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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. Selective settlement of the barnacle Semibalanus balanoides (L.) facilitates its growth and reproduction on mussel beds in the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Buschbaum, Christian

    2001-07-01

    On the unstable sedimentary tidal flats of the Wadden Sea, a suitable attachment substrate for sessile organisms is generally lacking. Epibenthic mussel beds (Mytilus edulis L.) provide the only and strongly limited settlement sites available for the barnacle, Semibalanus balanoides (L.). Field investigations showed that barnacles were non-randomly distributed within a mussel bed. They preferentially occurred near the siphonal apertures of living mussels but rarely grew on dead mussels or shell fragments. Field experiments revealed that this was due to selective settlement of barnacle cyprid larvae. Growth of barnacles was significantly higher upon living mussels than on empty mussel shells. Moreover, a higher reproductive output was obtained by individuals on living mussels which produced twice as many nauplii larvae than barnacles attached to empty shells. This study shows that selective settlement of S. balanoides cyprid larvae on living mussels is adaptive with respect to individual fitness.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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)

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. ACORN: a review.

    PubMed

    Yao, J X; Dodson, E J; Wilson, K S; Woolfson, M M

    2006-08-01

    The ACORN system was originally developed as a means of ab initio solution of protein structures when atomic resolution data were available. The first step is to obtain a starting set of phases, which must be at least slightly better than random. These may be calculated from a fragment of the structure, which can be anything from a single metal atom to a complete molecular-replacement model. A number of standard procedures are available in ACORN to orientate and position such a fragment. The fragment provides initial phases that give the first of a series of maps that are iteratively refined by a dynamic density-modification (DDM) process. Another FFT-based procedure is Sayre-equation refinement (SER), which modifies phases better to satisfy the Sayre equation. With good-quality atomic resolution data, the final outcome of applying DDM and SER is a map similar in appearance to that found from a refined structure, which is readily interpreted by automated procedures. Further development of ACORN now enables structures to be solved with less than atomic resolution data. A critical part of this development is the artificial extension of the data from the observed limit to 1 A resolution. These extended reflections are allocated unit normalized structure amplitudes and then treated in a similar way to observed reflections except that they are down-weighted in the calculation of maps. ACORN maps, especially at low resolution, tend to show C atoms less well, in particular C(alpha) atoms which fall within the first diffraction minimum of their three neighbours. Two new density-modification procedures (DDM1 and DDM2) and a density-enhancement procedure (ENH) have been devised to counter this problem. It is demonstrated that high-quality maps showing individual atoms can be produced with the new ACORN. ACORN has also been demonstrated to be very effective in refining phase sets derived from physical processes such as those using anomalous scattering or isomorphous

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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. PMID:24409892

  4. 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.

  5. 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.

  6. Acorn poisoning in cattle and sheep.

    PubMed

    2014-03-01

    • Multiple cases of acorn poisoning in cattle and sheep following bumper crop • Salmonella Dublin infection causes abortions in cattle • Respiratory disease affecting different age groups of pigs on a nursery finisher unit • Porcine dermatitis and nephropathy syndrome cases diagnosed • A further case of suspect Marek's disease in turkeys. These are among matters discussed in the Animal Health and Veterinary Laboratories Agency's (AHVLA's) disease surveillance report for November 2013 to January 2014. PMID:24578432

  7. Metamorphosis in a Silurian barnacle

    PubMed Central

    Briggs, Derek E.G; Sutton, Mark D; Siveter, David J; Siveter, Derek J

    2005-01-01

    Exceptionally preserved fossils from the Wenlock Series (Silurian) of Herefordshire, UK, provide unique evidence of metamorphosis from free-swimming cyprid larva to attached juvenile in a Palaeozoic barnacle. The larva had large brush-like anterior limbs. The juvenile shows the head transformed into a stalk and the development of the primordial condition of five mineralized plates within the carapace. The discovery of a cyprid larva indicates that crown group cirripedes had evolved by the Silurian. PMID:16243697

  8. The model barnacle Balanus balanus Linnaeus, 1758 (Crustacea: Maxillopoda: Sessilia) mitochondrial genome and gene rearrangements within the family Balanidae.

    PubMed

    Shen, Xin; Tsoi, Kwok-Ho; Cheang, Chi-Chiu

    2016-05-01

    Balanus balanus Linnaeus, 1758, the model organism in the order Sessilia (Crustacea: Maxillopoda) is a cold water acorn barnacle in the family Balanidae distributing over the entire northern hemisphere. We present complete mitochondrial genome of this barnacle and analyze mitochondrial genomic characters of the family Balanidae. The length of mitochondrial genome is 15,955 bp, which is larger than those of the other barnacles in the same family. An inversion of a six-gene block (trnPro- nad4L- nad4- trnHis- nad5- trnPhe) is found between B. balanus and two Megabalanus (M. ajax and M. volcano). Three types of mitochondrial gene arrangements revealed in Balanidae have indicated the non-conserved gene orders even at intrafamilial level. Compared to pancrustacean ground pattern, large-scale gene rearrangements are found in B. balanus. Translocations of at least six tRNAs (trnAla, trnGlu/trnSer(AGY), trnPro/trnThr, trnLys, trnGln and trnCys) are identified and translocation and inversion occurred simultaneously in one tRNAs (trnTyr). PMID:25405910

  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. How to manage oak forests for acorn production

    SciTech Connect

    Johnson, P.S.

    1994-03-01

    Oak forests are life support systems for the many animals that live in them. Acorns, a staple product of oak forests, are eaten by many species of birds and mammals including deer, bear, squirrels, mice, rabbits, foxes, raccoons, grackles, turkey, grouse, quail, blue jays, woodpeckers, and water-fowl. The population and health and wildlife often rise, and fall with the cyclic production of acorns. Acorns' importance to wildlife is related to several factors including their widespread occurrence, palatability, nutritiousness, and availability during the critical fall and winter period.

  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. 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.

  15. 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

  16. 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…

  17. 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…

  18. 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)

  19. 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

  20. 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.

  1. 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.

  2. Acorns containing deeper plumule survive better: how white oaks counter embryo excision by rodents

    PubMed Central

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

    2014-01-01

    Several squirrel species excise the embryo of acorns of most white oak species to arrest germination for long-term storage. However, it is not clear how these acorns counter embryo excision and survive in the arms race of coevolution. In this study, we simulated the embryo excision behavior of squirrels by removing 4 mm of cotyledon from the apical end of white oak acorns differing in embryo depths to investigate the effects of embryo excision on acorn germination and seedling performance of white oak species. The embryo depth in the cotyledons was significantly different among white oak acorns, with Quercus mongolica containing the embryo most deeply in the acorns. We found that artificial embryo excision significantly decreased acorn germination rates of Quercus variabilis, Quercus acutissima, Quercus aliena, Quercus aliena var. acutiserrata, Quercus serrata. var. brevipetiolata but not Q. mongolica. Artificial embryo excision exerted significant negative impacts on seedling performance of all oak species except Quercus aliena. Our study demonstrates the role of embryo depth of acorns in countering embryo excision by squirrels and may explain the fact that squirrels do not perform embryo excision in acorns of Q. mongolica with deeper embryos. This apparent adaptation of acorns sheds light on the coevolutionary dynamics between oaks and their seed predators. PMID:24455161

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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).

  10. 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

  11. The data acquisition system for the aCORN experiment

    NASA Astrophysics Data System (ADS)

    Dewey, Maynard; aCORN Collaboration

    2015-10-01

    The aCORN experiment measures the angular correlation between the electron and neutrino emitted in free neutron beta decay, via an electron-proton momentum correlation asymmetry. Doing so requires detecting neutron beta decay protons and electrons in coincidence. Protons are detected with a surface barrier detector while electrons are detected with a large scintillator whose light output is parceled into 19 photomultiplier tubes. Additionally there are eight scintillators that detect backscattered electrons so that these events may be removed from the data stream. This talk will discuss the novel data acquisition system (both hardware and software) that has been developed to handle the high throughput rates observed. NIST, DOE and NSF.

  12. 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

  13. Nanoscale structures and mechanics of barnacle cement.

    PubMed

    Sullan, Ruby May A; Gunari, Nikhil; Tanur, Adrienne E; Chan, Yuri; Dickinson, Gary H; Orihuela, Beatriz; Rittschof, Dan; Walker, Gilbert C

    2009-01-01

    Polymerized barnacle glue was studied by atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and chemical staining. Nanoscale structures exhibiting rod-shaped, globular and irregularly-shaped morphologies were observed in the bulk cement of the barnacle Amphibalanus amphitrite (=Balanus amphitrite) by AFM. SEM coupled with energy dispersive X-ray (EDX) provided chemical composition information, making evident the organic nature of the rod-shaped nanoscale structures. FTIR spectroscopy gave signatures of beta-sheet and random coil conformations. The mechanical properties of these nanoscale structures were also probed using force spectroscopy and indentation with AFM. Indentation data yielded higher elastic moduli for the rod-shaped structures when compared with the other structures in the bulk cement. Single molecule AFM force-extension curves on the matrix of the bulk cement often exhibited a periodic sawtooth-like profile, observed in both the extend and retract portions of the force curve. Rod-shaped structures stained with amyloid protein-selective dyes (Congo red and thioflavin-T) revealed that about 5% of the bulk cement were amyloids. A dominant 100 kDa cement protein was found to be mechanically agile, using repeating hydrophobic structures that apparently associate within the same protein or with neighbors, creating toughness on the 1-100 nm length scale. PMID:19180351

  14. 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

  15. 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

  16. 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

  17. Masting mediated by summer drought reduces acorn predation in Mediterranean oak forests.

    PubMed

    Espelta, Josep Maria; Cortés, Pilar; Molowny-Horas, Roberto; Sánchez-Humanes, Belén; Retana, Javier

    2008-03-01

    Temporally variable production of seed crops by perennial plants (masting) has been hypothesized to be a valuable mechanism in the reduction of seed predation by satiating and starving seed consumers. To achieve these benefits, coexisting species subjected to the same predator would benefit from a similar pattern of seeding fluctuation over time that could lead to a reduction in predation at the within-species level. We tested for the existence of an environmental factor enforcing synchrony in acorn production in two sympatric Mediterranean oaks (Quercus ilex and Q. humilis) and the consequences on within-species and between-species acorn predation, by monitoring 15 mixed forests (450 trees) over seven years. Acorn production in Q. ilex and Q. humilis was highly variable among years, with high population variability (CVp) values. The two species exhibited a very different pattern across years in their initial acorn crop size (sum of aborted, depredated, and sound acorns). Nevertheless, interannual differences in summer water stress modified the likelihood of abortion during acorn ripening and enforced within- and, particularly, between-species synchrony and population variability in acorn production. The increase in CVp from initial to mature acorn crop (after summer) accounted for 33% in Q. ilex, 59% in Q. humilis, and 60% in the two species together. Mean yearly acorn pre-dispersal predation by invertebrates was considerably higher in Q. humilis than in Q. ilex. Satiation and starvation of predators was recorded for the two oaks, and this effect was increased by the year-to-year variability in the size of the acorn crop of the two species combined. Moreover, at a longer time scale (over seven years), we observed a significant reduction in the mean proportion of acorns depredated for each oak and the variability in both species' acorn production combined. Therefore, our results demonstrate that similar patterns of seeding fluctuation over time in coexisting

  18. 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

  19. 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

  20. 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.

  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. 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).

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. The overwintering biology of the acorn weevil, Curculio glandium in southwestern Ontario.

