genes associated with carotenoid and carbohydrate metabolism were identified toward a resource for winter squash fruit quality trait dissection. This transcriptome represents a major advance in C. pepo genomics, providing significant new sequence information and revealing the repertoire of genes expressed throughout winter squash fruit and seed development. Future studies on the genetic basis of fruit quality and future breeding efforts will be enhanced by tools and insights developed from this resource. PMID:26504561

  11. An acorn squash (Cucurbita pepo ssp. ovifera) fruit and seed transcriptome as a resource for the study of fruit traits in Cucurbita.

    PubMed

    Wyatt, Lindsay E; Strickler, Susan R; Mueller, Lukas A; Mazourek, Michael

    2015-01-01

    Acorn squash (Cucurbita pepo) is an iconic fall vegetable in the United States, known for its unique fruit shape and also prized for its culinary properties. Little is known about the metabolism that underlies the development of fruit quality attributes such as color, sweetness, texture and nutritional qualities in acorn squash, or any other winter squash grown worldwide. To provide insight into winter squash fruit and seed development and add to the genomic resources in the Cucurbita genus, RNA sequencing was used to generate an acorn squash fruit and seed transcriptome from the cultivar Sweet REBA at critical points throughout fruit development. 141 838 600 high-quality paired-end Illumina reads were assembled into 55 949 unigenes. 85% of unigenes with predicted open reading frames had homology with previously identified genes and over 62% could be functionally annotated. Comparison with the watermelon and cucumber genomes provided confirmation that the unigenes are full-length and comprehensive, covering an average of 90% of the coding sequence of their homologs and 72% of the cucumber and watermelon exomes. Key candidate genes associated with carotenoid and carbohydrate metabolism were identified toward a resource for winter squash fruit quality trait dissection. This transcriptome represents a major advance in C. pepo genomics, providing significant new sequence information and revealing the repertoire of genes expressed throughout winter squash fruit and seed development. Future studies on the genetic basis of fruit quality and future breeding efforts will be enhanced by tools and insights developed from this resource.

  12. Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia).

    PubMed

    Chan, Benny K K; Chen, H-N; Dando, P R; Southward, A J; Southward, E C

    2016-01-01

    The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007) and C. newmani sp. nov.). These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters.

  13. Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia).

    PubMed

    Chan, Benny K K; Chen, H-N; Dando, P R; Southward, A J; Southward, E C

    2016-01-01

    The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007) and C. newmani sp. nov.). These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters. PMID:26958842

  14. Characterization of cement float buoyancy in the stalked barnacle Dosima fascicularis (Crustacea, Cirripedia).

    PubMed

    Zheden, Vanessa; Kovalev, Alexander; Gorb, Stanislav N; Klepal, Waltraud

    2015-02-01

    Dosima fascicularis is the only barnacle which can drift autonomously at the water surface with a foam-like cement float. The cement secreted by the animal contains numerous gas-filled cells of different size. When several individuals share one float, their size and not their number is crucial for the production of both volume and mass of the float. The gas content within the cells of the foam gives positive static buoyancy to the whole float. The volume of the float, the gas volume and the positive static buoyancy are positively correlated. The density of the cement float without gas is greater than that of seawater. This study shows that the secreted cement consists of more than 90% water and the gas volume is on average 18.5%. Our experiments demonstrate that the intact foam-like cement float is sealed to the surrounding water. PMID:25657839

  15. Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia)

    PubMed Central

    Chan, Benny K. K.; Chen, H. -N.; Dando, P. R.; Southward, A. J.; Southward, E. C.

    2016-01-01

    The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007) and C. newmani sp. nov.). These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters. PMID:26958842

  16. Characterization of cement float buoyancy in the stalked barnacle Dosima fascicularis (Crustacea, Cirripedia)

    PubMed Central

    Zheden, Vanessa; Kovalev, Alexander; Gorb, Stanislav N.; Klepal, Waltraud

    2015-01-01

    Dosima fascicularis is the only barnacle which can drift autonomously at the water surface with a foam-like cement float. The cement secreted by the animal contains numerous gas-filled cells of different size. When several individuals share one float, their size and not their number is crucial for the production of both volume and mass of the float. The gas content within the cells of the foam gives positive static buoyancy to the whole float. The volume of the float, the gas volume and the positive static buoyancy are positively correlated. The density of the cement float without gas is greater than that of seawater. This study shows that the secreted cement consists of more than 90% water and the gas volume is on average 18.5%. Our experiments demonstrate that the intact foam-like cement float is sealed to the surrounding water. PMID:25657839

  17. Cypris morphology in the barnacles Ibla and Paralepas (Crustacea: Cirripedia Thoracica) implications for cirripede evolution.

    PubMed

    Høeg, Jens T; Achituv, Yair; Chan, Benny K K; Chan, Karen; Jensen, Peter Gram; Pérez-Losada, Marcos

    2009-02-01

    We used scanning electron microscopy (SEM) to describe cypris morphology in species of the barnacles Ibla and Paralepas, both of which are pivotal in understanding cirripede evolution. In Ibla, we also studied late naupliar stages with video and SEM. Special emphasis was put on the lattice organs, the antennules and the thorax and telson. In Paralepas we had settled specimens only and could therefore only investigate the carapace with the lattice organs. Cyprids of Ibla quadrivalvis and Paralepas dannevigi have five sets of lattice organs, grouped as two anterior and three posterior pairs. The organs are of the pore-field type and the terminal pore is situated anteriorly in the first pair, just as in the Rhizocephala and the Thoracica. In Ibla the armament of antennular sensilla resembles that found in the Thoracica but differs from the Rhizocephala. The absence of setules on the A and B setae sited terminally on the fourth antennular segment is a similarity with the Acrothoracica. The attachment disc is angled rather than facing distally and is encircled by a low cuticular velum. The thoracopods have two-segmented endopods and exopods as in the Thoracica, but the number, shape, and position of thoracopodal setae differ somewhat from other species of that superorder. Both Ibla and Paralepas cyprids have a deeply cleaved telson, but no independent abdominal part. In cypris morphology, Ibla and Paralepas show several synapomorphies with the clade comprising Rhizocephala and Thoracica and there are no specific apomorphies with either the Acrothoracica, the Rhizocephala or any particular subgroup within the Thoracica. This is in agreement with recent molecular evidence that Ibla (Ibliformes) is the sister taxon to all other Thoracica and the ibliforms therefore become the outgroup of choice for studying character evolution within the superorder. Paralepas, and other pedunculated barnacles without shell plates, are apparently not primitive but are secondarily evolved

  18. Phylogenetic relationships of Darwin's "Mr. Arthrobalanus": The burrowing barnacles (Cirripedia: Acrothoracica).

    PubMed

    Lin, Hsiu-Chin; Kobasov, Gregory A; Chan, Benny K K

    2016-07-01

    The barnacles of the superorder Acrothoracica are small, burrowing, epibiotic, and dioecious (large female with dwarf male) crustaceans largely found in the carbonate sediments and skeletons of marine invertebrates. The acrothoracicans represent the Cirripedia with the most plesiomorphic characters and have prominently featured in phylogenetic speculations concerning these crustaceans. Traditionally, Acrothoracica was divided into two main orders, Pygophora and Apygophora. The Apygophora had uniramus cirri and no anus. The Pygophora had biramus terminal cirri and an anus and was further divided into two families, Lithoglyptidae and Cryptophialidae. Kolbasov (2009) revised the superorder Acrothoracica on the basis of morphological examinations of females, dwarf males, and cyprids and rearranged the acrothoracican species into two new orders, Lithoglyptida and Cryptophialida. The present study is the first attempt to reconstruct the phylogenetic relationships of acrothoracican barnacles by sequencing two mitochondrial (cytochrome C oxidase I and 16S ribosomal DNA) and two nuclear (18S ribosomal DNA and histone H3) markers of 8 of the 11 genera comprising 23 acrothoracican species. All monophylies of the eight acrothoracican genera sampled in this study were strongly supported. The deep interfamilial relationship constructed is consistent with the recent morphological phylogenetic relationship proposed by Kolbasov, Newman, and Høeg (Kolbasov, 2009) that Cryptophialidae (order Cryptophialida) is the sister group to all other acrothoracicans (order Lithoglyptida). According to an ancestral character state reconstruction analysis, the posterior lobes of females; armament of opercular bars, attachment stalk, lateral projections of the body, and aperture slits in dwarf males; and habitat use appear to have phylogenetic importance. PMID:26988415

  19. Spatial properties of the prolonged depolarizing afterpotential in barnacle photoreceptors. I. The induction process

    PubMed Central

    1986-01-01

    In invertebrate photoreceptors, when the light stimulus results in substantial net transfer of the visual pigment from the rhodopsin (R) to the metarhodopsin (M) state, the ordinary late receptor potential (LRP) is followed by a prolonged depolarizing afterpotential (PDA). The dependence of the amplitude of the PDA on the amount of pigment conversion is strongly supralinear, and the PDA duration also depends on this amount. These observations indicate an interaction among the elements of the PDA induction process and also make possible a test of the range of this interaction. The test consists of a comparison of the PDA after localized pigment conversion, obtained by strong spot illumination, to that after weaker diffuse illumination converting a comparable total amount of pigment. The experiment was performed on the barnacle lateral eye. The effective spot size was measured by the early receptor potential (ERP), in seawater saturated with CO2, which considerably reduced the electrical coupling between the photoreceptors. The ERP was also used to determine whether there is diffusion of R molecules into the illuminated spot. The spot illumination induced a PDA with small amplitude and long duration, while no detectable PDA was induced by the diffuse light. This indicates that the range of the PDA interaction is much smaller than the entire cell. In addition, the ERP results showed that there was no detectable diffusion of R molecules into the illuminated spot area over 30 min. This measurement, with a calculated correction for the microvillar geometry of the photoreceptor, enabled us to put an upper limit on the diffusion coefficient of the pigment molecules in the inact, unfixed barnacle photoreceptor of D less than 6 X 10(-9) cm2 s-1. PMID:3958692

  20. Passive signal propagation and membrane properties in median photoreceptors of the giant barnacle

    PubMed Central

    Hudspeth, A. J.; Poo, Mu Ming; Stuart, Ann E.

    1977-01-01

    1. The light-induced electrical responses of barnacle photoreceptors spread decrementally along the cells' axons. The decay of the depolarizing and hyperpolarizing components of the visual signal was studied by recording intracellularly from single receptor axons of the median ocellus of the giant barnacle. 2. The resistance of the photoreceptor neurone decreases markedly when the cell is depolarized with respect to its dark resting potential of -60 mV. This rectification results in differential attenuation of the depolarizing and hyperpolarizing components of the visual signal as they spread down the axon. Consequently, the visual signal entering the synaptic region is conspicuously distorted. 3. Bathing the photoreceptor axons in sodium-free or calcium-free saline or in isotonic sucrose does not significantly affect the spread of the visual signal to the terminals. Thus the signal is not amplified by an ionic mechanism along the axon. 4. Membrane characteristics of the photoreceptor for hyperpolarizing voltage changes were estimated from (a) the ratio of the amplitudes of the visual signals recorded simultaneously in the axon and in the soma, (b) the time constant, and (c) the input resistance of the cell. All three independent measurements are consistent with a length constant 1 to 2 times the total length of the cell (λ = 10-18 mm) and an unusually high membrane resistivity of about 300 kΩ cm2. This resistivity enables the receptor potential to spread passively to the terminal region. 5. Electron microscopic examination of receptor axons reveals an investment of glial lamellae, but demonstrates neither unusual structures which would lead to a high apparent membrane resistivity, nor junctions between cells which would seal off the extracellular space. Thus the observed high resistivity appears to be an intrinsic property of the receptor membrane. ImagesABCD PMID:592129

  1. Density drives polyandry and relatedness influences paternal success in the Pacific gooseneck barnacle, Pollicipes elegans

    PubMed Central

    2014-01-01

    Background Polyandry is a common mating strategy in animals, increasing female fitness through direct (material) and indirect (genetic) benefits. Most theories about the benefits of polyandry come from studies of terrestrial animals, which have relatively complex mating systems and behaviors; less is known about the potential benefits of polyandry in sessile marine animals, for which potential mates may be scarce and females have less control over pre-copulatory mate choice. Here, we used microsatellite markers to examine multiple paternity in natural aggregations of the Pacific gooseneck barnacle Pollicipes elegans, testing the effect of density on paternity and mate relatedness on male reproductive success. Results We found that multiple paternity was very common (79% of broods), with up to five fathers contributing to a brood, though power was relatively low to detect more than four fathers. Density had a significant and positive linear effect on the number of fathers siring a brood, though this relationship leveled off at high numbers of fathers, which may reflect a lack of power and/or an upper limit to polyandry in this species. Significant skew in male reproductive contribution in multiply-sired broods was observed and we found a positive and significant relationship between the proportion of offspring sired and the genetic similarity between mates, suggesting that genetic compatibility may influence reproductive success in this species. Conclusions To our knowledge, this is the first study to show high levels of multiple paternity in a barnacle, and overall, patterns of paternity in P. elegans appear to be driven primarily by mate availability. Evidence of paternity bias for males with higher relatedness suggests some form of post-copulatory sexual selection is taking place, but more work is needed to determine whether it operates during or post-fertilization. Overall, our results suggest that while polyandry in P. elegans is driven by mate availability, it

  2. Relationship between metal and polybrominated diphenyl ether (PBDE) body burden and health risks in the barnacle Balanus amphitrite.

    PubMed

    Chen, Lianguo; Lam, James C W; Zhang, Xiaohua; Pan, Ke; Guo, Cui; Lam, Paul K S; Wang, Wenxiong; Liu, Hongbin; Qian, Pei-Yuan

    2015-11-15

    In the present study, we employed the widespread and gregarious barnacle species Balanus amphitrite in a biomonitoring program to evaluate coastal pollution around three piers (i.e., Tso Wo Hang, Sai Kung and Hebe Haven) in Hong Kong. An integrated approach was used herein, combining both the chemical determination of contaminant concentrations, including metals and polybrominated diphenyl ethers (PBDEs), and a suite of biological responses across the entire barnacle lifecycle (i.e., adult, nauplius, cyprid and juvenile). The analytical results revealed a distinct geographical distribution of metals and PBDEs. Adult physiological processes and larval behaviors varied significantly among the three piers. Furthermore, a correlation analysis demonstrated a specific suite of biological responses towards metal and PBDE exposure, likely resulting from their distinct modes of action. Overall, the results of this study indicated that the combination of chemical and biological tests provided an integrated measure for the comprehensive assessment of marine pollution. PMID:26320980

  3. Effects of food availability on growth and reproduction of the deep-sea pedunculate barnacle Heteralepas canci

    NASA Astrophysics Data System (ADS)

    Yasuda, Natsumi; Miyamoto, Norio; Fujiwara, Yoshihiro; Yamamoto, Tomoko; Yusa, Yoichi

    2016-02-01

    Sessile animals living on continental shelves or slopes may adjust their growth and reproduction according to temporally and spatially variable food availability, but little information is available on these animals to date. We collected the pedunculate barnacle Heteralepas canci on a continental slope at a depth of 229 m off Cape Nomamisaki in southern Japan. We developed a rearing method for the barnacles and studied their growth and reproduction at different food levels in the laboratory. A total of 136 individual H. canci were fed with Artemia salina larvae and brewer's yeast at three different food levels for 100 days. Both the growth and the ovary development were delayed when food availability was low, whereas the survival rate was lower at the high food level. In addition, an individual survived under complete starvation for 167 days. We concluded that H. canci has plastic life history traits that are adaptive for variable food availability.

  4. Occurrence and diversity of barnacles on international ships visiting Osaka Bay, Japan, and the risk of their introduction.

    PubMed

    Otani, M; Oumi, T; Uwai, S; Hanyuda, T; Prabowo, R E; Yamaguchi, T; Kawai, H

    2007-01-01

    The occurrence and diversity of barnacles attached to the hulls of two intercontinental bulk carriers were studied at the port in Osaka Bay, Japan, to assess the potential risk of introduction of exotic species to the inner part of the bay. Barnacles were sampled from the bulbous bows, near the midship draft marks, and around the propeller posts and rudders. Twenty-two species were found, with 14 of these not previously recorded in Osaka Bay, including four species not previously recorded elsewhere in Japan. From an assessment of environmental similarity between Osaka Bay and native ranges, of the 14 species, Elminius modestus and Amphibalanus variegatus were considered to have the highest risk of introduction to the inner part of the bay.

  5. Accessing transcriptomic data for ecologically important genes in the goose barnacle (Pollicipes pollicipes), with particular focus on cement proteins.

    PubMed

    Perina, A; von Reumont, B M; Martínez-Lage, A; González-Tizón, A M

    2014-06-01

    In this study 4310 expressed sequence tags (ESTs) were used to identify potentially useful transcripts for future studies in the gooseneck barnacle Pollicipes pollicipes (Gmelin, 1789). 119 ESTs were obtained in this work and 4191 were taken from Meusemann et al. (2010). The gooseneck barnacle is a sessile pedunculate cirripede of great economic importance that occurs in dense aggregations, and is harvested for human consumption. The assembly of these ESTs yielded 1805 unigenes (461 contigs and 1344 singlets). The identification of cement proteins in our data is particularly interesting for cirripedes. Only a small part of the assembled unigenes could be functionally annotated. However, our results greatly improve our understanding of the biological features of P. pollicipes. In addition to this, a large number of potentially interesting genes were identified in order to serve as the base for future evolutionary studies in P. pollicipes.

  6. The effect of water temperature and flow on respiration in barnacles: patterns of mass transfer versus kinetic limitation.

    PubMed

    Nishizaki, Michael T; Carrington, Emily

    2014-06-15

    In aquatic systems, physiological processes such as respiration, photosynthesis and calcification are potentially limited by the exchange of dissolved materials between organisms and their environment. The nature and extent of physiological limitation is, therefore, likely to be dependent on environmental conditions. Here, we assessed the metabolic sensitivity of barnacles under a range of water temperatures and velocities, two factors that influence their distribution. Respiration rates increased in response to changes in temperature and flow, with an interaction where flow had less influence on respiration at low temperatures, and a much larger effect at high temperatures. Model analysis suggested that respiration is mass transfer limited under conditions of low velocity (<7.5 cm (-1)) and high temperature (20-25°C). In contrast, limitation by uptake reaction kinetics, when the biotic capacity of barnacles to absorb and process oxygen is slower than its physical delivery by mass transport, prevailed at high flows (40-150 cm s(-1)) and low temperatures (5-15°C). Moreover, there are intermediate flow-temperature conditions where both mass transfer and kinetic limitation are important. Behavioral monitoring revealed that barnacles fully extend their cirral appendages at low flows and display abbreviated 'testing' behaviors at high flows, suggesting some form of mechanical limitation. In low flow-high temperature treatments, however, barnacles displayed distinct 'pumping' behaviors that may serve to increase ventilation. Our results suggest that in slow-moving waters, respiration may become mass transfer limited as temperatures rise, whereas faster flows may serve to ameliorate the effects of elevated temperatures. Moreover, these results underscore the necessity for approaches that evaluate the combined effects of multiple environmental factors when examining physiological and behavioral performance.

  7. Preparation and characterization of acorn starch/poly(lactic acid) composites modified with functionalized vegetable oil derivates.

    PubMed

    Li, Shouhai; Xia, Jianling; Xu, Yuzhi; Yang, Xuejuan; Mao, Wei; Huang, Kun

    2016-05-20

    Composites of acorn starch (AS) and poly(1actic acid) (PLA) modified with dimer fatty acid (DFA) or dimer fatty acid polyamide (DFAPA) were produced by a hot-melt extrusion method. The effects of DFA and DFAPA contents on the mechanical, hydrophobic, thermal properties and melt fluidity of the composites were studied under an invariable AS-to-PLA mass ratio of 40/60. SEM and DMA research results show that the compatibility of AS/PLA composites are determined by the dosage of DFA or DFAPA. The hydrophobicity and melt fluidity of composites are improved with the addition of DFA and DFAPA. The glass transition temperatures of the composites are all reduced remarkably by additives DFA and DFAPA. However, DFA and DFAPA exert different effects on the mechanical properties of AS/PLA composites. In the DFAPA-modified system, the tensile and flexural strength first increase and then decrease with the increase of DFAPA dosage; the mechanical strength is maximized when the dosage of DFAPA is 2 wt% of total weight. In the DFA-modified system, the tensile and flexural strength decrease with the increase of DFA dosage.

  8. Enhancement of local species richness in tundra by seed dispersal through guts of muskox and barnacle goose.

    PubMed

    Bruun, Hans Henrik; Lundgren, Rebekka; Philipp, Marianne

    2008-02-01

    The potential contribution of vertebrate-mediated seed rain to the maintenance of plant community richness in a High Arctic ecosystem was investigated. We analyzed viable seed content in dung of the four numerically most important terrestrial vertebrates in Northeast Greenland - muskox (Ovibos moschatus), barnacle goose (Branta leucopsis), Arctic fox (Alopex lagopus) and Arctic hare (Lepus arcticus). High numbers of plant propagules were found in the dung of muskox and barnacle goose. Seeds of many plant species were found in the faeces of one vertebrate species only. Propagule composition in barnacle goose droppings was relatively uniform over samples, with a high abundance of the nutritious bulbils of Polygonum viviparum (Bistorta vivipara), suggesting that geese have a narrow habitat preference and feed selectively. Propagule composition in muskox dung was diverse and heterogeneous among samples, suggesting a generalist approach in terms of food selection and the haphazard ingestion of plant propagules with foliage. The species composition of plant propagules in dung samples was different from that of the receiving plant communities (in terms of the Sørensen and Czekanowski dissimilarity indices), and dung deposition, especially by muskox, often brought new species to the receiving community. The results suggest that endozoochorous propagule dispersal in the Arctic has a great potential in the generation and maintenance of local species richness, albeit being little specialized. It is further suggested that endozoochory is an important means of long-distance dispersal and, thereby, of plant migration in response to climate change.

  9. Effects of Toxic Leachate from Commercial Plastics on Larval Survival and Settlement of the Barnacle Amphibalanus amphitrite.

    PubMed

    Li, Heng-Xiang; Getzinger, Gordon J; Ferguson, P Lee; Orihuela, Beatriz; Zhu, Mei; Rittschof, Daniel

    2016-01-19

    Plastic pollution represents a major and growing global problem. It is well-known that plastics are a source of chemical contaminants to the aquatic environment and provide novel habitats for marine organisms. The present study quantified the impacts of plastic leachates from the seven categories of recyclable plastics on larval survival and settlement of barnacle Amphibalanus (=Balanus) amphitrite. Leachates from plastics significantly increased barnacle nauplii mortality at the highest tested concentrations (0.10 and 0.50 m(2)/L). Hydrophobicity (measured as surface energy) was positively correlated with mortality indicating that plastic surface chemistry may be an important factor in the effects of plastics on sessile organisms. Plastic leachates significantly inhibited barnacle cyprids settlement on glass at all tested concentrations. Settlement on plastic surfaces was significantly inhibited after 24 and 48 h, but settlement was not significantly inhibited compared to the controls for some plastics after 72-96 h. In 24 h exposure to seawater, we found larval toxicity and inhibition of settlement with all seven categories of recyclable commercial plastics. Chemical analysis revealed a complex mixture of substances released in plastic leachates. Leaching of toxic compounds from all plastics should be considered when assessing the risks of plastic pollution.

  10. Regional variations of heavy metal concentrations in tissues of barnacles from the subtropical Pacific Coast of Mexico

    SciTech Connect

    Paez-Osuna, F.; Bojorquez-Leyva, H.; Ruelas-Inzunza, J.

    1999-07-01

    Concentrations of Cd, Cu, Cr, Fe, Mn, Ni, Ag, Pb, and Zn in soft and hard tissues of barnacles from eight sampling sites in six harbors on the subtropical Pacific Coast of Mexico were determined by atomic absorption spectrophotometry. Some inter-regional differences in metal concentrations, especially concerning Zn, Mn, Fe, Cd, and Pb, were identified. The lowest concentrations of Cu, Cr, Fe, and Ag were observed in the barnacle populations from Ceuta Lagoon, an uncontaminated site with rural agriculture and semi-intensive shrimp farms in the surroundings. Conversely, the highest concentrations of: (1) Zn, Cu, and Ag were found in the soft tissues of Balanus eburneus from Mazatlan piers; (2) Pb, Ni, and Cd in the soft tissue of Megabalanus coccopoma from Puerto Vallarta; (3) Fe in the hard tissue of Balanus sp. from Guaymas Harbour; and (4) Mn in the hard tissue of M. coccopoma from Mazatlan Harbour. Inter-comparison of the present data indicates that the soft (mainly Cd, Cu, Pb, and Zn) and the hard (mainly for Fe and Mn) tissues are useful in detecting areas of selected metallic contaminants. Barnacles such as B. eburneus, M. coccopoma, and Fistulobalanus dentivarians appear to be convenient biomonitors for identification of coastal waters exposed to Cd, Pb, Cu, Zn, Ni, Mn, Fe, and Ag in the American region of the subtropical Pacific.

  11. A protective coat of microorganisms on macroalgae: inhibitory effects of bacterial biofilms and epibiotic microbial assemblages on barnacle attachment.

    PubMed

    Nasrolahi, Ali; Stratil, Stephanie B; Jacob, Katharina J; Wahl, Martin

    2012-09-01

    Effects of epibiotic bacteria associated with macroalgae on barnacle larval attachment were investigated. Eight bacterial isolates obtained from samples of three macroalga species were cultured as monospecies bacterial films and tested for their activity against barnacle (Amphibalanus improvisus) attachment in field experiments (Western Baltic Sea). Furthermore, natural biofilm communities associated with the surface of the local brown alga, Fucus vesiculosus, which were exposed to different temperatures (5, 15 and 20 °C), were harvested and subsequently tested. Generally, monospecies bacterial biofilms, as well as natural microbial assemblages, inhibited barnacle attachment by 20-67%. denaturing gradient gel electrophoresis fingerprints showed that temperature treatment shifted the bacterial community composition and weakened the repellent effects at 20 °C. Repellent effects were absent when settlement pressure of cyprids was high. Nonviable bacteria tended to repel cyprids when compared to the unfilmed surfaces. We conclude that biofilms can have a repellent effect benefiting the host by preventing heavy fouling on its surface. However, severe settlement pressure, as well as stressful temperature, may reduce the protective effects of the alga's biofilm. Our results add to the notion that the performance of F. vesiculosus may be reduced by multiple stressors in the course of global warming.

  12. Stable isotopes in barnacles as a tool to understand green sea turtle (Chelonia mydas) regional movement patterns

    NASA Astrophysics Data System (ADS)

    Detjen, M.; Sterling, E.; Gómez, A.

    2015-12-01

    Sea turtles are migratory animals that travel long distances between their feeding and breeding grounds. Traditional methods for researching sea turtle migratory behavior have important disadvantages, and the development of alternatives would enhance our ability to monitor and manage these globally endangered species. Here we report on the isotope signatures in green sea-turtle (Chelonia mydas) barnacles (Platylepas sp.) and discuss their potential relevance as tools with which to study green sea turtle migration and habitat use patterns. We analyzed oxygen (δ18O) and carbon (δ13C) isotope ratios in barnacle calcite layers from specimens collected from green turtles captured at the Palmyra Atoll National Wildlife Refuge (PANWR) in the central Pacific. Carbon isotopes were not informative in this study. However, the oxygen isotope results suggest likely regional movement patterns when mapped onto a predictive oxygen isotope map of the Pacific. Barnacle proxies could therefore complement other methods in understanding regional movement patterns, informing more effective conservation policy that takes into account connectivity between populations.

  13. Stable isotopes in barnacles as a tool to understand green sea turtle (Chelonia mydas) regional movement patterns

    NASA Astrophysics Data System (ADS)

    Detjen, M.; Sterling, E.; Gómez, A.

    2015-03-01

    Sea turtles are migratory animals that travel long distances between their feeding and breeding grounds. Traditional methods for researching sea turtle migratory behavior have important disadvantages, and the development of alternatives would enhance our ability to monitor and manage these globally endangered species. Here we report on the isotope signatures in green sea turtle (Chelonia mydas) barnacles (Platylepas sp.) and discuss their potential relevance as tools with which to study green sea turtle migration and habitat use patterns. We analyzed oxygen (δ18O) and carbon (δ13C) isotope ratios in barnacle calcite layers from specimens collected from green turtles captured at the Palmyra Atoll National Wildlife Refuge (PANWR) in the Central Pacific. Carbon isotopes were not informative in this study. However, the oxygen isotope results suggest likely regional movement patterns when mapped onto a predictive oxygen isotope map of the Pacific. Barnacle proxies could therefore complement other methods in understanding regional movement patterns, informing more effective conservation policy that takes into account connectivity between populations.

  14. Enhancement of local species richness in tundra by seed dispersal through guts of muskox and barnacle goose.

    PubMed

    Bruun, Hans Henrik; Lundgren, Rebekka; Philipp, Marianne

    2008-02-01

    The potential contribution of vertebrate-mediated seed rain to the maintenance of plant community richness in a High Arctic ecosystem was investigated. We analyzed viable seed content in dung of the four numerically most important terrestrial vertebrates in Northeast Greenland - muskox (Ovibos moschatus), barnacle goose (Branta leucopsis), Arctic fox (Alopex lagopus) and Arctic hare (Lepus arcticus). High numbers of plant propagules were found in the dung of muskox and barnacle goose. Seeds of many plant species were found in the faeces of one vertebrate species only. Propagule composition in barnacle goose droppings was relatively uniform over samples, with a high abundance of the nutritious bulbils of Polygonum viviparum (Bistorta vivipara), suggesting that geese have a narrow habitat preference and feed selectively. Propagule composition in muskox dung was diverse and heterogeneous among samples, suggesting a generalist approach in terms of food selection and the haphazard ingestion of plant propagules with foliage. The species composition of plant propagules in dung samples was different from that of the receiving plant communities (in terms of the Sørensen and Czekanowski dissimilarity indices), and dung deposition, especially by muskox, often brought new species to the receiving community. The results suggest that endozoochorous propagule dispersal in the Arctic has a great potential in the generation and maintenance of local species richness, albeit being little specialized. It is further suggested that endozoochory is an important means of long-distance dispersal and, thereby, of plant migration in response to climate change. PMID:17990003

  15. Multi-seasonal barnacle (Balanus improvisus) protection achieved by trace amounts of a macrocyclic lactone (ivermectin) included in rosin-based coatings.

    PubMed

    Pinori, Emiliano; Berglin, Mattias; Brive, Lena M; Hulander, Mats; Dahlström, Mia; Elwing, Hans

    2011-10-01

    Rosin-based coatings loaded with 0.1% (w/v) ivermectin were found to be effective in preventing colonization by barnacles (Balanus improvisus) both on test panels as well as on yachts for at least two fouling seasons. The leaching rate of ivermectin was determined by mass-spectroscopy (LC/MS-MS) to be 0.7 ng cm(-2) day(-1). This low leaching rate, as deduced from the Higuchi model, is a result of the low loading, low water solubility, high affinity to the matrix and high molar volume of the model biocide. Comparison of ivermectin and control areas of panels immersed in the field showed undisturbed colonisation of barnacles after immersion for 35 days. After 73 days the mean barnacle base plate area on the controls was 13 mm(2), while on the ivermectin coating it was 3 mm(2). After 388 days, no barnacles were observed on the ivermectin coating while the barnacles on the control coating had reached a mean of 60 mm(2). In another series of coated panels, ivermectin was dissolved in a cosolvent mixture of propylene glycol and glycerol formal prior to the addition to the paint base. This method further improved the anti-barnacle performance of the coatings. An increased release rate (3 ng cm(-2) day(-1)) and dispersion of ivermectin, determined by fluorescence microscopy, and decreased hardness of the coatings were the consequences of the cosolvent mixture in the paint. The antifouling mechanism of macrocyclic lactones, such as avermectins, needs to be clarified in further studies. Beside chronic intoxication as ivermectin is slowly released from the paint film even contact intoxication occurring inside the coatings, triggered by penetration of the coating by barnacles, is a possible explanation for the mode of action and this is under investigation.

  16. Patterns of distribution and abundance of the stalked barnacle (Pollicipes pollicipes) in the central and southwest coast of continental Portugal

    NASA Astrophysics Data System (ADS)

    Sousa, Alina; Jacinto, David; Penteado, Nélia; Martins, Pedro; Fernandes, Joana; Silva, Teresa; Castro, João J.; Cruz, Teresa

    2013-10-01

    The stalked barnacle Pollicipes pollicipes is a cirriped crustacean that lives on very exposed rocky shores. This barnacle is the most important economical resource on intertidal rocky shores of continental Portugal. It is highly prized as food and heavily exploited (professional and recreational fishery), but fishery data are scarce and do not estimate the real pressure upon this resource. Despite its socio-economic interest, specific regulations on this fishery are recent and different along the Portuguese coast. Four regions with different regulation can be identified: the marine reserve “Reserva Natural das Berlengas” (RNB) and the marine park “Parque Marinho Prof. Luiz Saldanha” (PMLS) (both in central Portugal); the natural park located in SW Portugal (“Parque Natural do Sudoeste Alentejano e Costa Vicentina”, PNSACV); and the rest of the coast. The main objective of the present study was to study the spatial patterns of percentage cover, biomass, density and size structure of P. pollicipes in areas with different exploitation regimes, including harvested areas and no-take areas. Additionally, variability between mid shore and low shore barnacles was also analysed. Seven areas were sampled with a variable number of sites (a total of 24) randomly sampled in each area during 2011. Photographs and image analysis (percentage cover) and destructive sampling (density, biomass and size) were used. In general, percentage cover, biomass and density were higher in mid shore when compared to low shore, namely in harvested areas. Low shore barnacles had a higher proportion of adults with moderate and high commercial value, while juveniles were relatively more abundant at mid shore. There were no consistent differences in the patterns of distribution and abundance of P. pollicipes among areas subject to different exploitation regimes. The most different area was the harvested area by professional fishers in RNB, where the highest biomass within the study was

  17. Growth and molting in epizoic pedunculate barnacles genus Octolasmis (Crustacea: Thecostraca: Cirripedia: Thoracica).

    PubMed

    Blomsterberg, Mikkel; Glenner, Henrik; Høeg, Jens T

    2004-05-01

    Scanning electron microscopy, light microscopy, and histology were used to study growth in species of the pedunculate barnacle genus Octolasmis (O. angulata, O. cor, O. californiana, O. mülleri). These species are epizoic in the gill chamber of portunid crabs and have highly reduced capitular shell plates, with large areas of general cuticle in between. The external integument grows by means of a system of narrow growth zones, one encircling the peduncle and a Y-shaped system on either side of the capitulum. Growth is by a regular series of molts, but shedding of old cuticle and production of new layers is entirely restricted to the growth zones. Just prior to ecdysis, the new cuticle lies in a highly folded fashion beneath the old cuticle that is about to be shed. At ecdysis, the old cuticle breaks along the margins of the growth zones and the resulting scars remain as a system of "ecdysial lines" along either side of the zone. Once exposed after ecdysis, the new cuticle remains as a part of the permanent external integument. The growth zones divide the externa into five cuticular areas, two on the peduncle and three on the capitulum. The calcareous shell plates (carina, paired scuta, and, when present, paired terga) all lie within the capitular regions and the ecdysial lines pass across, not around, these mineralized areas. The number, relative spacing, and topology of the ecdysial lines form a record of the growth history of the specimen. These and other growth patterns demonstrate that size increase is due to the formation of new cuticle by molting in the growth zones, while expansion of the shell plates by mineralization follows only after production of the new cuticle. Thus, although specialized, growth in Octolasmis still complies with the general crustacean model, complicated only by the mineralization of parts of the capitular cuticle into shell plates. The results are compared with the very scarce information on molting in other barnacles. We argue that

  18. Identification of a transformer homolog in the acorn worm, Saccoglossus kowalevskii, and analysis of its activity in insect cells.

    PubMed

    Suzuki, Masataka G; Tochigi, Mayuko; Sakaguchi, Honami; Aoki, Fugaku; Miyamoto, Norio

    2015-06-01

    The transformer (tra) gene is an intermediate component of the sex determination hierarchy in many insect species. The homolog of tra is also found in two branchiopod crustacean species but is not known outside arthropods. We have isolated a tra homolog in the acorn worm, Saccoglossus kowalevskii, which is a hemichordate belonging to the deuterostome superphylum. The full-length complementary DNA (cDNA) of the S. kowalevskii tra homolog (Sktra) has a 3786-bp open reading frame that encodes a 1261-amino acid sequence including a TRA-CAM domain and an arginine/serine (RS)-rich domain, both of which are characteristic of TRA orthologs. Reverse transcription PCR (RT-PCR) analyses demonstrated that Sktra showed no differences in expression patterns between testes and ovaries, but its expression level was approximately 7.5-fold higher in the testes than in the ovaries. TRA, together with the protein product of the transformer-2 (tra-2) gene, assembles on doublesex (dsx) pre-messenger RNA (mRNA) via the cis-regulatory element, enhancing female-specific splicing of dsx in Drosophila. To understand functional conservation of the SkTRA protein as a dsx-splicing activator, we investigated whether SkTRA is capable of inducing female-specific splicing of the Drosophila dsx. Ectopic expression of Sktra cDNA in insect cultured cells did not induce the female-specific splicing of dsx. On the other hand, forced expression of Sktra-2 (a tra-2 homolog of S. kowalevskii) was able to induce the female-specific dsx splicing. These results demonstrate that the function as a dsx-splicing activator is not conserved in SkTRA even though SkTRA-2 is capable of functionally replacing the Drosophila TRA-2. We have also found a tra homolog in an echinoderm genome. This study provides the first evidence that that tra is conserved not only in arthropods but also in basal species of deuterostoms.