    PubMed

    Udaka, Hiroko; Sinclair, Brent J

    2014-08-01

    The acorn weevil, Curculio glandium, is a widespread predator of acorns in eastern North America that overwinters in the soil as a larva. It is possible that low temperatures limit its northern geographic range, so we determined the cold tolerance strategy, seasonal variation in cold tolerance, and explored the physiological plasticity of overwintering larvae. Weevil larvae were collected from acorns of red and bur oak from Pelee Island, southwestern Ontario in fall 2010 and 2011. C. glandium larvae are freeze avoidant and larvae collected from bur oak acorns had lower supercooling points (SCPs: -7.6±0.36°C, LT50: -7.2°C) than those collected from red oak acorns (SCPs: -6.1±0.40°C, LT50: -6.1°C). In the winter of 2010-2011, SCPs and water content decreased, however these changes did not occur in 2011-2012, when winter soil temperatures fluctuated greatly in the absence of the buffering effect of snow. To examine whether larvae utilize cryoprotective dehydration, larvae from red oak acorns were exposed to -5°C in the presence of ice for seven days. These conditions decreased the SCP without affecting water content, suggesting that SCP and water content are not directly coupled. Finally, long-term acclimation at 0°C for six weeks slightly increased cold tolerance but also did not affect water content. Thus, although larval diet affects cold tolerance, there is limited plasticity after other treatments. The soil temperatures we observed were not close to lethal limits, although we speculate that soil temperatures in northerly habitats, or in years of reduced snow cover, has the potential to cause mortality in the field. PMID:25086980

  9. 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

  10. 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

  11. Acorn Consumption Improves the Immune Response of the Dung Beetle Thorectes lusitanicus

    PubMed Central

    Verdú, José R.; Casas, José L.; Cortez, Vieyle; Gallego, Belén; Lobo, Jorge M.

    2013-01-01

    Thorectes lusitanicus, a typically coprophagous species is also actively attracted to oak acorns, consuming, burying them, and conferring ecophysiological and reproductive advantages to both the beetle and the tree. In this study, we explored the possible relation between diet shift and the health status of T. lusitanicus using a generalist entomopathogenic fungus (Metarhizium anisopliae) as a natural pathogen. To measure the health condition and immune response of beetles, we analysed the protein content in the haemolymph, prophenoloxidase (proPO) content, phenoloxidase (PO) activity and mortality of beetles with diets based on either acorns or cow dung. Protein content, proPO levels and PO levels in the haemolymph of T. lusitanicus were found to be dependent on the type of diet. Furthermore, the beetles fed with acorns developed a more effective proPO-PO system than the beetles fed with cow dung. Furthermore, a significant decrease in mortality was observed when infected individuals were submitted to an acorn-based diet. In addition to enhancing an understanding of the relevance of dietary change to the evolutionary biology of dung beetles, these results provide a more general understanding of the ecophysiological implications of differential dietary selection in the context of fitness. PMID:23874934

  12. 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…

  13. 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…

  14. 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

  15. 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.

  16. 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.

  17. aCORN: A Measurement of the Beta-Antineutrino Correlation in Neutron Decay

    NASA Astrophysics Data System (ADS)

    Jones, Gordon

    2015-10-01

    The aCORN experiment has measured the electron-antineutrino angular correlation coefficient (the ``a'' coefficient) in free neutron decay. aCORN uses the dependence of the recoil proton momentum on the opening angle between the electron and the neutrino to form an asymmetry. The apparatus accepts decays where the antineutrino is restricted to two momentum groups having equal solid angle. In this geometry, proton time of flight distinguishes between decays with a large or small opening angle between the electron and the antineutrino. The correlation coefficient is determined from the asymmetry between two branches of the time of flight spectrum. The asymmetry was measured on the NG-6 neutron beam at the NIST Center for Neutron Research (NCNR), and a subsequent measurement has been started on the higher flux NG-C beam. An overview of the method and systematic effects will be presented, including results from the NG-6 dataset. National Science Foundation.

  18. Different responses to shade of evergreen and deciduous oak seedlings and the effect of acorn size

    NASA Astrophysics Data System (ADS)

    Ke, Guo; Werger, Marinus J. A.

    1999-11-01

    An evergreen oak species, Cyclobalanopsis multinervis, and a deciduous oak species, Quercus aliena var. acuteserrata were grown from acorns under two light levels (full sunlight and shade at about 18 % of full sunlight, simulating the light intensities in forest clearings and gaps, respectively) for one growing season. Three hypotheses were tested: (i) the deciduous species grows faster than the evergreen species in forest gaps and clearings; (ii) the deciduous species responds more strongly in terms of growth and morphology to variation in light climate than the evergreen species; and (iii) seedling size is positively correlated to acorn size. The results showed: (i) at both light levels, the deciduous seedlings gained significantly more growth in biomass and height than the evergreen seedlings; (ii) both species produced significantly more biomass in full sunlight than in shade, without showing any significant difference in height between treatments. Increase in light intensity improved the growth of the deciduous seedlings more strongly; (iii) at a similar age, the deciduous seedlings showed a greater response in leaf morphology and biomass allocation to variation in light levels, but when compared at a similar size, biomass allocation patterns did not differ significantly between species; (iv) bigger acorns tended to produce larger seedlings, larger leaf sizes and more leaf area, between and within species. These differences demonstrate that the deciduous species is gap-dependent and has the advantage over the evergreen species in forest gaps and clearings.

  19. 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.

  20. 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. PMID:24047186

  1. 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.

  2. 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. PMID:24333559

  3. 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

  4. 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. PMID:24909326

  5. 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

  6. 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.

  7. Hydramacin-1 in Action: Scrutinizing the Barnacle Model

    PubMed Central

    Michalek, Matthias; Vincent, Bruno; Podschun, Rainer; Grötzinger, Joachim; Bechinger, Burkhard

    2013-01-01

    Hydramacin-1 (HM1) from the metazoan Hydra exerts antimicrobial activity against a wide range of bacterial strains. Notably, HM1 induces the aggregation of bacterial cells, accompanied by precipitation. To date, the proposed mechanism of peptide-lipid interaction, termed the barnacle model, has not been described on the molecular level. Here, we show by biochemical and biophysical techniques that the lipid-peptide interactions of HM1 are initiated by electrostatic and hydrophobic effects, in particular, by tryptophan and neighboring polar amino acid residues that cause an interfacial localization of the peptide between two self-contained lipid bilayers. The high binding constants of HM1 upon lipid interaction are in the range of other potent antimicrobial peptides, e.g., magainin, and can be reasonably explained by two distinct epitopes on the surface of the peptide's global structure, which both contain SWT(K/R) motifs. The residues of this motif favor localization of the peptide in the head group region of phospholipid bilayers up to a penetration depth of 4 Å and a minor participation of the lipids' hydrocarbon regions. Our results expand the knowledge about the molecular modes of action antimicrobial peptides use to tackle their target cells. Furthermore, the aggregation of living bacteria by HM1 was observed for a broad range of Gram-positive and Gram-negative bacteria. Therefore, the detailed view of peptide-lipid interactions described by the barnacle model consolidates it among the established models. PMID:23587944

  8. 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

  9. 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

  10. 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. PMID:18568668

  11. 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

  12. 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

  13. 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

  14. 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

  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. 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.

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. Barnacle Geese Achieve Significant Energetic Savings by Changing Posture

    PubMed Central

    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. PMID:23071672

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

    PubMed

    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

  5. 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

  6. Worldwide genetic differentiation in the common fouling barnacle, Amphibalanus amphitrite.

    PubMed

    Chen, Hsi-Nien; Tsang, Ling Ming; Chong, Ving Ching; Chan, Benny K K

    2014-10-01

    Amphibalanus amphitrite is a common fouling barnacle distributed globally in tropical and subtropical waters. In the present study, the genetic (mitochondrial cytochrome oxidase subunit I) and morphological differentiation in A. amphitrite from 25 localities around the world were investigated. The results revealed three clades within A. amphitrite with a genetic divergence of ~ 4% among clades, whereas there were no diagnostic morphological differences among clades. Clade 1 is widely distributed in both temperate and tropical waters, whereas Clade 3 is currently restricted to the tropical region. The deep divergence among clades suggests historical isolation within A. amphitrite; thus, the present geographical overlaps are possibly a result of the combined effects of rising sea level and human-mediated dispersals. This study highlights the genetic differentiation that exists in a common, widely distributed fouling organism with great dispersal potential; future antifouling research should take into account the choice of lineages. PMID:25343722

  7. Antifouling Activity of Synthetic Alkylpyridinium Polymers Using the Barnacle Model

    PubMed Central

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

    2014-01-01

    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

  8. 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

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. Effects of Acorn (Quercus acutissima CARR.) Supplementation on Acetylcholine and Its Related Enzyme Activities in Brain of Dementia Model Mouse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was carried out to investigate the effects of acorn (Quercus acutissima CARR.) on brain dementia in mouse. Murine dementia model was induced by scopolamin administration to abdominal cavity (30 mg/kg BW). Male ICR mouse (30 ' 2 g BW) were fed basic diet (control group), or experimental d...

  14. 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

  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. The barnacle Balanus amphitrite as a bioindicator for Cd: Development and application of a simulation model

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    The efficacy of the barnacle Balanus amphitrite as a bioindicator for Cd in the environment was investigated through simulation exercises in an ecotoxicological simulation model based on field data. The study showed in general that B. amphitrite is a good bioindicator to record mean trends of the Cd bioavailability in the environment. The model correct reflected differences between high and low patterns of Cd concentrations in the barnacle in the field, but it did not accurately reflect short-term temporal variations. A model investigation pointed out three issues that must be taken into account when using B. amphitrite as bioindicator for Cd bioavailability in the environment: (1) variations in the mean weight of the sampled population may affect the barnacle's Cd concentration determination, specially if a size effect for the metal concentration in the organism is not detected; (2) a sampling effort approximately 5 times greater than that of usually applied in such studies would be required to detect an environmental change that caused a realistic increase in the main source of Cd to the barnacle; and (3) barnacle tissue better responds to long-term changes in the Cd level of its sources.

  17. 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. PMID:18252665

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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

  5. Analysis of the behaviours mediating barnacle cyprid reversible adhesion.

    PubMed

    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, inherently sticky and

  6. Properties of sodium pumps in internally perfused barnacle muscle fibers.

    PubMed

    Nelson, M T; Blaustein, M P

    1980-02-01

    To study the properties of the Na extrusion mechanism, giant muscle fibers from barnacle (Balanus nubilus) were internally perfused with solutions containing tracer 22Na. In fibers perfused with solutions containing adenosine 5'-triphosphate (ATP) and 30 mM Na, the Na efflux into 10 mM K seawater was approximately 25-30 pmol/cm2.s; 70% of this efflux was blocked by 50-100 microM ouabain, and approximately 30% was blocked by removal of external K. The ouabain-sensitive and K-dependent Na effluxes were abolished by depletion of internal ATP and were sigmoid-shaped functions of the internal Na concentration ([Na]i), with half-maxima at [Na]i approximately or equal to 20 mM. These sigmoid functions fit the Hill equation with Hill coefficients of approximately 3.5. Ouabain depolarized ATP-fueled fibers by 1.5-2 mV ([Na]i greater than or equal to 30 mM) but had very little effect on the membrane potential of ATP-depleted fibers; ATP depletion itself caused a 2-2.5-mV depolarization. When fueled fibers were treated with 3,4-diaminopyridine or Ba2+ (to reduce the K conductance and increase membrane resistance), application of ouabain produced a 4-5 mV depolarization. These results indicate that an electrogenic, ATP-dependent Na-K exchange pump is functional in internally perfused fibers; the internal perfusion technique provides a convenient method for performing transport studies that require good intracellular solute control. PMID:7373278

  7. 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. PMID:26809620

  8. 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

  9. 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

  10. 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

  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. 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

  13. Effects of ATP and vanadate on calcium efflux from barnacle muscle fibres.

    PubMed

    Nelson, M T; Blaustein, M P

    1981-01-22

    Calcium ions carry the inward current during depolarization of barnacle muscle fibres and are involved in the contraction process. Intracellular ionized calcium ([Ca2+]i) in barnacle muscle, as in other cells, is kept at a very low concentration, against a large electrochemical gradient. This large gradient is maintained by Ca2+ extrusion mechanisms. When [Ca2+]i is below the contraction threshold, Ca2+ efflux from giant barnacle muscle fibres is, largely, both ATP dependent and external Na+ (Na+0) dependent (see also refs 5,6). When [Ca2+]i is raised to the level expected during muscle contraction (2-5 muM), most of the Ca2+ efflux from perfused fibres is Na0 dependent; as in squid axons, this Na+0-dependent Ca2+ efflux is ATP independent. Orthovanadate is an inhibitor of (Na+ + K+) ATPase and the red cell Ca2+-ATpase. We report here that vanadate inhibits ATP-promoted, Na+0-dependent Ca2+ efflux from barnacle muscle fibres perfused with low [Ca2+]i (0.2-0.5 microM), but has little effect on the Na+0-dependent, ATP-independent Ca2+ efflux from fibres with a high [Ca]i (2-5 microM). Nevertheless, ATP depletion or vanadate treatment of high [Ca2+]i fibres causes an approximately 50-fold increase of Ca2+ efflux into Ca2+-containing lithium seawater. These results demonstrate that both vanadate and ATP affect Ca2+ extrusion, including the Na+0-dependent Ca2+ efflux (Na-Ca exchange), in barnacle muscle. PMID:6256662

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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

  19. 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

  20. Effect on Cessation Counseling of Documenting Smoking Status as a Routine Vital Sign: An ACORN Study

    PubMed Central

    Rothemich, Stephen F.; Woolf, Steven H.; Johnson, Robert E.; Burgett, Amy E.; Flores, Sharon K.; Marsland, David W.; Ahluwalia, Jasjit S.

    2008-01-01

    PURPOSE Guidelines encourage primary care clinicians to document smoking status when obtaining patients’ blood pressure, temperature, and pulse rate (vital signs), but whether this practice promotes cessation counseling is unclear. We examined whether the vital sign intervention influences patient-reported frequency and intensity of tobacco cessation counseling. METHODS This study was a cluster-randomized, controlled trial conducted in the Virginia Ambulatory Care Outcomes Research Network (ACORN). At intervention practices, nurses and medical assistants were instructed to assess the tobacco use status of every adult patient and record it with the traditional vital signs. Control practices did not use any systematic tobacco screening or identification system. Outcomes were the proportion of smokers reporting clinician counseling of any kind and the frequency of 2 counseling subcomponents: simple quit advice and more intensive discussion. RESULTS A total of 6,729 adult patients (1,149 smokers) at 18 primary care practices completed exit questionnaires during a 6-month comparison period. Among 561 smokers at intervention practices, 61.9% reported receiving any counseling, compared with 53.4% of the 588 smokers at control practices, for a difference of 8.6% (P = .04). The effect was largely restricted to simple advice, which was reported by 59.9% of intervention patients and 51.5% of control patients (P=.04). There was no significant increase in more extensive discussion, with 32.5% and 29.3% of patients at intervention and control practices, respectively, reporting this type of counseling (P=.18). CONCLUSIONS The vital sign intervention promotes tobacco counseling at primary care practices through a modest increase in simple advice to quit. When implemented as a stand-alone intervention, it does not appear to increase intensive counseling. PMID:18195316

  1. 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

  2. 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

  3. Complete mitochondrial genome of the Antarctic barnacle Lepas australis (Crustacea, Maxillopoda, Cirripedia).

    PubMed

    Baek, Ye-Seul; Min, Gi-Sik; Kim, Sanghee; Choi, Han-Gu

    2016-05-01

    We present the complete mitochondrial genome of the Antarctic barnacle Lepas australis (Cirripedia, Thoracica, Lepadidae). The genome sequence is 15,502 bp in size. Except for CO1, 12 protein-coding genes (PCGs) start with an ATN initiation codon (ATA, ATG, ATC and ATT). Twelve PCGs were terminated with TAA or TAG stop codon, whereas ND1 possessed an incomplete termination codon (T- -). We compared the mitogenome structure of L. australis to those of other cirripeds and a typical arthropod Homarus americanus. The PCGs in the L. australis mtgenome showed a typical gene arrangement, identical to the arthropod pattern in other cirriped genomes. However, at least 8 tRNA genes were translocated and 2 tRNA genes were inverted in the coding polarity. Unique differences in L. australis mtgenome included translocation of trnS2, trnD and trnI. These results are useful for understanding the phylogenetic relationships among cirripedians, and additional mtgenome information of barnacles including the polar species would allow exploration of the thoracican relationships and mtgenome modifications in the barnacle evolution. PMID:25228375

  4. 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. PMID:25483975

  5. 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

  6. 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

  7. 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

  8. 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

  9. Chromium halides mediated production of hydroxymethylfurfural from starch-rich acorn biomass in an acidic ionic liquid.

    PubMed

    Lee, Jin-Woo; Ha, Myoung-Gyu; Yi, Young-Byung; Chung, Chung-Han

    2011-02-01

    Chromium halides were introduced for the sustainable production of hydroxymethylfurfural (HMF) from raw acorn biomass using an acidic ionic liquid. The free sugars (glucose and maltose) released by the acidic hydrolysis of the biomass were confirmed by the FT-IR absorption bands around 995-1014cm(-1) and HPLC. FESEM analysis showed that the acorn biomass contains various sizes of starch granules and their structures were severely changed by the acidic hydrolysis. An optimal concentration of HCl for the HMF yields was 0.3M. The highest HMF yield (58.7+1.3dwt%) was achieved in the reaction mixture of 40% [OMIM]Cl+10% ethyl acetate+50% 0.3M HCl extract containing a mix of CrBr(3)/CrF(3). The combined addition of two halide catalysts was more effective in the synthesis of HMF (1.2-fold higher on average) than their single addition. The best productivity of HMF was found at 15% concentration of the biomass and at 50%, its relative productivity declined down to ca. 0.4-fold. PMID:21146811

  10. 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. PMID:25537316

  11. 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

  12. 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

  13. 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

  14. Design and features of the Acorn CorCap Cardiac Support Device: the concept of passive mechanical diastolic support.

    PubMed

    Walsh, Robert G

    2005-06-01

    The Laplace equation points to the importance of ventricular wall stress as a factor in heart failure development and progression. Based on animal and clinical experience with active and passive cardiomyoplasty, a synthetic passive constraint was proposed as a means of reducing excessive wall stress, and thus assuaging disease progression. The Acorn CorCap CSD Cardiac Support Device was designed to provide passive diastolic support and serve as a constraint against chronic cardiac dilation in heart failure. Basic and uncomplicated in appearance, the device nevertheless incorporates numerous sophisticated structural and functional features intended maximize therapeutic value. The device is fabricated from medical grade multifilament polyester yarn, in a specific knit construction chosen to provide structural integrity, low physical profile, pliability for intimate contact with the epicardial surface, ease of manipulation during implantation, and anisotropic compliance characteristics to encourage beneficial reverse remodeling. PMID:16258717

  15. 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

  16. 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

  17. 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

  18. 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

  19. Genetic consequences of breaking migratory traditions in barnacle geese Branta leucopsis.

    PubMed

    Jonker, R M; Kraus, R H S; Zhang, Q; van Hooft, P; Larsson, K; van der Jeugd, H P; Kurvers, R H J M; van Wieren, S E; Loonen, M J J E; Crooijmans, R P M A; Ydenberg, R C; Groenen, M A M; Prins, H H T

    2013-12-01

    Cultural transmission of migratory traditions enables species to deal with their environment based on experiences from earlier generations. Also, it allows a more adequate and rapid response to rapidly changing environments. When individuals break with their migratory traditions, new population structures can emerge that may affect gene flow. Recently, the migratory traditions of the Barnacle Goose Branta leucopsis changed, and new populations differing in migratory distance emerged. Here, we investigate the population genetic structure of the Barnacle Goose to evaluate the consequences of altered migratory traditions. We used a set of 358 single nucleotide polymorphism (SNP) markers to genotype 418 individuals from breeding populations in Greenland, Spitsbergen, Russia, Sweden and the Netherlands, the latter two being newly emerged populations. We used discriminant analysis of principal components, FST , linkage disequilibrium and a comparison of geneflow models using migrate-n to show that there is significant population structure, but that relatively many pairs of SNPs are in linkage disequilibrium, suggesting recent admixture between these populations. Despite the assumed traditions of migration within populations, we also show that genetic exchange occurs between all populations. The newly established nonmigratory population in the Netherlands is characterized by high emigration into other populations, which suggests more exploratory behaviour, possibly as a result of shortened parental care. These results suggest that migratory traditions in populations are subject to change in geese and that such changes have population genetic consequences. We argue that the emergence of nonmigration probably resulted from developmental plasticity. PMID:24118391

  20. 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

  1. 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

  2. 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

  3. 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

  4. Imaging SPR combined with stereoscopic 3D tracking to study barnacle cyprid-surface interactions

    NASA Astrophysics Data System (ADS)

    Maleshlijski, S.; Sendra, G. H.; Aldred, N.; Clare, A. S.; Liedberg, B.; Grunze, M.; Ederth, T.; Rosenhahn, A.

    2016-01-01

    Barnacle larvae (cyprids) explore surfaces to identify suitable settlement sites. This process is selective, and cyprids respond to numerous surface cues. To better understand the settlement process, it is desirable to simultaneously monitor both the surface exploration behavior and any close interactions with the surface. Stereoscopic 3D tracking of the cyprids provides quantitative access to surface exploration and pre-settlement rituals. Imaging surface plasmon resonance (SPR) reveals any interactions with the surfaces, such as surface inspection during bipedal walking and deposition of temporary adhesives. We report on a combination of both techniques to bring together information on swimming behavior in the vicinity of the interface and physical interactions of the cyprid with the surface. The technical requirements are described, and we applied the setup to cyprids of Balanus amphitrite. Initial data shows the applicability of the combined instrument to correlate exploration and touchdown events on surfaces with different chemical termination.

  5. 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

  6. Construction and nanomechanical properties of the exoskeleton of the barnacle, Amphibalanus reticulatus.

    PubMed

    Raman, Sangeetha; Kumar, Ravi

    2011-12-01

    Barnacles are some of the major inhabitants of intertidal zones and have calcite-based exoskeleton to anchor and armor their tissues. Structural characterization studies of the specie Ambhibalanus reticulatus were performed to understand the construction of the exoskeleton which forms a light-weight yet stiff structure. The parietal shell is constructed of six compartments to yield a truncated cone geometry, which is neatly fixed onto the basal shell that attaches the organism to the substrate surface. The connections among the different compartments happen through sutured edges and also have chemical interlocking to make the junctions impermeable. Also, the shell parts are furnished with hollow channels reducing the overall mass of the construction. The structure and functions of different parts of the exoskeleton are identified and outlined. Finally, the mechanical properties such as modulus, hardness and fracture toughness of the exoskeleton obtained by indentation techniques are discussed. PMID:21911065

  7. Degradation of ferric chelate of ethylenediaminetetraacetic acid by bacterium isolated from deep-sea stalked barnacle.