  19. Predators on rocky shores in the northern Atlantic: Can the results of local experiments be generalized on a geographical scale?

    NASA Astrophysics Data System (ADS)

    Ingólfsson, Agnar

    2009-07-01

    Experimental manipulations of invertebrate prey and predators on rocky shores have been done by many authors. In the northern Atlantic the predators involved are usually the green crab Carcinus maenas and/or the dogwhelk Nucella lapillus, and the prey species studied are acorn barnacles (balanid Cirripedia), mussels ( Mytilus spp.) and winkles ( Littorina spp.). Usually the predators are found to have a regulating "top-down" effect on the prey species. In Iceland the acorn barnacle Semibalanus balanoides, the blue mussel Mytilus edulis and the flat periwinkle Littorina obtusata (including to some extent Littorina mariae) are found on rocky shores all around Iceland in what would seem to be near-optimal physical conditions. The predators Carcinus maenas and Nucella lapillus, on the other hand, are relatively southern species that do not thrive on the colder coasts of Iceland. Thus general surveys of different coasts of Iceland would seem to offer opportunities to see whether the results of local experiments can be discerned on a geographical scale (hundreds of km). The roughly 4900 km of the rocky coastline in Iceland was in this study subdivided into four regions, I-IV, according to the commonness or presence of the two predators. With the hope of reducing compounding factors the surveys were confined to sheltered or semi-sheltered fucoid shores, which were further divided into Ascophyllum (more sheltered) and Fucus vesiculosus (less sheltered) shores. Estuaries or other low-salinity environments were avoided. The study was based on 761 stations distributed around the rocky coastline on these two types of shores. The results for barnacles and mussels, being generally more abundant in regions were predators were scarce or absent, and being less common in Ascophyllum than F. vesiculosus shores in contrast to the predatory dogwelks, were in large measure in accord with predictions from experiments indicating "top-down" regulation. The results for the periwinkles

  20. Population and life-stage specific sensitivities to temperature and salinity stress in barnacles.

    PubMed

    Nasrolahi, Ali; Havenhand, Jonathan; Wrange, Anna-Lisa; Pansch, Christian

    2016-01-01

    Temperature and salinity shape the distribution and genetic structure of marine communities. Future warming and freshening will exert an additional stress to coastal marine systems. The extent to which organisms respond to these shifts will, however, be mediated by the tolerances of all life-stages and populations of species and their potential to adapt. We investigated nauplius and cypris larvae of the barnacle Balanus (Amphibalanus) improvisus from the Swedish west coast with respect to temperature (12, 20, and 28 °C) and salinity (5, 15, and 30) tolerances. Warming accelerated larval development and increased overall survival and subsequent settlement success. Nauplii developed and metamorphosed best at intermediate salinity. This was also observed in cypris larvae when the preceding nauplii stages had been reared at a salinity of 30. Direct comparisons of the present findings with those on a population from the more brackish Baltic Sea demonstrate contrasting patterns. We conclude that i) B. improvisus larvae within the Baltic region will be favoured by near-future seawater warming and freshening, that ii) salinity tolerances of larvae from the two different populations reflect salinities in their native habitats, but are nonetheless suboptimal and that iii) this species is generally highly plastic with regard to salinity. PMID:27582433

  1. Modulation of barnacle (Balanus amphitrite Darwin) cyprid settlement behavior by sulfobetaine and carboxybetaine methacrylate polymer coatings.

    PubMed

    Aldred, Nick; Li, Guozhu; Gao, Ye; Clare, Anthony S; Jiang, Shaoyi

    2010-08-01

    Zwitterionic polymers such as poly(sulfobetaine methacrylate) (polySBMA) and poly(carboxybetaine methacrylate) (polyCBMA) have demonstrated impressive fouling-resistance against proteins and mammalian cells. In this paper, the effects of these surface chemistries on the settlement and behavior of an ubiquitous fouling organism, the cypris larva of the barnacle Balanus amphitrite (=Amphibalanus amphitrite), were studied in the laboratory. Conventional settlement assays and behavioral analysis of cyprids using Noldus Ethovision 3.1 demonstrated significant differences in settlement and behavior on different surfaces. Cyprids did not settle on the polySBMA or polyCBMA surfaces over the course of the assay, whereas settlement on glass occurred within expected limits. Individual components of cyprid behavior were shown to differ significantly between glass, polySBMA and polyCBMA. Cyprids also responded differently to the two zwitterionic surfaces. On polySBMA, cyprids were unwilling or unable to settle, whereas on polyCBMA cyprids did not attempt exploration and left the surface quickly. In neither case was toxicity observed. It is concluded that a zwitterionic approach to fouling-resistant surface development has considerable potential in marine applications. PMID:20658383

  2. Variations: Darwin's finches, sea barnacles and the side effects of antidepressants.

    PubMed

    Lieb, Julian

    2008-01-01

    "It may metaphorically be said," Darwin wrote, "that natural selection is daily and hourly scrutinizing, throughout the world, the slightest variations; rejecting those that are bad, preserving and adding up all that are good; silently and insensibly working, whenever and wherever opportunity offers..." Variation is a principle of nature, without which natural selection could not operate, and life exist. Darwin believed that natural selection would make nature "more and more diversified." Variation occurs in the clutch sizes of birds, the color of hair and skin, the annual temperature, in language and speech, the direction of local Magnetic North and True North, and the variation of pathogens (antigenic variation). Antidepressants act as probes, burrowing into the deepest recesses of cells, and signaling physiological and pathological information to observers. They have at least forty side effects that are not only variations, but often paradoxes that would have fascinated Charles Darwin, who had the keenest interest in the variation of the beaks of finches and in sea barnacles. PMID:17681431

  3. Effect of temperature on membrane potential and ionic fluxes in intact and dialysed barnacle muscle fibres

    PubMed Central

    Dipolo, Reinaldo; Latorre, Ramón

    1972-01-01

    1. The temperature-dependent component of the resting potential in intact, cannulated and dialysed fibres from the muscle of the barnacle Balanus nubilus was studied under a variety of different experimental conditions. A decrease in temperature from 22 to 12° C produced a mean depolarization of 10 mV. 2. Neither addition of strophanthidin, nor replacement of external sodium by lithium affect the voltage shift induced by temperature. However, the magnitude of the voltage shift depends on the external chloride and potassium concentration. 3. The dialysis technique was applied to measure the potassium, chloride and sodium fluxes as a function of temperature. The Q10 for the passive fluxes of these ions was 1·9, 1·7, and 1·4 respectively. 4. The temperature-dependent changes in the passive ionic fluxes combined with the inability of inhibitors of the sodium pump to alter the temperature dependence of the resting potential suggest that the change induced by temperature on the resting potential is primarily caused by a change in the passive permeability ratios, and is not related to active ion transport. PMID:5074384

  4. Phylogeographic structure and northward range expansion in the barnacle Chthamalus fragilis

    PubMed Central

    Bukša, Filip; Bockrath, Katherine; Wares, John P.; Pineda, Jesús

    2015-01-01

    The barnacle Chthamalus fragilis is found along the US Atlantic seaboard historically from the Chesapeake Bay southward, and in the Gulf of Mexico. It appeared in New England circa 1900 coincident with warming temperatures, and is now a conspicuous member of rocky intertidal communities extending through the northern shore of Cape Cod, Massachusetts. The origin of northern C. fragilis is debated. It may have spread to New England from the northern end of its historic range through larval transport by ocean currents, possibly mediated by the construction of piers, marinas, and other anthropogenic structures that provided new hard substrate habitat. Alternatively, it may have been introduced by fouling on ships originating farther south in its historic distribution. Here we examine mitochondrial cytochrome c oxidase I sequence diversity and the distribution of mitochondrial haplotypes of C. fragilis from 11 localities ranging from Cape Cod, to Tampa Bay, Florida. We found significant genetic structure between northern and southern populations. Phylogenetic analysis revealed three well-supported reciprocally monophyletic haplogroups, including one haplogroup that is restricted to New England and Virginia populations. While the distances between clades do not suggest cryptic speciation, selection and dispersal barriers may be driving the observed structure. Our data are consistent with an expansion of C. fragilis from the northern end of its mid-19th century range into Massachusetts. PMID:25945315

  5. Population and life-stage specific sensitivities to temperature and salinity stress in barnacles

    PubMed Central

    Nasrolahi, Ali; Havenhand, Jonathan; Wrange, Anna-Lisa; Pansch, Christian

    2016-01-01

    Temperature and salinity shape the distribution and genetic structure of marine communities. Future warming and freshening will exert an additional stress to coastal marine systems. The extent to which organisms respond to these shifts will, however, be mediated by the tolerances of all life-stages and populations of species and their potential to adapt. We investigated nauplius and cypris larvae of the barnacle Balanus (Amphibalanus) improvisus from the Swedish west coast with respect to temperature (12, 20, and 28 °C) and salinity (5, 15, and 30) tolerances. Warming accelerated larval development and increased overall survival and subsequent settlement success. Nauplii developed and metamorphosed best at intermediate salinity. This was also observed in cypris larvae when the preceding nauplii stages had been reared at a salinity of 30. Direct comparisons of the present findings with those on a population from the more brackish Baltic Sea demonstrate contrasting patterns. We conclude that i) B. improvisus larvae within the Baltic region will be favoured by near-future seawater warming and freshening, that ii) salinity tolerances of larvae from the two different populations reflect salinities in their native habitats, but are nonetheless suboptimal and that iii) this species is generally highly plastic with regard to salinity. PMID:27582433

  6. Speciation and the establishment of zonation in an intertidal barnacle: specific settlement vs. selection.

    PubMed

    Appelbaum, L; Achituv, Y; Mokady, O

    2002-09-01

    The tropical barnacle Tetraclita forms a belt on hard substrates in the intertidal zone of the Red Sea. Based on morphological data, three distinct species were suggested to exist, occupying different vertical levels - T. barnesorum, T. rufotincta and T. achituvi. In this study we used molecular (12S mitochondrial ribosomal DNA) and ecological data to examine whether this morphological variability reflects genetic differences, or is a result of environmental factors. Adults and spats, collected from settlement plates, were censused and screened genotypically using single strand conformation polymorphism (SSCP) analysis, and settlement dynamics was recorded. We provide evidence for the existence of only two distinct species, and point out both phenotypic plasticity and convergence within and between the proposed species. Cyprids of T. achituvi settle specifically at the lower part of the Tetraclita belt, and feature one phenotype. In contrast, T. rufotincta, occupying the upper and middle portions of the Tetraclita belt, settles throughout the range, shows phenotypic plasticity (three variants), and presumably undergoes selection at the lower part. Thus, the vertical zonation of Tetraclita is produced by the combination of pre-settlement and post-settlement factors, in T. achituvi and T. rufotincta, respectively. The examined system may offer a model in which to study the mechanisms underlying sympatric speciation.

  7. Can body burden in the barnacle Balanus amphitrite indicate seasonal variation in cadmium concentrations?

    NASA Astrophysics Data System (ADS)

    da Silva, Eduardo Teixeira; Ridd, Michael; Klumpp, David

    2005-10-01

    Two three-month sampling programs measuring Cd in the environment and a biomonitor ( Balanus amphitrite) were undertaken in the austral winter of 2002 and summer of 2004 in Ross Creek, North Queensland, Australia. The objective was to test whether the burden of Cd in the biomonitor responded to any variation in the dissolved and particulate phase Cd concentrations in Ross Creek, caused by rainfall variation. The barnacles from the most Cd contaminated site were exposed to a total Cd concentration twice that in winter (93.6 ng L -1) than in summer (45.6 ng L -1). However, no significant variation was identified for the Cd concentration in the biomonitor between winter (8.4 mg kg -1) and summer (7.4 mg kg -1). A budget analysis based on a bioenergetic kinetic model indicated that Cd flux from food contributes >80% to the Cd concentration in B. amphitrite. A sensitivity analysis showed that physiological characteristics of the biomonitor are the key parameters controlling Cd accumulation in B. amphitrite, rather than the metal concentration in the dissolved or particulate phases. These two model's outcomes suggest that a tight coupling between Cd in the biomonitor and its availability in the environment does not occur.

  8. Variations: Darwin's finches, sea barnacles and the side effects of antidepressants.

    PubMed

    Lieb, Julian

    2008-01-01

    "It may metaphorically be said," Darwin wrote, "that natural selection is daily and hourly scrutinizing, throughout the world, the slightest variations; rejecting those that are bad, preserving and adding up all that are good; silently and insensibly working, whenever and wherever opportunity offers..." Variation is a principle of nature, without which natural selection could not operate, and life exist. Darwin believed that natural selection would make nature "more and more diversified." Variation occurs in the clutch sizes of birds, the color of hair and skin, the annual temperature, in language and speech, the direction of local Magnetic North and True North, and the variation of pathogens (antigenic variation). Antidepressants act as probes, burrowing into the deepest recesses of cells, and signaling physiological and pathological information to observers. They have at least forty side effects that are not only variations, but often paradoxes that would have fascinated Charles Darwin, who had the keenest interest in the variation of the beaks of finches and in sea barnacles.

  9. Water and electrolyte content of the myofilament phase in the chemically skinned barnacle fiber

    PubMed Central

    1980-01-01

    Muscle fibers from the giant barnacle, Balanus nubilus, were placed inside the lumen of a porous glass capillary and equilibrated for 48 h in an electrolyte solution containing 2% Tween. The glass capillary prevented the chemically "skinned" fiber from swelling with a water content beyond 80%. Isotope exchange studies using 22Na, 42K, and 36Cl indicated the existence of an intermediate rate constant and compartment which varied with pH. This intermediate rate was attributed to counter-ions and co-ions in the myofilament phase. Analysis of the electrolyte composition of the fiber at pH 8 predicts that the myofilaments contain about 0.3 of the fiber water, and that a -15 mV Donnan potential exists at the myofilament surface. An open-tipped (1- micrometer) microelectrode in the skinned fiber measured a potential (similar in magnitude to the Donnan potential), which decreased and reversed sign as the pH was lowered. The measured cation contents of the fiber between pH 5 and 8 were found to be similar to the cation contents predicted from the measured Donnan potentials. The net negative charge of the myofilaments at pH 7.5 and at ionic strength 0.56 is estimated to be 41 eq per 10(5) g of dry weight. PMID:7189772

  10. The state of the fishery, conservation and management of the stalked barnacle Pollicipes pollicipes in Portugal.

    PubMed

    Cruz, Teresa; Jacinto, David; Sousa, Alina; Penteado, Nélia; Pereira, Diana; Fernandes, Joana N; Silva, Teresa; Castro, João J

    2015-12-01

    The stalked barnacle Pollicipes pollicipes is the most important intertidal economical resource in Portugal. The assessment of the state of the fishery, conservation and management of P. pollicipes in Portugal was made for the first time in three regions with different regulations regarding this fishery: two marine protected areas ("Reserva Natural das Berlengas", RNB; and "Parque Natural do Sudoeste Alentejano e Costa Vicentina", PNSACV); and the Center coast. Different approaches (independent observations, inquiries, logbooks) and sources of data (past and recent) were used. An overall negative tendency of the state of the fishery and conservation of this resource was observed in all regions, with the exception of the stable tendency detected in PNSACV when using the inquiries approach. A weak management was considered to be in practice at Center and at PNSACV, while an acceptable management was inferred for RNB. We recommend a change into a co-management system that should be tested in pilot regions as RNB and/or PNSACV.

  11. Population and life-stage specific sensitivities to temperature and salinity stress in barnacles.

    PubMed

    Nasrolahi, Ali; Havenhand, Jonathan; Wrange, Anna-Lisa; Pansch, Christian

    2016-09-01

    Temperature and salinity shape the distribution and genetic structure of marine communities. Future warming and freshening will exert an additional stress to coastal marine systems. The extent to which organisms respond to these shifts will, however, be mediated by the tolerances of all life-stages and populations of species and their potential to adapt. We investigated nauplius and cypris larvae of the barnacle Balanus (Amphibalanus) improvisus from the Swedish west coast with respect to temperature (12, 20, and 28 °C) and salinity (5, 15, and 30) tolerances. Warming accelerated larval development and increased overall survival and subsequent settlement success. Nauplii developed and metamorphosed best at intermediate salinity. This was also observed in cypris larvae when the preceding nauplii stages had been reared at a salinity of 30. Direct comparisons of the present findings with those on a population from the more brackish Baltic Sea demonstrate contrasting patterns. We conclude that i) B. improvisus larvae within the Baltic region will be favoured by near-future seawater warming and freshening, that ii) salinity tolerances of larvae from the two different populations reflect salinities in their native habitats, but are nonetheless suboptimal and that iii) this species is generally highly plastic with regard to salinity.

  12. siRNA transfection in larvae of the barnacle Amphibalanus amphitrite.

    PubMed

    Zhang, Gen; He, Li-Sheng; Wong, Yue Him; Yu, Li; Qian, Pei-Yuan

    2015-08-01

    RNA interference (RNAi) provides an efficient and specific technique for functional genomic studies. Yet, no successful application of RNAi has been reported in barnacles. In this study, siRNA against p38 MAPK was synthesized and then transfected into A. amphitrite larvae at either the nauplius or cyprid stage, or at both stages. Effects of siRNA transfection on the p38 MAPK level were hardly detectable in the cyprids when they were transfected at the nauplius stage. In contrast, larvae that were transfected at the cyprid stage showed lower levels of p38 MAPK than the blank and reagent controls. However, significantly decreased levels of phosphorylated p38 MAPK (pp38 MAPK) and reduced settlement rates were observed only in 'double transfections', in which larvae were exposed to siRNA solution at both the nauplius and cyprid stages. A relatively longer transfection time and more larval cells directly exposed to siRNA might explain the higher efficiency of double transfection experiments.

  13. The state of the fishery, conservation and management of the stalked barnacle Pollicipes pollicipes in Portugal.

    PubMed

    Cruz, Teresa; Jacinto, David; Sousa, Alina; Penteado, Nélia; Pereira, Diana; Fernandes, Joana N; Silva, Teresa; Castro, João J

    2015-12-01

    The stalked barnacle Pollicipes pollicipes is the most important intertidal economical resource in Portugal. The assessment of the state of the fishery, conservation and management of P. pollicipes in Portugal was made for the first time in three regions with different regulations regarding this fishery: two marine protected areas ("Reserva Natural das Berlengas", RNB; and "Parque Natural do Sudoeste Alentejano e Costa Vicentina", PNSACV); and the Center coast. Different approaches (independent observations, inquiries, logbooks) and sources of data (past and recent) were used. An overall negative tendency of the state of the fishery and conservation of this resource was observed in all regions, with the exception of the stable tendency detected in PNSACV when using the inquiries approach. A weak management was considered to be in practice at Center and at PNSACV, while an acceptable management was inferred for RNB. We recommend a change into a co-management system that should be tested in pilot regions as RNB and/or PNSACV. PMID:26507313

  14. siRNA transfection in larvae of the barnacle Amphibalanus amphitrite.

    PubMed

    Zhang, Gen; He, Li-Sheng; Wong, Yue Him; Yu, Li; Qian, Pei-Yuan

    2015-08-01

    RNA interference (RNAi) provides an efficient and specific technique for functional genomic studies. Yet, no successful application of RNAi has been reported in barnacles. In this study, siRNA against p38 MAPK was synthesized and then transfected into A. amphitrite larvae at either the nauplius or cyprid stage, or at both stages. Effects of siRNA transfection on the p38 MAPK level were hardly detectable in the cyprids when they were transfected at the nauplius stage. In contrast, larvae that were transfected at the cyprid stage showed lower levels of p38 MAPK than the blank and reagent controls. However, significantly decreased levels of phosphorylated p38 MAPK (pp38 MAPK) and reduced settlement rates were observed only in 'double transfections', in which larvae were exposed to siRNA solution at both the nauplius and cyprid stages. A relatively longer transfection time and more larval cells directly exposed to siRNA might explain the higher efficiency of double transfection experiments. PMID:26113139

  15. Phylogeographic structure and northward range expansion in the barnacle Chthamalus fragilis.

    PubMed

    Govindarajan, Annette F; Bukša, Filip; Bockrath, Katherine; Wares, John P; Pineda, Jesús

    2015-01-01

    The barnacle Chthamalus fragilis is found along the US Atlantic seaboard historically from the Chesapeake Bay southward, and in the Gulf of Mexico. It appeared in New England circa 1900 coincident with warming temperatures, and is now a conspicuous member of rocky intertidal communities extending through the northern shore of Cape Cod, Massachusetts. The origin of northern C. fragilis is debated. It may have spread to New England from the northern end of its historic range through larval transport by ocean currents, possibly mediated by the construction of piers, marinas, and other anthropogenic structures that provided new hard substrate habitat. Alternatively, it may have been introduced by fouling on ships originating farther south in its historic distribution. Here we examine mitochondrial cytochrome c oxidase I sequence diversity and the distribution of mitochondrial haplotypes of C. fragilis from 11 localities ranging from Cape Cod, to Tampa Bay, Florida. We found significant genetic structure between northern and southern populations. Phylogenetic analysis revealed three well-supported reciprocally monophyletic haplogroups, including one haplogroup that is restricted to New England and Virginia populations. While the distances between clades do not suggest cryptic speciation, selection and dispersal barriers may be driving the observed structure. Our data are consistent with an expansion of C. fragilis from the northern end of its mid-19th century range into Massachusetts. PMID:25945315

  16. Self-assembling peptide inspired by a barnacle underwater adhesive protein.

    PubMed

    Nakano, Masahiro; Shen, Jian-Ren; Kamino, Kei

    2007-06-01

    An underwater bioadhesive generally comprises a multiprotein complex that provides a molecular basis for self-assembly. We report here a new class of self-assembling peptide inspired by a 20 kDa barnacle cement protein. Studies on the chemically synthesized 24-residue peptide have revealed that (1) it underwent irreversible self-assembly upon the addition of salt, (2) the self-assembly was started at a salt concentration close to that of seawater with noncovalent intermolecular interactions, (3) the self-assembled material resembled a macroscopic membrane of interwoven nanofilaments, (4) incubation in an alkaline pH range formed the intramolecular disulfide bond of a peptide molecule, thus triggering a conformation change of the molecule, and (5) conformational change of the building block promoted the formation of a nanofiber, resulting in the display of a three-dimensional meshlike mesoscopic structure with defined pores having a diameter of approximately 200 nm. The peptide is likely to provide a suitable basis for further development of peptide-based materials.

  17. Kinetics of oxygen consumption after a flash of light in the lateral ocellus of the barnacle.

    PubMed

    Poitry, S; Widmer, H

    1988-10-01

    Until recently, polarographic methods for measuring the time course of transient changes in the rate of oxygen consumption (DeltaQO(2)) have been applied only to tissue preparations containing thousands of cells. Here, we describe DeltaQO(2) measurements on the lateral ocellus of the barnacle (Balanus eburneus) which contains only three photoreceptor cells. The decrement of partial pressure of oxygen (DeltaPO(2)) elicited by an 80 ms flash of light was measured near the cells with a microelectrode and the DeltaQO(2) was calculated from the DeltaPO(2) using a model of diffusion with spherical symmetry. As shown by mathematical simulation, the exact shape of the preparation is not crucial for our measurements of the time course of the DeltaQO(2). For a given DeltaQO(2), the model describes correctly the attenuation of the DeltaPO(2) measured at increased distances from the preparation. To know more about the mechanisms controlling the DeltaQO(2), we compared it with the electrical response of the photoreceptor cells: both responses have a similar spectral dependence, but only the DeltaQO(2) was abolished by a 10-min exposure to 50 muM dinitrophenol or to 3 mM amytal. We conclude that the DeltaQO(2) reflects an increase in mitochondrial respiration and that it is initiated by the phototransformation of rhodopsin, as was already found in the honeybee drone retina (Dimitracos and Tsacopoulos, 1985; Jones and Tsacopoulos, 1987).

  18. Changes and variations of polycyclic aromatic hydrocarbon concentrations in fish, barnacles and crabs following an oil spill in a mangrove of Guanabara Bay, Southeast Brazil.

    PubMed

    Soares-Gomes, Abílio; Neves, Roberta L; Aucélio, Ricardo; Van Der Ven, Paulo H; Pitombo, Fábio B; Mendes, Carla L T; Ziolli, Roberta L

    2010-08-01

    On April 26th, 2005, an accident caused a leak of 60,000L of Diesel Oil Type "B", freighted by train wagons upstream on a mangrove area within Guanabara Bay, Southeast Brazil. After the accident, samples from animals with different biological requirements were collected in order to monitor polycyclic aromatic hydrocarbons concentrations for the following 12months. Sessile, mobile, carnivorous, omnivorous, organic detritus feeders, planktivorous and suspension feeders were some of the attributes compared. Concentrations of PAHs did not vary in relation to different dietary habits and the best response was from the sessile suspensivorous barnacles. A background level of <50microgkg(-1) was suggested based on the reference site and on values observed in the following months after the accident. The highest values of PAH concentrations were observed in barnacles in the first month immediately after the spill, decreasing to background levels after few months. Barnacles are suggested as a sentinel species.

  19. A range extension of a deep-sea barnacle of the genus Aurivillialepas (Cirripedia, Scalpellomorpha), a Macaronesian and amphitropical refugial genus having Mesozoic affinities.

    PubMed

    Innocenti, Gianna; Geronimo, Raffaella Di; Newman, William A

    2015-06-22

    The scalpellomorph barnacle, Aurivillialepas calycula (Aurivillius, 1898), previously known only from Macaronesia, is reported from Banco de Galicia, off the NW corner of the Iberian Peninsula. One of the two specimens was attached to the scleractinian coral, Madrepora oculata Linnaeus, 1758. Since such pedunculate barnacles are little known, the potentially hermaphroditic specimens and its complemental male are illustrated photographically, and a key to the genus Aurivillialepas is provided. The genus, together with Scillaelepas Seguenza, 1876 and Gruvelialepas Newman, 1980, has long been considered to constitute a natural group of scalpellomorphs within the Calanticidae, and therefore the Scillaelepadinae subfam. nov. is proposed to accommodate them. Biogeographical aspects of these deep-sea barnacles support the hypothesis that not only the islands but the banks and guyots of Macaronesia constitute refugia for ancient as well as more recent forms, some of which may stem back to the late Mesozoic.

  20. A range extension of a deep-sea barnacle of the genus Aurivillialepas (Cirripedia, Scalpellomorpha), a Macaronesian and amphitropical refugial genus having Mesozoic affinities.

    PubMed

    Innocenti, Gianna; Geronimo, Raffaella Di; Newman, William A

    2015-01-01

    The scalpellomorph barnacle, Aurivillialepas calycula (Aurivillius, 1898), previously known only from Macaronesia, is reported from Banco de Galicia, off the NW corner of the Iberian Peninsula. One of the two specimens was attached to the scleractinian coral, Madrepora oculata Linnaeus, 1758. Since such pedunculate barnacles are little known, the potentially hermaphroditic specimens and its complemental male are illustrated photographically, and a key to the genus Aurivillialepas is provided. The genus, together with Scillaelepas Seguenza, 1876 and Gruvelialepas Newman, 1980, has long been considered to constitute a natural group of scalpellomorphs within the Calanticidae, and therefore the Scillaelepadinae subfam. nov. is proposed to accommodate them. Biogeographical aspects of these deep-sea barnacles support the hypothesis that not only the islands but the banks and guyots of Macaronesia constitute refugia for ancient as well as more recent forms, some of which may stem back to the late Mesozoic. PMID:26249902

  1. The influence of diet on comparative trace metal cadmium, copper and zinc accumulation in Thais clavigera (Gastropoda: Muricidae) preying on intertidal barnacles or mussels.

    PubMed

    Blackmore, Graham; Morton, Brian

    2002-09-01

    The influence of diet on comparative metal accumulation was investigated using a predatory muricid gastropod Thais clavigera. Individuals were fed for up to 56 days on either barnacles, i.e., Tetraclita squamosa, or mussels, i.e., Perna viridis, collected from metal-contaminated and clean sites. Barnacles and mussels have contrasting metal handling strategies and, therefore, different body concentrations, intracellular distributions and detoxification systems. Field collection of prey items that accumulated body metal concentrations over a lifetime of exposure allowed bioavailability to the predator, T. clavigera, to be assessed naturally, which may not be the case for prey exposed to metals for a short time in the laboratory. T. clavigera that was fed cadmium- and copper-contaminated barnacles or mussels ingested significantly greater amounts compared to those fed conspecifics collected from clean locations. T. clavigera body cadmium and copper concentrations were not, however, significantly different between individuals fed either contaminated or clean prey. Amount of zinc ingested was similar in mussels collected from clean and contaminated environments but much less when compared to the barnacle prey. The body concentrations of zinc in T. clavigera fed mussels collected from both sites fell. In contrast, the amount of zinc ingested from barnacle prey was significantly greater from those collected from the metal-contaminated site as compared to the clean one. This was reflected as significantly greater body zinc concentrations in T. clavigera fed contaminated barnacles compared to those fed clean individuals. Copper and zinc accumulation from prey was, therefore, complex. It varied between metal and between prey type, but appeared to be related to the amount ingested and the metal handling strategy of the prey.

  2. Unraveling the evolutionary radiation of the thoracican barnacles using molecular and morphological evidence: a comparison of several divergence time estimation approaches.

    PubMed

    Pérez-Losada, Marcos; Høeg, Jens T; Crandall, Keith A

    2004-04-01

    The Thoracica includes the ordinary barnacles found along the sea shore and is the most diverse and well-studied superorder of Cirripedia. However, although the literature abounds with scenarios explaining the evolution of these barnacles, very few studies have attempted to test these hypotheses in a phylogenetic context. The few attempts at phylogenetic analyses have suffered from a lack of phylogenetic signal and small numbers of taxa. We collected DNA sequences from the nuclear 18S, 28S, and histone H3 genes and the mitochondrial 12S and 16S genes (4,871 bp total) and data for 37 adult and 53 larval morphological characters from 43 taxa representing all the extant thoracican suborders (except the monospecific Brachylepadomorpha). Four Rhizocephala (highly modified parasitic barnacles) taxa and a Rhizocephala + Acrothoracica (burrowing barnacles) hypothetical ancestor were used as the outgroup for the molecular and morphological analyses, respectively. We analyzed these data separately and combined using maximum likelihood (ML) under "hill-climbing" and genetic algorithm heuristic searches, maximum parsimony procedures, and Bayesian inference coupled with Markov chain Monte Carlo techniques under mixed and homogeneous models of nucleotide substitution. The resulting phylogenetic trees answered key questions in barnacle evolution. The four-plated Iblomorpha were shown as the most primitive thoracican, and the plateless Heteralepadomorpha were placed as the sister group of the Lepadomorpha. These relationships suggest for the first time in an invertebrate that exoskeleton biomineralization may have evolved from phosphatic to calcitic. Sessilia (nonpedunculate) barnacles were depicted as monophyletic and appear to have evolved from a stalked (pedunculate) multiplated (5+) scalpelloidlike ancestor rather than a five-plated lepadomorphan ancestor. The Balanomorpha (symmetric sessile barnacles) appear to have the following relationship: (Chthamaloidea

  3. Hepoxilins and trioxilins in barnacles: an analysis of their potential roles in egg hatching and larval settlement.

    PubMed

    Vogan, Claire L; Maskrey, Ben H; Taylor, Graham W; Henry, Sheelagh; Pace-Asciak, Cecil R; Clare, Anthony S; Rowley, Andrew F

    2003-09-01

    The barnacle life cycle has two key stages at which eicosanoids are believed to be involved in cellular communication pathways, namely the hatching of nauplii and the settlement of cypris larvae. Barnacle egg-hatching activity has previously been reported to reside in a variety of eicosanoids, including 8-hydroxyeicosapentaenoic acid and a number of tri-hydroxylated polyunsaturated fatty acid derivatives, the trioxilins. The production of the eicosapentaenoic acid metabolite trioxilin A4 (8,11,12-trihydroxy-5,9,14,17-eicosatetraenoic acid) by the barnacles Balanus amphitrite and Elminius modestus was confirmed using a combination of high-performance liquid chromatography and gas chromatography, both linked to mass spectrometry. In addition, both species also generated trioxilin A3 (8,11,12-trihydroxy-5,9,14-eicosatrienoic acid; an arachidonic acid-derived product), 8,11,12-trihydroxy-9,14,17-eicosatrienoic acid (a omega3 analogue of trioxilin A3; derived from omega3 arachidonic acid) and 10,13,14-trihydroxy-4,7,11,16,19-docosapentaenoic acid (a docosahexaenoic acid-derived product). In contrast to earlier reports, trioxilin A3 had no E. modestus egg-hatching activity at any of the concentrations tested (10(-9)-10(-6) mol l(-1)). The unstable epoxide precursor hepoxilin A3, however, caused significant levels of hatching at 10(-6) mol l(-1). Furthermore, the stable hepoxilin B3 analogue PBT-3 stimulated hatching at 10(-7) mol l(-1). Neither trioxilin A3, hepoxilin A3 or PBT-3 at 0.25-30 micromol l(-1) served as settlement cues for B. amphitrite cypris larvae.

  4. Role of Upwelling on Larval Dispersal and Productivity of Gooseneck Barnacle Populations in the Cantabrian Sea: Management Implications

    PubMed Central

    Rivera, Antonella; Weidberg, Nicolás; Pardiñas, Antonio F.; González-Gil, Ricardo; García-Flórez, Lucía; Acuña, J. L.

    2013-01-01

    The effect of coastal upwelling on the recruitment and connectivity of coastal marine populations has rarely been characterized to a level of detail to be included into sound fishery management strategies. The gooseneck barnacle (Pollicipes pollicipes) fishery at the Cantabrian Coast (Northern Spain) is located at the fringes of the NW Spanish Upwelling system. This fishery is being co-managed through a fine-scale, interspersed set of protected rocks where each rock receives a distinct level of protection. Such interspersion is potentially beneficial, but the extent to which such spacing is consistent with mean larval dispersal distances is as yet unknown. We have simulated the spread of gooseneck barnacle larvae in the Central Cantabrian Coast using a high-resolution time-series of current profiles measured at a nearshore location. During a year of high upwelling activity (2009), theoretical recruitment success was 94% with peak recruitment predicted 56 km west of the emission point. However, for a year of low upwelling activity (2011) theoretical recruitment success dropped to 15.4% and peak recruitment was expected 13 km east of the emission point. This is consistent with a positive correlation between catch rates and the Integrated Upwelling Index, using a 4-year lag to allow recruits to reach commercial size. Furthermore, a net long-term westward larval transport was estimated by means of mitochondrial cytochrome c oxidase subunit I (COI) sequences for five populations in the Cantabrian Sea. Our results call into question the role of long distance dispersal, driven by the mesoscale processes in the area, in gooseneck barnacle populations and point to the prevalent role of small-scale, asymmetric connectivity more consistent with the typical scale of the co-management process in this fishery. PMID:24236020

  5. A checklist of the barnacles (Crustacea: Cirripedia: Thoracica) of the Persian Gulf and Gulf of Oman with nine new records.

    PubMed

    Shahdadi, Adnan; Sari, Alireza; Naderloo, Reza

    2014-03-28

    The present annotated checklist contains 43 species of thoracican barnacles known to date from the area, 33 and 26 from the Persian Gulf and the Gulf of Oman, respectively. Nine species are new records for the area including Amphibalunus subalbidus (Henry, 1973), Armatobalanus allium (Darwin, 1854), Chelonibia patula (Ranzani, 1818), Conchoderma hunteri (Owen, 1830), Lepas anserifera Linnaeus, 1767, Lithotrya valentiana Reinhardt, 1850, Megabalanus coccopoma (Darwin, 1854), Megabalanus occator (Darwin, 1854) and Platylepas hexastylos (Fabricius, 1798), of which A. subalbidus and M. coccopoma are reported as alien species from the region.

  6. The effect of water temperature and velocity on barnacle growth: Quantifying the impact of multiple environmental stressors.

    PubMed

    Nishizaki, Michael T; Carrington, Emily

    2015-12-01

    Organisms employ a wide array of physiological and behavioral responses in an effort to endure stressful environmental conditions. For many marine invertebrates, physiological and/or behavioral performance is dependent on physical conditions in the fluid environment. Although factors such as water temperature and velocity can elicit changes in respiration and feeding, the manner in which these processes integrate to shape growth remains unclear. In a growth experiment, juvenile barnacles (Balanus glandula) were raised in dockside, once-through flow chambers at water velocities of 2 versus 19 cm s(-1) and temperatures of 11.5 versus 14 °C. Over 37 days, growth rates (i.e., shell basal area) increased with faster water velocities and higher temperatures. Barnacles at high flows had shorter feeding appendages (i.e., cirri), suggesting that growth patterns are unlikely related to plastic responses in cirral length. A separate experiment in the field confirmed patterns of temperature- and flow-dependent growth over 41 days. Outplanted juvenile barnacles exposed to the faster water velocities (32±1 and 34±1 cm s(-1); mean±SE) and warm temperatures (16.81±0.05 °C) experienced higher growth compared to individuals at low velocities (1±1 cm s(-1)) and temperatures (13.67±0.02 °C). Growth data were consistent with estimates from a simple energy budget model based on previously measured feeding and respiration response curves that predicted peak growth at moderate temperatures (15 °C) and velocities (20-30 cm s(-1)). Low growth is expected at both low and high velocities due to lower encounter rates with suspended food particles and lower capture efficiencies respectively. At high temperatures, growth is likely limited by high metabolic costs, whereas slow growth at low temperatures may be a consequence of low oxygen availability and/or slow cirral beating and low feeding rates. Moreover, these results advocate for approaches that consider the combined effects of

  7. The effect of water temperature and velocity on barnacle growth: Quantifying the impact of multiple environmental stressors.

    PubMed

    Nishizaki, Michael T; Carrington, Emily

    2015-12-01

    Organisms employ a wide array of physiological and behavioral responses in an effort to endure stressful environmental conditions. For many marine invertebrates, physiological and/or behavioral performance is dependent on physical conditions in the fluid environment. Although factors such as water temperature and velocity can elicit changes in respiration and feeding, the manner in which these processes integrate to shape growth remains unclear. In a growth experiment, juvenile barnacles (Balanus glandula) were raised in dockside, once-through flow chambers at water velocities of 2 versus 19 cm s(-1) and temperatures of 11.5 versus 14 °C. Over 37 days, growth rates (i.e., shell basal area) increased with faster water velocities and higher temperatures. Barnacles at high flows had shorter feeding appendages (i.e., cirri), suggesting that growth patterns are unlikely related to plastic responses in cirral length. A separate experiment in the field confirmed patterns of temperature- and flow-dependent growth over 41 days. Outplanted juvenile barnacles exposed to the faster water velocities (32±1 and 34±1 cm s(-1); mean±SE) and warm temperatures (16.81±0.05 °C) experienced higher growth compared to individuals at low velocities (1±1 cm s(-1)) and temperatures (13.67±0.02 °C). Growth data were consistent with estimates from a simple energy budget model based on previously measured feeding and respiration response curves that predicted peak growth at moderate temperatures (15 °C) and velocities (20-30 cm s(-1)). Low growth is expected at both low and high velocities due to lower encounter rates with suspended food particles and lower capture efficiencies respectively. At high temperatures, growth is likely limited by high metabolic costs, whereas slow growth at low temperatures may be a consequence of low oxygen availability and/or slow cirral beating and low feeding rates. Moreover, these results advocate for approaches that consider the combined effects of

  8. Calcium channels in the high resistivity axonal membrane of photoreceptors of the giant barnacle.

    PubMed Central

    Edgington, D R; Stuart, A E

    1979-01-01

    1. The distribution of calcium channels in the cell membrane of the photoreceptor neurone of the giant barnacle, Balanus nubilus, was studied by recording intracellularly in or near the soma, in the axon, and near the presynaptic terminals. The membrane properties of these different regions of the cell could be studied by separately superfusing each region with test salines or by cutting the axon between two regions. 2. In the presence of tetraethylammonium (TEA) or 3-aminopyridine (3-AP), but not in their absence, Ca dependent action potentials could be evoked with depolarizing current pulses in the somatic, axonal, and terminal regions. Consequently, voltage-sensitive Ca channels and TEA-sensitive channels are present in all three regions of the cell. 3. The action potentials recorded from the three regions were similar in their slow times-to-peak (30-300 msec), long durations (0.2-2 sec in 100 mM-TEA), and long-lasting (0.2-10 sec) undershoots. The action potentials were inhibited by extracellular Co. 4. Clear differences were consistently observed between terminal action potentials and axonal or somatic action potentials in TEA. Terminal action potentials displayed a lower voltage threshold, faster rate of rise, and were less sensitive to inhibition by extracellular cobalt, suggesting that the Ca current is greater in the terminal region. 5. Bathing the receptor axon in low Ca or Co solutions led to a greater attenuation of large depolarizing components of the visual signal as they spread to the presynaptic terminals. PMID:512951

  9. Goose barnacle Pollicipes pollicipes as biomonitor of metal contamination in the northwest coast of Portugal.

    PubMed

    Reis, Pedro A; Salgado, Maria Antónia; Vasconcelos, Vitor

    2012-11-01

    The main objective of this work was to assess the potential use of goose barnacle Pollicipes pollicipes as biomonitor of metal contamination in northwest (NW) coast of Portugal. The concentrations of Cd, Cr, Cu, Fe, Mn, Ni and Zn were determined in coastal seawaters and tissues of P. pollicipes, which allowed establishing correlations between metals in coastal seawaters and P. pollicipes and calculating metal bioaccumulation factors (BAFs). The results of this study showed that P. pollicipes soft tissues can be used for monitoring metal contamination in these coastal seawaters: (1) there were significant correlations (p < 0.05) between metals in soft tissues and their concentrations in seawaters, except for Zn (p > 0.05); (2) soft tissues were sensitive to spatial variations of metal bioavailabilities and their concentrations ranged 0.70-2.22 mg Cd kg(-1), 0.49-1.40 mg Cr kg(-1), 1.37-2.07 mg Ni kg(-1), 2.4-3.3 mg Cu kg(-1), 5-59 mg Mn kg(-1), 134-578 mg Fe kg(-1)and 728-1,854 mg Zn kg(-1); (3) mean logarithmic bioaccumulation factors (log BAF) of Fe, Cd and Zn were higher, 5.57, 5.47 and 4.41, respectively, than mean log BAFs of Cr, Mn, Cu and Ni, 4.18, 4.14, 3.98 and 3.51, respectively. In contrary, P. pollicipes shell plates were not considered ideal material to monitor metal bioavailabilities in these coastal seawaters. Regarding the very high concentrations of Zn obtained in the coastal seawaters and P. pollicipes soft tissues, the NW coast of Portugal should be classified as "Class III/IV - Remarkably/Highly Polluted".

  10. First study on gene expression of cement proteins and potential adhesion-related genes of a membranous-based barnacle as revealed from Next-Generation Sequencing technology.

    PubMed

    Lin, Hsiu-Chin; Wong, Yue Him; Tsang, Ling Ming; Chu, Ka Hou; Qian, Pei-Yuan; Chan, Benny K K

    2014-02-01

    This is the first study applying Next-Generation Sequencing (NGS) technology to survey the kinds, expression location, and pattern of adhesion-related genes in a membranous-based barnacle. A total of 77,528,326 and 59,244,468 raw sequence reads of total RNA were generated from the prosoma and the basis of Tetraclita japonica formosana, respectively. In addition, 55,441 and 67,774 genes were further assembled and analyzed. The combined sequence data from both body parts generates a total of 79,833 genes of which 47.7% were shared. Homologues of barnacle cement proteins - CP-19K, -52K, and -100K - were found and all were dominantly expressed at the basis where the cement gland complex is located. This is the main area where transcripts of cement proteins and other potential adhesion-related genes were detected. The absence of another common barnacle cement protein, CP-20K, in the adult transcriptome suggested a possible life-stage restricted gene function and/or a different mechanism in adhesion between membranous-based and calcareous-based barnacles.

  11. Isolation and characterization of 2-nitroimidazole produced by Streptomyces species as an inhibitor of both carbonic anhydrase and shell formation in the barnacle Balanus amphitrite.

    PubMed

    Fukushima, Mari; Ozaki, Noriaki; Ikeda, Hiroyuki; Furihata, Keiko; Hayakawa, Yoichi; Sakuda, Shohei; Nagasawa, Hiromichi

    2002-03-01

    Carbonic anhydrase is thought to be involved in the process of calcium carbonate deposition in calcified tissues of many organisms. Barnacles form hard calcified shells for protection against predation, and represent a class of marine-fouling animals. In order to inhibit barnacle growth by inhibiting shell formation, we searched for carbonic anhydrase inhibitors from microbial secondary metabolites. A simple assay for assessing carbonic-anhydrase-inhibiting activity was developed. Screening of many microorganisms isolated from soil with this assay resulted in a microbial strain that produced a carbonic anhydrase inhibitor. This strain was identified as Streptomyces eurocidicus mf294. The inhibitor was isolated through 4 purification steps and identified as 2-nitroimidazole on the basis of spectroscopic data. 2-Nitroimidazole inhibited barnacle carbonic anhydrase dose-dependently and complete inhibition was reached at the concentration of 1 x 10(-5) M. 2-Nitroimidazole did not affect settlement or metamorphosis of barnacle larvae, but inhibited shell formation at concentrations higher than 1 x 10(-4) M. These findings strongly support the idea that carbonic anhydrase is involved in calcification.

  12. Fluorinated/siloxane copolymer blends for fouling release: chemical characterisation and biological evaluation with algae and barnacles.

    PubMed

    Marabotti, Ilaria; Morelli, Andrea; Orsini, Lorenzo M; Martinelli, Elisa; Galli, Giancarlo; Chiellini, Emo; Lien, Einar M; Pettitt, Michala E; Callow, Maureen E; Callow, James A; Conlan, Sheelagh L; Mutton, Robert J; Clare, Anthony S; Kocijan, Aleksandra; Donik, Crtomir; Jenko, Monika

    2009-01-01

    Fouling-release coatings were prepared from blends of a fluorinated/siloxane copolymer with a poly(dimethyl siloxane) (PDMS) matrix in order to couple the low modulus character of PDMS with the low surface tension typical for fluorinated polymers. The content of the surface-active copolymer was varied in the blend over a broad range (0.15-10 wt % with respect to PDMS). X-ray photoelectron spectroscopy depth profiling analyses were performed on the coatings to establish the distribution of specific chemical constituents throughout the coatings, and proved enrichment in fluorine of the outermost layers of the coating surface. Addition of the fluorinated/siloxane copolymer to the PDMS matrix resulted in a concentration-dependent decrease in settlement of barnacle, Balanus amphitrite, cyprids. The release of young plants of Ulva, a soft fouling species, and young barnacles showed that adhesion strength on the fluorinated/siloxane copolymer was significantly lower than the siloxane control. However, differences in adhesion strength were not directly correlated with the concentration of copolymer in the blends.

  13. Do tiny males grow up? Sperm competition and optimal resource allocation schedule of dwarf males of barnacles.

    PubMed

    Yamaguchi, Sachi; Ozaki, Yuki; Yusa, Yoichi; Takahashi, Satoshi

    2007-03-21

    Barnacles, marine crustaceans, have three sexual patterns: simultaneous hermaphroditism, dioecy and androdioecy. In dioecy and androdioecy, large individuals (females and hermaphrodites, respectively) are attached by dwarf males. Depending on species, some dwarf males grow up, others do not in their life time. To investigate which environmental conditions affect growth patterns of dwarf males of barnacles, we investigate the evolutionarily stable life history strategy of dwarf males using Pontryagin's maximum principle. Sperm competition among dwarf males and that among dwarf males and large hermaphrodites is taken into account. Dwarf males grow up in food-rich environments, while they do not grow at all in food-poor environments. ESS of the resource allocation schedule between reproduction and growth follows an "intermediate growth strategy" (simultaneous growth and reproduction) for dioecious species, in which sperm competition is not severe. On the other hand, it approaches "bang-bang control" (switching from allocating all resources toward growth then to reproduction), as sperm competition against surrounding large hermaphrodites becomes severe in androdioecious species.

  14. Metabolic effects of parasitization by the barnacle Polyascus plana (Cirripedia: Rhizocephala: Sacculinidae) on a grapsid host, Metopograpsus thukuhar.

    PubMed

    Hsiao, Chia-Jen; Wu, Yen-I; Tung, Tzu-An; Wang, Guan-Yi; Toullec, Jean-Yves; Liu, Shih-Ting; Huang, Wen-San; Lee, Chi-Ying

    2016-05-26

    Pathophysiological studies of rhizocephalan infections are rare. We describe differences in the levels of tissue and hemolymph metabolites between Polyascus plana-parasitized and unparasitized individuals of Metopograpsus thukuhar. Crabs were assigned to either a parasitized (carrying at least 1 externa, i.e. a protruding reproductive body) or an unparasitized (not carrying externae and determined to be rootlet-free by a barnacle 18S rRNA-based polymerase chain reaction) group. Quantification of metabolites showed that muscle glycogen levels were significantly lower and hepatopancreas levels were significantly higher in parasitized crabs compared to unparasitized crabs; hepatopancreas triacylglycerol levels were significantly higher and hemolymph levels significantly lower in parasitized hosts, and there was no significant difference in muscle triacylglycerol levels between unparasitized and parasitized animals. Glucose levels in the hepatopancreas, muscle, and hemolymph were all significantly higher in parasitized hosts. Significant levels of glucose, triacylglycerol, and glycogen were present in the barnacle externae. In addition, levels of crustacean hyperglycemic hormone in the sinus glands were not significantly different between unparasitized and parasitized animals. Glucose mobilized from the muscle is likely converted to glycogen and triacylglycerol in the rootlet-infiltrated hepatopancreas of parasitized hosts, and the eyestalk neuroendocrine system appears not to be significantly impaired, in terms of hormone production and storage, by parasitization. PMID:27225203

  15. iTRAQ-based proteomic profiling of the barnacle Balanus amphitrite in response to the antifouling compound meleagrin.

    PubMed

    Han, Zhuang; Sun, Jin; Zhang, Yu; He, Fei; Xu, Ying; Matsumura, Kiyotaka; He, Li-Sheng; Qiu, Jian-Wen; Qi, Shu-Hua; Qian, Pei-Yuan

    2013-05-01

    Marine biofouling refers to the unwanted accumulation of fouling organisms, such as barnacles, on artificial surfaces, resulting in severe consequences for marine industries. Meleagrin is a potential nontoxic antifoulant that is isolated from the fungus Penicillium sp.; however, its mechanistic effect mode of action on larval settlement remains unknown. Here, we applied iTRAQ coupled with 2D LC-MS/MS proteomic analysis to investigate the effect of meleagrin on the proteomic expression profile of cyprid development and aging in the barnacle Balanus amphitrite . Fifty proteins were differentially expressed in response to treatment with meleagrin, among which 26 proteins were associated with cyprid development/aging and 24 were specifically associated with the meleagrin treatment. The 66 proteins that were associated with aging only remained unaltered during exposure to meleagrin. Using KEGG analysis, those proteins were assigned to several groups, including metabolic pathways, ECM-receptor interactions, and the regulation of the actin cytoskeleton. Among the 24 proteins that were not related to the development/aging process, expression of the cyprid major protein (CMP), a vitellogenin-like protein, increased after the meleagrin treatment, which suggested that meleagrin might affect the endocrine system and prevent the larval molting cycle. With the exception of the chitin binding protein that mediates the molting process and ATPase-mediated energy processes, the majority of proteins with significant effects in previous studies in response to cyprid treatment with butenolide and polyether B remained unchanged in the present study, suggesting that meleagrin may exhibit a different mechanism.

  16. Alternative Curricular Options in Rural Networks (ACORNS): impact of early rural clinical exposure in the University of West Australia medical course.

    PubMed

    Talbot, J; Ward, A

    2000-02-01

    The aim of this study was to assess the impact of a 4-day rural placement in Western Australia on the interest of fourth year medical students in a career in rural general practice. Students undertaking their Alternative Curricular Options in Rural Networks attachment (ACORNS) completed pre- and post-questionnaires examining their expectations, experiences of, and attitudes to rural general practice. Of the 103 students who participated, 81% expressed an interest in a rural career after the placement, whereas prior to this experience only 48% had been interested. The students also recorded a wide range of learning experiences, both clinical and procedural, and expressed positive attitudes to the variety of experiences and the role of the rural GP. The study concluded that early exposure to rural general practice enhances students' interest in a potential rural practice career and provides them with a broad range of experiences. The role of rural practitioners as role models for students needs to be acknowledged and reinforced.

  17. Membrane properties of a barnacle photoreceptor examined by the voltage clamp technique

    PubMed Central

    Brown, H. Mack; Hagiwara, S.; Koike, H.; Meech, R. M.

    1970-01-01

    1. Electrical properties of the membrane of photoreceptor cells in the lateral ocelli of barnacles, Balanus amphitrite and B. eburneus were investigated by intracellular recording, polarization and voltage-clamp techniques. 2. The resting potential of a dark adapted cell was 36·3 ± 6·6 mV (S.D.) and depended mainly on the external K+ concentration. 3. Current—voltage relations obtained from voltage—clamp experiments in the absence of light were non-linear and varied with time after the onset of a step change in membrane potential; the steady state was reached after about 0·5 sec. 4. Illumination resulted in a membrane potential change under current clamp and in a change of membrane current (light-initiated membrane current (L.I.C.): total membrane current with illumination minus current without illumination) under voltage—clamp conditions. Amplitudes and time course of L.I.C. depended on the light intensity as well as membrane potential. 5. The L.I.C.-voltage relation was non-linear and corresponded with a slope conductance increase with increasing positive membrane potential. 6. The reversal potential of L.I.C. was independent of the light intensity and the time after onset of illumination; the average value obtained in normal saline was +26·9 ± 5·0 mV. 7. The membrane conductance estimated from instantaneous L.I.C.-voltage relations agreed with the chord conductance of the non-linear L.I.C.-voltage relation. 8. Decreasing external Na+ concentration decreased the inward component of L.I.C. but not the outward component. 9. Decreasing external Ca2+ concentration increased the inward as well as the outward component of L.I.C. 10. The reversal potential shifted in the negative direction with decreasing external Na+ concentration (the rate was 10-15 mV for a tenfold change in concentration) and the rate was augmented in the absence of Ca2+ but did not exceed 21 mV. 11. The change of reversal potential with changes of external Ca2+ concentration was

  18. Adaptation in the input-output relation of the synapse made by the barnacle's photoreceptor.

    PubMed Central

    Hayashi, J H; Moore, J W; Stuart, A E

    1985-01-01

    A study was made of synaptic transmission between the four median photoreceptors of the giant barnacle (Balanus nubilus) and their post-synaptic cells (I-cells). Simultaneous intracellular recordings were made from the presynaptic terminal region of a photoreceptor and from the soma of an I-cell. The photoreceptor's membrane potential provided feed-back to bath electrodes that passed current into the receptors' axons, permitting the voltage to be controlled at the point of arborization of their presynaptic terminals. Simultaneous recordings from a second photoreceptor showed that its voltage tracked the first. Step depolarizations of the receptors from their dark resting potential (about -60 mV) caused hyperpolarizations of the I-cell that reached a peak, then decayed to a plateau value. The amplitude of the I-cell's response grew with presynaptic depolarizations, saturating at presynaptic values 10-20 mV depolarized from dark rest. Step hyperpolarizations of the receptors from dark rest evoked depolarizations of the I-cell consisting of an initial peak, which varied greatly in amplitude and wave form from preparation to preparation, followed by a plateau. The presence of this post-synaptic response indicates that transmitter is released continuously from the receptors at their dark resting potential. An input-output relation of the synapse was obtained by presenting step depolarizations from a holding potential of -80 mV, where steady-state transmitter release is shut off. The relation is sigmoidal; in the exponentially rising phase of the curve, a 5-11 mV presynaptic change produces a 10-fold change in post-synaptic response. When the presynaptic holding potential was set at values ranging from -80 to -40 mV, the relation between the I-cell's response and the absolute potential to which the receptor was stepped shifted along the presynaptic voltage axis. The slopes of the input-output relations were roughly parallel or increased as the photoreceptors were held

  19. Adult Prey Neutralizes Predator Nonconsumptive Limitation of Prey Recruitment

    PubMed Central

    Scrosati, Ricardo A.; Romoth, Katharina; Molis, Markus

    2016-01-01

    Recent studies have shown that predator chemical cues can limit prey demographic rates such as recruitment. For instance, barnacle pelagic larvae reduce settlement where predatory dogwhelk cues are detected, thereby limiting benthic recruitment. However, adult barnacles attract conspecific larvae through chemical and visual cues, aiding larvae to find suitable habitat for development. Thus, we tested the hypothesis that the presence of adult barnacles (Semibalanus balanoides) can neutralize dogwhelk (Nucella lapillus) nonconsumptive effects on barnacle recruitment. We did a field experiment in Atlantic Canada during the 2012 and 2013 barnacle recruitment seasons (May–June). We manipulated the presence of dogwhelks (without allowing them to physically contact barnacles) and adult barnacles in cages established in rocky intertidal habitats. At the end of both recruitment seasons, we measured barnacle recruit density on tiles kept inside the cages. Without adult barnacles, the nearby presence of dogwhelks limited barnacle recruitment by 51%. However, the presence of adult barnacles increased barnacle recruitment by 44% and neutralized dogwhelk nonconsumptive effects on barnacle recruitment, as recruit density was unaffected by dogwhelk presence. For species from several invertebrate phyla, benthic adult organisms attract conspecific pelagic larvae. Thus, adult prey might commonly constitute a key factor preventing negative predator nonconsumptive effects on prey recruitment. PMID:27123994

  20. Adult Prey Neutralizes Predator Nonconsumptive Limitation of Prey Recruitment.

    PubMed

    Ellrich, Julius A; Scrosati, Ricardo A; Romoth, Katharina; Molis, Markus

    2016-01-01

    Recent studies have shown that predator chemical cues can limit prey demographic rates such as recruitment. For instance, barnacle pelagic larvae reduce settlement where predatory dogwhelk cues are detected, thereby limiting benthic recruitment. However, adult barnacles attract conspecific larvae through chemical and visual cues, aiding larvae to find suitable habitat for development. Thus, we tested the hypothesis that the presence of adult barnacles (Semibalanus balanoides) can neutralize dogwhelk (Nucella lapillus) nonconsumptive effects on barnacle recruitment. We did a field experiment in Atlantic Canada during the 2012 and 2013 barnacle recruitment seasons (May-June). We manipulated the presence of dogwhelks (without allowing them to physically contact barnacles) and adult barnacles in cages established in rocky intertidal habitats. At the end of both recruitment seasons, we measured barnacle recruit density on tiles kept inside the cages. Without adult barnacles, the nearby presence of dogwhelks limited barnacle recruitment by 51%. However, the presence of adult barnacles increased barnacle recruitment by 44% and neutralized dogwhelk nonconsumptive effects on barnacle recruitment, as recruit density was unaffected by dogwhelk presence. For species from several invertebrate phyla, benthic adult organisms attract conspecific pelagic larvae. Thus, adult prey might commonly constitute a key factor preventing negative predator nonconsumptive effects on prey recruitment.

  1. Adult Prey Neutralizes Predator Nonconsumptive Limitation of Prey Recruitment.

    PubMed

    Ellrich, Julius A; Scrosati, Ricardo A; Romoth, Katharina; Molis, Markus

    2016-01-01

    Recent studies have shown that predator chemical cues can limit prey demographic rates such as recruitment. For instance, barnacle pelagic larvae reduce settlement where predatory dogwhelk cues are detected, thereby limiting benthic recruitment. However, adult barnacles attract conspecific larvae through chemical and visual cues, aiding larvae to find suitable habitat for development. Thus, we tested the hypothesis that the presence of adult barnacles (Semibalanus balanoides) can neutralize dogwhelk (Nucella lapillus) nonconsumptive effects on barnacle recruitment. We did a field experiment in Atlantic Canada during the 2012 and 2013 barnacle recruitment seasons (May-June). We manipulated the presence of dogwhelks (without allowing them to physically contact barnacles) and adult barnacles in cages established in rocky intertidal habitats. At the end of both recruitment seasons, we measured barnacle recruit density on tiles kept inside the cages. Without adult barnacles, the nearby presence of dogwhelks limited barnacle recruitment by 51%. However, the presence of adult barnacles increased barnacle recruitment by 44% and neutralized dogwhelk nonconsumptive effects on barnacle recruitment, as recruit density was unaffected by dogwhelk presence. For species from several invertebrate phyla, benthic adult organisms attract conspecific pelagic larvae. Thus, adult prey might commonly constitute a key factor preventing negative predator nonconsumptive effects on prey recruitment. PMID:27123994

  2. Microsatellite loci discovery from next-generation sequencing data and loci characterization in the epizoic barnacle Chelonibia testudinaria (Linnaeus, 1758).

    PubMed

    Ewers-Saucedo, Christine; Zardus, John D; Wares, John P

    2016-01-01

    Microsatellite markers remain an important tool for ecological and evolutionary research, but are unavailable for many non-model organisms. One such organism with rare ecological and evolutionary features is the epizoic barnacle Chelonibia testudinaria (Linnaeus, 1758). Chelonibia testudinaria appears to be a host generalist, and has an unusual sexual system, androdioecy. Genetic studies on host specificity and mating behavior are impeded by the lack of fine-scale, highly variable markers, such as microsatellite markers. In the present study, we discovered thousands of new microsatellite loci from next-generation sequencing data, and characterized 12 loci thoroughly. We conclude that 11 of these loci will be useful markers in future ecological and evolutionary studies on C. testudinaria. PMID:27231653

  3. Biomonitoring of trace metal bioavailabilities to the barnacle Amphibalanus amphitrite along the Iranian coast of the Persian Gulf.

    PubMed

    Nasrolahi, A; Smith, B D; Ehsanpour, M; Afkhami, M; Rainbow, P S

    2014-10-01

    The fouling barnacle Amphibalanus amphitrite is a cosmopolitan biomonitor of trace metal bioavailabilities, with an international comparative data set of body metal concentrations. Bioavailabilities of As, Cd, Cr, Cu, Fe, Mn, Pb, V and Zn to A. amphitrite were investigated at 19 sites along the Iranian coast of the understudied Persian Gulf. Commercial and fishing ports showed extremely high Cu bioavailabilities, associated with high Zn bioavailabilities, possibly from antifouling paints and procedures. V availability was raised at one port, perhaps associated with fuel leakage. Cd bioavailabilities were raised at sites near the Strait of Hormuz, perhaps affected by adjacent upwelling off Oman. The As data allow a reinterpretation of the typical range of accumulated As concentrations in A. amphitrite. The Persian Gulf data add a new region to the A. amphitrite database, confirming its importance in assessing the ecotoxicologically significant trace metal contamination of coastal waters across the world.

  4. Assessing the sustainability and adaptive capacity of the gooseneck barnacle co-management system in Asturias, N. Spain.

    PubMed

    Rivera, Antonella; Gelcich, Stefan; García-Flórez, Lucía; Acuña, José Luis

    2016-03-01

    The gooseneck barnacle fishery in Asturias (N. Spain) has undergone three important changes: (1) the early implementation of a co-management system based on Territorial User Rights for Fishing, (2) a change in management measures (due to a decrease in landings), and (3) an economic crisis. This has allowed us to analyze the systems' sustainability in time through examining five critical variables: landings, effort, catch per unit effort (CPUE), mean market prices, and annual revenue. Additionally, we used focus groups and questionnaires to determine the response of the system to these three changes. Co-management has succeeded in maintaining or increasing CPUE throughout all management areas and produced stable mean market prices. This was achieved through flexible management policies and adaptive strategies adopted by the fishers, such as increased selectivity and diversification. The analysis of this fishery provides important lessons regarding the need to understand the evolutionary dynamics of co-management and the importance of embracing adaptive capacity. PMID:26204856

  5. Microsatellite loci discovery from next-generation sequencing data and loci characterization in the epizoic barnacle Chelonibia testudinaria (Linnaeus, 1758)

    PubMed Central

    Zardus, John D.; Wares, John P.

    2016-01-01

    Microsatellite markers remain an important tool for ecological and evolutionary research, but are unavailable for many non-model organisms. One such organism with rare ecological and evolutionary features is the epizoic barnacle Chelonibia testudinaria (Linnaeus, 1758). Chelonibia testudinaria appears to be a host generalist, and has an unusual sexual system, androdioecy. Genetic studies on host specificity and mating behavior are impeded by the lack of fine-scale, highly variable markers, such as microsatellite markers. In the present study, we discovered thousands of new microsatellite loci from next-generation sequencing data, and characterized 12 loci thoroughly. We conclude that 11 of these loci will be useful markers in future ecological and evolutionary studies on C. testudinaria. PMID:27231653

  6. Genetic divergence between subpopulations of the eastern Pacific goose barnacle Pollicipes elegans: mitochondrial cytochrome c subunit 1 nucleotide sequences.

    PubMed

    Van Syoc, R J

    1994-12-01

    Nucleotide sequence data derived from polymerase chain reaction products from the cytochrome oxidase subunit 1 gene of mitochondrial DNA provide evidence for interrupted gene flow and subsequent genetic divergence between geographically separate subpopulations of the edible goose barnacle, Pollicipes elegans, with a 4400-km latitudinal distribution in the eastern Pacific Ocean. The amphitropical subpopulations of Pollicipes elegans have a net nucleotide sequence divergence of about 1.2%. A range of mutation rates are applied to calculate estimates for the timing of this divergence. The earliest estimated time of divergence agrees with a Pliocene time of general warming in the eastern Pacific. The latest estimated times coincide with the Pleistocene epoch and periods of cooling and warming that could have allowed for a series of expansions and contractions of P. elegans populations in the eastern tropical Pacific. These expansions and contractions may, therefore, represent alternating periods of genetic exchange and isolation of the two populations.

  7. Assessing the sustainability and adaptive capacity of the gooseneck barnacle co-management system in Asturias, N. Spain.

    PubMed

    Rivera, Antonella; Gelcich, Stefan; García-Flórez, Lucía; Acuña, José Luis

    2016-03-01

    The gooseneck barnacle fishery in Asturias (N. Spain) has undergone three important changes: (1) the early implementation of a co-management system based on Territorial User Rights for Fishing, (2) a change in management measures (due to a decrease in landings), and (3) an economic crisis. This has allowed us to analyze the systems' sustainability in time through examining five critical variables: landings, effort, catch per unit effort (CPUE), mean market prices, and annual revenue. Additionally, we used focus groups and questionnaires to determine the response of the system to these three changes. Co-management has succeeded in maintaining or increasing CPUE throughout all management areas and produced stable mean market prices. This was achieved through flexible management policies and adaptive strategies adopted by the fishers, such as increased selectivity and diversification. The analysis of this fishery provides important lessons regarding the need to understand the evolutionary dynamics of co-management and the importance of embracing adaptive capacity.

  8. The Story of a Hitchhiker: Population Genetic Patterns in the Invasive Barnacle Balanus(Amphibalanus) improvisus Darwin 1854.

    PubMed

    Wrange, Anna-Lisa; Charrier, Gregory; Thonig, Anne; Alm Rosenblad, Magnus; Blomberg, Anders; Havenhand, Jonathan N; Jonsson, Per R; André, Carl

    2016-01-01

    Understanding the ecological and evolutionary forces that determine the genetic structure and spread of invasive species is a key component of invasion biology. The bay barnacle, Balanus improvisus (= Amphibalanus improvisus), is one of the most successful aquatic invaders worldwide, and is characterised by broad environmental tolerance. Although the species can spread through natural larval dispersal, human-mediated transport through (primarily) shipping has almost certainly contributed to the current global distribution of this species. Despite its worldwide distribution, little is known about the phylogeography of this species. Here, we characterize the population genetic structure and model dispersal dynamics of the barnacle B. improvisus, and describe how human-mediated spreading via shipping as well as natural larval dispersal may have contributed to observed genetic variation. We used both mitochondrial DNA (cytochrome c oxidase subunit I: COI) and nuclear microsatellites to characterize the genetic structure in 14 populations of B. improvisus on a global and regional scale (Baltic Sea). Genetic diversity was high in most populations, and many haplotypes were shared among populations on a global scale, indicating that long-distance dispersal (presumably through shipping and other anthropogenic activities) has played an important role in shaping the population genetic structure of this cosmopolitan species. We could not clearly confirm prior claims that B. improvisus originates from the western margins of the Atlantic coasts; although there were indications that Argentina could be part of a native region. In addition to dispersal via shipping, we show that natural larval dispersal may play an important role for further colonisation following initial introduction. PMID:26821161

  9. Barnacle settlement and the adhesion of protein and diatom microfouling to xerogel films with varying surface energy and water wettability.

    PubMed

    Finlay, John A; Bennett, Stephanie M; Brewer, Lenora H; Sokolova, Anastasiya; Clay, Gemma; Gunari, Nikhil; Meyer, Anne E; Walker, Gilbert C; Wendt, Dean E; Callow, Maureen E; Callow, James A; Detty, Michael R

    2010-08-01

    Previous work has shown that organosilica-based xerogels have the potential to control biofouling. In this study, modifications of chemistry were investigated with respect to their resistance to marine slimes and to settlement of barnacle cyprids. Adhesion force measurements of bovine serum albumin (BSA)-coated atomic force microscopy (AFM) tips to xerogel surfaces prepared from aminopropylsilyl-, fluorocarbonsilyl-, and hydrocarbonsilyl-containing precursors, indicated that adhesion was significantly less on the xerogel surfaces in comparison to a poly(dimethylsiloxane) elastomer (PDMSE) standard. The strength of adhesion of BSA on the xerogels was highest on surfaces with the highest and the lowest critical surface tensions, gamma(C) and surface energies, gamma(S), and duplicated the 'Baier curve'. The attachment to and removal of cells of the diatom Navicula perminuta from a similar series of xerogel surfaces were examined. Initial attachment of cells was comparable on all of the xerogel surfaces, but the percentage removal of attached cells by hydrodynamic shear stress increased with gamma(C) and increased wettability as measured by the static water contact angle, theta(Ws), of the xerogel surfaces. The percentage removal of cells of Navicula was linearly correlated with both properties (R(2) = 0.74 for percentage removal as a function of theta(Ws) and R(2) = 0.69 for percentage removal as a function of gamma(C)). Several of the aminopropylsilyl-containing xerogels showed significantly greater removal of Navicula compared to a PDMSE standard. Cypris larvae of the barnacle B. amphitrite showed preferred settlement on hydrophilic/higher energy surfaces. Settlement was linearly correlated with theta(Ws) (R(2) = 0.84) and gamma(C) (R(2) = 0.84). Hydrophilic xerogels should prove useful as coatings for boats in regions where fouling is dominated by microfouling (protein and diatom slimes). PMID:20645195

  10. The Story of a Hitchhiker: Population Genetic Patterns in the Invasive Barnacle Balanus(Amphibalanus) improvisus Darwin 1854

    PubMed Central

    Wrange, Anna-Lisa; Charrier, Gregory; Thonig, Anne; Alm Rosenblad, Magnus; Blomberg, Anders; Havenhand, Jonathan N.; Jonsson, Per R.; André, Carl

    2016-01-01

    Understanding the ecological and evolutionary forces that determine the genetic structure and spread of invasive species is a key component of invasion biology. The bay barnacle, Balanus improvisus (= Amphibalanus improvisus), is one of the most successful aquatic invaders worldwide, and is characterised by broad environmental tolerance. Although the species can spread through natural larval dispersal, human-mediated transport through (primarily) shipping has almost certainly contributed to the current global distribution of this species. Despite its worldwide distribution, little is known about the phylogeography of this species. Here, we characterize the population genetic structure and model dispersal dynamics of the barnacle B. improvisus, and describe how human-mediated spreading via shipping as well as natural larval dispersal may have contributed to observed genetic variation. We used both mitochondrial DNA (cytochrome c oxidase subunit I: COI) and nuclear microsatellites to characterize the genetic structure in 14 populations of B. improvisus on a global and regional scale (Baltic Sea). Genetic diversity was high in most populations, and many haplotypes were shared among populations on a global scale, indicating that long-distance dispersal (presumably through shipping and other anthropogenic activities) has played an important role in shaping the population genetic structure of this cosmopolitan species. We could not clearly confirm prior claims that B. improvisus originates from the western margins of the Atlantic coasts; although there were indications that Argentina could be part of a native region. In addition to dispersal via shipping, we show that natural larval dispersal may play an important role for further colonisation following initial introduction. PMID:26821161

  11. The mitochondrial genome of Nobia grandis Sowerby, 1839 (Cirripedia: Sessilia): the first report from the coral-inhabiting barnacles family Pyrgomatidae.

    PubMed

    Shen, Xin; Chan, Benny Kwok Kan; Tsang, Ling Ming

    2016-01-01

    This work presents the coral-inhabiting barnacle Nobia grandis Sowerby, 1839 complete mitochondrial genome, which is the first report from the family Pyrgomatidae (Cirripedia: Sessilia). The N. grandis mitochondrial genome is 15,032 bp in length, containing a total of 469 bp of non-coding nucleotides spreading in 11 intergenic regions (with the largest region of 376 bp). Compared with the pancrustacean ground pattern, there are not less than seven tRNAs rearranged in the N. grandis mitochondrial genome. Gene overlaps are founded in eight places. Nine PCGs (COX1-3, ATP6, ATP8, CYTB, ND2, ND3 and ND6) are encoded on the heavy strand while the remaining 4 PCGs and the two rRNAs are located on the light strand. As the first representative from the family Pyrgomatidae, the N. grandis mitochondrial genome will help us to explore the evolutionary history and molecular evolution of coral barnacles and Sessilia in future studies.