    PubMed

    Imada, Chiaki; Harada, Yohei; Kobayashi, Takeshi; Hamada-Sato, Naoko; Watanabe, Etsuo

    2005-01-01

    Twenty strains of marine bacteria that degrade ferric chelate of ethylenediaminetetraacetic acid (Fe-EDTA) were isolated from among 117 strains collected from a marine environment. Among them strain 02-N-2, which was isolated from stalked barnacle collected from the deep sea in the Indian Ocean, had the highest Fe-EDTA degradation ability and was selected for further study. The strain showed high Fe-EDTA degradation ability at different seawater concentrations. In addition, the intact cells of this strain had the ability to degrade such metal-EDTAs as Ca, Cu, and Mg. The strain was an aerobic, gram-variable, rod-shaped organism. The results of various taxonomic studies revealed that the strain had significant similarity to Bacillus jeotgali JCM 10885(T), which was isolated from a Korean traditional fermented seafood, Jeotgal. PMID:15747087

  8. 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

  9. 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

  10. Evidence for the Involvement of p38 MAPK Activation in Barnacle Larval Settlement

    PubMed Central

    He, Li-Sheng; Xu, Ying; Matsumura, Kiyotaka; Zhang, Yu; Zhang, Gen; Qi, Shu-Hua; Qian, Pei-Yuan

    2012-01-01

    The barnacle Balanus ( = Amphibalanus) amphitrite is a major marine fouling animal. Understanding the molecular mechanism of larval settlement in this species is critical for anti-fouling research. In this study, we cloned one isoform of p38 MAPK (Bar-p38 MAPK) from this species, which shares the significant characteristic of containing a TGY motif with other species such as yeast, Drosophila and humans. The activation of p38 MAPK was detected by an antibody that recognizes the conserved dual phosphorylation sites of TGY. The results showed that phospho-p38 MAPK (pp38 MAPK) was more highly expressed at the cyprid stage, particularly in aged cyprids, in comparison to other stages, including the nauplius and juvenile stages. Immunostaining showed that Bar-p38 MAPK and pp38 MAPK were mainly located at the cyprid antennules, and especially the third and fourth segments, which are responsible for substratum exploration during settlement. The expression and localization patterns of Bar-p38 MAPK suggest its involvement in larval settlement. This postulation was also supported by the larval settlement bioassay with the p38 MAPK inhibitor SB203580. Behavioral analysis by live imaging revealed that the larvae were still capable of exploring the surface of the substratum after SB203580 treatment. This shows that the effect of p38 MAPK on larval settlement might be by regulating the secretion of permanent proteinaceous substances. Furthermore, the level of pp38 MAPK dramatically decreased after full settlement, suggesting that Bar-p38 MAPK maybe plays a role in larval settlement rather than metamorphosis. Finally, we found that Bar-p38 MAPK was highly activated when larvae confronted extracts of adult barnacle containing settlement cues, whereas larvae pre-treated with SB203580 failed to respond to the crude adult extracts. PMID:23115639

  11. 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

  12. 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. PMID:26917397

  13. 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

  14. 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.

  15. 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.

  16. Barnacles as biomonitors of trace metal availabilities in Hong Kong coastal waters: changes in space and time.

    PubMed

    Rainbow, P S; Blackmore, G

    2001-06-01

    The use of selected organisms as biomonitors of trace metal bioavailabilities allows comparisons to be made over space and time. The concentrations of 11 trace metals (arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel, silver, zinc) were measured in the bodies of two barnacle species, Balanus amphitrite and Tetraclita squamosa, from up to 18 littoral sites from Hong Kong coastal waters in April 1998. These data provide evidence on the geographical variation in metal bioavailabilities at this time, and are compared selectively against historical data sets for 1986 and 1989. Geographical variation in bioavailabilities is clear for several metals, with hotspots for arsenic, copper, nickel and silver at Chai Wan Kok, and for lead in Junk Bay. Victoria Harbour sites head the rankings for silver and arsenic, and Tolo Harbour sites exhibit relatively elevated cobalt, manganese and zinc. Many bioavailabilities of trace metals to barnacles are lower in Hong Kong coastal waters in 1998 than in 1986. The two barnacle species are widespread and the extensive data set presented is a benchmark which can be compared to the results of similar biomonitoring programmes elsewhere in the Indo-Pacific and beyond. PMID:11488511

  17. 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.

  18. 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. PMID:26667586

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. The permeation of non-electrolytes through the single barnacle muscle cell

    PubMed Central

    Bunch, Wilton; Edwards, Charles

    1969-01-01

    The rate of movement of non-electrolytes and tritiated water (THO) across the muscle cell membrane of the giant barnacle Balanus nubilus has been studied and permeability coefficient calculated. The rate of permeation is more closely related to the oil—water partition coefficient than to size of the molecule or degree of hydrogen bonding. Calculations based on efflux from an ideal cylinder suggest that the membrane acts as a significant barrier to movement of these molecules. The cell was unable to concentrate dimethyl sulphoxide (DMSO); the steady state was reached at about 60% of the extracellular concentration. The energies of activation for water, urea and DMSO are 7·5, 20·3 and 26·1 kcal/mol. At 4° C the apparent pore size measured with urea, glycerol and DMSO was 3·5 Å. At 25° C the apparent pore size for urea and glycerol is unchanged but that for DMSO is 14 Å. PMID:5789944

  6. 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

  7. /sup 31/P nuclear magnetic resonance measurements of intracellular pH in giant barnacle muscle

    SciTech Connect

    Hamm, J.R.; Yue, G.M.

    1987-01-01

    The accuracy of intracellular pH (pH/sub i/) measurements by /sup 31/P nuclear magnetic resonance (NMR) spectroscopy was examined in single muscle fibers from the giant barnacle, Balanus nubilis. The pH/sub i/ was derived from the chemical shifts of 2-deoxy-D-glucose-6-phosphate and inorganic phosphate. In fibers superfused with sea water at pH 7.7, pH/sub i/ = 7.30 +/- 0.02 at 20/sup 0/C. Experimentally induced pH/sub i/ changes were followed with a time resolution of 3 min. Intracellular alkalinization was induced by exposure to NH/sub 3/Cl and intracellular acidification followed when NH/sub 3/ was removed. Then acid extrusion was stimulated by exposure to bicarbonate containing sea water. In single muscle fibers /sup 31/P NMR results were in excellent agreement with microelectrode studies over the pH range of 6.5 to 8.0. The initial acid extrusion rate was 1.7 +/- 0.3 mmol x 1/sup -1/ x min/sup -1/ at pH/sub i/ 6.75. The authors results showed that /sup 31/P NMR is a reliable in vivo pH probe.

  8. 31P nuclear magnetic resonance measurements of intracellular pH in giant barnacle muscle.

    PubMed

    Hamm, J R; Yue, G M

    1987-01-01

    The accuracy of intracellular pH (pHi) measurements by 31P nuclear magnetic resonance (NMR) spectroscopy was examined in single muscle fibers from the giant barnacle, Balanus nubilis. The pHi was derived from the chemical shifts of 2-deoxy-D-glucose-6-phosphate and inorganic phosphate. In fibers superfused with sea water at pH 7.7, pHi = 7.30 +/- 0.02 at 20 degrees C. Experimentally induced pHi changes were followed with a time resolution of 3 min. Intracellular alkalinization was induced by exposure to NH4Cl and intracellular acidification followed when NH3 was removed. Then acid extrusion was stimulated by exposure to bicarbonate containing sea water. In single muscle fibers 31P NMR results were in excellent agreement with microelectrode studies over the pH range of 6.5 to 8.0. The initial acid extrusion rate was 1.7 +/- 0.3 mmol X l-1 X min-1 at pHi 6.75. Our results showed that 31P NMR is a reliable in vivo pH probe. PMID:3812665

  9. 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

  10. 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. PMID:20538307

  11. 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

  12. 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

  13. 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. PMID:25868907

  14. 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

  15. Gut fluorescence analysis of barnacle larvae: An approach to quantify the ingested food

    NASA Astrophysics Data System (ADS)

    Gaonkar, Chetan A.; Anil, Arga Chandrashekar

    2012-10-01

    Gut fluorescence analysis can provide a snapshot of ingested food and has been employed in feeding studies of various organisms. In this study we standardised the gut fluorescence method using laboratory-reared barnacle larvae (Balanus amphitrite) fed with mono-algal diet Chaetoceros calcitrans, a unicellular diatom at a cell concentration of 2 × 105 cells ml-1. The gut fluorescence of IV-VI instar nauplii was found to be 370(±12) ng chlorophyll a larva-1 and in faecal pellets it was 224(±63) ng chlorophyll a larva-1. A phaeopigment concentration in larval gut was found to be 311(±13) ng larva-1 and in faecal pellets it was 172(±61) ng larva-1. The study also analysed larval samples collected from the field during different seasons from a tropical environment influenced by monsoons (Dona Paula bay, Goa, west coast of India), with characteristic temporal variations in phytoplankton abundance and diversity. Gut fluorescence of larvae obtained during the post-monsoon season was consistently higher when compared to the pre-monsoon season, suggesting the predominance of autotrophic forms in the larval gut during the post-monsoon season. Whereas, the low gut fluorescence obtained during the pre-monsoon season indicated the ingestion of food sources other than autotrophs. Such differences observed in the feeding behaviour of larvae could be due to differential availability of food for the larvae during different seasons and indicate the capability of larvae to feed on wide range of food sources. This study shows the value of the fluorescence method in feeding studies of planktotrophic organisms and in the evaluation of ecosystem dynamics.

  16. 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

  17. Kinetics of Oxygen Consumption after a Flash of Light in the Lateral Ocellus of the Barnacle

    PubMed Central

    Poitry, S.; Widmer, H.

    1988-01-01

    Until recently, polarographic methods for measuring the time course of transient changes in the rate of oxygen consumption (ΔQO2) have been applied only to tissue preparations containing thousands of cells. Here, we describe ΔQO2 measurements on the lateral ocellus of the barnacle (Balanus eburneus) which contains only three photoreceptor cells. The decrement of partial pressure of oxygen (ΔPO2) elicited by an 80 ms flash of light was measured near the cells with a microelectrode and the ΔQO2 was calculated from the ΔPO2 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 ΔQO2. For a given ΔQO2, the model describes correctly the attenuation of the ΔPO2 measured at increased distances from the preparation. To know more about the mechanisms controlling the ΔQO2, we compared it with the electrical response of the photoreceptor cells: both responses have a similar spectral dependence, but only the ΔQO2 was abolished by a 10-min exposure to 50 μM dinitrophenol or to 3 mM amytal. We conclude that the ΔQO2 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). ImagesFIGURE 1 PMID:19431731

  18. 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

  19. 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

  20. Spectral correlates of a quasi-stable depolarization in barnacle photoreceptor following red light.

    PubMed

    Brown, H M; Cornwall, M C

    1975-07-01

    1. Illumination of B. eburneus photoreceptors with intense red light produces a membrane depolarization that persists in darkness. This quasistable depolarization (latch-up) can be terminated with green light. The phenomenon was investigated with electrophysiological, spectrochemical, and microspectrophotometric techniques. 2. Latch-up was associated with a stable inward current in cells with the membrane potential voltage-clamped at the resting potential in darkness. The stable current could only be elicited at wave-lengths greater than 580 nm. 3. Light-induced current (LIC) was measured at various wave-lengths in dark-adapted photoreceptors with the membrane voltage-clamped to the resting potential. The minimum number of photons required to elicit a fixed amount of LIC occurred at 540 nm, indicating that the photoreceptor is maximally sensitive to this wave-length of light. The photoreceptor was also sensitive to wave-lengths in the near-U.V. region of the spectrum (380-420 nm). 4. Steady red adapting light reduced the magnitude of the LIC uniformly at all wave-lengths except in the near-U.V. region of the spectrum; sensitivity was reduced less in this region. 5. The spectrum for termination of the stable inward current following or during red light was shifted to the blue (peak about 510 nm) compared to the peak for LIC (peak about 540 nm). 6. Absorbance of single cells prepared under bright, red light decreased maximally at 480 nm following exposure to wave-lengths of light longer than 540 nm. 7. A pigment extract of 1000 barnacle ocelli prepared under dim, red light had a maximum absorbance change at 480 nm when bleached with blue-gree light. 8. There was no evidence in the latter two experiments of photointerconversion of pigments with absorbance maxima at 480 and 540 nm. Rather, the maximum absorption of the bleaching products seemed to occur at wave-lengths shorter than 420 nm. 9. Since latch-up induction occurs at wave-lengths longer than 580 nm, it may