  12. Molecular Characterization of the α-Subunit of Na+/K+ ATPase from the Euryhaline Barnacle Balanus improvisus Reveals Multiple Genes and Differential Expression of Alternative Splice Variants

    PubMed Central

    Lind, Ulrika; Alm Rosenblad, Magnus; Wrange, Anna-Lisa; Sundell, Kristina S.; Jonsson, Per R.; André, Carl; Havenhand, Jonathan; Blomberg, Anders

    2013-01-01

    The euryhaline bay barnacle Balanus improvisus has one of the broadest salinity tolerances of any barnacle species. It is able to complete its life cycle in salinities close to freshwater (3 PSU) up to fully marine conditions (35 PSU) and is regarded as one of few truly brackish-water species. Na+/K+ ATPase (NAK) has been shown to be important for osmoregulation when marine organisms are challenged by changing salinities, and we therefore cloned and examined the expression of different NAKs from B. improvisus. We found two main gene variants, NAK1 and NAK2, which were approximately 70% identical at the protein level. The NAK1 mRNA existed in a long and short variant with the encoded proteins differing only by 27 N-terminal amino acids. This N-terminal stretch was coded for by a separate exon, and the two variants of NAK1 mRNAs appeared to be created by alternative splicing. We furthermore showed that the two NAK1 isoforms were differentially expressed in different life stages and in various tissues of adult barnacle, i.e the long isoform was predominant in cyprids and in adult cirri. In barnacle cyprid larvae that were exposed to a combination of different salinities and pCO2 levels, the expression of the long NAK1 mRNA increased relative to the short in low salinities. We suggest that the alternatively spliced long variant of the Nak1 protein might be of importance for osmoregulation in B. improvisus in low salinity conditions. PMID:24130836

  13. Dispersant Corexit 9500A and chemically dispersed crude oil decreases the growth rates of meroplanktonic barnacle nauplii (Amphibalanus improvisus) and tornaria larvae (Schizocardium sp.).

    PubMed

    Almeda, Rodrigo; Bona, Shawn; Foster, Charles R; Buskey, Edward J

    2014-08-01

    Our knowledge of the lethal and sublethal effects of dispersants and dispersed crude oil on meroplanktonic larvae is limited despite the importance of planktonic larval stages in the life cycle of benthic invertebrates. We determined the effects of Light Louisiana Sweet crude oil, dispersant Corexit 9500A, and dispersant-treated crude oil on the survival and growth rates of nauplii of the barnacle Amphibalanus improvisus and tornaria larvae of the enteropneust Schizocardium sp. Growth rates of barnacle nauplii and tornaria larvae were significantly reduced after exposure to chemically dispersed crude oil and dispersant Corexit 9500A at concentrations commonly found in the water column after dispersant application in crude oil spills. We also found that barnacle nauplii ingested dispersed crude oil, which may have important consequences for the biotransfer of petroleum hydrocarbons through coastal pelagic food webs after a crude oil spill. Therefore, application of chemical dispersants increases the impact of crude oil spills on meroplanktonic larvae, which may affect recruitment and population dynamics of marine benthic invertebrates.

  14. Dispersant Corexit 9500A and chemically dispersed crude oil decreases the growth rates of meroplanktonic barnacle nauplii (Amphibalanus improvisus) and tornaria larvae (Schizocardium sp.).

    PubMed

    Almeda, Rodrigo; Bona, Shawn; Foster, Charles R; Buskey, Edward J

    2014-08-01

    Our knowledge of the lethal and sublethal effects of dispersants and dispersed crude oil on meroplanktonic larvae is limited despite the importance of planktonic larval stages in the life cycle of benthic invertebrates. We determined the effects of Light Louisiana Sweet crude oil, dispersant Corexit 9500A, and dispersant-treated crude oil on the survival and growth rates of nauplii of the barnacle Amphibalanus improvisus and tornaria larvae of the enteropneust Schizocardium sp. Growth rates of barnacle nauplii and tornaria larvae were significantly reduced after exposure to chemically dispersed crude oil and dispersant Corexit 9500A at concentrations commonly found in the water column after dispersant application in crude oil spills. We also found that barnacle nauplii ingested dispersed crude oil, which may have important consequences for the biotransfer of petroleum hydrocarbons through coastal pelagic food webs after a crude oil spill. Therefore, application of chemical dispersants increases the impact of crude oil spills on meroplanktonic larvae, which may affect recruitment and population dynamics of marine benthic invertebrates. PMID:25028258

  15. Effect of pH, ionic strength, and background electrolytes on Cr(VI) and total chromium removal by acorn shell of Quercus crassipes Humb. & Bonpl.

    PubMed

    Aranda-García, Erick; Morales-Barrera, Liliana; Pineda-Camacho, Gabriela; Cristiani-Urbina, Eliseo

    2014-10-01

    The ability of Quercus crassipes acorn shells (QCS) to remove Cr(VI) and total chromium from aqueous solutions was investigated as a function of the solution pH, ionic strength, and background electrolytes. It was found that Cr(VI) and total chromium removal by QCS depended strongly on the pH of the solution. Cr(VI) removal rate increased as the solution pH decreased. The optimum pH for total chromium removal varied depending on contact time. NaCl ionic strengths lower than 200 mM did not affect chromium removal. The presence of 20 mM monovalent cations and anions, and of divalent cations, slightly decreased the removal of Cr(VI) and total chromium by QCS; in contrast, divalent anions (SO₄(2-), PO₄(2-), CO₃(2-)) significantly affected the removal of Cr(VI) and total chromium. The biosorption kinetics of chromium ions followed the pseudo-second-order model at all solution pH levels, NaCl ionic strengths and background electrolytes tested. Results suggest that QCS may be a potential low-cost biosorbent for the removal of Cr(VI) and total chromium from aqueous solutions containing various impurities.

  16. Effects of spatial structure of population size on the population dynamics of barnacles across their elevational range.

    PubMed

    Fukaya, Keiichi; Okuda, Takehiro; Nakaoka, Masahiro; Noda, Takashi

    2014-11-01

    Explanations for why population dynamics vary across the range of a species reflect two contrasting hypotheses: (i) temporal variability of populations is larger in the centre of the range compared to the margins because overcompensatory density dependence destabilizes population dynamics and (ii) population variability is larger near the margins, where populations are more susceptible to environmental fluctuations. In both of these hypotheses, positions within the range are assumed to affect population variability. In contrast, the fact that population variability is often related to mean population size implies that the spatial structure of the population size within the range of a species may also be a useful predictor of the spatial variation in temporal variability of population size over the range of the species. To explore how population temporal variability varies spatially and the underlying processes responsible for the spatial variation, we focused on the intertidal barnacle Chthamalus dalli and examined differences in its population dynamics along the tidal levels it inhabits. Changes in coverage of barnacle populations were monitored for 10.5 years at 25 plots spanning the elevational range of this species. Data were analysed by fitting a population dynamics model to estimate the effects of density-dependent and density-independent processes on population growth. We also examined the temporal mean-variance relationship of population size with parameters estimated from the population dynamics model. We found that the relative variability of populations tended to increase from the centre of the elevational range towards the margins because of an increase in the magnitude of stochastic fluctuations of growth rates. Thus, our results supported hypothesis (2). We also found that spatial variations in temporal population variability were well characterized by Taylor's power law, the relative population variability being inversely related to the mean

  17. Temporal and spatial variability in the recruitment of barnacles and the local dominance of Elminius modestus Darwin in SW Ireland

    NASA Astrophysics Data System (ADS)

    Watson, Douglas I.; O'Riordan, Ruth M.; Barnes, David K. A.; Cross, Tom

    2005-04-01

    Deployment of processed natural substrata is a common method of investigating early settlement and recruitment processes, but has been under-utilised as a multi-depth method for barnacle study and analysis. Replicate, machined-slate panels (15 cm×15 cm×1 cm) were placed at 0 m (lower portion of the intertidal with ≈2 h emersion per tidal cycle), 6 m and 12 m at two sites of differing flow rate in Lough Hyne, SW Ireland. These panels were replaced serially every 30-60 days for a period of 3 years (2000-2003) to give monthly recruitment rates. Panels were also submersed for 60-120 days (Whirlpool Cliff, two locations) to show seasonal patterns and 370-400 days (Labhra Cliff) to show annual recruitment and survival patterns. The number, percentage cover and identity of all cirripede recruits were recorded. The greatest source of variability was with depth: between the intertidal (with many recruits) and the subtidal zones (few recruits). In general, intertidal recruitment was dominated by the introduced barnacle Elminius modestus Darwin. The high degree of water retention in Lough Hyne, combined with the high reproductive potential of E. modestus, has led to it becoming a self-perpetuating and locally dominant population. Balanus crenatus and Verruca stroemia dominated the longer immersed panels, highlighting the importance of post-recruitment processes to the survival of E. modestus recruits in the subtidal. Although E. modestus were found on subtidal monthly and seasonal panels, none were present on the subtidal annual panels. Temporally, month, season and time of placement were all found to be significant in explaining recruit number variability. Spatially, depth explained most variability of recruit numbers (6 m spatial separation), whilst site (≈200 m spatial separation) only ever being significant in combination with other factors, as was location (≈50 m spatial separation). The work highlights the importance of examining both temporal and spatial scales

  18. Phylogeography of a Marine Insular Endemic in the Atlantic Macaronesia: The Azorean Barnacle, Megabalanus azoricus (Pilsbry, 1916)

    PubMed Central

    González, José A.; Almeida, Corrine; Lopes, Evandro; Araújo, Ricardo; Carreira, Gilberto P.

    2015-01-01

    The Azorean barnacle, Megabalanus azoricus (Pilsbry, 1916), is a Macaronesian endemic whose obscure taxonomy and the unknown relationships among forms inhabiting isolated Northern Atlantic oceanic islands is investigated by means of molecular analysis herein. Mitochondrial data from the 16S rRNA and COX1 genes support its current species status, tropical ancestry, and the taxonomic homogeneity throughout its distribution range. In contrast, at the intraspecific level and based on control region sequences, we detected an overall low level of genetic diversity and three divergent lineages. The haplogroups α and γ were sampled in the Azores, Madeira, Canary, and Cabo Verde archipelagos; whereas haplogroup β was absent from Cabo Verde. Consequently, population analysis suggested a differentiation of the Cabo Verde population with respect to the genetically homogenous northern archipelagos generated by current oceanographic barriers. Furthermore, haplogroup α, β, and γ demographic expansions occurred during the interglacial periods MIS5 (130 Kya - thousands years ago -), MIS3 (60 Kya), and MIS7 (240 Kya), respectively. The evolutionary origin of these lineages is related to its survival in the stable southern refugia and its demographic expansion dynamics are associated with the glacial-interglacial cycles. This phylogeographic pattern suggests the occurrence of genetic discontinuity informative to the delimitation of an informally defined biogeographic entity, Macaronesia, and its generation by processes that delineate genetic diversity of marine taxa in this area. PMID:25919141

  19. Atomic force microscopy of the morphology and mechanical behaviour of barnacle cyprid footprint proteins at the nanoscale.

    PubMed

    Phang, In Yee; Aldred, Nick; Ling, Xing Yi; Huskens, Jurriaan; Clare, Anthony S; Vancso, G Julius

    2010-02-01

    Barnacles are a major biofouler of man-made underwater structures. Prior to settlement, cypris larvae explore surfaces by reversible attachment effected by a 'temporary adhesive'. During this exploratory behaviour, cyprids deposit proteinaceous 'footprints' of a putatively adhesive material. In this study, footprints deposited by Balanus amphitrite cyprids were probed by atomic force microscopy (AFM) in artificial sea water (ASW) on silane-modified glass surfaces. AFM images obtained in air yielded better resolution than in ASW and revealed the fibrillar nature of the secretion, suggesting that the deposits were composed of single proteinaceous nanofibrils, or bundles of fibrils. The force curves generated in pull-off force experiments in sea water consisted of regions of gradually increasing force, separated by sharp drops in extension force manifesting a characteristic saw-tooth appearance. Following the relaxation of fibrils stretched to high strains, force-distance curves in reverse stretching experiments could be described by the entropic elasticity model of a polymer chain. When subjected to relaxation exceeding 500 ms, extended footprint proteins refolded, and again showed saw-tooth unfolding peaks in subsequent force cycles. Observed rupture and hysteresis behaviour were explained by the 'sacrificial bond' model. Longer durations of relaxation (>5 s) allowed more sacrificial bond reformation and contributed to enhanced energy dissipation (higher toughness). The persistence length for the protein chains (L(P)) was obtained. At high elongation, following repeated stretching up to increasing upper strain limits, footprint proteins detached at total stretched length of 10 microm.

  20. Host-Specific Phenotypic Plasticity of the Turtle Barnacle Chelonibia testudinaria: A Widespread Generalist Rather than a Specialist

    PubMed Central

    Chu, Ka Hou; Cheng, I-Jiunn; Chan, Benny K. K.

    2013-01-01

    Turtle barnacles are common epibionts on marine organisms. Chelonibia testudinaria is specific on marine turtles whereas C. patula is a host generalist, but rarely found on turtles. It has been questioned why C. patula, being abundant on a variety of live substrata, is almost absent from turtles. We evaluated the genetic (mitochondrial COI, 16S and 12S rRNA, and amplified fragment length polymorphism (AFLP)) and morphological differentiation of C. testudinaia and C. patula from different hosts, to determine the mode of adaptation exhibited by Chelonibia species on different hosts. The two taxa demonstrate clear differences in shell morphology and length of 4–6th cirri, but very similar in arthropodal characters. Moreover, we detected no genetic differentiation in mitochondrial DNA and AFLP analyses. Outlier detection infers insignificant selection across loci investigated. Based on combined morphological and molecular evidence, we proposed that C. testudinaria and C. patula are conspecific, and the two morphs with contrasting shell morphologies and cirral length found on different host are predominantly shaped by developmental plasticity in response to environmental setting on different hosts. Chelonibia testudinaria is, thus, a successful general epibiotic fouler and the phenotypic responses postulated can increase the fitness of the animals when they attach on hosts with contrasting life-styles. PMID:23469208

  1. Phylogeography of a Marine Insular Endemic in the Atlantic Macaronesia: The Azorean Barnacle, Megabalanus azoricus (Pilsbry, 1916).

    PubMed

    Quinteiro, Javier; Manent, Pablo; Pérez-Diéguez, Lois; González, José A; Almeida, Corrine; Lopes, Evandro; Araújo, Ricardo; Carreira, Gilberto P; Rey-Méndez, Manuel; González-Henríquez, Nieves

    2015-01-01

    The Azorean barnacle, Megabalanus azoricus (Pilsbry, 1916), is a Macaronesian endemic whose obscure taxonomy and the unknown relationships among forms inhabiting isolated Northern Atlantic oceanic islands is investigated by means of molecular analysis herein. Mitochondrial data from the 16S rRNA and COX1 genes support its current species status, tropical ancestry, and the taxonomic homogeneity throughout its distribution range. In contrast, at the intraspecific level and based on control region sequences, we detected an overall low level of genetic diversity and three divergent lineages. The haplogroups α and γ were sampled in the Azores, Madeira, Canary, and Cabo Verde archipelagos; whereas haplogroup β was absent from Cabo Verde. Consequently, population analysis suggested a differentiation of the Cabo Verde population with respect to the genetically homogenous northern archipelagos generated by current oceanographic barriers. Furthermore, haplogroup α, β, and γ demographic expansions occurred during the interglacial periods MIS5 (130 Kya - thousands years ago -), MIS3 (60 Kya), and MIS7 (240 Kya), respectively. The evolutionary origin of these lineages is related to its survival in the stable southern refugia and its demographic expansion dynamics are associated with the glacial-interglacial cycles. This phylogeographic pattern suggests the occurrence of genetic discontinuity informative to the delimitation of an informally defined biogeographic entity, Macaronesia, and its generation by processes that delineate genetic diversity of marine taxa in this area. PMID:25919141

  2. Phylogeography of a Marine Insular Endemic in the Atlantic Macaronesia: The Azorean Barnacle, Megabalanus azoricus (Pilsbry, 1916).

    PubMed

    Quinteiro, Javier; Manent, Pablo; Pérez-Diéguez, Lois; González, José A; Almeida, Corrine; Lopes, Evandro; Araújo, Ricardo; Carreira, Gilberto P; Rey-Méndez, Manuel; González-Henríquez, Nieves

    2015-01-01

    The Azorean barnacle, Megabalanus azoricus (Pilsbry, 1916), is a Macaronesian endemic whose obscure taxonomy and the unknown relationships among forms inhabiting isolated Northern Atlantic oceanic islands is investigated by means of molecular analysis herein. Mitochondrial data from the 16S rRNA and COX1 genes support its current species status, tropical ancestry, and the taxonomic homogeneity throughout its distribution range. In contrast, at the intraspecific level and based on control region sequences, we detected an overall low level of genetic diversity and three divergent lineages. The haplogroups α and γ were sampled in the Azores, Madeira, Canary, and Cabo Verde archipelagos; whereas haplogroup β was absent from Cabo Verde. Consequently, population analysis suggested a differentiation of the Cabo Verde population with respect to the genetically homogenous northern archipelagos generated by current oceanographic barriers. Furthermore, haplogroup α, β, and γ demographic expansions occurred during the interglacial periods MIS5 (130 Kya - thousands years ago -), MIS3 (60 Kya), and MIS7 (240 Kya), respectively. The evolutionary origin of these lineages is related to its survival in the stable southern refugia and its demographic expansion dynamics are associated with the glacial-interglacial cycles. This phylogeographic pattern suggests the occurrence of genetic discontinuity informative to the delimitation of an informally defined biogeographic entity, Macaronesia, and its generation by processes that delineate genetic diversity of marine taxa in this area.

  3. Improvement of cardiac sarcoplasmic reticulum calcium cycling in dogs with heart failure following long-term therapy with the Acorn Cardiac Support Device.

    PubMed

    Gupta, Ramesh C; Mishra, Sudhish; Rastogi, Sharad; Sharov, Victor G; Sabbah, Hani N

    2005-06-01

    Abnormal Ca(2+)-homeostasis is a hall-marked characteristic of the failing heart. In the normal myocardium, the sarcoplasmic reticulum (SR) is a principal organelle that controls intracellular Ca(2+) concentration during the cardiac cycle. The SR consists of longitudinal and terminal cisternea regions. The former contains the Ca(2+)-ATPase pump or SERCA-2a whose function is to transport cytosolic Ca(2+) into the lumen of the SR during diastole and whose activity is regulated by reversible phosphorylation of the endogenously SR-bound phospholamban (PLB). The SR's terminal cisternea region contains ryanodine-sensitive Ca(2+)-release channels (RR), the activity of which is regulated by direct and indirect reversible phosphorylation. These channels release the SR-stored Ca(2+) during contraction. We have shown that in left ventricular (LV) myocardium from dogs with coronary microembolization-induced heart failure, ability of the SR to sequester and release Ca(2+) during the cardiac cycles is impaired. This abnormality was associated with reduced expression (protein and mRNA) levels of Ca(2+)-ATPase, PLB, and reduced PLB phosphorylation. Long-term therapy with the Acorn Cardiac Support Device (CSD) is associated with restoration of the ability of the SR to sequester Ca(2+). This improvement in SR function following chronic CSD therapy was due primarily to increased affinity of the SERCA-2a for calcium. The later was associated with (1) increased phosphorylation of PLB at serine 16 and threonine 17, (2) unchanged protein expression of PLB and (3) unchanged protein expression of SERCA-2a in LV myocardium of CSD-treated dogs compared to controls. This review summarizes our current understanding of the role of the CSD in modulating SR calcium cycling in an experimental canine model of chronic heart failure produced by multiple sequential intracoronary microembolizations. PMID:16258722

  4. Management of Neonatal Respiratory Distress Syndrome Employing ACoRN Respiratory Sequence Protocol versus Early Nasal Continuous Positive Airway Pressure Protocol

    PubMed Central

    Niknafs, Pedram; Faghani, Asadallah; Afjeh, Seyed-Abolfazl; Moradinazer, Mehdi; Bahman-Bijari, Bahareh

    2014-01-01

    Objective: Respiratory distress syndrome (RDS) is a common cause of respiratory distress in premature infants. This study was designed to evaluate two different RDS treatment protocols by comparing the outcomes. Methods: This study was a double center cross sectional study performed from June to December 2012. During that period, 386 neonates with RDS were hospitalized and treated according to two different therapeutic protocols so-called Acute Care of at-Risk Newborns (ACoRN) respiratory sequence protocol (group I) and Early Nasal Continuous Positive Airway Pressure (E-NCPAP) protocol (group II). The variables and main outcomes of this study were gestational age, birth weight, bronchopulmonary dysplasia (BPD), pulmonary hemorrhage (PH), intraventricular hemorrhage (IVH), air leak and mortality rate (MR). Findings : Out of 386 infants, 202 infants were in group I (male 60.4%, female 39.6%, mean gestational age 316/7 weeks, mean birth weight=1688 grams) and group II included 184 infants (male 61.4%, female 38.6%, mean gestational age 32 weeks, mean birth weight 1787 grams), P= 0.07. The ratios of BPD of group I to group II and PH of group I to group two were not significant (P=0.63 and P=0.84, respectively). Air leak ratio in group I was higher than in group II (P=0.001). Although IVH ratio in group II was higher than in group I (P=0.01), grade III and IV IVH was higher in group I (30% vs. 4.6%). In case of MR, it was higher in group I than in group II (P=0.001). Conclusion: According to the findings the incidence of air leak, grade III and IV IVH and MR was less common in E-NCPAP protocol, so it may show the effectiveness of this protocol. The authors suggest that more researches are needed for more accurate results. PMID:25793046

  5. Zoogeography of intertidal communities in the West Indian Ocean as determined by ocean circulation systems: patterns from the Tetraclita barnacles.

    PubMed

    Tsang, Ling Ming; Achituv, Yair; Chu, Ka Hou; Chan, Benny Kwok Kan

    2012-01-01

    The Indian Ocean is the least known ocean in the world with the biogeography of marine species in the West Indian Ocean (WIO) understudied. The hydrography of WIO is characterized by four distinct oceanographic systems and there were few glacial refugia formations in the WIO during the Pleistocene. We used the widely distributed intertidal barnacle Tetraclita to test the hypothesis that the distribution and connectivity of intertidal animals in the WIO are determined by the major oceanographic regime but less influenced by historical events such as Pleistocene glaciations. Tetraclita were studied from 32 locations in the WIO. The diversity and distribution of Tetraclita species in the Indian Ocean were examined based on morphological examination and sequence divergence of two mitochondrial genes (12S rDNA and COI) and one nuclear gene (histone 3, H3). Divergence in DNA sequences revealed the presence of seven evolutionarily significant units (ESUs) of Tetraclita in WIO, with most of them recognized as valid species. The distribution of these ESUs is closely tied to the major oceanographic circulation systems. T. rufotincta is distributed in the Monsoonal Gyre. T. ehsani is present in the Gulf of Oman and NW India. Tetraclita sp. nov. is associated with the Hydrochemical Front at 10°S latitude. T. reni is confined to southern Madagascan and Mauritian waters, influenced by the West Wind Drift. The endemic T. achituvi is restricted to the Red Sea. Tetraclita serrata consists of two ESUs (based on mtDNA analysis) along the east to west coast of South Africa. The two ESUs could not be distinguished from morphological analysis and nuclear H3 sequences. Our results support that intertidal species in the West Indian Ocean are associated with each of the major oceanographic circulation systems which determine gene flow. Geographical distribution is, however, less influenced by the geological history of the region. PMID:23024801

  6. Water in barnacle muscle. III. NMR studies of fresh fibers and membrane-damaged fibers equilibrated with selected solutes.

    PubMed Central

    Burnell, E E; Clark, M E; Hinke, J A; Chapman, N R

    1981-01-01

    Water in barnacle muscle has been studied using NMR techniques. Fresh fibers are compared with membrane-damaged fibers treated with solutes that greatly alter fixed charge and total water content. Both water (97%) and solute (3%) protons are visible in continuous wave spectra of oriented fresh fibers. No local field inhomogeneities were detected, nor are cell solutes significantly bound. In pulse experiments, all cell water is visible and exhibits a single exponential decay. In fresh fibers, T2 approximately or equal to 40 ms; faster decaying signals are assigned to immobile and mobile protons on macromolecules. T1 and T1p are frequency dependent. Using equations derived for a two-compartment model with fast exchange, we calculate the following: tau b, the correlation time for anisotropic rotational motion of bound water; Sb, its order parameter; tau ex, the correlation time for exchange between bound and free fractions; f, the fraction of water bound; and Hr, the grams of water bound per gram of macromolecule. Whereas f varies inversely with total water content, the other parameters are virtually constant, with values: tau b approximately or equal to 1.3 X 10(-8) S; tau ex approximately or equal to 8 X 10(-6) s; Sb approximately or equal to 0.06; and Hr approximately or equal to 0.1g H2O/g macromolecule. Thus, the NMR relaxation detectable properties of water bound to macromolecules are unaffected by solutes that greatly alter the macromolecular surface charge. PMID:7272435

  7. Morphology and responses to light of the somata, axons, and terminal regions of individual photoreceptors of the giant barnacle

    PubMed Central

    Hudspeth, A. J.; Stuart, Ann E.

    1977-01-01

    1. The median eye of the giant barnacle, B. nubilus, comprises four large photoreceptor neurones which are visible under the dissecting microscope for almost their entire length. We have studied the structure of, and the responses to light recorded in, the somata, axons, and terminal regions of these neurones. 2. The photoreceptor somata, each 40-70 μm in diameter, extend numerous light-sensitive dendritic processes whose membranes form rhabdomeric microvilli. Recordings from the soma show that dim light evokes a steady, noisy depolarization; brighter light elicits a transient depolarization which decays to a maintained plateau, followed by a hyperpolarization when the light is turned off. 3. Light-induced voltage changes spread decrementally along the photoreceptor axons, which average 10 mm in length and 25 μm in diameter. In distal parts of the axon, near the presynaptic terminals, depolarizations and hyperpolarizations can be as large as 50% or more of their values in the soma. 4. There is no demonstrable electrical coupling between photoreceptor neurones as shown by simultaneous recordings from two receptor somata or axons. 5. Each photoreceptor axon enters the mid line commissure of the supraoesophageal ganglion, bifurcates, and arborizes in a restricted zone of neuropil in each hemiganglion. The large size of the terminal processes of these neurones and their characteristic cytoplasmic inclusions enable one to trace them with the electron microscope as they branch in the neuropil. 6. The terminal processes subdivide and end in 1-3 μm diameter branches which are the sites of apparently chemical synapses. Vesicle-containing, presynaptic loci on these processes of the receptor cell are invariably apposed to two post-synaptic processes from cells as yet unidentified. ImagesABCDEABCABCDABCABCDEFG PMID:592112

  8. Zoogeography of Intertidal Communities in the West Indian Ocean as Determined by Ocean Circulation Systems: Patterns from the Tetraclita Barnacles

    PubMed Central

    Tsang, Ling Ming; Achituv, Yair; Chu, Ka Hou; Chan, Benny Kwok Kan

    2012-01-01

    The Indian Ocean is the least known ocean in the world with the biogeography of marine species in the West Indian Ocean (WIO) understudied. The hydrography of WIO is characterized by four distinct oceanographic systems and there were few glacial refugia formations in the WIO during the Pleistocene. We used the widely distributed intertidal barnacle Tetraclita to test the hypothesis that the distribution and connectivity of intertidal animals in the WIO are determined by the major oceanographic regime but less influenced by historical events such as Pleistocene glaciations. Tetraclita were studied from 32 locations in the WIO. The diversity and distribution of Tetraclita species in the Indian Ocean were examined based on morphological examination and sequence divergence of two mitochondrial genes (12S rDNA and COI) and one nuclear gene (histone 3, H3). Divergence in DNA sequences revealed the presence of seven evolutionarily significant units (ESUs) of Tetraclita in WIO, with most of them recognized as valid species. The distribution of these ESUs is closely tied to the major oceanographic circulation systems. T. rufotincta is distributed in the Monsoonal Gyre. T. ehsani is present in the Gulf of Oman and NW India. Tetraclita sp. nov. is associated with the Hydrochemical Front at 10°S latitude. T. reni is confined to southern Madagascan and Mauritian waters, influenced by the West Wind Drift. The endemic T. achituvi is restricted to the Red Sea. Tetraclita serrata consists of two ESUs (based on mtDNA analysis) along the east to west coast of South Africa. The two ESUs could not be distinguished from morphological analysis and nuclear H3 sequences. Our results support that intertidal species in the West Indian Ocean are associated with each of the major oceanographic circulation systems which determine gene flow. Geographical distribution is, however, less influenced by the geological history of the region. PMID:23024801

  9. Cellular synthesis and axonal transport of gamma-aminobutyric acid in a photoreceptor cell of the barnacle.

    PubMed Central

    Koike, H; Tsuda, K

    1980-01-01

    1. [3H]glutamate or [3H]gamma-aminobutyric acid (GABA) was injected into the photoreceptor cell of the lateral ocellus of Balanus eburneus, in order to study the transmitter substance of the cell. 2. The photoreceptor cell synthesized [3H]GABA from injected [3H]glutamate. 3. The newly formed [3H]GABA moved inside the photoreceptor axon towards the axon terminal with a velocity of about 0.9 mm/hr. Injected [3H]GABA moved at 0.9 mm/hr and also at 0.4 mm/hr. 4. Axonally transported [3H]GABA reached the axon terminal within several hours following the injection. It did not accumulate at the terminal, but gradually disappeared. 5. Light-microscope and electron-microscope autoradiography following the injection of [3H]GABA revealed that [3H]-reacted silver grains were present in a certain type of axon terminal. The terminal thus identified as that of a photoreceptor cell contains many clear, polymorphic synaptic vesicles about 300-500 A in diameter, some dense-cored vesicles 700-1300 A in diameter, and glycogen granules. The terminal forms many synapses, and each synapse has a synaptic dense body. The terminal always faces two post-synaptic elements at the synapse, forming a triad with a gap distance of about 160-200 A. 6. A GABA analogue, [3H]di-aminobutyric acid, was selectively taken up into the terminals previously identified as those of photoreceptors. 7. These results support the notion that the transmitter substance of the photoreceptor cell of the barnacle is GABA. Images Plate 1 Plate 2 PMID:6160239

  10. Population genetic analysis of a recent range expansion: mechanisms regulating the poleward range limit in the volcano barnacle Tetraclita rubescens.

    PubMed

    Dawson, Michael N; Grosberg, Richard K; Stuart, Yoel E; Sanford, Eric

    2010-04-01

    As range shifts coincident with climate change have become increasingly well documented, efforts to describe the causes of range boundaries have increased. Three mechanisms-genetic impoverishment, migration load, or a physical barrier to dispersal-are well described theoretically, but the data needed to distinguish among them have rarely been collected. We describe the distribution, abundance, genetic variation, and environment of Tetraclita rubescens, an intertidal barnacle that expanded its northern range limit by several hundreds of kilometres from San Francisco, CA, USA, since the 1970s. We compare geographic variation in abundance with abiotic and biotic patterns, including sea surface temperatures and the distributions of 387 co-occurring species, and describe genetic variation in cytochrome c oxidase subunit I, mitochondrial noncoding region, and nine microsatellite loci from 27 locations between Bahia Magdalena (California Baja Sur, Mexico) and Cape Mendocino (CA, USA). We find very high gene flow, high genetic diversity, and a gradient in physical environmental variation coincident with the range limit. We infer that the primary cause of the northern range boundary in T. rubescens is migration load arising from flow of maladapted alleles into peripheral locations and that environmental change, which could have reduced selection against genotypes immigrating into the newly colonized portion of the range, is the most likely cause of the observed range expansion. Because environmental change could similarly affect all taxa in a region whose distributional limits are established by migration load, these mechanisms may be common causes of range boundaries and largely synchronous multi-species range expansions. PMID:20345681

  11. Zoogeography of intertidal communities in the West Indian Ocean as determined by ocean circulation systems: patterns from the Tetraclita barnacles.

    PubMed

    Tsang, Ling Ming; Achituv, Yair; Chu, Ka Hou; Chan, Benny Kwok Kan

    2012-01-01

    The Indian Ocean is the least known ocean in the world with the biogeography of marine species in the West Indian Ocean (WIO) understudied. The hydrography of WIO is characterized by four distinct oceanographic systems and there were few glacial refugia formations in the WIO during the Pleistocene. We used the widely distributed intertidal barnacle Tetraclita to test the hypothesis that the distribution and connectivity of intertidal animals in the WIO are determined by the major oceanographic regime but less influenced by historical events such as Pleistocene glaciations. Tetraclita were studied from 32 locations in the WIO. The diversity and distribution of Tetraclita species in the Indian Ocean were examined based on morphological examination and sequence divergence of two mitochondrial genes (12S rDNA and COI) and one nuclear gene (histone 3, H3). Divergence in DNA sequences revealed the presence of seven evolutionarily significant units (ESUs) of Tetraclita in WIO, with most of them recognized as valid species. The distribution of these ESUs is closely tied to the major oceanographic circulation systems. T. rufotincta is distributed in the Monsoonal Gyre. T. ehsani is present in the Gulf of Oman and NW India. Tetraclita sp. nov. is associated with the Hydrochemical Front at 10°S latitude. T. reni is confined to southern Madagascan and Mauritian waters, influenced by the West Wind Drift. The endemic T. achituvi is restricted to the Red Sea. Tetraclita serrata consists of two ESUs (based on mtDNA analysis) along the east to west coast of South Africa. The two ESUs could not be distinguished from morphological analysis and nuclear H3 sequences. Our results support that intertidal species in the West Indian Ocean are associated with each of the major oceanographic circulation systems which determine gene flow. Geographical distribution is, however, less influenced by the geological history of the region.

  12. The whale barnacle Cryptolepas rhachianecti (Cirripedia: Coronulidae), a phoront of the grey whale Eschrichtius robustus (Cetacea: Eschrichtiidae), from a sandy beach in The Netherlands.

    PubMed

    Bosselaers, Mark; Collareta, Alberto

    2016-08-22

    An isolated compartment of a whale barnacle is herein described from Recent beach deposits in Zoutelande (Walcheren, The Netherlands). This specimen is identified as belonging to the extant coronulid species Cryptolepas rhachianecti, currently known as an epizoic symbiont of the grey whale Eschrichtius robustus. This find represents the first occurrence of C. rhachianecti outside the North Pacific, and the first one as a (sub)fossil. In view of the fact that E. robustus, which is currently confined to the North Pacific, is known as a subfossil from the northeastern Atlantic between late Late Pleistocene (c. 45,000 years ago) and historical (c. 1700 AD) times, we propose a similar (late Quaternary) age for the isolated compartment. The find indicates that the extinct late Quaternary northeastern Atlantic population of E. robustus was infected by Cryptolepas rhachianecti. Our find is, therefore, compatible with the hypothesis of an ancient grey whale migration route running between the subtropical/temperate waters of the northeast Atlantic (or Mediterranean Basin), and the cold waters of the Baltic Sea (or southern Arctic Ocean), through the southern North Sea. Finally, we discuss the systematic placement of the fossil barnacle species Cryptolepas murata and propose the possibility of its removal from the genus Cryptolepas pending further investigations.

  13. Phylogeny of coral-inhabiting barnacles (Cirripedia; Thoracica; Pyrgomatidae) based on 12S, 16S and 18S rDNA analysis.

    PubMed

    Simon-Blecher, N; Huchon, D; Achituv, Y

    2007-09-01

    The traditional phylogeny of the coral-inhabiting barnacles, the Pyrgomatidae, is based on morphological characteristics, mainly of the hard parts. It has been difficult to establish the phylogenetic relationships among Pyrgomatidae because of the apparent convergence of morphological characteristics, and due to the use of non-cladistic systematics, which emphasize ancestor-descendant relationships rather than sister-clade relationships. We used partial sequences of two mithochondrial genes, 12S rDNA and 16S rDNA, and a nuclear gene, 18S rDNA, to infer the molecular phylogeny of the pyrgomatids. Our phylogenetic results allowed us to reject previous classifications of Pyrgomatidae based on morphological characteristics. Our results also suggested the possibility of paraphyly of the Pyrgomatidae. The hydrocoral barnacle Wanella is not found on the same clade as the other pyrgomatids, but rather, with the free-living balanids. The basal position of Megatrema and Ceratoconcha is supported. The archeaobalanid Armatobalanus is grouped with Cantellius at the base of the Indo-Pacific pyrgomatines. Fusion of the shell plate and modification of the opercular valves are homoplasious features that occurred more than three times on different clades. The monophyly of the "Savignium" group, comprising four nominal genera, is also not supported, and the different taxa are placed on different clades.

  14. Evaluation of the floating time of a corpse found in a marine environment using the barnacle Lepas anatifera L. (Crustacea: Cirripedia: Pedunculata).

    PubMed

    Magni, Paola A; Venn, Cynthia; Aquila, Isabella; Pepe, Francesca; Ricci, Pietrantonio; Di Nunzio, Ciro; Ausania, Francesco; Dadour, Ian R

    2015-02-01

    Human activities involving water may result in a crime scene. Typically, death may be due to natural causes, homicide, or mass disasters. Decomposition in water is a complex process where many factors may interplay. Human remains in water are subject to many potential interactions, depending upon the remains themselves, the type of water and the characteristics of the water. A number of studies are focused on the decomposition process of the corpse in water, on the identification of the post mortem submersion interval (PMSI) and on the diagnosis of drowning, but very few studies consider the fate of floating remains in any aquatic environment. The following case describes a corpse found on a shore of the Tyrrhenian Sea (South West of Italy, Calabria Region). The corpse and the soles of his shoes were colonized by the barnacle Lepas anatifera L. (Crustacea: Cirripedia: Pedunculata). The analyses of the barnacles present on the corpse aided in the evaluation of the floating time of the corpse which assisted in estimating the minimum time since death.

  15. On the morphology of antennular sensory and attachment organs in cypris larvae of the deep-sea vent/seep barnacles, Ashinkailepas and Neoverruca.

    PubMed

    Yorisue, Takefumi; Chan, Benny K K; Kado, Ryusuke; Watanabe, Hiromi; Inoue, Koji; Kojima, Shigeaki; Høeg, Jens T

    2016-05-01

    Barnacle cypris larvae show high morphological variation in the organs used in search of and attaching to a substratum. This variation may represent adaptation to the habitat of the species. Here, we studied SEM level morphologies of cypris antennular sensory and attachment organs in a deep-sea vent endemic species (Neoverruca sp.) and a vent/seep inhabiting species (Ashinkailepas seepiophila). We compare them with three species from other environments. The antennular morphologies of Neoverruca sp. and A. seepiophila were similar, which is consistent with recent molecular studies showing a close relationship of the two species. The setation pattern of the antennules was very conservative among species from various environments. In contrast, striking differences were observed in the structure of the attachment organ (the third antennular segment). Neoverruca sp. and A. seepiophila had no velum or a skirt surrounding the attachment disc on the third segment, while other cirripede cyprids almost always have either of these structures. In addition, both cyprids of A. seepiophila and Neoverruca sp. had the attachment disc angled toward the substratum, whereas it faces distally in cyprids from hard bottom inhabiting barnacles. We suggest that both velum/skirt and the angle of the attachment disc play an important role, when the antennules are contacting the substratum during surface exploration. Differences in attachment organ structures may be highly adaptive, enabling cirripede species to enter new habitats during evolution.

  16. On the morphology of antennular sensory and attachment organs in cypris larvae of the deep-sea vent/seep barnacles, Ashinkailepas and Neoverruca.

    PubMed

    Yorisue, Takefumi; Chan, Benny K K; Kado, Ryusuke; Watanabe, Hiromi; Inoue, Koji; Kojima, Shigeaki; Høeg, Jens T

    2016-05-01

    Barnacle cypris larvae show high morphological variation in the organs used in search of and attaching to a substratum. This variation may represent adaptation to the habitat of the species. Here, we studied SEM level morphologies of cypris antennular sensory and attachment organs in a deep-sea vent endemic species (Neoverruca sp.) and a vent/seep inhabiting species (Ashinkailepas seepiophila). We compare them with three species from other environments. The antennular morphologies of Neoverruca sp. and A. seepiophila were similar, which is consistent with recent molecular studies showing a close relationship of the two species. The setation pattern of the antennules was very conservative among species from various environments. In contrast, striking differences were observed in the structure of the attachment organ (the third antennular segment). Neoverruca sp. and A. seepiophila had no velum or a skirt surrounding the attachment disc on the third segment, while other cirripede cyprids almost always have either of these structures. In addition, both cyprids of A. seepiophila and Neoverruca sp. had the attachment disc angled toward the substratum, whereas it faces distally in cyprids from hard bottom inhabiting barnacles. We suggest that both velum/skirt and the angle of the attachment disc play an important role, when the antennules are contacting the substratum during surface exploration. Differences in attachment organ structures may be highly adaptive, enabling cirripede species to enter new habitats during evolution. PMID:26948410

  17. The whale barnacle Cryptolepas rhachianecti (Cirripedia: Coronulidae), a phoront of the grey whale Eschrichtius robustus (Cetacea: Eschrichtiidae), from a sandy beach in The Netherlands.

    PubMed

    Bosselaers, Mark; Collareta, Alberto

    2016-01-01

    An isolated compartment of a whale barnacle is herein described from Recent beach deposits in Zoutelande (Walcheren, The Netherlands). This specimen is identified as belonging to the extant coronulid species Cryptolepas rhachianecti, currently known as an epizoic symbiont of the grey whale Eschrichtius robustus. This find represents the first occurrence of C. rhachianecti outside the North Pacific, and the first one as a (sub)fossil. In view of the fact that E. robustus, which is currently confined to the North Pacific, is known as a subfossil from the northeastern Atlantic between late Late Pleistocene (c. 45,000 years ago) and historical (c. 1700 AD) times, we propose a similar (late Quaternary) age for the isolated compartment. The find indicates that the extinct late Quaternary northeastern Atlantic population of E. robustus was infected by Cryptolepas rhachianecti. Our find is, therefore, compatible with the hypothesis of an ancient grey whale migration route running between the subtropical/temperate waters of the northeast Atlantic (or Mediterranean Basin), and the cold waters of the Baltic Sea (or southern Arctic Ocean), through the southern North Sea. Finally, we discuss the systematic placement of the fossil barnacle species Cryptolepas murata and propose the possibility of its removal from the genus Cryptolepas pending further investigations. PMID:27615844

  18. Evaluation of the floating time of a corpse found in a marine environment using the barnacle Lepas anatifera L. (Crustacea: Cirripedia: Pedunculata).

    PubMed

    Magni, Paola A; Venn, Cynthia; Aquila, Isabella; Pepe, Francesca; Ricci, Pietrantonio; Di Nunzio, Ciro; Ausania, Francesco; Dadour, Ian R

    2015-02-01

    Human activities involving water may result in a crime scene. Typically, death may be due to natural causes, homicide, or mass disasters. Decomposition in water is a complex process where many factors may interplay. Human remains in water are subject to many potential interactions, depending upon the remains themselves, the type of water and the characteristics of the water. A number of studies are focused on the decomposition process of the corpse in water, on the identification of the post mortem submersion interval (PMSI) and on the diagnosis of drowning, but very few studies consider the fate of floating remains in any aquatic environment. The following case describes a corpse found on a shore of the Tyrrhenian Sea (South West of Italy, Calabria Region). The corpse and the soles of his shoes were colonized by the barnacle Lepas anatifera L. (Crustacea: Cirripedia: Pedunculata). The analyses of the barnacles present on the corpse aided in the evaluation of the floating time of the corpse which assisted in estimating the minimum time since death. PMID:25538026

  19. The behavior of the ouabain-insensitive sodium efflux in single barnacle muscle fibers toward the microinjection of aluminum.

    PubMed

    Bittar, E E; Huang, Y P

    1990-10-01

    Recent work with single muscle fibers from the barnacle Balanus nubilus has shown that the injection of Al into these fibers leads to inhibition of the resting Na efflux and that this involves both the ouabain-sensitive and the ouabain-insensitive components of the efflux. This work also showed that the injection of Al into ouabain-poisoned fibers often leads to a rise in the remaining Na efflux. This observation suggested the possibility that Al is able to stimulate the ouabain-insensitive Na by increasing myoplasmic free Ca2+ and that trigger Ca2+ reaches the myoplasm via voltage-dependent Ca2+ channels. The results obtained are as follows: (i) The injection of AlCl3 into fibers poisoned with ouabain produces a biphasic or monophasic effect on the remaining Na efflux. That is, stimulation is followed by inhibition, or there is only stimulation. (ii) This response is dose-dependent and is seen to take place following the injection of Al in a concentration as low as 0.01 M. (iii) Both Ga3+ and Sc3+ are able to mimic the effect of Al. (iv) Injection of EGTA following peak stimulation of the ouabain-insensitive Na efflux by injected AlCl3 leads to reversal of this response. If, however, EGTA is injected long after the onset of peak stimulation and after ouabain reaches its maximum effect, it is found to be ineffective. (v) The magnitude of the stimulatory response of the ouabain-insensitive Na efflux is a sigmoidal function of external Ca2+ and is almost completely abolished by verapamil, devapamil, and Cd2+ but is unaffected by injecting Mg2+ before or after AlCl3. (vi) Whereas preinjection of Al reduces the response to ryanodine, external preapplication of ryanodine fails to alter the response to Al. The preinjection of deferoxamine (a potent chelator of Al) fails to stop the stimulatory response to Al injection from occurring. Taken together, these findings support the hypothesis that the stimulatory response elicited by Al injection is due to a fall in myoplasmic

  20. Numerical simulations of barnacle larval dispersion coupled with field observations on larval abundance, settlement and recruitment in a tropical monsoon influenced coastal marine environment

    NASA Astrophysics Data System (ADS)

    Gaonkar, Chetan A.; Samiksha, S. V.; George, Grinson; Aboobacker, V. M.; Vethamony, P.; Anil, Arga Chandrashekar

    2012-06-01

    Larval abundance in an area depends on various factors which operate over different spatial and temporal scales. Identifying the factors responsible for variations in larval supply and abundance is important to understand the settlement and recruitment variability of their population in a particular area. In view of this, observations were carried out to monitor the larval abundance, settlement and recruitment of barnacles on a regular basis for a period of two years. The results were then compared with the numerical modelling studies carried out along the west coast of India. Field observations of larval abundance showed temporal variations. The least abundance of larvae was mostly observed during the monsoon season and the peak in abundance was mostly observed during the pre-monsoon season. Numerical simulations also showed a seasonal change in larval dispersion and retention patterns. During pre-monsoon season the larval movement was mostly found towards south and the larvae released from the northern release sites contributed to larval abundance within the estuaries, whereas during the monsoon season the larval movement was mostly found towards north and the larvae released from southern release sites contributed to larval abundance within the estuary. During post-monsoon season, the larval movement was found towards the north in the beginning of the season and is shifted towards the south at the end of the season, but the movement was mostly restricted near to the release sites. Larval supply from the adjacent rocky sites to the estuaries was higher during the pre-monsoon season and the retention of larvae released from different sites within the estuaries was found to be highest during the late post-monsoon and early pre-monsoon season. Maximum larval supply and retention during the pre-monsoon season coincided with maximum larval abundance, settlement and recruitment of barnacles observed in the field studies. These observations showed that the pattern of

  1. Environmental studies on natural halogen compounds. I Estimation of biomass of the acorn wormPtychodera flava Eschscholtz (Hemichordata: Enteropneusta) and excretion rate of metabolites at Kattore Bay, Kohama Island, Okinawa.

    PubMed

    Higa, T; Sakemi, S

    1983-04-01

    In order to study the environmental significance of the acorn wormPtychodera flava, which excretes a copious amount of halogenated metabolites, the biomass and the excretion rate were estimated at Kattore Bay, Kohama Island, Okinawa. The habitat, which extends over 1 km(2), could be divided into two areas: zone A, 3.0 × 10(5)m(2), density 95.6/m(2); and zone B, 7.2 × 10(5) m(2), density 48.8/m(2), according to the densities. The total population was estimated to be 6.4 × 10(7) ± 2.0 × 10(7) individuals or 93.0 ± 28.9 tons. These worms daily excrete about 480 tons of fecal sand which was estimated to contain 43 kg of the material extractable with organic solvents. The material contained halogenated metabolites which showed antimicrobial activity. PMID:24407456

  2. Environmental studies on natural halogen compounds. I Estimation of biomass of the acorn wormPtychodera flava Eschscholtz (Hemichordata: Enteropneusta) and excretion rate of metabolites at Kattore Bay, Kohama Island, Okinawa.

    PubMed

    Higa, T; Sakemi, S

    1983-04-01

    In order to study the environmental significance of the acorn wormPtychodera flava, which excretes a copious amount of halogenated metabolites, the biomass and the excretion rate were estimated at Kattore Bay, Kohama Island, Okinawa. The habitat, which extends over 1 km(2), could be divided into two areas: zone A, 3.0 × 10(5)m(2), density 95.6/m(2); and zone B, 7.2 × 10(5) m(2), density 48.8/m(2), according to the densities. The total population was estimated to be 6.4 × 10(7) ± 2.0 × 10(7) individuals or 93.0 ± 28.9 tons. These worms daily excrete about 480 tons of fecal sand which was estimated to contain 43 kg of the material extractable with organic solvents. The material contained halogenated metabolites which showed antimicrobial activity.

  3. Cross-species, amplifiable microsatellite markers for neoverrucid barnacles from deep-sea hydrothermal vents developed using next-generation sequencing.

    PubMed

    Nakajima, Yuichi; Shinzato, Chuya; Khalturina, Mariia; Watanabe, Hiromi; Inagaki, Fumio; Satoh, Nori; Mitarai, Satoshi

    2014-08-18

    Barnacles of the genus Neoverruca are abundant near deep-sea hydrothermal vents of the northwestern Pacific Ocean, and are useful for understanding processes of population formation and maintenance of deep-sea vent faunas. Using next-generation sequencing, we isolated 12 polymorphic microsatellite loci from Neoverruca sp., collected in the Okinawa Trough. These microsatellite loci revealed 2-19 alleles per locus. The expected and observed heterozygosities ranged from 0.286 to 1.000 and 0.349 to 0.935, respectively. Cross-species amplification showed that 9 of the 12 loci were successfully amplified for Neoverruca brachylepadoformis in the Mariana Trough. A pairwise FST value calculated using nine loci showed significant genetic differentiation between the two species. Consequently, the microsatellite markers we developed will be useful for further population genetic studies to elucidate genetic diversity, differentiation, classification, and evolutionary processes in the genus Neoverruca.

  4. Seasonal variation of metal contamination in the barnacles Pollicipes pollicipes in northwest coast of Portugal show clear correlation with levels in the surrounding water.

    PubMed

    Reis, Pedro A; Salgado, Maria Antónia; Vasconcelos, Vitor

    2013-05-15

    The concentrations of metals were determined in northwest (NW) coast of Portugal seawaters and soft tissues of goose barnacles Pollicipes pollicipes. P. pollicipes can be used for monitoring metal contamination in these coastal seawaters, because there were significant correlations (p<0.05) for all metals between soft tissues and seawaters during the four seasons. Metal concentrations in seawaters and P. pollicipes had significant (p<0.05) spatial and seasonal variations and mean log BAFs for Fe and Cd were higher than for Cr, Cu, Mn and Zn. Regarding the metal concentrations obtained in the coastal seawaters, all NW coast of Portugal should be classified as "Class IV--Bad", except two locations (location 7 at Summer and location 10 at Winter), which should be classified as "Class III--Moderate". However, considering the metal concentrations bioaccumulated in P. pollicipes, all locations should be classified as "Class III--Remarkably Polluted" during all seasons of 2011.

  5. Two new species of the gorgonian inhabiting barnacle, Conopea (Crustacea, Cirripedia, Thoracica), from the Gulf of Guinea

    PubMed Central

    Carrison-Stone, Dana; Syoc, Robert Van; Williams, Gary; Simison, W. Brian

    2013-01-01

    Abstract Two new species of Conopea (Say 1822) are described from the Gulf of Guinea: Conopea saotomensis sp. n.and Conopea fidelis sp. n. These two new species were collected from the historically isolated volcanic islands of São Tomé and Príncipe. The relationship between Conopea saotomensis sp. n., Conopea fidelis sp. n.and two other Atlantic barnacle species, Conopea calceola (Ellis 1758) and Conopea galeata (Linnaeus 1771), is examined. The methods employed are the construction of a molecular phylogeny using mitochondrial COI and nuclear H3 gene sequence data along with morphological comparisons of calcareous and cuticular body parts. It is found that Conopea saotomensis sp. n., Conopea fidelis sp. n.and Conopea calceola are most closely related to each other but the relationship among them is unresolved. Gorgonian hosts are identified. Preliminary observations show species level host specificity for Conopea fidelis sp. n. PMID:23730186

  6. Importance of plasticity and local adaptation for coping with changing salinity in coastal areas: a test case with barnacles in the Baltic Sea

    PubMed Central

    2014-01-01

    Background Salinity plays an important role in shaping coastal marine communities. Near-future climate predictions indicate that salinity will decrease in many shallow coastal areas due to increased precipitation; however, few studies have addressed this issue. The ability of ecosystems to cope with future changes will depend on species’ capacities to acclimatise or adapt to new environmental conditions. Here, we investigated the effects of a strong salinity gradient (the Baltic Sea system – Baltic, Kattegat, Skagerrak) on plasticity and adaptations in the euryhaline barnacle Balanus improvisus. We used a common-garden approach, where multiple batches of newly settled barnacles from each of three different geographical areas along the Skagerrak-Baltic salinity gradient were exposed to corresponding native salinities (6, 15 and 30 PSU), and phenotypic traits including mortality, growth, shell strength, condition index and reproductive maturity were recorded. Results We found that B. improvisus was highly euryhaline, but had highest growth and reproductive maturity at intermediate salinities. We also found that low salinity had negative effects on other fitness-related traits including initial growth and shell strength, although mortality was also lowest in low salinity. Overall, differences between populations in most measured traits were weak, indicating little local adaptation to salinity. Nonetheless, we observed some population-specific responses – notably that populations from high salinity grew stronger shells in their native salinity compared to the other populations, possibly indicating adaptation to differences in local predation pressure. Conclusions Our study shows that B. improvisus is an example of a true brackish-water species, and that plastic responses are more likely than evolutionary tracking in coping with future changes in coastal salinity. PMID:25038588

  7. The Influence of Pleistocene Climatic Changes and Ocean Currents on the Phylogeography of the Southern African Barnacle, Tetraclita serrata (Thoracica; Cirripedia)

    PubMed Central

    Reynolds, Terry V.; Matthee, Conrad A.; von der Heyden, Sophie

    2014-01-01

    The evolutionary effects of glacial periods are poorly understood for Southern Hemisphere marine intertidal species, particularly obligatory sessile organisms. We examined this by assessing the phylogeographic patterns of the southern African volcano barnacle, Tetraclita serrata, a dominant species on rocky intertidal shores. Restricted gene flow in some geographical areas was hypothesized based on oceanic circulation patterns and known biogeographic regions. Barnacle population genetic structure was investigated using the mitochondrial cytochrome oxidase subunit 1 (COI) region for 410 individuals sampled from 20 localities spanning the South African coast. The mtDNA data were augmented by generating nuclear internal transcribed spacer 1 (ITS1) sequences from a subset of samples. Phylogenetic and population genetic analyses of mitochondrial DNA data reveal two distinct clades with mostly sympatric distributions, whereas nuclear analyses reveal only a single lineage. Shallow, but significant structure (0.0041–0.0065, P<0.01) was detected for the mtDNA data set, with the south-west African region identified as harbouring the highest levels of genetic diversity. Gene flow analyses on the mtDNA data show that individuals sampled in south-western localities experience gene flow primarily in the direction of the Benguela Current, while south and eastern localities experience bi-directional gene flow, suggesting an influence of both the inshore currents and the offshore Agulhas Current in the larval distribution of T. serrata. The mtDNA haplotype network, Bayesian Skyline Plots, mismatch distributions and time since expansion indicate that T. serrata population numbers were not severely affected by the Last Glacial Maximum (LGM), unlike other southern African marine species. The processes resulting in the two morphologically cryptic mtDNA lineages may be the result of a recent historical allopatric event followed by secondary contact or could reflect selective pressures

  8. The influence of Pleistocene climatic changes and ocean currents on the phylogeography of the southern African barnacle, Tetraclita serrata (Thoracica; Cirripedia).

    PubMed

    Reynolds, Terry V; Matthee, Conrad A; von der Heyden, Sophie

    2014-01-01

    The evolutionary effects of glacial periods are poorly understood for Southern Hemisphere marine intertidal species, particularly obligatory sessile organisms. We examined this by assessing the phylogeographic patterns of the southern African volcano barnacle, Tetraclita serrata, a dominant species on rocky intertidal shores. Restricted gene flow in some geographical areas was hypothesized based on oceanic circulation patterns and known biogeographic regions. Barnacle population genetic structure was investigated using the mitochondrial cytochrome oxidase subunit 1 (COI) region for 410 individuals sampled from 20 localities spanning the South African coast. The mtDNA data were augmented by generating nuclear internal transcribed spacer 1 (ITS1) sequences from a subset of samples. Phylogenetic and population genetic analyses of mitochondrial DNA data reveal two distinct clades with mostly sympatric distributions, whereas nuclear analyses reveal only a single lineage. Shallow, but significant structure (0.0041-0.0065, P<0.01) was detected for the mtDNA data set, with the south-west African region identified as harbouring the highest levels of genetic diversity. Gene flow analyses on the mtDNA data show that individuals sampled in south-western localities experience gene flow primarily in the direction of the Benguela Current, while south and eastern localities experience bi-directional gene flow, suggesting an influence of both the inshore currents and the offshore Agulhas Current in the larval distribution of T. serrata. The mtDNA haplotype network, Bayesian Skyline Plots, mismatch distributions and time since expansion indicate that T. serrata population numbers were not severely affected by the Last Glacial Maximum (LGM), unlike other southern African marine species. The processes resulting in the two morphologically cryptic mtDNA lineages may be the result of a recent historical allopatric event followed by secondary contact or could reflect selective pressures

  9. The influence of Pleistocene climatic changes and ocean currents on the phylogeography of the southern African barnacle, Tetraclita serrata (Thoracica; Cirripedia).

    PubMed

    Reynolds, Terry V; Matthee, Conrad A; von der Heyden, Sophie

    2014-01-01

    The evolutionary effects of glacial periods are poorly understood for Southern Hemisphere marine intertidal species, particularly obligatory sessile organisms. We examined this by assessing the phylogeographic patterns of the southern African volcano barnacle, Tetraclita serrata, a dominant species on rocky intertidal shores. Restricted gene flow in some geographical areas was hypothesized based on oceanic circulation patterns and known biogeographic regions. Barnacle population genetic structure was investigated using the mitochondrial cytochrome oxidase subunit 1 (COI) region for 410 individuals sampled from 20 localities spanning the South African coast. The mtDNA data were augmented by generating nuclear internal transcribed spacer 1 (ITS1) sequences from a subset of samples. Phylogenetic and population genetic analyses of mitochondrial DNA data reveal two distinct clades with mostly sympatric distributions, whereas nuclear analyses reveal only a single lineage. Shallow, but significant structure (0.0041-0.0065, P<0.01) was detected for the mtDNA data set, with the south-west African region identified as harbouring the highest levels of genetic diversity. Gene flow analyses on the mtDNA data show that individuals sampled in south-western localities experience gene flow primarily in the direction of the Benguela Current, while south and eastern localities experience bi-directional gene flow, suggesting an influence of both the inshore currents and the offshore Agulhas Current in the larval distribution of T. serrata. The mtDNA haplotype network, Bayesian Skyline Plots, mismatch distributions and time since expansion indicate that T. serrata population numbers were not severely affected by the Last Glacial Maximum (LGM), unlike other southern African marine species. The processes resulting in the two morphologically cryptic mtDNA lineages may be the result of a recent historical allopatric event followed by secondary contact or could reflect selective pressures

  10. Protect Taxpayers From ACORN Act

    THOMAS, 112th Congress

    Sen. Vitter, David [R-LA

    2011-01-25

    01/25/2011 Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  11. Kinetics and stoichiometry of coupled Na efflux and Ca influx (Na/Ca exchange) in barnacle muscle cells

    PubMed Central

    1989-01-01

    Coupled Na+ exit/Ca2+ entry (Na/Ca exchange operating in the Ca2+ influx mode) was studied in giant barnacle muscle cells by measuring 22Na+ efflux and 45Ca2+ influx in internally perfused, ATP-fueled cells in which the Na+ pump was poisoned by 0.1 mM ouabain. Internal free Ca2+, [Ca2+]i, was controlled with a Ca-EGTA buffering system containing 8 mM EGTA and varying amounts of Ca2+. Ca2+ sequestration in internal stores was inhibited with caffeine and a mitochondrial uncoupler (FCCP). To maximize conditions for Ca2+ influx mode Na/Ca exchange, and to eliminate tracer Na/Na exchange, all of the external Na+ in the standard Na+ sea water (NaSW) was replaced by Tris or Li+ (Tris-SW or LiSW, respectively). In both Na-free solutions an external Ca2+ (Cao)-dependent Na+ efflux was observed when [Ca2+]i was increased above 10(-8) M; this efflux was half-maximally activated by [Ca2+]i = 0.3 microM (LiSW) to 0.7 microM (Tris-SW). The Cao-dependent Na+ efflux was half-maximally activated by [Ca2+]o = 2.0 mM in LiSW and 7.2 mM in Tris-SW; at saturating [Ca2+]o, [Ca2+]i, and [Na+]i the maximal (calculated) Cao-dependent Na+ efflux was approximately 75 pmol#cm2.s. This efflux was inhibited by external Na+ and La3+ with IC50's of approximately 125 and 0.4 mM, respectively. A Nai-dependent Ca2+ influx was also observed in Tris-SW. This Ca2+ influx also required [Ca2+]i greater than 10(-8) M. Internal Ca2+ activated a Nai-independent Ca2+ influx from LiSW (tracer Ca/Ca exchange), but in Tris-SW virtually all of the Cai-activated Ca2+ influx was Nai-dependent (Na/Ca exchange). Half-maximal activation was observed with [Na+]i = 30 mM. The fact that internal Ca2+ activates both a Cao-dependent Na+ efflux and a Nai- dependent Ca2+ influx in Tris-SW implies that these two fluxes are coupled; the activating (intracellular) Ca2+ does not appear to be transported by the exchanger. The maximal (calculated) Nai-dependent Ca2+ influx was -25 pmol/cm2.s. At various [Na+]i between 6 and 106 m

  12. Barnacle Bill Spectra

    NASA Technical Reports Server (NTRS)

    1997-01-01

    These IMP spectra show the characteristics of the rock surface measured by the Alpha Proton X-Ray Spectrometer (blue), the soil trapped in pits on the rock surface (red), and the deposit of bright drift on the top of the rock. The area measured by the APXS has the properties expected for nearly unweathered igneous rock, and the soil trapped in the pits is intermediate to the unweathered rock and the highly weathered drift material.

  13. vasa-related genes and their expression in stem cells of colonial parasitic rhizocephalan barnacle Polyascus polygenea (Arthropoda: Crustacea: Cirripedia: Rhizocephala).

    PubMed

    Shukalyuk, Andrey I; Golovnina, Kseniya A; Baiborodin, Sergei I; Gunbin, Konstantin V; Blinov, Alexander G; Isaeva, Valeria V

    2007-02-01

    vasa (vas)-related genes are members of the DEAD-box protein family and are expressed in the germ cells of many Metazoa. We cloned vasa-related genes (PpVLG, CpVLG) and other DEAD-box family related genes (PpDRH1, PpDRH2, CpDRH, AtDRHr) from the colonial parasitic rhizocephalan barnacle Polyascus polygenea, the non-colonial Clistosaccus paguri (Crustacea: Cirripedia: Rhizocephala), and the parasitic isopodan Athelgis takanoshimensis (Crustacea: Isopoda). The colonial Polyascus polygenea, a parasite of the coastal crabs Hemigrapsus sanguineus and Hemigrapsus longitarsis was used as a model object for further detailed investigations. Phylogenetic analysis suggested that PpVLG and CpVLG are closely related to vasa-like genes of other Arthropoda. The rest of the studied genes form their own separate branch on the phylogenetic tree and have a common ancestry with the p68 and PL10 subfamilies. We suppose this group may be a new subfamily of the DEAD-box RNA helicases that is specific for parasitic Crustacea. We found PpVLG and PpDRH1 expression products in stem cells from stolons and buds of internae, during asexual reproduction of colonial P. polygenea, and in germ cells from sexually reproducing externae, including male spermatogenic cells and female oogenic cells.

  14. Acrothoracican barnacles (Lithoglyptida) in Taiwan, including the taxonomic status of Balanodytes taiwanus Utinomi, 1950 and cryptic diversity of Auritoglyptes bicornis (Aurivillius, 1892).

    PubMed

    Chan, Benny K K; Cheang, Chi Chiu; Chen, I-Han; Kolbasov, Gregory A

    2013-01-01

    We list five acrothoracican barnacles of the order Lithoglyptida currently found in Taiwanese waters, including two new records, Trypetesa habei Utinomi, 1962 and Berndtiapurpurea Utinomi, 1950 and a new undescribed species of the genus Lithoglyptes. We also investigate the morphology and molecular genetics of Balanodytes taiwanus Utinomi, from its type locality, Taiwan. The original description of B. taiwanus in Utinomi (1950a) reported the absence of caudal appendages. Re-examination of the somatic body of one of the syntype specimens (the other syntype only having an opercular bar remaining) of B. taiwanus deposited in the Seto Marine Laboratory in Japan, revealed the presence of caudal appendages. The morphology of our specimens collected in various locations in Taiwan fits the description in Utinomi (1950a) and all have caudal appendages. The diagnosis of Balanodytes Utinomi, 1950 is revised herein. The genus Armatoglyptes Kolbasov & Newman, 2005 is a nomen nudum and ajunior synonym of Balanodytes. Our results also show that the widespread species Lithoglyptes habei Tomlinson, 1963 is a junior synonym of B. taiwanensis. The molecular sequence divergencse of the 16S RNA and COI genes were studied for samples of another monotypic genus Auritoglyptes (A. bicornis) from different regions of Taiwan. It was shown that there are at least three phylogenetic clades in Taiwan, suggesting that Auritoglyptes represents a cryptic species complex.

  15. Characterization of the phosphatic mineral of the barnacle Ibla cumingi at atomic level by solid-state nuclear magnetic resonance: comparison with other phosphatic biominerals.

    PubMed

    Reid, David G; Mason, Matthew J; Chan, Benny K K; Duer, Melinda J

    2012-07-01

    Ibliform barnacles are among the few invertebrate animals harnessing calcium phosphate to construct hard tissue. The (31)P solid-state NMR (SSNMR) signal from the shell plates of Ibla cumingi (Iblidae) is broader than that of bone, and shifted by ca 1 ppm to low frequency. (1)H-(31)P heteronuclear correlation (HETCOR) experiments show a continuum of different phosphorus/phosphate atomic environments, close to hydrogen populations with resonance frequencies between ca 10 and 20 ppm. Associated (1)H and (31)P chemical shifts argue the coexistence of weakly (high (31)P frequency, low (1)H frequency) to more strongly (lower (31)P frequency, higher (1)H frequency) hydrogen-bonded hydrogen phosphate-like molecular/ionic species. There is no resolved signal from discrete OH(-) ions. (13)C SSNMR shows chitin, protein and other organic biomolecules but, unlike bone, there are no significant atomic scale organic matrix-mineral contacts. The poorly ordered hydrogen phosphate-like iblid mineral is strikingly different, structurally and compositionally, from both vertebrate bone mineral and the more crystalline fluoroapatite of the linguliform brachiopods. It probably represents a previously poorly characterized calcium phosphate biomineral, the evolution of which may have reflected either the chemical conditions of ancestral seas or the mechanical advantages of phosphatic biomineralization over a calcium carbonate equivalent.

  16. Baseline Immune Activity Is Associated with Date Rather than with Moult Stage in the Arctic-Breeding Barnacle Goose (Branta leucopsis)

    PubMed Central

    Sandström, Cecilia A. M.; Prop, Jouke; van der Jeugd, Henk; Loonen, Maarten J. J. E.

    2014-01-01

    Variation in immune defence in birds is often explained either by external factors such as food availability and disease pressure or by internal factors such as moult and reproductive effort. We explored these factors together in one sampling design by measuring immune activity over the time frame of the moulting period of Arctic-breeding barnacle geese (Branta leucopsis). We assessed baseline innate immunity by measuring levels of complement-mediated lysis and natural antibody-mediated agglutination together with total and differential leukocyte counts. Variation in immune activity during moult was strongly associated with calendar date and to a smaller degree with the growth stage of wing feathers. We suggest that the association with calendar date reflected temporal changes in the external environment. This environmental factor was further explored by comparing the immune activity of geese in the Arctic population with conspecifics in the temperate climate zone at comparable moult stages. In the Arctic environment, which has a lower expected disease load, geese exhibited significantly lower values of complement-mediated lysis, their blood contained fewer leukocytes, and levels of phagocytic cells and reactive leukocytes were relatively low. This suggests that lower baseline immune activity could be associated with lower disease pressure. We conclude that in our study species, external factors such as food availability and disease pressure have a greater effect on temporal variation of baseline immune activity than internal factors such as moult stage. PMID:25517982

  17. Invasion and morphological variation of the non-indigenous barnacle Chthamalus challengeri (Hoek, 1883) in Yangshan Port and its surrounding areas

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Xue, Junzeng; Lin, Junda; Wu, Huixian

    2015-06-01

    Invasive species generally possess unique characteristics that allow them to survive the invasion process in order to establish and spread in new habitats. Successful invaders must resist both physical and physiological stresses associated with the changing environment. A common littoral barnacle, Chthamalus challengeri Hoek, 1883 (Crustacea, Cirripedia), which is native to Japan, South Korea and northern China, has become established in the high-littoral zone adjacent to Yangshan Port, Shanghai, China. A comparison of the morphology of Chthamlus species from Zhoushan archipelago with previous description indicates the occurrence of C. challengeri. The new immigrant becomes a dominant species in certain high-intertidal habitats of the adjacent area to of Yangshan Port. C. challengeri was found in part of sampling sites in Zhoushan in 2010; however, it dispersed to all the eleven sampling sites in 2012. Densities of C.challengeri had increased over 10 times in the last 2 years, with the highest mean value reaching 39533 ± 6243 ind. m-2 in the new habitat. The specific ratios of both operculum area ( Sa) to base area ( SA) and average height of parietal plates ( H) to length of base ( L) revealed that C. challengeri displays morphological changes to resist stronger currents in the new habitats for invasion.

  18. Vulcanolepas scotiaensis sp. nov., a new deep-sea scalpelliform barnacle (Eolepadidae: Neolepadinae) from hydrothermal vents in the Scotia Sea, Antarctica.

    PubMed

    Buckeridge, John S; Linse, Katrin; Jackson, Jennifer A

    2013-12-09

    A new deep-sea stalked barnacle, Vulcanolepas scotiaensis sp. nov. is described from hydrothermal vents at depths of 2400-2600 metres along segments of the East Scotia Ridge and from 1400 metres in the Kemp Caldera. Both locations are areas of volcanic activity that lie on the Antarctic-South American Ocean Ridge complex near the South Sandwich Islands. This discovery confirms a wide distribution in southern seas for Vulcanolepas, complementing the previous records from deep-sea vents in the Lau Basin and Kermadec Ridge in the southwest Pacific, and the Pacific Antarctic Ridge in the southeast Pacific. V. scotiaensis sp. nov., the third described species of Vulcanolepas shows an extraordinary range in morphology, requiring a reassessment of the original diagnosis for Vulcanolepas. Although the morphological envelope of V. scotiaensis sp. nov. includes representatives with a peduncle to capitulum ratio similar to that observed in most neolepadines, the peduncle generally shows greater proportional length than in species in any neolepadine genus except Leucolepas; it is distinguished from other species of Vulcanolepas by a broader capitulum, much smaller imbricating scales on the peduncle and more ornamented capitulum plates. The morphological diversity of V. scotiaensis sp. nov. is interpreted as having arisen due to abrupt changes in water temperature.LSID: urn:lsid:zoobank.org:act:AA2AFDA5-0B08-466A-A584-D3FDBDE9DA61.

  19. A histological investigation of the maturation of the acorn worm, an inhabitant of the Sea of Japan, and a suggestion about the relationship between synchronized spawning/spermiation and the tidal level.

    PubMed

    Ogiso, Shouzo; Sakai, Kei-ichi; Matada, Masahiro; Sasayama, Yuichi

    2005-05-01

    One species of Hemichordata, Balanoglossus misakiensis, is then acorn worm originally reported from the intertidal zone of the Miura Peninsula on the Pacific Ocean side of Japan. We histologically examined the reproductive cycle of the population of this species, which inhabits only the sublittoral zone in the Sea of Japan. Testes and ovaries began to develop at the beginning of May 2003 and were almost mature in the latter half of June in males and in the first half of July in females in the same year. Subsequently, spermiation and spawning followed in the latter half of July in males and in the first half of August in females. Progress in maturation appeared to be related to increases in the water temperature. Although some experiments were conducted in aquariums to identify the conditions responsible for the synchronization of the occurrence of spontaneous spawning/spermiation, no clues were obtained. During the experiments, however, 11, 2, and 4 individuals out of the 67 used achieved spawning/spermiation on separate days. The occurrence of spawning/spermiation in the laboratory corresponded to the latter half of the switch from high tide to low tide on those days. Also in the field, it was known that they released the gametes according to this specific schedule. Therefore, it was suggested that, in the Japan Sea population of this species, the tide level may be a condition for synchronized spawning/spermiation. PMID:15930831

  20. A histological investigation of the maturation of the acorn worm, an inhabitant of the Sea of Japan, and a suggestion about the relationship between synchronized spawning/spermiation and the tidal level.

    PubMed

    Ogiso, Shouzo; Sakai, Kei-ichi; Matada, Masahiro; Sasayama, Yuichi

    2005-05-01

    One species of Hemichordata, Balanoglossus misakiensis, is then acorn worm originally reported from the intertidal zone of the Miura Peninsula on the Pacific Ocean side of Japan. We histologically examined the reproductive cycle of the population of this species, which inhabits only the sublittoral zone in the Sea of Japan. Testes and ovaries began to develop at the beginning of May 2003 and were almost mature in the latter half of June in males and in the first half of July in females in the same year. Subsequently, spermiation and spawning followed in the latter half of July in males and in the first half of August in females. Progress in maturation appeared to be related to increases in the water temperature. Although some experiments were conducted in aquariums to identify the conditions responsible for the synchronization of the occurrence of spontaneous spawning/spermiation, no clues were obtained. During the experiments, however, 11, 2, and 4 individuals out of the 67 used achieved spawning/spermiation on separate days. The occurrence of spawning/spermiation in the laboratory corresponded to the latter half of the switch from high tide to low tide on those days. Also in the field, it was known that they released the gametes according to this specific schedule. Therefore, it was suggested that, in the Japan Sea population of this species, the tide level may be a condition for synchronized spawning/spermiation.