  1. Ionic mechanism of a quasi-stable depolarization in barnacle photoreceptor following red light.

    PubMed

    Brown, H M; Cornwall, M C

    1975-07-01

    1. The membrane mechanism of a quasi-stable membrane depolarization (latch-up) that persists in darkness following red light was examined in barnacle photoreceptor with micro-electrode techniques including voltage-clamp and Na+-sensitive micro-electrodes. 2. Current-voltage (I-V) relations of the membrane in darkness following red light (latch-up) and in darkness following termination of latch-up with green light, indicate that latch-up is associated with an increase of membrane conductance. 3. The latch-current (membrane current in darkness following red light minus membrane current in darkness following a gree flash that terminates latch-up) was inward at the resting potential, reversed sign at about +26mV (mean of six cells), and became outward at more positive membrance potentials. 4. Current-voltage relations of the membrane during green light (no latch-up) closely resembled those during latch-up. The light-induced current (LIC) elicited by green ligh (membrane current during the light flash minus membrane current in darkness following the light flash) was inward from the resting potential to +26mV (mean of six cells), then reversed sign and became outward. 5. The latch-current and LIC were both augmented in reduced Ca2+ solutions and decreased as Na-+ was reduced at a fixed Ca2+ concentration. 6. Both LIC and latch-current reversed sign at a more negative membrane potential (increment V equals 14mV) in solutions containing one quarter the normal amount of Na+. 7. The internal Na-+ activity (a-iNa) of a photoreceptor increased from about 10-18 mM upon illumination with long steps of intense red or white illumination. Five minutes in darkness after white light, a-iNa had recovered significantly, whereas a-iNa remained elecated following red illumination. 8. Latch-up seems to be a persistence in darkness of the same membrane mechanism that normally occurs during illumination; i.e. a conductance increase to Na+ ions. Ca2+ ions act primarily to suppress this

  2. Activation of Na-H exchange by intracellular lithium in barnacle muscle fibers.

    PubMed

    Davis, B A; Hogan, E M; Boron, W F

    1992-07-01

    We internally dialyzed single barnacle muscle fibers (BMF) for 90 min with a dialysis fluid (DF) containing no Na+ and either 0 or 100 mM Li+ and measured intracellular pH (pHi) with a microelectrode. During dialysis, the pH 8.0 artificial seawater (ASW) contained neither Na+ nor HCO3-. After we halted dialysis with a Li(+)-free/low-pH DF and allowed pHi to stabilize at approximately 6.8, adding 440 mM Na(+)-10 mM HCO3- to the ASW caused pHi to recover rapidly and stabilize at 7.32. In contrast, when the DF contained 100 mM Li+, pHi stabilized at 7.49. In fibers dialyzed to a pHi of approximately 7.2, Li+ stimulated a component of acid extrusion that was dependent on Na+ but not affected by SITS. Thus Li+ activates a Na(+)-dependent acid-extrusion mechanism other than the well characterized Na(+)-dependent Cl-HCO3 exchanger. To study the Li(+)-activated mechanism, we minimized Na(+)-dependent Cl-HCO3 exchange by raising pHDF to 7.35 and pretreated BMFs with SITS. We found that dialysis with Li+ elicits a Na(+)-dependent pHi increase that is largely blocked by amiloride, consistent with the hypothesis that Li+ activates a latent Na-H exchanger even at a normal pHi. In the absence of Li+, the Na-H exchanger is relatively inactive at pHi 7.35 (net acid-extrusion rate, Jnet = 9.5 microM/min) but modestly stimulated by reducing pHi to 6.8 (Jnet = 64 microM/min). In the presence of Li+, the Na-H exchanger is very active at pHi values of both 7.35 (Jnet = 141 microM/min) and 6.8 (Jnet = 168 microM/min). Thus Li+ alters the pHi sensitivity of the Na-H exchanger. Because the Na-H exchanger is only approximately 6% as active as the Na(+)-dependent Cl-HCO3 exchanger in the absence of Li+ at a pHi of approximately 6.8, we suggest that the major role of the Na-H exchanger may not be in pHi regulation but in another function such as cell-volume regulation. PMID:1322042

  3. 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

  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. 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

  6. 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

  7. 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

  8. The use of a classification of residential neighbourhoods (ACORN) to demonstrate differences in dental health of children resident within the south Birmingham health district and of different socio-economic backgrounds.

    PubMed

    Elley, K M; Langford, J W

    1993-06-01

    This study was undertaken to evaluate variations in the dental health of children living within fluoridated South Birmingham, using a classification of residential neighbourhoods (ACORN) as a descriptor of socio-economic status, and to evaluate the change in these differences over time. Five-year-old children were examined as part of the rolling programme of epidemiological surveys co-ordinated by the British Association for the Study of Community Dentistry (BASCD) in 1987 and 1989/90. The ACORN classification of each child was determined from the postal code of the home address. ACORN groups were amalgamated into three ranked divisions. There was a variation in dental health both in 1987 and 1989/90; children from disadvantaged groups had the poorest dental health. There was more marked variation in 1987 than in 1989/90. The reduction in inequality during this period was due to a relatively greater improvement in the dental health of the children from the more socially deprived areas. PMID:8402299

  9. 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

  10. 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

  11. 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

  12. 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

  13. MKK3 was involved in larval settlement of the barnacle Amphibalanus amphitrite through activating the kinase activity of p38MAPK.

    PubMed

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

    2013-01-01

    The p38 mitogen-activated protein kinase (p38MAPK) plays a key role in larval settlement of the barnacle Amphibalanus amphitrite. To study the signaling pathway associated with p38MAPK during larval settlement, we sought to identify the upstream kinase of p38MAPK. Three MKKs (MKK3, MKK4 and MKK7) and three MAPKs (p38MAPK, ERK and JNK) in A. amphitrite were cloned and recombinantly expressed in E. coli. Through kinase assays, we found that MKK3, but not MKK4 or MKK7, phosphorylated p38MAPK. Furthermore, MKK3 activity was specific to p38MAPK, as it did not phosphorylate ERK or JNK. To further investigate the functional relationship between MKK3 and p38MAPK in vivo, we studied the localization of phospho-MKK3 (pMKK3) and MKK3 by immunostaining. Consistent with the patterns of p38MAPK and phospho-p38MAPK (pp38MAPK), pMKK3 and MKK3 mainly localized to the antennules of the cyprids. Western blot analysis revealed that pMKK3 levels, like pp38MAPK levels, were elevated at cyprid stage, compared to nauplii and juvenile stages. Moreover, pMKK3 levels increased after treatment with adult barnacle crude extracts, suggesting that MKK3 might mediate the stimulatory effects of adult barnacle extracts on the p38MAPK pathway. PMID:23922727

  14. 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. PMID:24880725

  15. Adsorption of Disperse Orange 30 dye onto activated carbon derived from Holm Oak (Quercus Ilex) acorns: A 3(k) factorial design and analysis.

    PubMed

    Tezcan Un, Umran; Ates, Funda; Erginel, Nihal; Ozcan, Oznur; Oduncu, Emre

    2015-05-15

    In this study, samples of activated carbon were prepared from Holm Oak acorns by chemical activation with H3PO4, ZnCl2 and KOH as activating agents. The samples were characterized by SEM, BET, FTIR and elemental analysis, and were then evaluated for the removal of Disperse Orange 30 (DO30) dyes from aqueous solutions. A 3(k) factorial design was used to determine the interaction effects of carbonization temperature, pH, dosage of adsorbent and type of activating agent on the amount of dye removal. Also, level of effectiveness factors were determined by conducting regression models for maximum adsorption efficiency. Of all the samples, the sample generated using ZnCl2 as an activating agent showed a maximum dye removal efficiency of 93.5% at a carbonization temperature of 750 °C, a pH of 2 and an adsorbent dosage of 0.15 g/25 ml. The analysis shows that the adsorption process depends significantly on the type of activating agent used in the preparation of activated carbon. PMID:25776797

  16. 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

  17. 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

  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. 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

  20. Atomic force microscopy of the morphology and mechanical behaviour of barnacle cyprid footprint proteins at the nanoscale

    PubMed Central

    Phang, In Yee; Aldred, Nick; Ling, Xing Yi; Huskens, Jurriaan; Clare, Anthony S.; Vancso, G. Julius

    2010-01-01

    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 (LP) was obtained. At high elongation, following repeated stretching up to increasing upper strain limits, footprint proteins detached at total stretched length of 10 µm. PMID:19570797

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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. PMID:24660915

  7. 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

  8. 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

  9. 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

  10. 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. PMID:17560131

  11. 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

  12. 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

  13. Cross-Species, Amplifiable Microsatellite Markers for Neoverrucid Barnacles from Deep-Sea Hydrothermal Vents Developed Using Next-Generation Sequencing

    PubMed Central

    Nakajima, Yuichi; Shinzato, Chuya; Khalturina, Mariia; Watanabe, Hiromi; Inagaki, Fumio; Satoh, Nori; Mitarai, Satoshi

    2014-01-01

    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. PMID:25196437

  14. Seasonal and short-term variations in abundance of barnacle larvae near the South-West of the Isle of Man

    NASA Astrophysics Data System (ADS)

    Salman, S. D.

    1982-09-01

    Larvae of five species of sessile barnacles were found to be common within 4 miles of Port Erin, Isle of Man. These are Balanus balanoides, B. crenatus, B. balanus, B. hameri and Verucca stroemia. Larvae of other recorded species were very rare or absent. The major larval release of all the common species occurred in late winter and spring, but V. stroemia continued to breed throughout most of the year, and there was some evidence of autumn breeding of B. crenatus on a very small scale. The major release of nauplii by most of these species occurred at the time of the spring diatom outburst. The larval life of each of the four species of Balanus is estimated to last 3-5 weeks, that of V. stroemia 7-8 weeks. Some observations suggested that the larval release of B. balanoides may be stimulated by spring tides, but other observations seemed to contradict this. Larval release may be inhibited by turbulence.

  15. 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

  16. 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

  17. 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

  18. 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

  19. Kinetics and stoichiometry of coupled Na efflux and Ca influx (Na/Ca exchange) in barnacle muscle cells.

    PubMed

    Rasgado-Flores, H; Santiago, E M; Blaustein, M P

    1989-06-01

    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

  20. 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.

  1. 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

  2. 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.

  3. 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

    2013-01-01

    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. PMID:25113370

  4. 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

  5. Baseline immune activity is associated with date rather than with moult stage in the Arctic-breeding barnacle goose (Branta leucopsis).

    PubMed

    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

  6. The regulatory role of the NO/cGMP signal transduction cascade during larval attachment and metamorphosis of the barnacle Balanus (=Amphibalanus) amphitrite.

    PubMed

    Zhang, Yu; He, Li-Sheng; Zhang, Gen; Xu, Ying; Lee, On-On; Matsumura, Kiyotaka; Qian, Pei-Yuan

    2012-11-01

    The barnacle Balanus amphitrite is among the most dominant fouling species on intertidal rocky shores in tropical and subtropical areas and is thus a target organism in antifouling research. After being released from adults, the swimming nauplius undertakes six molting cycles and then transforms into a cyprid. Using paired antennules, a competent cyprid actively explores and selects a suitable substratum for attachment and metamorphosis (collectively known as settlement). This selection process involves the reception of exogenous signals and subsequent endogenous signal transduction. To investigate the involvement of nitric oxide (NO) and cyclic GMP (cGMP) during larval settlement of B. amphitrite, we examined the effects of an NO donor and an NO scavenger, two nitric oxide synthase (NOS) inhibitors and a soluble guanylyl cyclase (sGC) inhibitor on settling cyprids. We found that the NO donor sodium nitroprusside (SNP) inhibited larval settlement in a dose-dependent manner. In contrast, both the NO scavenger carboxy-PTIO and the NOS inhibitors aminoguanidine hemisulfate (AGH) and S-methylisothiourea sulfate (SMIS) significantly accelerated larval settlement. Suppression of the downstream guanylyl cyclase (GC) activity using a GC-selective inhibitor ODQ could also significantly accelerate larval settlement. Interestingly, the settlement inhibition effects of SNP could be attenuated by ODQ at all concentrations tested. In the developmental expression profiling of NOS and sGC, the lowest expression of both genes was detected in the cyprid stage, a crucial stage for the larval decision to attach and metamorphose. In summary, we concluded that NO regulates larval settlement via mediating downstream cGMP signaling. PMID:22855617

  7. 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

  8. 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

  9. 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

  10. Coating modulus and barnacle bioadhesion.

    PubMed

    Berglin, Mattias; Lönn, Nina; Gatenholm, Paul

    2003-04-01

    The effect of coating modulus on the strength of pseudobarnacle adhesive bonding was investigated. A radical polymerized poly(butylmethacrylate) coating cross-linked with allylmethacrylate was used as a model coating. The coating Tg was determined to be 18 degrees C by differential scanning calorimetry (DSC). Dynamic contact angle measurements (DCA) at different temperatures indicated that the surface chemistry was not significantly affected in the range investigated (5-50 degrees C). However, an increased noise level in the force vs. displacement curves indicated an increased molecular mobility with a fast reorganization of hydrophilic ester groups during the measurement. Dynamic mechanical analysis (DMA) as a function of temperature revealed a large drop in storage modulus (G') from 20 degrees C to 70 degrees C, as expected. A good correlation between the coating storage modulus and the detachment stress of pseudobarnacles was observed even though energy dissipation during the analysis was observed. The decreased adhesion might be a result of the increased molecular flexibility as determined by DCA and DMA at increased temperature. The increased molecular mobility might increase the tendency for interfacial slip, which ultimately results in decreased adhesion strength. PMID:14618706

  11. Group sex in the acorn woodpecker.

    PubMed

    Koenig, Walter; Haydock, Joey

    2002-08-01

    Family-base societies are frequently faced with the conundrum of balancing the competing reproductive interests of closely related group members. How this is accomplished is the subject of considerable current research, and is epitomized in the complexities of a bizarre species of woodpecker, common in California's oak woodlands. PMID:12167747

  12. Combining Traits and Density to Model Recruitment of Sessile Organisms

    PubMed Central

    Giménez, Luis; Jenkins, Stuart R.