  1. The Bassian Isthmus and the major ocean currents of southeast Australia influence the phylogeography and population structure of a southern Australian intertidal barnacle Catomerus polymerus (Darwin).

    PubMed

    York, Katherine L; Blacket, Mark J; Appleton, Belinda R

    2008-04-01

    Southern Australia is currently divided into three marine biogeographical provinces based on faunal distributions and physical parameters. These regions indicate eastern and western distributions, with an overlap occurring in the Bass Strait in Victoria. However, studies indicate that the boundaries of these provinces vary depending on the species being examined, and in particular on the mode of development employed by that species, be they direct developers or planktonic larvae dispersers. Mitochondrial DNA sequence analysis of the surf barnacle Catomerus polymerus in southern Australia revealed an east-west phylogeographical split involving two highly divergent clades (cytochrome oxidase I 3.5 +/- 0.76%, control region 6.7 +/- 0.65%), with almost no geographical overlap. Spatial genetic structure was not detected within either clade, indicative of a relatively long-lived planktonic larval phase. Five microsatellite loci indicated that C. polymerus populations exhibit relatively high levels of genetic divergence, and fall into four subregions: eastern Australia, central Victoria, western Victoria and Tasmania, and South Australia. F(ST) values between eastern Australia (from the eastern mitochondrial DNA clade) and the remaining three subregions ranged from 0.038 to 0.159, with other analyses indicating isolation by distance between the subregions of western mitochondrial origin. We suggest that the east-west division is indicative of allopatric divergence resulting from the emergence of the Bassian land-bridge during glacial maxima, preventing gene flow between these two lineages. Subsequently, contemporary ecological conditions, namely the East Australian, Leeuwin, and Zeehan currents and the geographical disjunctions at the Coorong and Ninety Mile Beach are most likely responsible for the four subregions indicated by the microsatellite data. PMID:18363669

  2. Predator nonconsumptive effects on prey recruitment weaken with recruit density.

    PubMed

    Ellrich, Julius A; Scrosati, Ricardo A; Molis, Markus

    2015-03-01

    We investigated the nonconsumptive effects (NCEs) of predatory dogwhelks (Nucella lapillus) on intertidal barnacle (Semibalanus balanoides) recruitment through field experiments on the Gulf of St. Lawrence coast and the Atlantic coast of Nova Scotia, Canada. We studied the recruitment seasons (May-June) of 2011 and 2013. In 2011, the Gulf coast had five times more nearshore phytoplankton (food for barnacle larvae and recruits) during the recruitment season and yielded a 58% higher barnacle recruit density than the Atlantic coast at the end of the recruitment season. In 2013, phytoplankton levels and barnacle recruit density were similar on both coasts and also lower than for the Gulf coast in 2011. Using the comparative-experimental method, the manipulation of dogwhelk presence (without allowing physical contact with prey) revealed that dogwhelk cues limited barnacle recruitment under moderate recruit densities (Atlantic 2011/2013 and Gulf 2013) but had no effect under a high recruit density (Gulf 2011). Barnacle recruits attract settling larvae through chemical cues. Thus, the highest recruit density appears to have neutralized dogwhelk effects. This study suggests that the predation risk perceived by settling larvae may decrease with increasing recruit density and that prey food supply may indirectly influence predator NCEs on prey recruitment. PMID:26236858

  3. Barnacles Tell no Lies - Bioclastic deposits and in-situ balanid colonies delineate shorelines of the Holocene palaeolake at Tayma (NW Saudi Arabia)

    NASA Astrophysics Data System (ADS)

    Engel, Max; Frenzel, Peter; Pint, Anna; Dinies, Michèle; Gleixner, Gerd; Hoelzmann, Philipp; Neugebauer, Ina; Plessen, Birgit; Brückner, Helmut

    2016-04-01

    The reconstruction of abrupt and gradual climatic changes of the recent geologic past is key to understand patterns of landscape change, prehistoric human migration and settlement, in particular within sensitive arid environments. While a considerable number of Late Pleistocene to Holocene climate records exist from the Sahara, the Levant, and the southern Arabian Peninsula, Northern Arabia is understudied. Moreover, reliable records of environmental changes are strongly required as inferences on perennial lake bodies in the wake of the early to mid-Holocene pluvial phase in Arabia have recently been challenged and the magnitude of this phase is still under debate (Enzel et al. 2015). The continental sabkha of Tayma is one of very few North Arabian sites, where substantial landscape changes are recorded in a laminated lacustrine sequence, disjunct balanid and gastropod shell accumulations (Engel et al. 2012), and pollen spectra (Dinies et al. 2015). Here, we report on a recent mapping campaign of early to mid-Holocene shoreline features of a palaeolake, supposedly fed by both groundwater and enhanced precipitation. Shoreline index points include (i) in-situ populations of Amphibalanus amphitrite, a barnacle originating from marginal marine habitats, either attached to Ordovician bedrock or parautochthonous bedrock clasts, and (ii) in-situ or parautochthonous sequences of varying percentages and taphonomic states of shell detritus from A. amphitrite, gastropods (Melanoides tuberculatus, Hydrobia sp.), marginal marine foraminifers, the brackish water ostracod Cyprideis torosa, and quartz sand. Their thickness reaches up to >2.50 m and they occur either as laterally confined pockets or more extensive sheets. Despite strong wadi dynamics, widespread aeolian deposition, and the actively retreating escarpment framing the palaeolake basin in the north, a remarkably high number of remnant shoreline features is still preserved at elevations between 808-813 m a.s.l. Based on

  4. Larval development of the pedunculate barnacles Octolasmis angulata Aurivillius 1894 and Octolasmis cor Aurivillius 1892 (Cirripedia: Thoracica: Poecilasmatidae) from the gills of the mud crab, Scylla tranquebarica Fabricius, 1798.

    PubMed

    Yap, F C; Wong, W L; Maule, A G; Brennan, G P; Lim, L H S

    2015-05-01

    Detailed studies of larval development of Octolasmis angulata and Octolasmis cor are pivotal in understanding the larval morphological evolution as well as enhancing the functional ecology. Six planktotrophic naupliar stages and one non-feeding cyprid stage are documented in details for the first time for the two species of Octolasmis. Morphologically, the larvae of O. angulata and O. cor are similar in body size, setation patterns on the naupliar appendages, labrum, dorsal setae-pores, frontal horns, cyprid carapace, fronto-lateral gland pores, and lattice organs. Numbers of peculiarities were observed on the gnathobases of the antennae and mandible throughout the naupliar life-cycle. The setation pattern on the naupliar appendages are classified based on the segmentation on the naupliar appendages. The nauplius VI of both species undergoes a conspicuous change before metamorphosis into cyprid stage. The cyprid structures begin to form and modify beneath the naupliar body towards the end of stage VI. This study emphasises the importance of the pedunculate barnacle larval developmental studies not only to comprehend the larval morphological evolution but also to fill in the gaps in understanding the modification of the naupliar structures to adapt into the cyprid life-style.

  5. Larval development of the pedunculate barnacles Octolasmis angulata Aurivillius 1894 and Octolasmis cor Aurivillius 1892 (Cirripedia: Thoracica: Poecilasmatidae) from the gills of the mud crab, Scylla tranquebarica Fabricius, 1798.

    PubMed

    Yap, F C; Wong, W L; Maule, A G; Brennan, G P; Lim, L H S

    2015-05-01

    Detailed studies of larval development of Octolasmis angulata and Octolasmis cor are pivotal in understanding the larval morphological evolution as well as enhancing the functional ecology. Six planktotrophic naupliar stages and one non-feeding cyprid stage are documented in details for the first time for the two species of Octolasmis. Morphologically, the larvae of O. angulata and O. cor are similar in body size, setation patterns on the naupliar appendages, labrum, dorsal setae-pores, frontal horns, cyprid carapace, fronto-lateral gland pores, and lattice organs. Numbers of peculiarities were observed on the gnathobases of the antennae and mandible throughout the naupliar life-cycle. The setation pattern on the naupliar appendages are classified based on the segmentation on the naupliar appendages. The nauplius VI of both species undergoes a conspicuous change before metamorphosis into cyprid stage. The cyprid structures begin to form and modify beneath the naupliar body towards the end of stage VI. This study emphasises the importance of the pedunculate barnacle larval developmental studies not only to comprehend the larval morphological evolution but also to fill in the gaps in understanding the modification of the naupliar structures to adapt into the cyprid life-style. PMID:25770075

  6. Dynamics of species interaction strength in space, time and with developmental stage.

    PubMed

    Kordas, Rebecca L; Dudgeon, Steve

    2011-06-22

    Quantifying species interaction strengths enhances prediction of community dynamics, but variability in the strength of species interactions in space and time complicates accurate prediction. Interaction strengths can vary in response to density, indirect effects, priority effects or a changing environment, but the mechanism(s) causing direction and magnitudes of change are often unclear. We designed an experiment to characterize how environmental factors influence the direction and the strength of priority effects between sessile species. We estimated per capita non-trophic effects of barnacles (Semibalanus balanoides) on newly settled germlings of the fucoid, Ascophyllum nodosum, in the presence and absence of consumers in experiments on rocky shores throughout the Gulf of Maine, USA. Per capita effects on germlings varied among environments and barnacle life stages, and these interaction strengths were largely unaltered by changing consumer abundance. Whereas previous evidence shows adult barnacles facilitate fucoids, here, we show that recent settlers and established juveniles initially compete with germlings. As barnacles mature, they switch to become facilitators of fucoids. Consumers caused variable mortality of germlings through time comparable to that from competition. Temporally variable effects of interactors (e.g. S. balanoides), or spatial variation in their population structure, in different regions differentially affect target populations (e.g. A. nodosum). This may affect abundance of critical stages and the resilience of target species to environmental change in different geographical regions.

  7. Dynamics of species interaction strength in space, time and with developmental stage.

    PubMed

    Kordas, Rebecca L; Dudgeon, Steve

    2011-06-22

    Quantifying species interaction strengths enhances prediction of community dynamics, but variability in the strength of species interactions in space and time complicates accurate prediction. Interaction strengths can vary in response to density, indirect effects, priority effects or a changing environment, but the mechanism(s) causing direction and magnitudes of change are often unclear. We designed an experiment to characterize how environmental factors influence the direction and the strength of priority effects between sessile species. We estimated per capita non-trophic effects of barnacles (Semibalanus balanoides) on newly settled germlings of the fucoid, Ascophyllum nodosum, in the presence and absence of consumers in experiments on rocky shores throughout the Gulf of Maine, USA. Per capita effects on germlings varied among environments and barnacle life stages, and these interaction strengths were largely unaltered by changing consumer abundance. Whereas previous evidence shows adult barnacles facilitate fucoids, here, we show that recent settlers and established juveniles initially compete with germlings. As barnacles mature, they switch to become facilitators of fucoids. Consumers caused variable mortality of germlings through time comparable to that from competition. Temporally variable effects of interactors (e.g. S. balanoides), or spatial variation in their population structure, in different regions differentially affect target populations (e.g. A. nodosum). This may affect abundance of critical stages and the resilience of target species to environmental change in different geographical regions. PMID:21106597

  8. Landscape of fear influences the relative importance of consumptive and nonconsumptive predator effects.

    PubMed

    Matassa, Catherine M; Trussell, Geoffrey C

    2011-12-01

    Predators can initiate trophic cascades by consuming and/or scaring their prey. Although both forms of predator effect can increase the overall abundance of prey's resources, nonconsumptive effects may be more important to the spatial and temporal distribution of resources because predation risk often determines where and when prey choose to forage. Our experiment characterized temporal and spatial variation in the strength of consumptive and nonconsumptive predator effects in a rocky intertidal food chain consisting of the predatory green crab (Carcinus maenas), an intermediate consumer (the dogwhelk, Nucella lapillus), and barnacles (Semibalanus balanoides) as a resource. We tracked the survival of individual barnacles through time to map the strength of predator effects in experimental communities. These maps revealed striking spatiotemporal patterns in Nucella foraging behavior in response to each predator effect. However, only the nonconsumptive effect of green crabs produced strong spatial patterns in barnacle survivorship. Predation risk may play a pivotal role in determining the small-scale distribution patterns of this important rocky intertidal foundation species. We suggest that the effects of predation risk on individual foraging behavior may scale up to shape community structure and dynamics at a landscape level. PMID:22352165

  9. Age-dependent zonation of the periwinkle Littorina littorea (L.) in the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Saier, Bettina

    2000-12-01

    On sedimentary tidal flats near the island of Sylt (German Bight, North Sea) abundance and size distribution of periwinkles, Littorina littorea L., were studied in low intertidal and in shallow and deep subtidal mussel beds ( Mytilus edulis L.). In low intertidal mussel beds, surveys revealed that high densities (1,369±571 m-2) of juvenile snails (≤13 mm) were positively correlated with strong barnacle epigrowth ( Semibalanus balanoides L. and Balanus crenatus Bruguière) on mussels. A subsequent field experiment showed that recruitment of L. littorea was restricted to the intertidal zone. Abundances of periwinkles (213±114 m-2) and barnacles abruptly decreased in the adjacent shallow subtidal zone, which served as a habitat for older snails (>13 mm). L. littorea was completely absent from disjunct deep (5 m) subtidal mussel beds. Snail abundance varied seasonally with maxima of >4,000 m-2 in low intertidal mussel beds in October and minima in July, just before the onset of new recruitment. I suggest that the presence of cracks and crevices among the dense barnacle overgrowth in intertidal mussel beds favoured recruitment and survival of juvenile snails. Larger (older) specimens are assumed to actively migrate to the less favourable adjacent subtidal. Therefore, intertidal mussel beds are considered as nurseries for the population of L. littorea in the Wadden Sea.

  10. Landscape of fear influences the relative importance of consumptive and nonconsumptive predator effects.

    PubMed

    Matassa, Catherine M; Trussell, Geoffrey C

    2011-12-01

    Predators can initiate trophic cascades by consuming and/or scaring their prey. Although both forms of predator effect can increase the overall abundance of prey's resources, nonconsumptive effects may be more important to the spatial and temporal distribution of resources because predation risk often determines where and when prey choose to forage. Our experiment characterized temporal and spatial variation in the strength of consumptive and nonconsumptive predator effects in a rocky intertidal food chain consisting of the predatory green crab (Carcinus maenas), an intermediate consumer (the dogwhelk, Nucella lapillus), and barnacles (Semibalanus balanoides) as a resource. We tracked the survival of individual barnacles through time to map the strength of predator effects in experimental communities. These maps revealed striking spatiotemporal patterns in Nucella foraging behavior in response to each predator effect. However, only the nonconsumptive effect of green crabs produced strong spatial patterns in barnacle survivorship. Predation risk may play a pivotal role in determining the small-scale distribution patterns of this important rocky intertidal foundation species. We suggest that the effects of predation risk on individual foraging behavior may scale up to shape community structure and dynamics at a landscape level.

  11. A comparative study of the anti-settlement properties of mytilid shells

    PubMed Central

    Bers, A.V; Prendergast, G.S; Zürn, C.M; Hansson, L; Head, R.M; Thomason, J.C

    2005-01-01

    Marine organisms have evolved defence mechanisms to prevent epibiosis. This study investigated the anti-settlement properties of natural periostracal microtopographies of two mytilid species, Mytilus edulis (from North, Baltic and White Seas) and Perna perna (from the SW Atlantic). Resin replicas of shells were exposed to cyprids of the barnacle Semibalanus balanoides. Replicas with intact isotropic microtopographies and smooth controls were much less fouled than roughened anisotropic surfaces. This indicates that in both M. edulis and P. perna the periostracum possesses a generic anti-settlement property, at least against S. balanoides cyprids, which is not regionally adapted. Such a potential globally effective anti-settlement mechanism possibly contributes to the invasive success of Mytilidae. PMID:17148334

  12. The Successful Parent: Growing Mighty Oaks from Little Acorns

    ERIC Educational Resources Information Center

    Metzker, Carol

    2006-01-01

    Appreciative intelligence is the factor that makes some people more successful than others, more resilient to life's lumps and bumps, more creative and persistent when dealing with challenges, and more often able to smile at the end of a tough day. It is the same type of intelligence found in exceptional business leaders, entrepreneurs and…

  13. Susceptibility of sprouted oak acorns to Phytophthora ramorum zoospores

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora ramorum is a recently emerged pathogen, having established in Europe and several western U.S. states, including California and Oregon. It has a wide host range and is a threat to forest ecology and the nursery industry. In California, coast live oak (Quercus agrifolia) is a major host...

  14. Interactions between ecosystem engineers: A native species indirectly facilitates a non-native one

    NASA Astrophysics Data System (ADS)

    Sueiro, María Cruz; Schwindt, Evangelina; Mendez, María Martha (Pitu); Bortolus, Alejandro

    2013-08-01

    The positive impact that native species have on the survival, persistence and/or range-expansion of invasive species, is receiving increasing attention from ecologists and land managers trying to better understand and predict future invasions worldwide. Ecosystem engineers are among the best-known model organisms for such studies. The austral cordgrass Spartina densiflora is an ecosystem engineer native to South America coast, where it colonizes rocky shores that were recently successfully invaded by the acorn barnacle Balanus glandula. We conducted a field experiment combining living Spartina transplants and artificial model plants in order to address the following questions: Does the native ecosystem engineer S. densiflora facilitate the invasion of rocky shores by B. glandula? If so, how much of this facilitation is caused by its physical structure alone? We found that S. densiflora had a positive effect on the invasive barnacle by trapping among its stems, the mussels, shells and gravels where B. glandula settles. Dislodged mussels, cobbles, and small shells covered and agglutinated by living barnacles were retained within the aboveground structures of S. densiflora while the control plots (without living or artificial plant structures) remained mostly bare throughout the experiment, showing how plant structures speed the colonization process. Moreover, transplanting living Spartina and artificial Spartina models led to a maximum increase in the area covered by barnacles of more than 1700% relative to the unvegetated control plots. Our study clearly shows how a native ecosystem engineers can enhance the success of invasive species and facilitate their local spread.

  15. Resource identity modifies the influence of predation risk on ecosystem function.

    PubMed

    Trussell, Geoffrey C; Ewanchuk, Patrick J; Matassa, Catherine M

    2008-10-01

    It is well established that predators can scare as well as consume their prey. In many systems, the fear of being eaten causes trait-mediated cascades whose strength can rival or exceed that of more widely recognized density-mediated cascades transmitted by predators that consume their prey. Despite this progress it is only beginning to be understood how the influence of predation risk is shaped by environmental context and whether it can exert an important influence on ecosystem-level processes. This study used a factorial mesocosm experiment that manipulated basal-resource identity (either barnacles, Semibalanus balanoides, or mussels, Mytilus edulis) to determine how resources modify the influence of predation risk, cascade strength, and the efficiency of energy transfer in two, tritrophic, rocky-shore food chains containing the predatory green crab (Carcinus maenas) and an intermediate consumer (the snail, Nucella lapillus). The effect of predation risk and the strength of trait-mediated cascades (both in absolute and relative terms) were much stronger in the barnacle than in the mussel food chain. Moreover, predation risk strongly diminished the efficiency of energy transfer in the barnacle food chain but had no significant effect in the mussel food chain. The influence of resource identity on indirect-effect strength and energy transfer was likely caused by differences in how each resource shapes the degree of risk perceived by prey. We suggest that our understanding of the connection between trophic dynamics and ecosystem functioning will improve considerably once the effects of predation risk on individual behavior and physiology are considered. PMID:18959317

  16. Resource identity modifies the influence of predation risk on ecosystem function.

    PubMed

    Trussell, Geoffrey C; Ewanchuk, Patrick J; Matassa, Catherine M

    2008-10-01

    It is well established that predators can scare as well as consume their prey. In many systems, the fear of being eaten causes trait-mediated cascades whose strength can rival or exceed that of more widely recognized density-mediated cascades transmitted by predators that consume their prey. Despite this progress it is only beginning to be understood how the influence of predation risk is shaped by environmental context and whether it can exert an important influence on ecosystem-level processes. This study used a factorial mesocosm experiment that manipulated basal-resource identity (either barnacles, Semibalanus balanoides, or mussels, Mytilus edulis) to determine how resources modify the influence of predation risk, cascade strength, and the efficiency of energy transfer in two, tritrophic, rocky-shore food chains containing the predatory green crab (Carcinus maenas) and an intermediate consumer (the snail, Nucella lapillus). The effect of predation risk and the strength of trait-mediated cascades (both in absolute and relative terms) were much stronger in the barnacle than in the mussel food chain. Moreover, predation risk strongly diminished the efficiency of energy transfer in the barnacle food chain but had no significant effect in the mussel food chain. The influence of resource identity on indirect-effect strength and energy transfer was likely caused by differences in how each resource shapes the degree of risk perceived by prey. We suggest that our understanding of the connection between trophic dynamics and ecosystem functioning will improve considerably once the effects of predation risk on individual behavior and physiology are considered.

  17. The concentration of ionized magnesium in barnacle muscle fibres.

    PubMed Central

    Brinley, F J; Scarpa, A; Tiffert, T

    1977-01-01

    1. The total Mg in isolated fibres of Balanus aquila was 10-5 m-mole/kg wet wt. 2. The intracellular free Mg was measured by a null point method using Eriochrome Blue as an indicator of free Mg, and internal dialysis with solutions of varying ionized Mg concentrations. The results indicated a free Mg of 6 mM or 4-2 m-mole/kg wet wt. in the intracellular water immediately surrounding the dialysis capillary. 3. The ATP concentration was estimated to be 4-9 m-mole/kg wet wt. 4. A tentative partitioning of Mg among various intracellular constitutents based on present data combined with published work by others is (m-mole/kg wet wt): free, 4-2; MgATP, 4-2; myofibrillar bound, 1; residual (presumably bound to arginine phosphate and phosphate) ca. 1. PMID:17002

  18. Habitat effects on the relative importance of trait- and density-mediated indirect interactions.

    PubMed

    Trussell, Geoffrey C; Ewanchuk, Patrick J; Matassa, Catherine M

    2006-11-01

    Classical views of trophic cascades emphasize the primacy of consumptive predator effects on prey populations to the transmission of indirect effects [density-mediated indirect interactions (DMIIs)]. However, trophic cascades can also emerge without changes in the density of interacting species because of non-consumptive predator effects on prey traits such as foraging behaviour [trait-mediated indirect interactions (TMIIs)]. Although ecologists appreciate this point, measurements of the relative importance of each indirect predator effect are rare. Experiments with a three-level, rocky shore food chain containing an invasive predatory crab (Carcinus maenas), an intermediate consumer (the snail, Nucella lapillus) and a basal resource (the barnacle, Semibalanus balanoides) revealed that the strength of TMIIs is comparable with, or exceeds, that of DMIIs. Moreover, the sign and strength of each indirect predator effect depends on whether it is measured in risky or refuge habitats. Because habitat shifts are often responsible for the emergence of TMIIs, attention to the sign and strength of these interactions in both habitats will improve our understanding of the link between individual behaviour and community dynamics.

  19. Phylogeography and historical ecology of the North Atlantic intertidal.

    PubMed

    Wares, J P; Cunningham, C W

    2001-12-01

    Recent glaciation covered the full extent of rocky intertidal habitat along the coasts of New England and the Canadian Maritimes. To test whether this glaciation in fact caused wholesale extinction of obligate rocky intertidal invertebrates, and thus required a recolonization from Europe, we compared American and European populations using allelic diversity and techniques adapted from coalescent theory. Mitochondrial DNA sequences were collected from amphi-Atlantic populations of three cold-temperate obligate rocky intertidal species (a barnacle, Semibalanus balanoides, and two gastropods, Nucella lapillus and Littorina obtusata) and three cold-temperate habitat generalist species (a seastar, Asterias rubens; a mussel, Mytilus edulis, and an isopod, Idotea balthica). For many of these species we were able to estimate the lineage-specific mutation rate based on trans-Arctic divergences between Pacific and Atlantic taxa. These data indicate that some obligate rocky intertidal taxa have colonized New England from European populations. However, the patterns of persistence in North America indicate that other life-history traits, including mech anisms of dispersal, may be more important for surviving dramatic environmental and climatic change. PMID:11831661

  20. Habitat effects on the relative importance of trait- and density-mediated indirect interactions.

    PubMed

    Trussell, Geoffrey C; Ewanchuk, Patrick J; Matassa, Catherine M

    2006-11-01

    Classical views of trophic cascades emphasize the primacy of consumptive predator effects on prey populations to the transmission of indirect effects [density-mediated indirect interactions (DMIIs)]. However, trophic cascades can also emerge without changes in the density of interacting species because of non-consumptive predator effects on prey traits such as foraging behaviour [trait-mediated indirect interactions (TMIIs)]. Although ecologists appreciate this point, measurements of the relative importance of each indirect predator effect are rare. Experiments with a three-level, rocky shore food chain containing an invasive predatory crab (Carcinus maenas), an intermediate consumer (the snail, Nucella lapillus) and a basal resource (the barnacle, Semibalanus balanoides) revealed that the strength of TMIIs is comparable with, or exceeds, that of DMIIs. Moreover, the sign and strength of each indirect predator effect depends on whether it is measured in risky or refuge habitats. Because habitat shifts are often responsible for the emergence of TMIIs, attention to the sign and strength of these interactions in both habitats will improve our understanding of the link between individual behaviour and community dynamics. PMID:17040327

  1. Development of the swimming acorn worm Glandiceps hacksi: similarity to holothuroids.

    PubMed

    Urata, Makoto; Iwasaki, Sadaharu; Ohtsuka, Susumu; Yamaguchi, Masaaki

    2014-05-01

    Spawnings of Glandiceps hacksi (Hemichordata: Enteropneusta) were stimulated in the laboratory by a brief increase in temperature, and the development from fertilization through metamorphosis is described for the first time for a member of the family Spengelidae. When fertilized, the spawned female gametes, which are primary oocytes, rapidly raise a fertilization membrane and undergo two maturation divisions. Holoblastic, radial cleavage produces a blastula; a gastrula then forms by invagination from the vegetal pole, and the blastopore closes soon thereafter. In previously described enteropneust embryos, the archenteron buds off the protocoel before the latter connects to the exterior via the proboscis pore. By contrast, in G. hacksi the archenteron precociously connects with the exterior before the protocoel forms. Soon thereafter, the embryo becomes uniformly ciliated and then hatches from the fertilization envelope at approximately 32 h (15°C culture temperature). At day 3 of development, the protocoel separates from the gut, which establishes a mouth opening to the exterior; by this time, the gut has differentiated into an esophagus, a stomach, and an intestine that opens posteriorly as an anus. The larva grows to form a tornaria with distinctive pigment patches along its ciliary bands. PMID:24712896

  2. Diversification of acorn worms (Hemichordata, Enteropneusta) revealed in the deep sea.

    PubMed

    Osborn, Karen J; Kuhnz, Linda A; Priede, Imants G; Urata, Makoto; Gebruk, Andrey V; Holland, Nicholas D

    2012-04-22

    Enteropneusts (phylum Hemichordata), although studied extensively because of their close relationship to chordates, have long been considered shallow-water, burrowing animals. The present paper more than doubles the number of enteropneust species recorded in the deep sea based on high-resolution imaging and sampling with remotely operated vehicles. We provide direct evidence that some enteropneusts are highly mobile-using changes in posture and currents to drift between feeding sites-and are prominent members of deep, epibenthic communities. In addition, we provide ecological information for each species. We also show that despite their great morphological diversity, most deep-living enteropneusts form a single clade (the rediagnosed family Torquaratoridae) on the basis of rDNA sequences and morphology of the proboscis skeleton and stomochord. The phylogenetic position of the torquaratorids indicates that the group, after evolving from near-shore ancestors, radiated extensively in the deep sea. PMID:22090391

  3. Methods and Strategies: Using Acorns to Generate an Entire Alphabet. Nature Walks Empower Young Bilingual Learners

    ERIC Educational Resources Information Center

    Arreguin-Anderson, Maria Guadalupe; Alanis, Iliana; Gonzalez, Irasema Salinas

    2016-01-01

    The increasing presence of linguistically diverse young children in U.S. public schools has prompted science educators to recognize the need for approaches that are inclusive and sensitive to students' academic needs. The challenge is to design lessons that provide language support while actively engaging children in authentic scientific inquiry.…

  4. From Little Acorns..: Environmental Action as a Source of Well-Being for Schoolchildren

    ERIC Educational Resources Information Center

    Waite, S.; Goodenough, A.; Norris, V.; Puttick, N.

    2016-01-01

    Pastoral care in education may take many forms but increasing emphasis on education for sustainable development (ESD) and concern about children's disconnection from nature suggests that our understanding of care should perhaps encompass the more than human world. The study described in this article examines longer term perspectives on well-being…

  5. ACORNS: A Tool for the Visualisation and Modelling of Atypical Development

    ERIC Educational Resources Information Center

    Moore, D. G.; George, R.

    2011-01-01

    Across many academic disciplines visualisation and notation systems are used for modelling data and developing theory, but in child development visual models are not widely used; yet researchers and students of developmental difficulties may benefit from a visualisation and notation system which can clearly map developmental outcomes and…

  6. Resolving the Dilemma between Organizing and Services: Los Angeles Acorn's Welfare Advocacy

    ERIC Educational Resources Information Center

    Brooks, Fred

    2005-01-01

    The issue of providing individual services historically has been a major dilemma for social action, Alinsky-style community organizations. Empirical evidence suggests that most action organizations that moved into service provision lost mass-based participation, militant tactics, and a power-building orientation. The author presents a case study…

  7. Autoimmunity since the 1957 clonal selection theory: a little acorn to a large oak.

    PubMed

    Mackay, Ian R

    2008-01-01

    Knowledge on autoimmunity is examined from the launch of clonal selection theory 1957-1959. Crucial elements then were 'forbidden clones' of immunocytes as agents of tissue damage, somatic mutations that generated such clones and 'homeostatic mechanisms' that controlled them. The understanding of autoimmunity over the succeeding 50 years has expanded immensely, and many more diseases now come under this rubric. Examined here are current problems of definition including 'adaptive' and 'innate' types of autoimmunity, estimations of population burdens of autoimmune diseases, the nature of autoepitopes in the context of the diabetes autoantigen GAD65, and the complexities of immune tolerance and the genetic influences thereon, leading to the nomination of multiple 'tolerance/autoimmunity' genes as critical components of pathogenesis. Burnet's concept of mutagenesis as a basic feature of various pathologies including autoimmunity is given a contemporary focus, his views on deletional tolerance have been well vindicated, his 'forbidden clones' remain as unphysiological as before albeit phenotypically resembling normal lymphocytes, and his 'homeostatic mechanisms' can be now interpreted in terms of immunoregulatory networks. PMID:18040284

  8. Development of the swimming acorn worm Glandiceps hacksi: similarity to holothuroids.

    PubMed

    Urata, Makoto; Iwasaki, Sadaharu; Ohtsuka, Susumu; Yamaguchi, Masaaki

    2014-05-01

    Spawnings of Glandiceps hacksi (Hemichordata: Enteropneusta) were stimulated in the laboratory by a brief increase in temperature, and the development from fertilization through metamorphosis is described for the first time for a member of the family Spengelidae. When fertilized, the spawned female gametes, which are primary oocytes, rapidly raise a fertilization membrane and undergo two maturation divisions. Holoblastic, radial cleavage produces a blastula; a gastrula then forms by invagination from the vegetal pole, and the blastopore closes soon thereafter. In previously described enteropneust embryos, the archenteron buds off the protocoel before the latter connects to the exterior via the proboscis pore. By contrast, in G. hacksi the archenteron precociously connects with the exterior before the protocoel forms. Soon thereafter, the embryo becomes uniformly ciliated and then hatches from the fertilization envelope at approximately 32 h (15°C culture temperature). At day 3 of development, the protocoel separates from the gut, which establishes a mouth opening to the exterior; by this time, the gut has differentiated into an esophagus, a stomach, and an intestine that opens posteriorly as an anus. The larva grows to form a tornaria with distinctive pigment patches along its ciliary bands.

  9. Diversification of acorn worms (Hemichordata, Enteropneusta) revealed in the deep sea.

    PubMed

    Osborn, Karen J; Kuhnz, Linda A; Priede, Imants G; Urata, Makoto; Gebruk, Andrey V; Holland, Nicholas D

    2012-04-22

    Enteropneusts (phylum Hemichordata), although studied extensively because of their close relationship to chordates, have long been considered shallow-water, burrowing animals. The present paper more than doubles the number of enteropneust species recorded in the deep sea based on high-resolution imaging and sampling with remotely operated vehicles. We provide direct evidence that some enteropneusts are highly mobile-using changes in posture and currents to drift between feeding sites-and are prominent members of deep, epibenthic communities. In addition, we provide ecological information for each species. We also show that despite their great morphological diversity, most deep-living enteropneusts form a single clade (the rediagnosed family Torquaratoridae) on the basis of rDNA sequences and morphology of the proboscis skeleton and stomochord. The phylogenetic position of the torquaratorids indicates that the group, after evolving from near-shore ancestors, radiated extensively in the deep sea.

  10. From Little Acorns...Self Awareness Activity for Junior High and High School Students.

    ERIC Educational Resources Information Center

    Hooper, Rosemary

    The document contains nine self awareness activities designed to precede or accompany typical career awareness activities in the junior high school and high school curricula. Four objectives for the career education goal of self awareness are stated. The activities require little or no materials, media, or advance preparation. Purposes and…

  11. What's the Point of Me? James Hillman's Acorn Theory and the Role of Teachers

    ERIC Educational Resources Information Center

    Roberts, Susan C.

    2015-01-01

    On the subject of identity crises which we all face from time to time, The late James Hillman, a maverick Jungian psychologist, summed up the problem this way: "Today's main paradigm for understanding a human life, the interplay of genetics and environment, omits something essential the particularity you feel to be you." In his 1996…

  12. Hot limpets: predicting body temperature in a conductance-mediated thermal system.

    PubMed

    Denny, Mark W; Harley, Christopher D G

    2006-07-01

    Living at the interface between the marine and terrestrial environments, intertidal organisms may serve as a bellwether for environmental change and a test of our ability to predict its biological consequences. However, current models do not allow us to predict the body temperature of intertidal organisms whose heat budgets are strongly affected by conduction to and from the substratum. Here, we propose a simple heat-budget model of one such animal, the limpet Lottia gigantea, and test the model against measurements made in the field. Working solely from easily measured physical and meteorological inputs, the model predicts the daily maximal body temperatures of live limpets within a fraction of a degree, suggesting that it may be a useful tool for exploring the thermal biology of limpets and for predicting effects of climate change. The model can easily be adapted to predict the temperatures of chitons, acorn barnacles, keyhole limpets, and encrusting animals and plants. PMID:16788024

  13. A new species of sponge inhabiting barnacle Bryozobia (Archaeobalanidae, Bryozobiinae) in the West Pacific.

    PubMed

    Yu, Meng-Chen; Kolbasov, Gregory A; Chan, Benny K K

    2016-01-01

    This paper describes a new species, Bryozobia rossi sp. n., collected by scuba diving in both Taiwan and Japan. Bryozobia rossi sp. n., a member of the subfamily Bryozobiinae (Ross and Newman 1996), has atria and open end portals and a single irregular basal whorl of portals at the same level as basal hemiportals; this morphology varies from all previously described bryozobiines. According to our review of relevant literature, this is the first reported Bryozobia in the Pacific, and this study is the first to describe the morphology of oral cone, cirri, and penis for the genus Bryozobia. PMID:27110156

  14. Trevathana noae, a new species of coral inhabiting barnacle (Cirripedia: Thoracica: Pyrgomatidae).

    PubMed

    Achituv, Yair; Hosie, Andrew M

    2013-10-29

    We describe a new species from the genus Trevathana Anderson, 1992, collected from the Cocos/Keeling Islands in the Indian Ocean. Trevathana noae sp. nov. is similar to other species of Trevathana by its external shell and opercular valve morphology. It is distinct from congeners in that the tergum has a distinct spur which lacks an internal tooth in adult specimens. A key to the known species of Trevathana is given. 

  15. Terpenes from the red alga Sphaerococcus coronopifolius inhibit the settlement of barnacles.

    PubMed

    Piazza, Veronica; Roussis, Vassilios; Garaventa, Francesca; Greco, Giuliano; Smyrniotopoulos, Vangelis; Vagias, Constantinos; Faimali, Marco

    2011-08-01

    In this study, we screened eight terpenes isolated from the organic extract of Sphaerococcus coronopifolius for their antifouling activity in order to find possible new sources of non-toxic or less toxic bioactive antifoulants. The anti-settlement activity (EC₅₀) and the degree of toxicity (LC₅₀) of S. coronopifolius metabolites was evaluated using larvae of the cirriped crustacean Amphibalanus (Balanus) amphitrite (cyprids and nauplii) as model organism. For five of eight tested metabolites EC₅₀ was lower than 5 mg/L. The most promising results were observed for bromosphaerol (3), which expressed an EC₅₀ value of 0.23 mg/L, in combination with low toxicity levels (LC₅₀ > 100 mg/L). The therapeutic ratio--an index used to estimate whether settlement inhibition is due to toxicity or other mechanisms--is also calculated and discussed.

  16. Bats, Barnacles, and Bread Mold: An "Organism Day" Laboratory for General Biology.

    ERIC Educational Resources Information Center

    Loehr, Karen A.

    1983-01-01

    Describes a laboratory exercise in which students select and identify an organism, study it as it interacts within its environment, collect further information through library research, and bring the organism (alive, preserved, or photographed) to lab for a five-minute presentation. (JN)

  17. Metamorphosis in balanomorphan, pedunculated, and parasitic barnacles: a video-based analysis.

    PubMed

    Høeg, Jens T; Maruzzo, Diego; Okano, Keiju; Glenner, Henrik; Chan, Benny K K

    2012-09-01

    Cypris metamorphosis was followed using video microscopy in four species of cirripeds representing the suspension-feeding pedunculated and sessile Thoracica and the parasitic Rhizocephala. Cirripede metamorphosis involves one or more highly complex molts that mark the change from a free cypris larva to an attached suspension feeder (Thoracica) or an endoparasite (Rhizocephala). The cyprids and juveniles are so different in morphology that they are functionally incompatible. The drastic reorganization of the body implicated in the process can therefore only commence after the cyprid has irreversibly cemented itself to a substratum. In both Megabalanus rosa and Lepas, the settled cyprid first passes through a quiescent period of tissue reorganization, in which the body is raised into a position vertical to the substratum. In Lepas, this is followed by extension of the peduncle. In both Lepas and M. rosa, the juvenile must free itself from the cypris cuticle by an active process before it can extend the cirri for suspension feeding. In M. rosa, the juvenile performs intensely pulsating movements that result in shedding of the cypris carapace ~8 h after settlement. Lepas sp. sheds the cypris cuticle ~2 days after settlement due to contractile movements of the peduncle. In Lepas anserifera, the juvenile actively breaks through the cypris carapace, which can thereafter remain for several days without impeding cirral feeding. Formation of the shell plates begins after 1-2 days under the cyprid carapace in Lepas. In M. rosa, the free juvenile retains its very thin cuticle and flexible shape for some time, and shell plates do not appear until sometime after shedding of the cypris cuticles. In Sacculina carcini, the cypris settles at the base of a seta on the host crab and remains quiescent and aligned at an angle of ~60° to the crab's cuticle. The metamorphosis involves two molts, resulting in the formation of an elongated kentrogon stage with a hollow injection stylet. Due to the orientation of the cyprid, the stylet points directly towards the base of the crab's seta. Approximately 60 h after settlement the stylet penetrates down one of the cyprid antennules and into the crab. Almost immediately afterwards the unsegmented vermigon stage, preformed in the kentrogon, passes down through the hollow stylet and into the crab's hemocoel in a process lasting only 30 s. In S. carcini, the carapace can remain around the metamorphosing individual without impeding the process.

  18. The cypris larvae of the parasitic barnacle Heterosaccus lunatus (Crustacea, Cirripedia, Rhizocephala): some laboratory observations.

    PubMed

    Walker; Lester

    2000-11-20

    Heterosaccus lunatus parasitizes the portunid crab, Charybdis callianassa in Moreton Bay, Australia. With the host crabs maintained at 22.5 degrees C this sacculinid rhizocephalan released larval broods every 6-7 days. During July-August 1996 and particularly August 1999 such broods showed the change-over from male only larvae in the early broods to females only in the later broods. As the host crabs were maintained under similar aquarium conditions in both years it is concluded that the light/dark cycle is the principal cue triggering this larval sex reversal. Oogenesis in the parasite externa is somehow controlled to produce two different sized ova - male larvae develop from large ova and females from small ova. A working hypothesis outlining how sex is probably determined for the larvae of sacculinids is erected. H. lunatus is considered the ideal sacculinid for the further experimental work necessary to verify the proposed sex-determining mechanism and its control processes. Measurements of the maximum swimming speeds of H. lunatus male and female cyprids showed the larger males to be the faster in absolute terms (27.95 compared with 17.60 mm s(-1), respectively), however, the calculated relative speeds were almost identical at approximately 90 body lengths s(-1). Settlement experiments confirmed that female H. lunatus cyprids settle only on the gills of C. callianassa; these cyprids needed to be at least 2 days old before they were able to settle.

  19. A new species of sponge inhabiting barnacle Bryozobia (Archaeobalanidae, Bryozobiinae) in the West Pacific.

    PubMed

    Yu, Meng-Chen; Kolbasov, Gregory A; Chan, Benny K K

    2016-01-01

    This paper describes a new species, Bryozobia rossi sp. n., collected by scuba diving in both Taiwan and Japan. Bryozobia rossi sp. n., a member of the subfamily Bryozobiinae (Ross and Newman 1996), has atria and open end portals and a single irregular basal whorl of portals at the same level as basal hemiportals; this morphology varies from all previously described bryozobiines. According to our review of relevant literature, this is the first reported Bryozobia in the Pacific, and this study is the first to describe the morphology of oral cone, cirri, and penis for the genus Bryozobia.

  20. Zevinaella-a new barnacle genus (Scalpellomorpha: Arcoscalpellinae) associated with crinoids (Echinodermata) from the Caribbean.

    PubMed

    Shalaeva, Kate; Newman, William A

    2016-01-01

    A new genus, Zevinaella (Cirripedia: Scalpellomorpha: Scalpellidae: Arcoscalpellinae), is proposed to accommodate Trianguloscalpellum rodstromi (Boone, 1927) from Belize and Z. volentis gen. et sp. nov. from the Lesser Antilles, both occurring on crinoids. These two species are unique in lacking lower lateral plates (inframedian or second latera, L2s). We see no compelling evidence that the lack of L2s in Zevinaella is a consequence of fusion with the carinolatera (CLs), as appears to be the case in a near relative T. pentacrinarum, or of progressive reduction and potential loss, as in older specimens of Amigdoscalpellum spp. (Zevina, 1978b). However, this does not weaken the diagnosis of the new genus and, accordingly, the diagnoses for the family Scalpellidae Pilsbry, 1907 and the subfamily Arcoscalpellinae Zevina, 1978b are amended to accommodate the absence of the L2s. PMID:27395916

  1. A new species of sponge inhabiting barnacle Bryozobia (Archaeobalanidae, Bryozobiinae) in the West Pacific

    PubMed Central

    Yu, Meng-Chen; Kolbasov, Gregory A.; Chan, Benny K.K.

    2016-01-01

    Abstract This paper describes a new species, Bryozobia rossi sp. n., collected by scuba diving in both Taiwan and Japan. Bryozobia rossi sp. n., a member of the subfamily Bryozobiinae (Ross and Newman 1996), has atria and open end portals and a single irregular basal whorl of portals at the same level as basal hemiportals; this morphology varies from all previously described bryozobiines. According to our review of relevant literature, this is the first reported Bryozobia in the Pacific, and this study is the first to describe the morphology of oral cone, cirri, and penis for the genus Bryozobia. PMID:27110156

  2. Zevinaella-a new barnacle genus (Scalpellomorpha: Arcoscalpellinae) associated with crinoids (Echinodermata) from the Caribbean.

    PubMed

    Shalaeva, Kate; Newman, William A

    2016-01-29

    A new genus, Zevinaella (Cirripedia: Scalpellomorpha: Scalpellidae: Arcoscalpellinae), is proposed to accommodate Trianguloscalpellum rodstromi (Boone, 1927) from Belize and Z. volentis gen. et sp. nov. from the Lesser Antilles, both occurring on crinoids. These two species are unique in lacking lower lateral plates (inframedian or second latera, L2s). We see no compelling evidence that the lack of L2s in Zevinaella is a consequence of fusion with the carinolatera (CLs), as appears to be the case in a near relative T. pentacrinarum, or of progressive reduction and potential loss, as in older specimens of Amigdoscalpellum spp. (Zevina, 1978b). However, this does not weaken the diagnosis of the new genus and, accordingly, the diagnoses for the family Scalpellidae Pilsbry, 1907 and the subfamily Arcoscalpellinae Zevina, 1978b are amended to accommodate the absence of the L2s.

  3. Natural Underwater Adhesives

    PubMed Central

    Stewart, Russell J.; Ransom, Todd C.; Hlady, Vladimir

    2011-01-01

    The general topic of this review is protein-based underwater adhesives produced by aquatic organisms. The focus is on mechanisms of interfacial adhesion to native surfaces and controlled underwater solidification of natural water-borne adhesives. Four genera that exemplify the broad range of function, general mechanistic features, and unique adaptations are discussed in detail: blue mussels, acorn barnacles, sandcastle worms, and freshwater caddisfly larva. Aquatic surfaces in nature are charged and in equilibrium with their environment, populated by an electrical double layer of ions as well as adsorbed natural polyelectrolytes and microbial biofilms. Surface adsorption of underwater bioadhesives likely occurs by exchange of surface bound ligands by amino acid sidechains, driven primarily by relative affinities and effective concentrations of polymeric functional groups. Most aquatic organisms exploit modified amino acid sidechains, in particular phosphorylated serines and hydroxylated tyrosines (dopa), with high-surface affinity that form coordinative surface complexes. After delivery to the surfaces as a fluid, permanent natural adhesives solidify to bear sustained loads. Mussel plaques are assembled in a manner superficially reminiscent of in vitro layer-by-layer strategies, with sequentially delivered layers associated through Fe(dopa)3 coordination bonds. The adhesives of sandcastle worms, caddisfly larva, and barnacles may be delivered in a form somewhat similar to in vitro complex coacervation. Marine adhesives are secreted, or excreted, into seawater that has a significantly higher pH and ionic strength than the internal environment. Empirical evidence suggests these environment triggers could provide minimalistic, fail-safe timing mechanisms to prevent premature solidification (insolubilization) of the glue within the secretory system, yet allow rapid solidification after secretion. Underwater bioadhesives are further strengthened by secondary covalent

  4. Applying digital particle image velocimetry to animal-generated flows: Traps, hurdles and cures in mapping steady and unsteady flows in Re regimes between 10-2 and 105

    NASA Astrophysics Data System (ADS)

    Stamhuis, E. J.; Videler, J. J.; van Duren, L. A.; Müller, U. K.

    2002-09-01

    Digital particle image velocimetry (DPIV) has been applied to animal-generated flows since 1993 to map the flow patterns and vortex wakes produced by a range of feeding and swimming aquatic animals, covering a Re range of 10-2-105. In this paper, the special circumstances, problems and some solutions on many aspects of PIV, which arise from working with living animals, are discussed and illustrated. Topics covered are the experimental set-up, animal housing, restraining animals, animal training, flow tanks, seeding, illumination, imaging, analysis accuracy and result interpretation. Examples include the feeding currents of different juvenile stages of copepods, filter feeding in acorn barnacles, filter feeding in cockles and soft-shelled clams, the wake of burst-swimming zebra danios, burrow ventilation in a mudshrimp and the vortex chain wake of a swimming mullet. DPIV appeared to be a powerful tool for studying animal-generated flows. However, PIV has to be applied with caution and often needs to be adapted to the particular circumstances to take into account the presence of animals and to ensure that the mapped flow phenomena arise from normal behaviour.

  5. Two new species of scalpelliform barnacles (Cirripedia: Thoracica) from the Plio-Pleistocene of Cotentin, northwest France.

    PubMed

    Carriol, René-Pierre

    2013-01-01

    Two new species of pedunculate cirripede are described from the Plio-Pleistocene of Cotentin, northwest France. Scalpellum carentanensis sp. nov. is only the third species of this genus to be recorded from Pliocene strata in Europe. It is characterised by a triangular tergum with an apico-basal fold, without an outward extension, the inner surface of which has the raised part marked by wide growth lines, cut by a groove; the scutum has a ridge between the umbo and the tergo-lateral angle, lacks an apico-basal ridge, and possesses a line formed by the convergence of the growth zones; the length of the upper lateral exceeds its width by about 1.25 times, the umbo being situated at one-fifth the length of the plate from the apex. Arcoscalpelluin concavitectum sp. nov. is the second species of this genus on record from the Pliocene of Europe. It possesses a carina with a concave tectum bordered on each side by a smooth rounded rib; the tergum has an apico-basal line formed by the convergence of growth zones; and the upper lateral has the basi-scutal angle more widely truncated than the basi-tergal angle.

  6. Two new species of scalpelliform barnacles (Cirripedia: Thoracica) from the Plio-Pleistocene of Cotentin, northwest France.

    PubMed

    Carriol, René-Pierre

    2013-01-01

    Two new species of pedunculate cirripede are described from the Plio-Pleistocene of Cotentin, northwest France. Scalpellum carentanensis sp. nov. is only the third species of this genus to be recorded from Pliocene strata in Europe. It is characterised by a triangular tergum with an apico-basal fold, without an outward extension, the inner surface of which has the raised part marked by wide growth lines, cut by a groove; the scutum has a ridge between the umbo and the tergo-lateral angle, lacks an apico-basal ridge, and possesses a line formed by the convergence of the growth zones; the length of the upper lateral exceeds its width by about 1.25 times, the umbo being situated at one-fifth the length of the plate from the apex. Arcoscalpelluin concavitectum sp. nov. is the second species of this genus on record from the Pliocene of Europe. It possesses a carina with a concave tectum bordered on each side by a smooth rounded rib; the tergum has an apico-basal line formed by the convergence of growth zones; and the upper lateral has the basi-scutal angle more widely truncated than the basi-tergal angle. PMID:26287063

  7. Morphology of a new deep-sea acorn worm (class Enteropneusta, phylum Hemichordata): a part-time demersal drifter with externalized ovaries.

    PubMed

    Holland, Nicholas D; Kuhnz, Linda A; Osborn, Karen J

    2012-07-01

    Ten individuals of an enteropneust in the family Torquaratoridae were videotaped between 2,900 and 3,500 m in the Eastern Pacific--one drifting a few centimeters above the bottom, two exposed on the substrate, and seven partly burrowed, reflecting a bentho-pelagic life style. Here, we describe a captured specimen (26 cm living length) as the holotype of Allapasus aurantiacus n. gen., n. sp. The small proboscis is dome-shaped, and the collar is only slightly wider than deep; both of these body regions are more muscular than in other torquaratorids, which presumably facilitates burrowing. The proboscis complex, in contrast to that of shallow-living enteropneusts, lacks a pericardial sac and is located relatively posteriorly in the proboscis stalk. The stomochord is separated from the main course of the gut by the intervention of a small, plate-like proboscis skeleton lacking posterior horns. The most anterior region of the trunk houses the pharynx, in which the pharyngeal skeletal bars are not connected by synapticles. The postpharyngeal trunk comprises three intestinal regions: prehepatic, hepatic (with conspicuous sacculations), and posthepatic. On either side of the worm, a flap of body wall (lateral wing) runs the entire length of the trunk. The two lateral wings can wrap the body so their edges meet in the dorsal midline, although they often gape open along the pharyngeal region. The holotype is a female (presumably the species is gonochoric) with numerous ovaries located in the lateral wings along the pharyngeal region. Each larger ovary contains a single primary oocyte (up to 1,500 μm in diameter) and bulges outwards in an epidermal pouch attached to the rest of the body by a slender stalk. Such externalized ovaries are unprecedented in any animal, and nothing is yet known of their role in the reproductive biology of A. aurantiacus. PMID:22419131

  8. Testing putative hemichordate homologues of the chordate dorsal nervous system and endostyle: expression of NK2.1 (TTF-1) in the acorn worm Ptychodera flava (Hemichordata, Ptychoderidae).

    PubMed

    Takacs, Carter M; Moy, Vanessa N; Peterson, Kevin J

    2002-01-01

    Recent phylogenetic investigations have confirmed that hemichordates and echinoderms are sister taxa. However, hemichordates share several cardinal characterstics with chordates and are thus an important taxon for testing hypotheses of homology between key chordate characters and their putative hemichordate antecedents. The chordate dorsal nervous system (DNS) and endostyle are intriguing characters because both hemichordate larval and adult structures have been hypothesized as homologues. This study attempts to test these purported homologies through examination of the expression pattem of a Ptychodera flava NK2 gene, PfNK2.1, because this gene is expressed both in the DNS and endostyle/thyroid in a wide range of chordate taxa. We found that PfNK2.1 is expressed in both neuronal and pharyngeal structures, but its expression pattem is broken up into distinct embryonic and juvenile phases. During embryogenesis, PfNK2.1 is expressed in the apical ectoderm, with transcripts later detected in presumable neuronal structures, including the apical organ and ciliated feeding band. In the developing juvenile we detected PfNK2.1 signal throughout the pharynx, including the stomochord, and later in the hindgut. We conclude that the similar utilization of NK2.1 in apical organ development and chordate DNS is probably due to a more general role for NK2.1 in neurogenesis and that hemichordates do not possess a homologue of the chordate DNS. In addition, we conclude that P. flava most likely does not possess a true endostyle; rather during the evolution of the endostyle NK2.1 was recruited from its more general role in pharynx development. PMID:12492141

  9. Testing putative hemichordate homologues of the chordate dorsal nervous system and endostyle: expression of NK2.1 (TTF-1) in the acorn worm Ptychodera flava (Hemichordata, Ptychoderidae)

    NASA Technical Reports Server (NTRS)

    Takacs, Carter M.; Moy, Vanessa N.; Peterson, Kevin J.

    2002-01-01

    Recent phylogenetic investigations have confirmed that hemichordates and echinoderms are sister taxa. However, hemichordates share several cardinal characterstics with chordates and are thus an important taxon for testing hypotheses of homology between key chordate characters and their putative hemichordate antecedents. The chordate dorsal nervous system (DNS) and endostyle are intriguing characters because both hemichordate larval and adult structures have been hypothesized as homologues. This study attempts to test these purported homologies through examination of the expression pattem of a Ptychodera flava NK2 gene, PfNK2.1, because this gene is expressed both in the DNS and endostyle/thyroid in a wide range of chordate taxa. We found that PfNK2.1 is expressed in both neuronal and pharyngeal structures, but its expression pattem is broken up into distinct embryonic and juvenile phases. During embryogenesis, PfNK2.1 is expressed in the apical ectoderm, with transcripts later detected in presumable neuronal structures, including the apical organ and ciliated feeding band. In the developing juvenile we detected PfNK2.1 signal throughout the pharynx, including the stomochord, and later in the hindgut. We conclude that the similar utilization of NK2.1 in apical organ development and chordate DNS is probably due to a more general role for NK2.1 in neurogenesis and that hemichordates do not possess a homologue of the chordate DNS. In addition, we conclude that P. flava most likely does not possess a true endostyle; rather during the evolution of the endostyle NK2.1 was recruited from its more general role in pharynx development.

  10. Testing putative hemichordate homologues of the chordate dorsal nervous system and endostyle: expression of NK2.1 (TTF-1) in the acorn worm Ptychodera flava (Hemichordata, Ptychoderidae).

    PubMed

    Takacs, Carter M; Moy, Vanessa N; Peterson, Kevin J

    2002-01-01

    Recent phylogenetic investigations have confirmed that hemichordates and echinoderms are sister taxa. However, hemichordates share several cardinal characterstics with chordates and are thus an important taxon for testing hypotheses of homology between key chordate characters and their putative hemichordate antecedents. The chordate dorsal nervous system (DNS) and endostyle are intriguing characters because both hemichordate larval and adult structures have been hypothesized as homologues. This study attempts to test these purported homologies through examination of the expression pattem of a Ptychodera flava NK2 gene, PfNK2.1, because this gene is expressed both in the DNS and endostyle/thyroid in a wide range of chordate taxa. We found that PfNK2.1 is expressed in both neuronal and pharyngeal structures, but its expression pattem is broken up into distinct embryonic and juvenile phases. During embryogenesis, PfNK2.1 is expressed in the apical ectoderm, with transcripts later detected in presumable neuronal structures, including the apical organ and ciliated feeding band. In the developing juvenile we detected PfNK2.1 signal throughout the pharynx, including the stomochord, and later in the hindgut. We conclude that the similar utilization of NK2.1 in apical organ development and chordate DNS is probably due to a more general role for NK2.1 in neurogenesis and that hemichordates do not possess a homologue of the chordate DNS. In addition, we conclude that P. flava most likely does not possess a true endostyle; rather during the evolution of the endostyle NK2.1 was recruited from its more general role in pharynx development.

  11. Morphology of a new deep-sea acorn worm (class Enteropneusta, phylum Hemichordata): a part-time demersal drifter with externalized ovaries.

    PubMed

    Holland, Nicholas D; Kuhnz, Linda A; Osborn, Karen J

    2012-07-01

    Ten individuals of an enteropneust in the family Torquaratoridae were videotaped between 2,900 and 3,500 m in the Eastern Pacific--one drifting a few centimeters above the bottom, two exposed on the substrate, and seven partly burrowed, reflecting a bentho-pelagic life style. Here, we describe a captured specimen (26 cm living length) as the holotype of Allapasus aurantiacus n. gen., n. sp. The small proboscis is dome-shaped, and the collar is only slightly wider than deep; both of these body regions are more muscular than in other torquaratorids, which presumably facilitates burrowing. The proboscis complex, in contrast to that of shallow-living enteropneusts, lacks a pericardial sac and is located relatively posteriorly in the proboscis stalk. The stomochord is separated from the main course of the gut by the intervention of a small, plate-like proboscis skeleton lacking posterior horns. The most anterior region of the trunk houses the pharynx, in which the pharyngeal skeletal bars are not connected by synapticles. The postpharyngeal trunk comprises three intestinal regions: prehepatic, hepatic (with conspicuous sacculations), and posthepatic. On either side of the worm, a flap of body wall (lateral wing) runs the entire length of the trunk. The two lateral wings can wrap the body so their edges meet in the dorsal midline, although they often gape open along the pharyngeal region. The holotype is a female (presumably the species is gonochoric) with numerous ovaries located in the lateral wings along the pharyngeal region. Each larger ovary contains a single primary oocyte (up to 1,500 μm in diameter) and bulges outwards in an epidermal pouch attached to the rest of the body by a slender stalk. Such externalized ovaries are unprecedented in any animal, and nothing is yet known of their role in the reproductive biology of A. aurantiacus.

  12. Post Earthquake Investigation Of The Mw7.8 Haida Gwaii, Canada, Rupture Area And Constraints On Earthquake Source Models

    NASA Astrophysics Data System (ADS)

    Haeussler, P. J.; Witter, R. C.; Wang, K.

    2013-12-01

    The October 28, 2012 Mw 7.8 Haida Gwaii, British Columbia, earthquake was the second largest historical earthquake recorded in Canada. Earthquake seismology and GPS geodesy shows this was an underthrusting event, in agreement with prior studies that indicated oblique underthrusting of the Haida Gwaii by the Pacific plate. Coseismic deformation is poorly constrained by geodesy, with only six GPS sites and two tide gauge stations anywhere near the rupture area. In order to better constrain the coseismic deformation, we measured the upper limit of sessile intertidal organisms at 26 sites relative to sea level. We dominantly measured the positions of bladder weed (fucus distichus - 617 observations) and the common acorn barnacle (Balanus balanoides - 686 observations). Physical conditions control the upper limit of sessile intertidal organisms, so we tried to find the quietest water conditions, with steep, but not overhanging faces, where slosh from wave motion was minimized. We focused on the western side of the islands as rupture models indicated that the greatest displacement was there. However, we were also looking for calm water sites in bays located as close as possible to the often tumultuous Pacific Ocean. In addition, we made 322 measurements of sea level that will be used to develop a precise tidal model and to evaluate the position of the organisms with respect to a common sea level datum. We anticipate the resolution of the method will be about 20-30 cm. The sites were focused on the western side of the Haida Gwaii from Wells Bay on the south up to Otard Bay to the north, with 5 transects across strike. We also collected data at the town of Masset, which lies outside of the deformation zone of the earthquake. We observed dried and desiccated bands of fucus and barnacles at two sites on the western coast of southern Moresby Island (Gowgia Bay and Wells Bay). Gowgia Bay had the strongest evidence of uplift with fucus that was dried out and apparently dead. A

  13. Parasitic crustaceans as vectors of viruses, with an emphasis on three penaeid viruses.

    PubMed

    Overstreet, Robin M; Jovonovich, Jean; Ma, Hongwei

    2009-08-01

    Parasitic crustaceans serve as both hosts and vectors of viruses as well as of parasites and other microbial pathogenic agents. Few of the presumably numerous associations are known, but many can be anticipated. Recently, branchiurans and gnathiid isopods have been documented to host helminths and blood parasites. Because the agents can be observed readily with a microscope, these are better recognized than are the smaller viral, bacterial, and fungal agents. Some agents are harmful to the host of the crustacean parasite and others are not. Viruses probably fit both these categories, since viruses that do not appear pathogenic are often seen in ultrastructural images from a range of invertebrate hosts, including crustaceans. Some viruses have been implicated in causing disease in the host, at least under appropriate conditions. For example, lymphocystis virus may possibly be transmitted to the dermis of its fish hosts by copepods and to the visceral organs by a cymothoid isopod. Similarly, argulid branchiurans seem to transmit the viral agent of spring viremia of carp as well as carp pox, and copepods have been implicated in transmitting infectious hematopoietic necrosis, infectious salmon anemia, and infectious pancreatic necrosis to salmon. Other viruses can be vectored to their hosts through an additional animal. We exposed three viruses, Taura syndrome virus (TSV), white spot syndrome virus (WSSV), and yellowhead virus (YHV), all of which cause mortalities in wild and cultured penaeid shrimps, to crustacean parasites on fish and crabs. Using real-time polymerase chain reaction analysis, we show that TSV in the cyclopoid copepod Ergasilus manicatus on the gill filaments of the Gulf killifish, Fundulus grandis, the acorn barnacle Chelonibia patula on the carapace of the blue crab, Callinectes sapidus, and gooseneck barnacle Octolasmis muelleri on the gills of C. sapidus, can replicate for at least 2 weeks and establish what should be an infective dose. This

  14. Horseshoe crab, Tachypleus gigas (Müller, 1785) spawning population at Balok Beach, Kuantan, Pahang, Malaysia.

    PubMed

    Tan, A N; Christianus, A; Shakibazadeh, S; Hajeb, P

    2012-07-01

    Local and regional decline of Asian horseshoe crabs has spurred a study on its spawning population at Balok Beach, Kuantan, Pahang, Malaysia. This location was identified as spawning site due to the occurrence of horseshoe crab spawning pairs and nests. Size-frequency, length-weight relationships, sex ratio and epibiont infestation of Tachypleus gigas were studied. Instar stage was estimated based on prosomal width. Condition of the horseshoe crab carapace was reported. Visual search technique of horseshoe crab was conducted during high tide of new and full moons. Prosomal, opisthosomal and telson length and weight of each horseshoe crab were measured. Largest female was recorded with mean prosomal length and width of 154.4 and 246.9 mm, respectively. About 69.8% of the males belonged to size group of 151-200 mm and 53.3% of females were grouped into 201-250 mm. All individuals were of fourteenth to sixteenth instar stages. Sex ratio varied from 0.313 to 2.5 and attributed to commercial harvest and monsoon season. Sand sediment of study site showed 93% of fine sands with grain size ranged from 120 to 250 microm. Acorn and pedunculate barnacle, conical and flat slipper shells were found on the carapace of the specimens. Most males had damaged eyes and carapaces while females with broken telsons. Body damages of about 19.9% on the specimens were likely due to nearby fishing activities. Lack of satellite male indicated low spawning population. The finding of this study showed that the species is extremely threatened by human activities and coastal development. PMID:24218930

  15. Horseshoe crab, Tachypleus gigas (Müller, 1785) spawning population at Balok Beach, Kuantan, Pahang, Malaysia.

    PubMed

    Tan, A N; Christianus, A; Shakibazadeh, S; Hajeb, P

    2012-07-01

    Local and regional decline of Asian horseshoe crabs has spurred a study on its spawning population at Balok Beach, Kuantan, Pahang, Malaysia. This location was identified as spawning site due to the occurrence of horseshoe crab spawning pairs and nests. Size-frequency, length-weight relationships, sex ratio and epibiont infestation of Tachypleus gigas were studied. Instar stage was estimated based on prosomal width. Condition of the horseshoe crab carapace was reported. Visual search technique of horseshoe crab was conducted during high tide of new and full moons. Prosomal, opisthosomal and telson length and weight of each horseshoe crab were measured. Largest female was recorded with mean prosomal length and width of 154.4 and 246.9 mm, respectively. About 69.8% of the males belonged to size group of 151-200 mm and 53.3% of females were grouped into 201-250 mm. All individuals were of fourteenth to sixteenth instar stages. Sex ratio varied from 0.313 to 2.5 and attributed to commercial harvest and monsoon season. Sand sediment of study site showed 93% of fine sands with grain size ranged from 120 to 250 microm. Acorn and pedunculate barnacle, conical and flat slipper shells were found on the carapace of the specimens. Most males had damaged eyes and carapaces while females with broken telsons. Body damages of about 19.9% on the specimens were likely due to nearby fishing activities. Lack of satellite male indicated low spawning population. The finding of this study showed that the species is extremely threatened by human activities and coastal development.

  16. The complete mitochondrial genome of the fire coral-inhabiting barnacle Megabalanus ajax (Sessilia: Balanidae): gene rearrangements and atypical gene content.

    PubMed

    Shen, Xin; Chu, Ka Hou; Chan, Benny Kwok Kan; Tsang, Ling Ming

    2016-01-01

    The complete mitochondrial genome of Megabalanus ajax Darwin, 1854 (Sessilia: Balanidae) is reported. Compared to typical gene content of metazoan mitochondrial genomes, duplication of one tRNA gene (trnL2) and absence of another tRNA gene (trnS1) are identified in M. ajax mitochondrial genome. There is a replacement of one tRNA (trnS1) by another tRNA (trnL2) in M. ajax mitochondrial genome compared to Megabalanus volcano mitochondrial genome. Inversion of a six-gene block (trnP-nd4L-nd4-trnH-nd5-trnF) is found between M. ajax/M. volcano and Tetraclita japonica mitochondrial genomes. With reference to the pancrustacean mitochondrial ground pattern, there is an inversion of a large gene block from the light strand to heavy strand in the two Megabalanus mitochondrial genomes, including three PCGs and two tRNAs (nd4L-nd4-trnH-nd5-trnF). Furthermore, four tRNAs (trnA, trnE, trnQ and trnC) exhibit translocation, while translocation and inversion occur in three tRNAs (trnP, trnY and trnK). PMID:25050875

  17. Cross-shore transport in a daily varying upwelling regime: A case study of barnacle larvae on the southwestern Iberian coast

    NASA Astrophysics Data System (ADS)

    Trindade, A.; Peliz, A.; Dias, J.; Lamas, L.; Oliveira, P. B.; Cruz, T.

    2016-09-01

    With favored offshore and downstream advection, the question of which physical mechanism may promote onshore transport of larvae in upwelling systems is of central interest. We have conducted a semi-realistic high resolution (0.25 km) numerical study of Lagrangian transports across the inner-shelf under upwelling-favorable wind forcing conditions, focusing on the shelf area of the Southwestern Portuguese coast, in the lee of Cape Sines. We add our findings to several years of biological observations of C. montagui, a planktonic species with higher recruitment during the upwelling peak timely with the daylight flood. Simulations cover a fifteen days period during the summer of 2006. We focused on Spring and Neap tide periods and observed upfront differences between simulations and the in situ observations. However, the model is capable of representing the main dynamics of the region, namely the repetitive character of the inner-shelf currents. We find that the cross-shore flow varies significantly in the daily cycle, and locally within a scale of a few kilometers in association with local topography and the presence of the cape. We consider the region immediately in the lee of the cape to be an upwelling shadow where the larvae became retained, and found that tidally tied migration proves beneficial for successful recruitment during the spring tides period. Our work suggested that the wind is not the only mechanism responsible for the daily variability of the cross-shore exchange. However, its sharp reversal at midday is critical for the advection of larvae towards the coast.

  18. An illustrated catalogue of the scalpellid barnacles (Crustacea: Cirripedia: Scalpellidae) collected during the HMS "challenger" expedition and deposited in the Natural History Museum, London.

    PubMed

    Shalaeva, Kate; Boxshall, Geoff

    2014-05-29

    For the first time since 1883, the "Challenger" collection of scalpellids stored in the Natural History Museum (London) and studied by Hoek, has been reviewed. It comprises 40 species now assigned to 17 genera and three subfamilies within the family Scalpellidae. A checklist of published records, type status, sources of supplementary descriptive information, updated distributions and known depth records is given. New photographs are included which may be useful for species identification and for any future systematic rearrangement of the scalpellids. Trianguloscalpellum weltnerianum (Pilsbry, 1911) is recognised as a junior subjective synonym of Trianguloscalpellum album (Hoek, 1883).

  19. Local adaptation along a continuous coastline: prey recruitment drives differentiation in a predatory snail.

    PubMed

    Sanford, Eric; Worth, David J

    2010-03-01

    Recent work demonstrates that nearshore oceanography can generate strong variation in the delivery of resources (nutrients and larvae) to benthic marine communities over spatial scales of tens to hundreds of kilometers. Moreover, variation in the strength of these bottom-up inputs is often spatially consistent, linked to regional centers of upwelling, coastal topography, and other stable features of the coastline. Whereas the ecological effects of these oceanographic links are increasingly clear, the possibility that these same bottom-up forces might impose spatially varying selection on consumers has not been addressed. Here, we test the hypothesis that a carnivorous snail (Nucella canaliculata) with direct development is locally adapted to persistent differences in prey recruitment within two adjacent oceanographic regions (northern California and Oregon, USA). Previous laboratory studies demonstrated that snails from Oregon rarely drilled the thick-shelled mussel Mytilus californianus, whereas snails from California readily drilled this prey. To test whether these differences reflect local adaptation, snails from two populations in each region were raised through two laboratory generations to minimize the potential influence of nongenetic effects. We then reciprocally outplanted these F2 generation snails to field enclosures at each of the four sites and monitored their growth for 11 months. Recruitment and availability of preferred prey (the acorn barnacle Balanus glandula and blue mussel Mytilus trossulus) at the experimental sites were 1-3 orders of magnitude lower in California than in Oregon. At the California sites, snails that originated from Oregon sources failed to drill larger M. californianus, encountered few alternative prey, and showed almost no growth. In contrast, snails from California drilled M. californianus and showed substantial growth. These results strongly suggest that the capacity of California snails to drill M. californianus allows

  20. Secret Apartheid II. Race, Regents, and Resources.

    ERIC Educational Resources Information Center

    New York Chapter of Association of Community Organizations for Reform Now, New York.

    The New York Association of Community Organizations for Reform Now (ACORN) is a grass-roots community organization representing 20,000 mostly low-income residents of New York City. This report presents information about students relegated to the low achievement track that ACORN suggested, in a previous report, was inevitable when parents of color…

  1. Oviposition Preference and Offspring Performance of Mechoris ursulus (Coleoptera: Attelabidae) in Cyclobalanopsis glaucoides (Fagales: Fagaceae) and Quercus franchetii (Fagales: Fagaceae) in Central Yunnan, China

    PubMed Central

    Wang, Xu; Hu, Shao-Ji; Zhang, Zhi-Ying; Geng, Yu-Peng; Bai, Xue

    2015-01-01

    Mechoris ursulus (Roelofs) (Coleoptera: Attelabidae) is a pest weevil of Fagaceae oak trees in eastern Asia. The female has a distinct branch-cutting behavior in conjunction with oviposition in the acorns of its host plant. This study analyzed the factors influencing oviposition preference by carrying out continuous field surveys over the course of 2009–2010 and through laboratory rearing. The field survey showed that for both of the hosts, Cyclobalanopsis glaucoides Schottky (Fagales: Fagaceae) and Quercus franchetii Skan, M. ursulus preferred branches with fewer acorns and larger acorns on the same branch for oviposition. Laboratory rearing experiments showed offspring performance (i.e., survival rate and fresh weight of larvae) was significantly and positively correlated with acorn size. Preference for larger acorns could maximize the fitness of offspring by providing sufficient food source and space. PMID:25791200

  2. On a New Species of Parasitic Barnacle (Crustacea: Rhizocephala), Sacculina shiinoi sp. nov., Parasitizing Japanese Mud Shrimps Upogebia spp. (Decapoda: Thalassinidea: Upogebiidae), Including a Description of a Novel Morphological Structure in the Rhizocephala.

    PubMed

    Lützen, Jørgen; Itani, Gyo; Jespersen, Åse; Hong, Jae-Sang; Rees, David; Glenner, Henrik

    2016-04-01

    The rhizocephalan Sacculina shiinoi sp. nov. parasitizes three species of Upogebia in Japan. It is described morphologically and compared with another Upogebia parasite, Sacculina upogebiae Shiino, 1943 from Japan and Korea. These two species are the only sacculinids that parasitize mud shrimps. DNA analyses clearly show the two species to be separate and not closely related. The cuticle differs in being provided with close-set, branched, and spiny excrescences in S. shiinoi, while it lacks excrescences, but forms small scales in S. upogebiae. In S. upogebiae, the bulbous sperm-producing part and the narrow receptacle duct are separated by a compartmentalized mid portion, which is missing in S. shiinoi. A ridge, having a thickened, fluffy cuticle with a U-shaped course, passes across the visceral mass between the two receptacle openings in S. shiinoi. Such a structure has never been described in other rhizocephalans, and its function is uncertain.

  3. On a New Species of Parasitic Barnacle (Crustacea: Rhizocephala), Sacculina shiinoi sp. nov., Parasitizing Japanese Mud Shrimps Upogebia spp. (Decapoda: Thalassinidea: Upogebiidae), Including a Description of a Novel Morphological Structure in the Rhizocephala.