    2013-01-01

    We propose an integrative approach that explains patterns of recruitment to adult populations in sessile organisms by considering the numbers of individuals and their body size. A recruitment model, based on a small number of parameters, was developed for sessile organisms and tested using the barnacle Semibalanus balanoides, a marine invertebrate inhabiting North Atlantic intertidal shores. Incorporating barnacle body size improved model fit beyond that based on density alone, showing that growth played an important role in how resource limitation affected survival. Our approach uncovered the following: First, changes in the shape of the recruitment curve resulted from the balance between individual growth and mortality. Second, recruitment was limited by the least plastic trait used to characterise body size, operculum area. Basal area, a trait that responded to increases in barnacle density, did not contribute significantly to explain patterns of recruitment. Third, some temporal variation is explained by changes in the amount of space occupied by shells of dead barnacles: at high cover barnacles are densely packed and these shells remain long after death. Fourth, seasonal variation and spatial variation in survival can be separated from that resulting from resource limitation; survival was predicted for two different shores and four sampling times using a single recruitment model. We conclude that applying this integrative approach to recruitment will lead to a considerable advance in understanding patterns of mortality of early stages of sessile organisms. PMID:23469247

  13. 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

  14. Dynamics of species interaction strength in space, time and with developmental stage

    PubMed Central

    Kordas, Rebecca L.; Dudgeon, Steve

    2011-01-01

    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

  15. 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.

  16. 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

  17. 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...

  18. 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…

  19. 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.

  20. 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

  1. Freezing point and melting point of barnacle muscle fibers.

    PubMed

    Caillé, J P

    1983-10-01

    The freezing point and the melting point of myoplasm were measured with two experimental models. In all samples, a supercooled stage was reached by lowering the temperature of the sample to approximately - 7 degrees C, and the freezing of the sample was mechanically induced. The freezing process was associated with a phase transition in the interstices between the contractile filaments. In intact muscle fibers, the freezing point showed a structural component (0.43 degrees C), and the melting point indicated that the intracellular and the extracellular compartments are isotonic. When the sample of myoplasm, previously inserted in a cylindrical cavity was incubated in an electrolyte solution, the freezing point showed a structural component similar to that of the intact muscle fiber, but the melting point was lower than the freezing and the melting points of the embedding solution. This was interpreted as evidence that the counterions around the contractile filaments occupied a nonnegligible fraction of the intracellular compartment. PMID:6640420

  2. 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…

  3. 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

  4. 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

  5. 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…

  6. 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…

  7. 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…

  8. Diversification of acorn worms (Hemichordata, Enteropneusta) revealed in the deep sea

    PubMed Central

    Osborn, Karen J.; Kuhnz, Linda A.; Priede, Imants G.; Urata, Makoto; Gebruk, Andrey V.; Holland, Nicholas D.

    2012-01-01

    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

  9. 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

  10. The invasion of the intertidal canopy-forming alga Fucus serratus L. to southwestern Iceland: Possible community effects

    NASA Astrophysics Data System (ADS)

    Ingólfsson, Agnar

    2008-04-01

    The intertidal serrated wrack, Fucus serratus L. (Fucales: Phaeophyceae), has become an abundant canopy-forming alga along a ca. 100 km stretch of shore in southwestern Iceland in the last century. Its distribution has not changed noticeably since a survey in 1975/1976. Many experimental studies have shown that canopy-forming algae can have profound effects on the community structure. Although such experiments involving F. serratus are few it was decided to test predictions from these experiments on a geographical scale by comparing community compositions within the area where F. serratus is a dominant algae (since at least 1975/1976) with an adjacent area of similar size where F. serratus is absent (with a single exception without consequences). The work is based on measurements on some 372 stations in the F. serratus area, termed region A, and 227 stations from the F. serratus-free area, termed region B. Percentage cover of algae and sessile invertebrates was estimated on 2 m 2 on each station and animals collected from 800 cm 2 from each station. The vertical distribution of F. serratus was most similar to that of Fucus distichus and the two species often grew intermingled on the lower part of the shore. F. serratus appeared to have reduced the cover of F. distichus in the lowermost part of the shore, while having little or no effect on other canopy-forming species. The low abundance of Semibalanus balanoides in the F. serratus area (region A) is in line with experiments showing detrimental effect on this barnacle by whiplash of F. serratus. In general algal grazers were more abundant in region A, consistent with the greater attractiveness of F. serratus than other canopy-forming species to grazers, although this may be partly explained by the abundance of understorey algae in region A.

  11. 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

  12. 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

  13. 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)

  14. ACUTE TOXICITY AND SUBLETHAL BEHAVIORAL EFFECTS OF COPPER ON BARNACLE NAUPLII 'BALANUS IMPROVISUS'

    EPA Science Inventory

    This study documents the effects of short-term (24 h) sublethal copper exposures on undirected swimming activity and photobehavior of Balanus improvisus stage II nauplii. All Cu treatments were static, with temperature and salinity conditions at 20 C and 15 or 30 percent. The 24 ...

  15. 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

  16. 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

  17. G-protein alpha subunits distribution in the cyprid of Balanus amphitrite (=Amphibalanus amphitrite) (Cirripedia, Crustacea).

    PubMed

    Gallus, Lorenzo; Ferrando, Sara; Gambardella, Chiara; Amaroli, Andrea; Faimali, Marco; Piazza, Veronica; Masini, Maria Angela

    2012-12-01

    The acorn barnacle Balanus amphitrite is a marine crustacean with six nauplius and one cyprid larval stages and a sessile adult, that represent one of the main constituents of sea biofouling. The cyprid is the last larval stage, specialized for settlement, and the study of its biology is interesting also in the frame of antifouling strategies. In this study, a novel approach to the neurobiology of B. amphitrite cyprid has undertaken, studying immunohistochemically the distribution of some G-protein α subunits (Gαs, Gαo Gαi, and Gαq) on B. amphitrite cyprid. Gαs-like immunoreactivity was observed in the intestinal mucosa, oral cone, epithelial cells along the outer face of the mantle and thorax; Gαo into the fibers of the neuropile of the central nervous system; Gαi in oil cells, epithelial cells, and limbs and thorax muscles; Gαq was not detected. The results suggest the involvement of the G-protein α subunits in different tissues and functions that seem to be in agreement with the distribution of the ones from the same class of G-proteins in vertebrates. PMID:22833248

  18. 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.

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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

  6. Secret Apartheid III: Follow Up to Failure.

    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) studies of public schools continue with this report on course work for gifted students and public middle school students in general. Fourteen ACORN volunteers made 52 visits to 28 schools studied in 1996. Findings from these visits and the review of school system documents…

  7. Secret Apartheid. A Report on Racial Discrimination against Black and Latino Parents and Children in the New York City Public Schools.

    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 evidence uncovered by ACORN of institutional racism in the New York City public schools that prevents parents of color from making informed…

  8. 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

  9. 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

    2014-01-01

    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. PMID:25283658

  10. 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

  11. 7 CFR 210.10 - Meal requirements for lunches and requirements for afterschool snacks.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... considered to have a disability under 7 CFR 15b.3 and whose disability restricts their diet. Substitutions... vegetables. This subgroup includes vegetables such as acorn squash, butternut squash, carrots,...

  12. 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,...

  13. 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 ...

  14. 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)

  15. 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)

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. [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

  5. 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.

  6. 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.

  7. Effects of early recruits on temperate sessile marine community composition depend on other species recruiting at the time.

    PubMed

    Sams, Michael A; Keough, Michael J

    2013-09-01

    In many environments recruitment of dispersive propagules (e.g. seeds, spores and larvae) can vary from situations when particular taxa recruit in relative isolation to times when they recruit simultaneously with other, functionally quite different taxa. Differences in the identity and density of recruiting taxa can have important consequences on community structure, but it is still not clear how the effects of individual taxa on communities are modified when they recruit together with other species. Using an experimental approach we compared early development of a temperate marine sessile community after the recruitment of mixtures of botryllid ascidians and barnacles to that when barnacles or botryllid ascidians recruited alone. Communities exposed to recruitment of botryllid ascidians in isolation differed from those that received barnacles, a mixture of botryllids and barnacles or no recruitment in 2-week-old communities. These early differences were driven by higher abundances of the species that were present as initial recruits in experimental treatments. After 2 months communities also differed between barnacle and mixed recruitment treatments but not mixed and botryllid or botryllid and barnacle treatments. These differences were not directly due to differences in the abundances of our manipulated taxa but occurred because of two abundant arborescent bryozoans, Bugula dentata, which occupied more space in communities that initially received mixed recruitment than in those that received barnacle or no recruitment, and Zoobotryon verticillatum, which occupied more space in communities that initially received only barnacle recruitment than those that initially received botryllid or mixed recruitment. These effects did not persist, and communities did not differ after 6 months. These results suggest that, more generally, species may influence community dynamics differently when they recruit alongside other species than when they recruit in relative isolation

  8. Characterization of two 20kDa-cement protein (cp20k) homologues in Amphibalanus amphitrite.

    PubMed

    He, Li-Sheng; Zhang, Gen; Qian, Pei-Yuan

    2013-01-01

    The barnacle, Amphibalanus amphitrite, is a common marine fouling organism. Understanding the mechanism of barnacle adhesion will be helpful in resolving the fouling problem. Barnacle cement is thought to play a key role in barnacle attachment. Although several adult barnacle cement proteins have been identified in Megabalanus rosa, little is known about their function in barnacle settlement. In this study, two homologous 20k-cement proteins (cp20k) in Amphibalanus amphitrite, named Bamcp20k-1 and Bamcp20k-2, were characterized. The two homologues share primary sequence structure with proteins from other species including Megabalanus rosa and Fistulobalanus albicostatus. The conserved structure included repeated Cys domains and abundant charged amino acids, such as histidine. In this study we demonstrated that Bamcp20k-1 localized at the α secretory cells in the cyprid cement gland, while Bamcp20k-2 localized to the β secretory cells. The differential localizations suggest differential regulation for secretion from the secretory cells. Both Bamcp20k-1 and Bamcp20k-2 from cyprids dissolved in PBS. However, adult Bamcp20k-2, which was dominant in the basal shell of adult barnacles, was largely insoluble in PBS. Solubility increased in the presence of the reducing reagent Dithiothreitol (DTT), suggesting that the formation of disulfide bonds plays a role in Bamcp20k-2 function. In comparison, Bamcp20k-1, which was enriched in soft tissue, could not be easily detected in the shell and base by Western blot and easily dissolved in PBS. These differential solubilities and localizations indicate that Bamcp20k-1 and Bamcp20k-2 have distinct functions in barnacle cementing. PMID:23717550

  9. 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

  10. 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

  11. Root susceptibility and inoculum production from roots of Eastern United States oak species to Phytophthora ramorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about root susceptibility of eastern U.S. tree species to Phytophthora ramorum. In this study, we examined root susceptibility and inoculum production from roots. Sprouted acorns of Q. rubra, Q. palustrus, Q. coccinia, Q. alba, Q. michauxii and Q. prinus were exposed to motile zoos...

  12. Propagation container and timing of propagation affects growth and quality of oak seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two experiments were conducted to determine the container effect and the timeline of seed propagation on germination and subsequent shoot and root development for container-grown oaks. Quercus nigra and Q. texana had equal or better growth and better root ratings when acorns were sown in Anderson t...

  13. Oak-black bear relationships in southeastern uplands

    USGS Publications Warehouse

    Clark, Joseph D.

    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.

  14. Responsive Reading: Caring for Chicken Little

    ERIC Educational Resources Information Center

    Maderazo, Catherine

    2009-01-01

    Media images and news about current events have the potential to strike like acorns. In these moments, children, like Chicken Little, need caring adults who can help them understand what is happening. As early childhood educators, one must recognize and provide opportunities to guide children's social and emotional well-being in addition to…

  15. Seed to Seedling: A California Native Oak Curriculum for Kindergarten through Sixth Grade Children.

    ERIC Educational Resources Information Center

    de Mayolo, Kay Antunez

    This activity guide provides children in grades kindergarten through six with hands-on learning experiences while they nurture an acorn into a young oak tree. Each of 10 activities and numerous extensions help students gain awareness, understanding, and appreciation of the important role oaks play in the natural and cultural history associated…

  16. Publishers' Views of Electronic Short-Loan Collections and Copyright Clearance Issues.

    ERIC Educational Resources Information Center

    Muir, Adrienne

    1998-01-01

    Reports findings of Project ACORN (Access to COurse Readings Across Networks) an eLib-funded project eliciting views of publishers on issues associated with electronic short-loan collections and the policies/procedures for granting copyright clearance. Findings show little consensus in policies and views; publishers wary of electronic environment;…

  17. 7 CFR 319.37-6 - Specific treatment and other requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...)) and other insect pests of chestnut and acorn. Guizotia abyssinica (niger) seeds All (see paragraph (c) of this section) Cuscuta spp., and other noxious weeds listed in 7 CFR 360.200. Hibiscus spp... America and Central America Insects of the family Bruchidae. Lens spp. (lentil) seeds All except...

  18. Emergy analysis of a silvo-pastoral system, a case study in southern Portugal

    EPA Science Inventory

    The Mediterranean silvo-pastoral system known as Montado, in Portugal, is a complex land use system composed of an open tree stratum in various densities and an herbaceous layer, used for livestock grazing. Livestock also profit from the acorns, and the grazing contributes to avo...

  19. 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.…

  20. Keeping FCS Relevant with Technology

    ERIC Educational Resources Information Center

    Hays, Annette

    2007-01-01

    Acorn School campus is located in the shadow of Rich Mountain, near Mena, Arizona. In fall 2006, the school enrollment (K-12) was 476 students, with 76% eligible for free or reduced-cost meals. Its one-teacher family and consumer services (FCS) department offers two programs of study: Family and Consumer Sciences Education and Food Production…

  1. 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.

  2. Nature Study Tips: Native American Foods.

    ERIC Educational Resources Information Center

    Russell, Helen Ross

    1984-01-01

    Discusses Native American foods, focusing on Native American cultivated crops, methods of cooking, and methods of preserving food. Includes suggestions for 19 classroom activities, including collecting wild plants used as food, gathering/drying and eating various wild plants and plant products (such as acorns and corn), and making a garden. (JN)

  3. 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…

  4. 77 FR 3319 - TapSlide, Inc., TTC Technology Corp. (f/k/a SmarTire Systems Inc.), TWL Corp., TXP Corp...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-23

    ... [Federal Register Volume 77, Number 14 (Monday, January 23, 2012)] [Notices] [Pages 3319-3320] [FR..., through 11:59 p.m. EST on February 1, 2012. By the Commission. Elizabeth M. Murphy, Secretary. [FR Doc... Corp. (f/k/a SmarTire Systems Inc.), TWL Corp., TXP Corp., Valentec Systems, Inc. (f/k/a Acorn...

  5. Context-dependent seed dispersal by a scatter-hoarding corvid.

    PubMed

    Pesendorfer, Mario B; Sillett, T Scott; Morrison, Scott A; Kamil, Alan C

    2016-05-01

    Corvids (crows, jays, magpies and nutcrackers) are important dispersers of large-seeded plants. Studies on captive or supplemented birds suggest that they flexibly adjust their scatter-hoarding behaviour to the context of social dynamics and relative seed availability. Because many corvid-dispersed trees show high annual variation in seed production, context-dependent foraging can have strong effects on natural corvid scatter-hoarding behaviour. We investigated how seed availability and social dynamics affected scatter-hoarding in the island scrub jays (Aphelocoma insularis). We quantified rates of scatter-hoarding behaviour and territorial defence of 26 colour-marked birds over a three-year period with variable acorn crops. We tested whether caching parameters were correlated with variation in annual seed production of oaks as predicted by the predator dispersal hypothesis, which states that caching rates and distances should vary with seed abundance in ways that benefit tree fitness. We also tested whether antagonistic interactions with conspecifics would affect scatter-hoarding adversely, as found in experimental studies. Caching behaviour varied with acorn availability. Caching distances correlated positively with annual acorn crop size, increasing by as much as 40% between years. Caching rates declined over time in years with small acorn crops, but increased when crops were large. Acorn foraging and caching rates were also negatively correlated with rates of territorial aggression. Overall foraging rates, however, were not associated with aggression, suggesting that reduced dispersal rates were not simply due to time constraints. Our field results support laboratory findings that caching rates and distances by scatter-hoarding corvids are context-dependent. Furthermore, our results are consistent with predictions of the predator dispersal hypothesis and suggest that large seed crops and social interactions among scatter-hoarders affect dispersal benefits for

  6. [The new applications of NMR technology in the field of characterization of surface properties of the material].

    PubMed

    Liang, Ni; Zhang, Di; Wei, Chao-xian

    2015-02-01

    Nuclear magnetic resonance (NMR) technology has been developed continuely because of its rapid, accurate and high resolution advantages, The technology has become an important method to analyze the soil properties, and to identify the structure of matters, food analysis, medical imaging fields. This study summarized two aspects of the important applications of NMR in the characterization of the surface properties of materials. First, the use of NMR techniques for the adsorption, desorption and diffusion behaviors of polymer on solid particles (mainly SiO2 particles). Sencond, to investigate the wettability and water uptake progress of contaminated soils using NMR techniques. This study summarized the important applications of NMR techniques in the characterization of surface properties. It also showed the unique application in the field of polymer materials and environment. This study introduced the measured method for the relaxation time of substance using acorn surface area analyzer in the liquid environment. It reflect the surface properties and structural features of substance. It also provided data support for the explanation of environmental behaviors of contaminants and thus, it played an important role in the environmental field. Compared to the conventional BET method, acorn surface area analyzer showed the advantages in terms of conditions and time measurement. Especially, traditional BET method cannot get the information of the specific surface area of substances in the liquid directly, but acorn surface area analyzer solved the difficult problem. It is a new breakthrough in the field of characterization of the surface properties of materials by NMR in the liquid. We analyzed the application of acorn surface area analyzer in pharmaceuticals, cosmetic materials, electronic products because acorn surface area analyzer could reflects the important characteristics of the surface properties and structural features of substance. And we provide the prospective

  7. Chemical Component and Proteomic Study of the Amphibalanus (= Balanus) amphitrite Shell

    PubMed Central

    Zhang, Gen; He, Li-sheng; Wong, Yue-Him; Xu, Ying; Zhang, Yu; Qian, Pei-yuan

    2015-01-01

    As typical biofoulers, barnacles possess hard shells and cause serious biofouling problems. In this study, we analyzed the protein component of the barnacle Amphibalanus (= Balanus) amphitrite shell using gel-based proteomics. The results revealed 52 proteins in the A. Amphitrite shell. Among them, 40 proteins were categorized into 11 functional groups based on KOG database, and the remaining 12 proteins were unknown. Besides the known proteins in barnacle shell (SIPC, carbonic anhydrase and acidic acid matrix protein), we also identified chorion peroxidase, C-type lectin-like domains, serine proteases and proteinase inhibitor proteins in the A. Amphitrite shell. The sequences of these proteins were characterized and their potential functions were discussed. Histology and DAPI staining revealed living cells in the shell, which might secrete the shell proteins identified in this study. PMID:26222041

  8. Preparation and Analysis of Type II Xerogel Films with Antifouling/Foul Release Characteristics

    NASA Astrophysics Data System (ADS)

    Sokolova, Anastasiya

    In order to combat biofouling, xerogel coatings comprised of aminopropyl, fluorocarbon, and hydrocarbon silanes were prepared and tested for their antifouling/foul release properties against Ulva, Navicula, barnacles, and tubeworms. Many of the coatings showed settlement and removal of Ulva to be as good as or better than the poly(dimethylsiloxane) (PDMSE) standard. Barnacle removal assays showed excellent results for some coatings while others did not fair so well. The best foul release coatings for barnacles were comprised of aminopropyl/hydrocarbon- and fluorocarbon/hydrocarbon-modified silanes. For the majority of coatings tested, water wettability and surface energy did not play a role in the antifouling/ foul release properties of the coatings.

  9. Chemical Component and Proteomic Study of the Amphibalanus (= Balanus) amphitrite Shell.

    PubMed

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

    2015-01-01

    As typical biofoulers, barnacles possess hard shells and cause serious biofouling problems. In this study, we analyzed the protein component of the barnacle Amphibalanus (= Balanus) amphitrite shell using gel-based proteomics. The results revealed 52 proteins in the A. Amphitrite shell. Among them, 40 proteins were categorized into 11 functional groups based on KOG database, and the remaining 12 proteins were unknown. Besides the known proteins in barnacle shell (SIPC, carbonic anhydrase and acidic acid matrix protein), we also identified chorion peroxidase, C-type lectin-like domains, serine proteases and proteinase inhibitor proteins in the A. Amphitrite shell. The sequences of these proteins were characterized and their potential functions were discussed. Histology and DAPI staining revealed living cells in the shell, which might secrete the shell proteins identified in this study. PMID:26222041

  10. Ecology of a key ecosystem engineer on hard coastal infrastructure and natural rocky shores.

    PubMed

    Martins, Gustavo M; Neto, Ana I; Cacabelos, Eva

    2016-02-01

    The numbers of hard coastal artificial structures is increasing worldwide and there is now cumulative evidence that they support assemblages that are less diverse than natural shores. Here we investigated patterns of distribution and demography of the native barnacle Chthamalus stellatus on hard coastal structures and on natural rocky shores. Barnacles were 35% less abundant on hard structures regardless of substratum type (concrete or basalt). On a subset of sites we found that temporal population stability, growth and mortality were similar on natural rocky shores and hard structures. In contrast, barnacles were significantly larger and recruited more onto natural rocky shores. These results emphasise the important role of recruitment in determining the abundance of a key space occupier on hard coastal structures. Experimental work building on these results may generate insights that can be used as guidelines for the management of urbanised coastal areas. PMID:26686564

  11. Localized effects of macrofouling species on electrochemical corrosion of high grade alloys

    SciTech Connect

    Hodgkiess, T.; Nevilie, A.