    PubMed

    Lützen, Jørgen; Itani, Gyo; Jespersen, Åse; Hong, Jae-Sang; Rees, David; Glenner, Henrik

    2016-04-01

    The rhizocephalan Sacculina shiinoi sp. nov. parasitizes three species of Upogebia in Japan. It is described morphologically and compared with another Upogebia parasite, Sacculina upogebiae Shiino, 1943 from Japan and Korea. These two species are the only sacculinids that parasitize mud shrimps. DNA analyses clearly show the two species to be separate and not closely related. The cuticle differs in being provided with close-set, branched, and spiny excrescences in S. shiinoi, while it lacks excrescences, but forms small scales in S. upogebiae. In S. upogebiae, the bulbous sperm-producing part and the narrow receptacle duct are separated by a compartmentalized mid portion, which is missing in S. shiinoi. A ridge, having a thickened, fluffy cuticle with a U-shaped course, passes across the visceral mass between the two receptacle openings in S. shiinoi. Such a structure has never been described in other rhizocephalans, and its function is uncertain. PMID:27032686

  4. Two new deep-sea stalked barnacles, Arcoscalpellum epeeum sp. nov. and Gymnoscalpellum indopacificum sp. nov., from the Coral Sea, with descriptions of the penis in Gymnoscalpellum dwarf males.

    PubMed

    Chan, Benny K K; Corbari, Laure; Moreno, Paula A Rodriguez; Jones, Diana S

    2014-09-23

    The present study describes a new species of Arcoscalpellum Hoek, 1907, and a new species of Gymnoscalpellum Newman & Ross, 1971, collected by deep-sea expeditions led by the Muséum national d'Histoire naturelle (Paris) in the Coral Sea off New Caledonia, Papua New Guinea (PNG), the Solomon Islands and Vanuatu. Arcoscalpellum epeeum sp. nov. differs from all described species of Arcoscalpellum by the presence of a long, sharp, sword-shaped carina, which extends beyond the apices of the terga by 1/3 to 1/4 of their length. The species is dioecious, with large females and dwarf males that are sac-like, lack shell plates and are housed in paired receptacles at the inner edges of the scutal plates. Arcoscalpellum epeeum sp. nov. was collected in the waters of New Caledonia and Vanuatu. Gymnoscalpellum indopacificum sp. nov. differs from the six currently described species of Gymnoscalpellum by having a very small inframedian latus and a branched upper latus. The species is dioecious, with large females and dwarf males, the latter composed of 4 shell plates and housed in paired receptacles at the inner edges of the scutal plates. The penis of the dwarf males of G. indopacificum sp. nov. is about 0.8 of the total length of the male and has five side branches extending out along its length. Gymnoscalpellum indopacificum sp. nov. is distributed in the waters of Papua New Guinea, the Solomon Islands and Vanuatu, and represents the first record of this genus in the Indo-Pacific region.

  5. Effects of tannins on digestion and detoxification activity in gray squirrels (Sciurus carolinensis).

    PubMed

    Chung-MacCoubrey, A L; Hagerman, A E; Kirkpatrick, R L

    1997-01-01

    Acorn tannins may affect food preferences and foraging strategies of squirrels through effects on acorn palatability and digestibility and squirrel physiology. Captive eastern gray squirrels (Sciurus carolinensis) were fed 100% red oak (Quercus rubra) or white oak (Quercus alba) acorn diets to determine effects on intake, digestion, and detoxification activity. Red oak acorns had higher phenol and tannin levels, which may explain the lower dry matter intakes and apparent protein digestibilities and the higher glucuronidation activities observed in squirrels. Although the white oak acorn diet had lower apparent protein digestibilities than the reference diet, it did not suppress dry matter intake for a prolonged period or stimulate glucuronidation. Negative physiological effects of a 100% red oak acorn diet suggest gray squirrels may require other foods to dilute tannin intake and provide additional nutrients. To distinguish the roles of different tannin types in the observed effects of acorn diets on squirrels, squirrels were fed rat chow containing no tannins, 4% or 8% tannic acid (hydrolyzable tannin), or 3% or 6% quebracho (condensed tannin). Apparent protein digestibilities were reduced by tannic acid and quebracho diets. Only the 8% tannic acid diet tended to increase glucuronidation. Specific effects of tannins may largely depend on tannin type, composition, and source and on other nutritional and physiological factors. PMID:9231400

  6. Evaluation of 0.4- to 2.2-μm atmospheric correction techniques using the spectral similarity scale

    NASA Astrophysics Data System (ADS)

    Granahan, James C.; Sweet, James N.

    2001-12-01

    The purpose of this research study is to evaluate the effectiveness of atmospheric correction and radiometric calibration techniques by measuring the differences of corrected data and ground truth spectra. Several atmospheric correction methods have been performed utilizing the ATREM and ACORN software packages. A variety of different settings (14 for ATREM and 5 for ACORN) have been tested and evaluated. The Spectral Similarity Scale (SSS) developed by BAE SYSTEMS is a measure of spectral similarity based on spectral magnitude and shape. The SSS-based spectral comparison process indicates that the default settings for iron rich soils are the best ATREM inputs for the Shelton, NEAVIRIS scene. The SSS comparison of the ACORN results with the spectral ground truth revealed that ACORN with the artifact type 1 was the best correction setting available for both ATREM and ACORN. For atmospheric water we find that ACORN is superior to ATREM. ATREM does correct for gain offsets that ACORN does not correct for with default settings. When used incorrectly, it is possible to severely reduce the spectral accuracy with either software package.

  7. Nutrient composition and starch characteristics of Quercus glandulifera Bl. seeds from China.

    PubMed

    Li, Songnan; Zhou, Yibin; Liu, Mei; Zhang, Yang; Cao, Shengnan

    2015-10-15

    The chemical composition and starch characteristics of acorn (Quercus glandulifera Bl.) were studied. The moisture content of acorn seeds was 7.55%. The crude fat, crude protein, dietary fiber, total ash, and nitrogen-free extract contents of acorn seed were 4.20%, 10.16%, 2.95%, 0.03%, and 82.66%, respectively, on a dry weight basis. Linoleic, oleic, and palmitic were the most predominant fatty acids. UFA:SFA and SFA:MUFA:PUFA ratios were 2.6:1 and 1.25:1.34:1, respectively. The essential amino acid content from acorn seeds was low based on FAO reference values. Acorn seeds were a good source of Fe, Zn, and Mn. The contents of vitamins A and E were 1.40 mg RE/100g and 10.78 mg/100 g, respectively. Starch extracted from acorn seeds had round, triangle, and elliptical morphology with granule size of 3.3-126.2 μm. The ratio between amylose and amylopectin contents was 25.39:72.94. Acorn starch had a typical A-type crystal pattern with 23.53% relative crystallinity. The gelatinization temperature was 66.53 °C and the transition enthalpy was 4.33 J/g.

  8. Larval settlement rate: a leading determinant of structure in an ecological community of the marine intertidal zone

    SciTech Connect

    Gaines, S.; Roughgarden, J.

    1985-06-01

    Field studies demonstrate that the population structure of the barnacle Balanus glandula differs between locations of high and low larval settlement rate. These observations, together with results from a model for the demography of an open, space-limited population, suggest that the settlement rate may be a more important determinant of rocky intertidal community structure than is presently realized. At the low-settlement location mortality of barnacles is independent of the area occupied by barnacles. At the high-settlement location mortality is cover-dependent due to increased predation by starfish on areas of high barnacle cover. In both locations the cover-independent component of mortality does not vary with age during the first 60 weeks. Generalizations that the highest species diversity in a rocky intertidal community is found at locations of intermediate disturbance, and that competition causes zonation between species of the barnacle genera Balanus and Chthamalus, seem to apply only to locations with high-settlement rates.

  9. Bored to Death: Community-Wide Effect of Predation on a Foundation Species in a Low-Disturbance Arctic Subtidal System

    PubMed Central

    Yakovis, Eugeniy; Artemieva, Anna

    2015-01-01

    The strength of top-down control by consumers is predicted to decrease with latitude, but most data confirming this assumption come from latitudes <60°, while empirical studies of predation in sub-arctic and arctic marine habitats are few. A barnacle Balanus crenatus is a native foundation species in the shallow subtidal of the White Sea (65° N), hosting a diverse (250+ species) assemblage of macrobenthic organisms. On mixed sediments live barnacles share primary substrates (shells and gravel) with numerous empty barnacle tests, 7% of which had drill holes of an unidentified origin. We manipulated the densities of (i) adult muricid whelks Boreotrophon clathratus (of previously unknown feeding habits), to check if they prey on barnacles, (ii) other predators to reveal their effect on juvenile Boreotrophon, and (iii) empty tests to assess the community-wide effect of predation on barnacles. The abundance of drilled empty tests in the field correlated with that of Boreotrophon. A year-long caging experiment clearly confirmed predation, showing the highest barnacle mortality and proportion of drilled tests in whelk enclosures, and the lowest — in predator exclosure treatments. Boreotrophon preferred the barnacles attached to conspecifics to those from primary substrates. Because of its scarcity Boreotrophon had a minor direct effect on barnacle abundance in the field. Yet, initially defaunated empty tests and live barnacles developed markedly different macrobenthic assemblages, suggesting a strong indirect effect of the predation. Juvenile Boreotrophon were 5-6 times less abundant in open and partial cages than in exclosures and enclosures, which indicates that the recruitment and, consequently, the abundance of Boreotrophon and its predation on Balanus are top-down controlled by apex predators. In contrast, in tropical and temperate intertidal the predation on barnacles is stronger and primarily limited by environmental stress and prey availability. PMID:26186648

  10. Bored to Death: Community-Wide Effect of Predation on a Foundation Species in a Low-Disturbance Arctic Subtidal System.

    PubMed

    Yakovis, Eugeniy; Artemieva, Anna

    2015-01-01

    The strength of top-down control by consumers is predicted to decrease with latitude, but most data confirming this assumption come from latitudes <60°, while empirical studies of predation in sub-arctic and arctic marine habitats are few. A barnacle Balanus crenatus is a native foundation species in the shallow subtidal of the White Sea (65° N), hosting a diverse (250+ species) assemblage of macrobenthic organisms. On mixed sediments live barnacles share primary substrates (shells and gravel) with numerous empty barnacle tests, 7% of which had drill holes of an unidentified origin. We manipulated the densities of (i) adult muricid whelks Boreotrophon clathratus (of previously unknown feeding habits), to check if they prey on barnacles, (ii) other predators to reveal their effect on juvenile Boreotrophon, and (iii) empty tests to assess the community-wide effect of predation on barnacles. The abundance of drilled empty tests in the field correlated with that of Boreotrophon. A year-long caging experiment clearly confirmed predation, showing the highest barnacle mortality and proportion of drilled tests in whelk enclosures, and the lowest--in predator exclosure treatments. Boreotrophon preferred the barnacles attached to conspecifics to those from primary substrates. Because of its scarcity Boreotrophon had a minor direct effect on barnacle abundance in the field. Yet, initially defaunated empty tests and live barnacles developed markedly different macrobenthic assemblages, suggesting a strong indirect effect of the predation. Juvenile Boreotrophon were 5-6 times less abundant in open and partial cages than in exclosures and enclosures, which indicates that the recruitment and, consequently, the abundance of Boreotrophon and its predation on Balanus are top-down controlled by apex predators. In contrast, in tropical and temperate intertidal the predation on barnacles is stronger and primarily limited by environmental stress and prey availability.

  11. Bored to Death: Community-Wide Effect of Predation on a Foundation Species in a Low-Disturbance Arctic Subtidal System.

    PubMed

    Yakovis, Eugeniy; Artemieva, Anna

    2015-01-01

    The strength of top-down control by consumers is predicted to decrease with latitude, but most data confirming this assumption come from latitudes <60°, while empirical studies of predation in sub-arctic and arctic marine habitats are few. A barnacle Balanus crenatus is a native foundation species in the shallow subtidal of the White Sea (65° N), hosting a diverse (250+ species) assemblage of macrobenthic organisms. On mixed sediments live barnacles share primary substrates (shells and gravel) with numerous empty barnacle tests, 7% of which had drill holes of an unidentified origin. We manipulated the densities of (i) adult muricid whelks Boreotrophon clathratus (of previously unknown feeding habits), to check if they prey on barnacles, (ii) other predators to reveal their effect on juvenile Boreotrophon, and (iii) empty tests to assess the community-wide effect of predation on barnacles. The abundance of drilled empty tests in the field correlated with that of Boreotrophon. A year-long caging experiment clearly confirmed predation, showing the highest barnacle mortality and proportion of drilled tests in whelk enclosures, and the lowest--in predator exclosure treatments. Boreotrophon preferred the barnacles attached to conspecifics to those from primary substrates. Because of its scarcity Boreotrophon had a minor direct effect on barnacle abundance in the field. Yet, initially defaunated empty tests and live barnacles developed markedly different macrobenthic assemblages, suggesting a strong indirect effect of the predation. Juvenile Boreotrophon were 5-6 times less abundant in open and partial cages than in exclosures and enclosures, which indicates that the recruitment and, consequently, the abundance of Boreotrophon and its predation on Balanus are top-down controlled by apex predators. In contrast, in tropical and temperate intertidal the predation on barnacles is stronger and primarily limited by environmental stress and prey availability. PMID:26186648

  12. Pioneer Profile.

    ERIC Educational Resources Information Center

    Butcher, Channa Beth

    1987-01-01

    Profiles Herbert A. Sweet, founder and director of Acorn Farms Day Camp (Indiana) for 44 years. Includes reminiscences about the camp's program, staffing, food, World War II, affiliation with the American Camping Association, and camps/directors of today. (NEC)

  13. Foraging Experiences with Children

    ERIC Educational Resources Information Center

    Russell, Helen Ross

    1976-01-01

    Provided are foraging experiences and wild foods information for utilization in the urban school curriculum. Food uses are detailed for roses, dandelions, wild onions, acorns, cattails, violets and mints. (BT)

  14. When you have diarrhea

    MedlinePlus

    ... or syrup. You should eat vegetables, including carrots, green beans, mushrooms, beets, asparagus tips, acorn squash, and ... as broccoli, peppers, beans, peas, berries, prunes, chickpeas, green leafy vegetables, and corn. Avoid caffeine, alcohol, and ...

  15. 77 FR 281 - Green Mountain Power Corporation; Notice of Application Accepted for Filing, Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-04

    ... Federal Energy Regulatory Commission Green Mountain Power Corporation; Notice of Application Accepted for...: Green Mountain Power Corporation. e. Name of Projects: Waterbury Hydroelectric Project. f. Location.... h. Applicant Contact: Mr. Jason Lisai, Green Mountain Power Corporation, 163 Acorn Lane,...

  16. Pollen-limited reproduction in blue oak: Implications for wind pollination in fragmented populations

    USGS Publications Warehouse

    Knapp, E.E.; Goedde, M.A.; Rice, K.J.

    2001-01-01

    Human activities are fragmenting forests and woodlands worldwide, but the impact of reduced tree population densities on pollen transfer in wind-pollinated trees is poorly understood. In a 4-year study, we evaluated relationships among stand density, pollen availability, and seed production in a thinned and fragmented population of blue oak (Quercus douglasii). Geographic coordinates were established and flowering interval determined for 100 contiguous trees. The number of neighboring trees within 60 m that released pollen during each tree's flowering period was calculated and relationships with acorn production explored using multiple regression. We evaluated the effects of female flower production, average temperature, and relative humidity during the pollination period, and number of pollen-producing neighbors on individual trees' acorn production. All factors except temperature were significant in at least one of the years of our study, but the combination of factors influencing acorn production varied among years. In 1996, a year of large acorn crop size, acorn production was significantly positively associated with number of neighboring pollen producers and density of female flowers. In 1997, 1998, and 1999, many trees produced few or no acorns, and significant associations between number of pollen-producing neighbors and acorn production were only apparent among moderately to highly reproductive trees. Acorn production by these reproductive trees in 1997 was significantly positively associated with number of neighboring pollen producers and significantly negatively associated with average relative humidity during the pollination period. In 1998, no analysis was possible, because too few trees produced a moderate to large acorn crop. Only density of female flowers was significantly associated with acorn production of moderately to highly reproductive trees in 1999. The effect of spatial scale was also investigated by conducting analyses with pollen producers

  17. On the replacement of the red squirrel in Britain: a phytotoxic explanation.

    PubMed

    Kenward, R E; Holm, J L

    1993-03-22

    Diffusion modelling has shown that conservative demographic traits combined with feeding competition could explain red squirrel replacement by grey squirrels. We used field data from seven separate red and grey squirrel populations, in oak-hazel woods and Scots pines, to reject the hypothesis that red squirrel density and breeding is intrinsically poorer than that of grey squirrels. In oak-hazel woods, grey squirrel foraging, density and productivity were related to oak and acorn abundance. In contrast, red squirrels foraged where hazels were abundant; their relatively low density and breeding success were related to the abundance of hazel nuts. Red squirrels failed to exploit good acorn crops, although acorns were more abundant than hazels, but in Scots pines had densities and breeding success as high as grey squirrels in deciduous woods. Captive grey squirrels thrived on a diet of acorns, but red squirrels had a comparative digestive efficiency of only 59%, apparently because they were much less able than grey squirrels to neutralize acorn polyphenols. A model with simple competition for the autumn hazel crop, which was eaten by grey squirrels before the acorn crop, shows that red squirrels are unlikely to persist with grey squirrels in woods with more than 14% oak canopy. With oaks in most British deciduous woods giving grey squirrels a food refuge which red squirrels fail to exploit, replacement of red squirrels can be explained by feeding competition alone, exacerbated by the post-war decline in coppiced hazel. PMID:8097326

  18. Trying to fit in: are patterns of orientation of a keystone grazer set by behavioural responses to ecosystem engineers or wave action?

    PubMed

    Fraser, Clarissa M L; Coleman, Ross A; Seebacher, Frank

    2014-01-01

    The distribution of animals varies at different temporal and spatial scales. At the smallest scale, distribution may be orientated in regard to particular environmental variables or habitat features. For animals on the rocky intertidal, the processes which set and maintain patterns of distribution and abundance in wave-exposed areas are well studied, with explanatory models focused on wave action and, more recently, the role of biogenic habitats. In contrast, patterns of orientation by intertidal animals have received less attention, although having ecological and fitness consequences. Here, we report tests of competing models to explain the observation that limpets on steeply sloped surfaces orientate downwards. A greater proportion of downwards-facing limpets was found in sheltered sites and areas without barnacles and this pattern was consistent across many shores and sampling occasions. Additionally, the frequency at which limpets were dislodged after a storm was independent of orientation. To test whether orientation is a behavioural response to habitat-forming barnacles, barnacles were removed and/or killed from patches of substrata and the change in proportion of downwards-facing limpets measured. The proportion increased with barnacle removal and this behaviour was a response to the structure of the barnacles, not a biotic effect associated with the living organism. Our study suggests that biogenic habitat not wave action sets patterns of limpet orientation and barnacle shells, regardless of whether the barnacle is alive or not, limit the ability of limpets to adopt a downward orientation.

  19. Development of oak plantations established for wildlife

    USGS Publications Warehouse

    Twedt, D.J.; Wilson, R.R.

    2002-01-01

    Extensive areas that are currently in agricultural production within the Mississippi Alluvial Valley are being restored to bottomland hardwood forests. Oaks (Quercus sp.), sown as seeds (acorns) or planted as seedlings, are the predominant trees established on most afforested sites. To compare stand development and natural invasion on sites afforested by planting seedlings or by sowing acorns, we sampled woody vegetation on ten 14- to 18-year-old oak plantations established to provide wildlife habitat. Stem densities of about 900 oaks/ha were comparable between stands established by sowing 4000 acorns/ha and stands established by planting 900 seedlings/ha. Densities of oaks in stands established from seedlings increased 38% from densities detected when these stands were 4- to 8-year-old. Densities of oaks established from field-sown acorns increased >100% during this same 10-year span. Oaks that were planted as seedlings were larger than those established from acorns, but trees resulting from either afforestation method were larger than trees naturally colonizing these sites. Natural invasion of woody species varied greatly among afforested sites, but was greater and more diverse on sites sown with acorns. Afforested stands were dominated by planted species, whereas naturally invading species were rare among dominant canopy trees. When afforestation objectives are primarily to provide wildlife habitat, we recommend, sowing acorns rather than planting seedlings. Additionally, planting fewer seeds or seedlings, diversifying the species planted, and leaving non-planted gaps will increase diversity of woody species and promote a more complex forest structure that enhances the suitability of afforested sites for wildlife.

  20. Differential recolonization of Atlantic intertidal habitats after disturbance reveals potential bottom-up community regulation

    PubMed Central

    Petzold, Willy; Scrosati, Ricardo A.

    2014-01-01

    In the spring of 2014, abundant sea ice that drifted out of the Gulf of St. Lawrence caused extensive disturbance in rocky intertidal habitats on the northern Atlantic coast of mainland Nova Scotia, Canada. To monitor recovery of intertidal communities, we surveyed two wave-exposed locations in the early summer of 2014. Barnacle recruitment and the abundance of predatory dogwhelks were low at one location (Tor Bay Provincial Park) but more than 20 times higher at the other location (Whitehead). Satellite data indicated that the abundance of coastal phytoplankton (the main food source for barnacle larvae) was consistently higher at Whitehead just before the barnacle recruitment season, when barnacle larvae were in the water column. These observations suggest bottom-up forcing of intertidal communities. The underlying mechanisms and their intensity along the NW Atlantic coast could be investigated through studies done at local and regional scales. PMID:26213609

  1. Removal of ice and marine growth from ship surfaces: A concept

    NASA Technical Reports Server (NTRS)

    Bauman, A. J.

    1975-01-01

    Proposed surface is structured from sections of low-melting-point alloy. Sections are separated by network of passages for compressed air. Ice or barnacles are removed by passing electrical current through alloy and bursts of compressed air through passages.

  2. Differential recolonization of Atlantic intertidal habitats after disturbance reveals potential bottom-up community regulation.

    PubMed

    Petzold, Willy; Scrosati, Ricardo A

    2014-01-01

    In the spring of 2014, abundant sea ice that drifted out of the Gulf of St. Lawrence caused extensive disturbance in rocky intertidal habitats on the northern Atlantic coast of mainland Nova Scotia, Canada. To monitor recovery of intertidal communities, we surveyed two wave-exposed locations in the early summer of 2014. Barnacle recruitment and the abundance of predatory dogwhelks were low at one location (Tor Bay Provincial Park) but more than 20 times higher at the other location (Whitehead). Satellite data indicated that the abundance of coastal phytoplankton (the main food source for barnacle larvae) was consistently higher at Whitehead just before the barnacle recruitment season, when barnacle larvae were in the water column. These observations suggest bottom-up forcing of intertidal communities. The underlying mechanisms and their intensity along the NW Atlantic coast could be investigated through studies done at local and regional scales.

  3. A novel channel for vacuum decay

    NASA Astrophysics Data System (ADS)

    Czech, Bartłomiej

    2012-07-01

    I show that cosmological bubble walls in the thin wall approximation are unstable to the creation of "barnacles" - loci of different wall tension adjacent to regions filled with a third vacuum. Barnacle formation appears to have the same observational consequences as the extensively studied bubble collision scenario, but occurs exponentially more often. The process is described by a saddle point of the thin wall action with two negative modes.

  4. Probathylepadidae, a new family of Scalpelliformes (Thoracica: Cirripedia: Crustacea), for Probathylepas faxian gen. nov., sp. nov., from a hydrothermal vent in the Okinawa Trough.

    PubMed

    Ren, Xian-Qiu; Sha, Zhong-Li

    2015-10-21

    A new pedunculate barnacle, Probathylepas faxian gen. and sp. nov., is described from a hydrothermal vent in the Okinawa Trough. A new scalpelliform family, Probathylepadidae, is also proposed for the new genus and species. Probathylepadidae differs from all other five families of the order Scalpelliformes by the capitulum bearing eight primal plates and two whorls of imbricating supplementary plates, and the peduncle being without scales. The relationships between the species of the new family and sessile barnacles are also discussed.

  5. Probathylepadidae, a new family of Scalpelliformes (Thoracica: Cirripedia: Crustacea), for Probathylepas faxian gen. nov., sp. nov., from a hydrothermal vent in the Okinawa Trough.

    PubMed

    Ren, Xian-Qiu; Sha, Zhong-Li

    2015-01-01

    A new pedunculate barnacle, Probathylepas faxian gen. and sp. nov., is described from a hydrothermal vent in the Okinawa Trough. A new scalpelliform family, Probathylepadidae, is also proposed for the new genus and species. Probathylepadidae differs from all other five families of the order Scalpelliformes by the capitulum bearing eight primal plates and two whorls of imbricating supplementary plates, and the peduncle being without scales. The relationships between the species of the new family and sessile barnacles are also discussed. PMID:26624398

  6. Nutritional value of winter foods for whooping cranes

    USGS Publications Warehouse

    Nelson, J.T.; Slack, R.D.; Gee, G.F.

    1996-01-01

    We measured metabolizable energy and digestibility of Whooping Crane (Grus americana) winter foods (blue crab [Callinectes sapidus]), common Rangia clam (Rangia cuneata), wolfberry fruit (Lycium carolinianurn [wolfberry]), and live oak acorn (Ouercus virginiana [acorn])] with feeding trials to captive-reared Whooping Cranes. Apparent metabolizable energy coefficients (expressed as %) were for crab (34.1), Rangia clam (75.0), wolfberry (44.8), and acorn (43.2). Digestion coefficients for protein were lower for plant foods (48.9 and 53.4) than for animal foods (69.4 and 75.2). Digestion coefficients for total lipid differed among foods: highest and lowest lipid digestibility was for acorn (87.2) and wolfberry (60.0), respectively. We also determined total energy and percent protein and lipid of the four foods and stout razor clam (Tagelus plebeius); gross energy was 2-5x higher for acorn and wolfberry on a dry-weight basis than for blue crab and stout razor clam. Crude protein was 2-3x higher for blue crab than for wolfberry and stout razor clam. Wolfberry ranked the highest of five foods for metabolic energy and total lipid nutrient availability per kg of food ingested, and blue crab ranked highest for crude protein availability.

  7. [Utilizable value of wild economic plant resource--acron kernel].

    PubMed

    He, R; Wang, K; Wang, Y; Xiong, T

    2000-04-01

    Peking whites breeding hens were selected. Using true metabolizable energy method (TME) to evaluate the available nutritive value of acorn kernel, while maize and rice were used as control. The results showed that the contents of gross energy (GE), apparent metabolizable energy (AME), true metabolizable energy (TME) and crude protein (CP) in the acorn kernel were 16.53 mg/kg-1, 11.13 mg.kg-1, 11.66 mg.kg-1 and 10.63%, respectively. The apparent availability and true availability of crude protein were 45.55% and 49.83%. The gross content of 17 amino acids, essential amino acids and semiessential amino acids were 9.23% and 4.84%. The true availability of amino acid and the content of true available amino acid were 60.85% and 6.09%. The contents of tannin and hydrocyanic acid were 4.55% and 0.98% in acorn kernel. The available nutritive value of acorn kernel is similar to maize or slightly lower, but slightly higher than that of rice. Acorn kernel is a wild economic plant resource to exploit and utilize but it contains higher tannin and hydrocyanic acid. PMID:11767593

  8. Masting in oaks: Disentangling the effect of flowering phenology, airborne pollen load and drought

    NASA Astrophysics Data System (ADS)

    Fernández-Martínez, Marcos; Belmonte, Jordina; Maria Espelta, Josep

    2012-08-01

    Quercus species exhibit an extreme inter-annual variability in seed production often synchronized over large geographical areas (masting). Since this reproductive behavior is mostly observed in anemophilous plants, pollination efficiency is suggested as one hypothesis to explain it, although resource-based hypotheses are also suggested as alternatives. We analyzed the effect of flowering phenology, airborne pollen presence and meteorological conditions in the pattern of acorn production in mixed evergreen-deciduous oak forests (Quercus ilex and Quercus pubescens) in NE Spain for twelve years (1998-2009). In both oaks, higher temperatures advanced the onset of flowering and increased the amount of airborne pollen. Nevertheless, inter-annual differences in pollen production did not influence acorn crop size. Acorn production was enhanced by a delay in flowering onset in Q. ilex but not in Q. pubescens. This suggests that in perennial oaks a larger number of photosynthates produced before flowering could benefit reproduction while the lack of effects on deciduous oaks could be because these species flush new leaves and flowers at the same time. Notwithstanding this effect, spring water deficit was the most relevant factor in explaining inter-annual variability in acorn production in both species. Considering that future climate scenarios predict progressive warmer and dryer spring seasons in the Mediterranean Basin, this might result in earlier onsets of flowering and higher water deficits that would constrain acorn production.

  9. Of trees, geese and cirripedes: man's quest for understanding.

    PubMed

    Buckeridge, John

    2011-03-01

    At least zoologists know that barnacles are arthropods rather than mollusks. However, this knowledge is surprisingly new, for it was as recent as 1830 before J. Vaughan Thompson showed, through a careful study of barnacle larvae, that they were crustaceans. In the 1850s, Charles Darwin unraveled much of the taxonomy of barnacles, and, significantly, his observations and classification of them follow the structure that was to be published later as his evolutionary theory. Irrespective of these works, knowledge of the systematic placement of barnacles remains surprisingly poor in the wider population today, with most non-biologists viewing barnacles as shallow-water fouling organisms related to oysters and limpets. The present paper reviews the way humans have perceived barnacles for at least a millennium; it evaluates why they were thought to have grown from trees and to have been part of the life cycle of birds; it concludes by contemplating the manner in which we perceive our environment and by doing so try to make sense of our world. PMID:21392358

  10. Of trees, geese and cirripedes: man's quest for understanding.

    PubMed

    Buckeridge, John

    2011-03-01

    At least zoologists know that barnacles are arthropods rather than mollusks. However, this knowledge is surprisingly new, for it was as recent as 1830 before J. Vaughan Thompson showed, through a careful study of barnacle larvae, that they were crustaceans. In the 1850s, Charles Darwin unraveled much of the taxonomy of barnacles, and, significantly, his observations and classification of them follow the structure that was to be published later as his evolutionary theory. Irrespective of these works, knowledge of the systematic placement of barnacles remains surprisingly poor in the wider population today, with most non-biologists viewing barnacles as shallow-water fouling organisms related to oysters and limpets. The present paper reviews the way humans have perceived barnacles for at least a millennium; it evaluates why they were thought to have grown from trees and to have been part of the life cycle of birds; it concludes by contemplating the manner in which we perceive our environment and by doing so try to make sense of our world.

  11. Correlated Biogeographic Variation of Magnesium across Trophic Levels in a Terrestrial Food Chain

    PubMed Central

    Sun, Xiao; Kay, Adam D.; Kang, Hongzhang; Small, Gaston E.; Liu, Guofang; Zhou, Xuan; Yin, Shan; Liu, Chunjiang

    2013-01-01

    Using samples from eastern China (c. 25 – 41° N and 99 – 123° E) and from a common garden experiment, we investigate how Mg concentration varies with climate across multiple trophic levels. In soils, plant tissue (Oriental oak leaves and acorns), and a specialist acorn predator (the weevil Curculio davidi), Mg concentration increased significantly with different slopes from south to north, and generally decreased with both mean annual temperature (MAT) and precipitation (MAP). In addition, soil, leaf, acorn and weevil Mg showed different strengths of association and sensitivity with climatic factors, suggesting that distinct mechanisms may drive patterns of Mg variation at different trophic levels. Our findings provide a first step toward determining whether anticipated changes in temperature and precipitation due to climate change will have important consequences for the bioavailability and distribution of Mg in food chain. PMID:24223807

  12. Correlated biogeographic variation of magnesium across trophic levels in a terrestrial food chain.

    PubMed

    Sun, Xiao; Kay, Adam D; Kang, Hongzhang; Small, Gaston E; Liu, Guofang; Zhou, Xuan; Yin, Shan; Liu, Chunjiang

    2013-01-01

    Using samples from eastern China (c. 25 - 41° N and 99 - 123° E) and from a common garden experiment, we investigate how Mg concentration varies with climate across multiple trophic levels. In soils, plant tissue (Oriental oak leaves and acorns), and a specialist acorn predator (the weevil Curculio davidi), Mg concentration increased significantly with different slopes from south to north, and generally decreased with both mean annual temperature (MAT) and precipitation (MAP). In addition, soil, leaf, acorn and weevil Mg showed different strengths of association and sensitivity with climatic factors, suggesting that distinct mechanisms may drive patterns of Mg variation at different trophic levels. Our findings provide a first step toward determining whether anticipated changes in temperature and precipitation due to climate change will have important consequences for the bioavailability and distribution of Mg in food chain. PMID:24223807

  13. Savannah River Technology Center monthly report

    SciTech Connect

    Not Available

    1994-03-01

    This document contains information about the research programs being conducted at the Savannah River Plant. Topics of discussion include: Acorn Cleaning Study, tritium, separation processes, bioremediation programs, environmental remediation, environmental sampling, waste management, statistical design, phase I array experiments, and, Monte Carlo Neutron Photon input files.

  14. Into the Woods: Nature Experience and Conceptual Change.

    ERIC Educational Resources Information Center

    Fellows, Nancy J.

    One key to effective conceptual change teaching is to discover each student's conceptions about the conditions before instruction. The teacher then provides experiences that create dissatisfaction with existing ideas and models a new conception that is intelligible, plausible, and fruitful. The purpose of the Acorn Project of the Chicago office of…

  15. The Varieties of Religious Experience: Baptized Indians at Mission San Francisco de Asis, 1776-1821

    ERIC Educational Resources Information Center

    Newell, Quincy D.

    2008-01-01

    Paseos, which are defined as trips away from the mission authorized by the Franciscan priests, were common among Indians baptized at Mission San Francisco during the period between 1700s to 1800s. Indians went on these journeys in order to harvest acorns and other wild foods, to hunt and fish, and to visit friends and family outside the mission.…

  16. 21 CFR 172.260 - Oxidized polyethylene.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Oxidized polyethylene. 172.260 Section 172.260 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD..., papaya, peas (in pods), pineapple, plantain, pumpkin, rutabaga, squash (acorn), sweetpotatoes,...

  17. Oak-black bear relationships in southeastern uplands

    USGS Publications Warehouse

    Clark, Joseph D.; Spetich, Martin A.

    2004-01-01

    Bears (Ursus americanus) primarily occur in upland habitats in the Southeast because uplands were the last to be developed for agriculture and were more likely to become publicly owned. National parks and forests created in the early to mid-1900s served as sources to supply surrounding uplands with bears. Bears could not survive in southeastern uplands without oak mast. Bear reproductive and mortality rates in the region have been shown to be directly linked with acorn production. Masting is thought to be an adaptation by oaks to satiate predators during good acorn years, thus ensuring that the remainder will germinate. Acorn predator populations, however, cannot respond numerically to increased acorn production because the masting is episodic and synchronous. Consequently, bears have developed physiological, behavioral, and ecological adaptations to cope with such food shortages. Despite such adaptations, upland hardwood forests in the Southeast are of lower quality than they once were. The loss of the American chestnut (Castanea dentata), higrading, and soil degradation have markedly decreased the carrying capacity for bears and other wildlife. Other changes such as recent forest management practices, forest fragmentation, invasion by the gypsy moth (Lymantria dispar), and oak decline threaten to further degrade the capability of southeastern uplands to support bears.

  18. Negative correlation does not imply a tradeoff between growth and reproduction in California oaks

    PubMed Central

    Knops, Johannes M. H.; Koenig, Walter D.; Carmen, William J.

    2007-01-01

    A tradeoff between growth and reproduction, often inferred from an inverse correlation between these two variables, is a fundamental paradigm of life-history evolution. Oak species provide a unique test of this relationship because different species mature acorns either in the year of pollination or in the year after pollination. This difference allows for an interspecific comparison testing whether the apparent tradeoff is causal or the result of confounding factors influencing growth and reproduction independently. Based on 13 years of data on five California oak species, we found significant negative correlations between radial growth and seed production in the three species that produce acorns the same year in which pollination occurs, but not in two species that mature acorns the year after pollination. Rainfall, which correlates positively with radial growth and correlates negatively with acorn production (based on the year of pollination), appears to be driving this pattern. We conclude that the observed negative correlations are not causal, but rather a consequence of growth and reproduction being dependent, in opposite ways, on environmental conditions. Thus, contrary to the current consensus, growth and reproduction in these species are apparently largely independent of each other. In contrast, tradeoffs between current and future reproduction appear to be much more important in the life-history evolution of these long-lived plants. We also conclude that a negative correlation does not necessarily imply a causal mechanism and should not be used as the only evidence supporting a tradeoff. PMID:17940035

  19. Nature's Palette

    ERIC Educational Resources Information Center

    McBride, Brooke B.; Brewer, Carol A.

    2010-01-01

    Flower petals, acorn hats, exoskeletons of beetles, and lichens are just a few of the objects students may find in a surprising array of vivid colors. These tiny examples from nature's palette can be discovered in a school yard, a park, or even along the edges of a paved sidewalk...it simply takes careful observation! This article describes a…

  20. The Early Years: Fostering Environmental Stewardship

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2016-01-01

    For young children, a found acorn, stone, or lichen-covered branch can be a touchstone of an experience in nature. Children, however, should also be taught to "leave no trace." As the National Park Service advocates, visitors to natural areas should "Preserve the sense of discovery for others by leaving all natural and cultural…