    1998-12-31

    Interactions between macrofouling and corrosion on some stainless steels, UNS N06625 and UNS R30006 have been studied in long-term tests conducted in natural seawater off the west coast of Scotland. After a 18-month exposure period, the specimens were heavily fouled primarily with barnacles and mussels and all the materials exhibited crevice corrosion although this was less extensive on the Ni-base alloy. Localized corrosion was observed under the base of live barnacles on UNS S31603 stainless steel. DC electrochemical anodic polarization tests undertaken after the 18-month exposure period, yielded unusually high currents in the range of potential between the free corrosion value and the breakdown potential. This observation was associated with the appearance, after the anodic polarization, of black sulfide corrosion products at the specimen/resin crevices, around barnacles and around mussel byssus threads.

  12. Southern hemisphere deep-water stylasterid corals including a new species, Errina labrosa sp. n. (Cnidaria, Hydrozoa, Stylasteridae), with notes on some symbiotic scalpellids (Cirripedia, Thoracica, Scalpellidae)

    PubMed Central

    Pica, Daniela; Cairns, Stephen D.; Puce, Stefania; Newman, William A.

    2015-01-01

    Abstract A number of stylasterid corals are known to act as host species and create refuges for a variety of mobile and sessile organisms, which enhances their habitat complexity. These include annelids, anthozoans, cirripeds, copepods, cyanobacteria, echinoderms, gastropods, hydroids and sponges. Here we report the first evidence of a diverse association between stylasterids and scalpellid pedunculate barnacles and describe a new stylasterid species, Errina labrosa, from the Tristan da Cunha Archipelago. Overall, five stylasterid species are found to host eight scalpellid barnacles from several biogeographic regions in the southern hemisphere (Southern Ocean, temperate South America and the southern Indo-Pacific realms). There is an apparent lack of specificity in this kind of association and different grades of reaction to the symbiosis have been observed in the coral. These records suggest that the association between pedunculate barnacles and hard stylasterid corals has a wide distribution among different biogeographic realms and that it is relatively rare and confined largely to deep water. PMID:25632246

  13. Southern hemisphere deep-water stylasterid corals including a new species, Errinalabrosa sp. n. (Cnidaria, Hydrozoa, Stylasteridae), with notes on some symbiotic scalpellids (Cirripedia, Thoracica, Scalpellidae).

    PubMed

    Pica, Daniela; Cairns, Stephen D; Puce, Stefania; Newman, William A

    2015-01-01

    A number of stylasterid corals are known to act as host species and create refuges for a variety of mobile and sessile organisms, which enhances their habitat complexity. These include annelids, anthozoans, cirripeds, copepods, cyanobacteria, echinoderms, gastropods, hydroids and sponges. Here we report the first evidence of a diverse association between stylasterids and scalpellid pedunculate barnacles and describe a new stylasterid species, Errinalabrosa, from the Tristan da Cunha Archipelago. Overall, five stylasterid species are found to host eight scalpellid barnacles from several biogeographic regions in the southern hemisphere (Southern Ocean, temperate South America and the southern Indo-Pacific realms). There is an apparent lack of specificity in this kind of association and different grades of reaction to the symbiosis have been observed in the coral. These records suggest that the association between pedunculate barnacles and hard stylasterid corals has a wide distribution among different biogeographic realms and that it is relatively rare and confined largely to deep water. PMID:25632246

  14. Non-linear density-dependent effects of an intertidal ecosystem engineer.

    PubMed

    Harley, Christopher D G; O'Riley, Jaclyn L

    2011-06-01

    Ecosystem engineering is an important process in a variety of ecosystems. However, the relationship between engineer density and engineering impact remains poorly understood. We used experiments and a mathematical model to examine the role of engineer density in a rocky intertidal community in northern California. In this system, the whelk Nucella ostrina preys on barnacles (Balanus glandula and Chthamalus dalli), leaving empty barnacle tests as a resource (favorable microhabitat) for other species. Field experiments demonstrated that N. ostrina predation increased the availability of empty tests of both barnacle species, reduced the density of the competitively dominant B. glandula, and indirectly increased the density of the competitively inferior C. dalli. Empty barnacle tests altered microhabitat humidity, but not temperature, and presumably provided a refuge from wave action. The herbivorous snail Littorina plena was positively associated with empty test availability in both observational comparisons and experimental manipulations of empty test availability, and L. plena density was elevated in areas with foraging N. ostrina. To explore the effects of variation in N. ostrina predation, we constructed a demographic matrix model for barnacles in which we varied predation intensity. The model predicted that number of available empty tests increases with predation intensity to a point, but declines when predation pressure was strong enough to severely reduce adult barnacle densities. The modeled number of available empty tests therefore peaked at an intermediate level of N. ostrina predation. Non-linear relationships between engineer density and engineer impact may be a generally important attribute of systems in which engineers influence the population dynamics of the species that they manipulate. PMID:21170751

  15. Rover tracks

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Tracks made by the Sojourner rover are visible in this image, taken by one of the cameras aboard Sojourner on Sol 3. The tracks represent the rover maneuvering towards the rock dubbed 'Barnacle Bill.' The rover, having exited the lander via the rear ramp, first traveled towards the right portion of the image, and then moved forward towards the left where Barnacle Bill sits. The fact that the rover was making defined tracks indicates that the soil is made up of particles on a micron scale.

    Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration.

  16. Balanus eburneus: a sensitive indicator of copper and zinc pollution in the coastal zone

    SciTech Connect

    Barber, S.; Trefry, J.H.

    1981-12-01

    Barnacles were collected in the Eau Gallie Harbor waters, Florida, and were examined for copper and zinc by atomic absorption spectrophotometry. Results suggest that a 1 ppb increase in dissolved copper brings about a 36 ppm increase in tissue copper levels and that B. eburneus a sensitive indicator of copper and zinc pollution. However, this pollution is non-detectable 1 km away in the barnacles of Indian River Lagoon. This suggests minimal input or rapid dilution of the metals in the Indian River waters and raises concern for pollutant enrichment in restricted coastal embayments. (JMT)

  17. Antifouling properties of hydrogels

    NASA Astrophysics Data System (ADS)

    Murosaki, Takayuki; Ahmed, Nafees; Gong, Jian Ping

    2011-12-01

    Marine sessile organisms easily adhere to submerged solids such as rocks, metals and plastics, but not to seaweeds and fishes, which are covered with soft and wet 'hydrogel'. Inspired by this fact, we have studied long-term antifouling properties of hydrogels against marine sessile organisms. Hydrogels, especially those containing hydroxy group and sulfonic group, show excellent antifouling activity against barnacles both in laboratory assays and in the marine environment. The extreme low settlement on hydrogels in vitro and in vivo is mainly caused by antifouling properties against the barnacle cypris.

  18. UPTAKE OF METALS FROM CHROMATED-COPPER-ARSENATE (CCA)-TREATED LUMBER BY EPIBIOTA IN ESTUARIES

    EPA Science Inventory

    Previous studies have shown that Cu, Cr, and As leach from chromated-copper-arsenate (CCA) in the aboratory. e nvestigated concentrations of these metals in tissues of estuarine organisms, including algae, barnacles, and oysters, collected from CCA pressure-treated wood in a resi...

  19. THE COMPARATIVE PHOTOBEHAVIOR OF LABORATORY-HATCHED AND PLANKTON-CAUGHT 'BALANUS IMPROVISUS' (DARWIN) NAUPLII AND THE EFFECTS OF 24-HOUR STARVATION

    EPA Science Inventory

    Stage II nauplii of Balanus improvisus were obtained from laboratory maintained adult barnacles. The immediate phototactic and photokinetic response of laboratory nauplii to light stimuli of known wavelength (460-540 nm) and quantal intensity was determined. Spectral and light in...

  20. Recruitment dynamics in complex life cycles. [of organisms living in marine rocky zone

    NASA Technical Reports Server (NTRS)

    Roughgarden, Jonathan; Possingham, Hugh; Gaines, Steven

    1988-01-01

    Factors affecting marine population fluctuations are discussed with particular attention given to a common barnacle species of the Pacific coast of North America. It is shown how models combining larval circulation with adult interactions can potentially forecast population fluctuations. These findings demonstrate how processes in different ecological habitats are coupled.

  1. Seascapes: Glimpses of Our Water World.

    ERIC Educational Resources Information Center

    Hardin, Jan

    Presented is a collection of newspaper articles prepared by the Delaware Sea Grant Marine Advisory Service during the summer of 1978. Subjects addressed are bioluminescence, beachcomber finds, gulls, beach erosion, marine research activities, barnacles, sand, seaweed, jellyfish, shore restaurants, diving mammals, and tides. (Author/BW)

  2. Comparing regeneration techniques for afforesting previously farmed bottomland hardwood sites in the Lower Mississippi Alluvial Valley, USA

    USGS Publications Warehouse

    Lockhart, B.R.; Keeland, B.; McCoy, J.; Dean, T.J.

    2003-01-01

    A study was implemented to test site preparation methods and artificial regeneration of three oak (Quercus spp.) species on four agricultural fields in the Lower Mississippi Alluvial Valley in Louisiana, USA. Six years after establishment, few consistent differences were found in oak density between sowing acorn methods (seed drill versus broadcast seeding), autumn sowing versus spring sowing, and sowing acorns versus planting oak seedlings. Results indicated that some degree of site preparation is needed to establish oak seedlings but few differences were found between site preparation treatments. These results indicate that no one prescription for oak regeneration fits all potential afforestation projects in the Lower Mississippi Alluvial Valley. Successful bottomland hardwood afforestation projects will require plans that include specific objectives, site evaluation, and a regeneration prescription prior to sowing the first seed or planting the first seedling.

  3. Investigation of the impacts of clearcutting, feral hogs, and white-tailed deer on the native vegetative resources of the Congaree Swamp National Monument (revised). Technical report

    SciTech Connect

    Nix, L.E.; Barry, J.E.

    1992-07-27

    Vegetation surveys, large mammal exclosures, and acorn collections were used to study the effects of past cuttings, feral hogs, and deer on the continued presence of large, majestic oaks on the monument. Few oaks other than laurel oak remain in the harvested areas of the western half of the monument which are dominated by green ash and sweetgum. This species composition is very similar to that of the predisturbance condition, sweetgum-green ash-laurel oak, bottomland forest type. The scattered, remaining large oaks (cherrybark, Shumard, water and willow oak) have failed to reproduce adequately under the conditions created by the harvest practices. Lack of acorn production and seedling establishment rather than large mammal predation of oaks appear to be the primary factors in the decline of oaks in the disturbed areas.

  4. Food habits of the raccoon in eastern Texas

    USGS Publications Warehouse

    Baker, R.H.; Newman, C.C.; Wilke, F.

    1945-01-01

    The food habits of raccoons were studied along the Neches River in three counties of eastern Texas in 1940-42. Field studies mere supplemented by laboratory analyses of 344 scats collected in all months and of 23 stomachs and 11 intestines obtained in winter. Acorns and crayfish constitute more than half of the yearly diet and both are consumed in considerable amount at all seasons. Persimmons and grapes were utilized heavily when available and other fruits in smaller amounts. Insects and other invertebrates formed an important part of the diet. Vertebrates were eaten sparingly but species of water snakes were preyed upon as were winter and spring concentrations of water fowl.....Raccoons were found to concentrate in timbered river bottoms during the winter and spring, feeding largely on acorns and crayfish. Under these conditions they are readily trapped. In the summer and autumn the populations appear to be dispersed through the uplands as well as bottomlands in search of seasonal foods.

  5. Antioxidant Characterization of Oak Extracts Combining Spectrophotometric Assays and Chemometrics

    PubMed Central

    Popović, Boris M.; Štajner, Dubravka; Orlović, Saša; Galić, Zoran

    2013-01-01

    Antioxidant characteristics of leaves, twigs, and acorns from two Serbian oak species Quercus robur L. and Quercus petraea L. from Vojvodina province (northern Serbia) were investigated. 80% ethanol (in water) extracts were used for antiradical power (ARP) determinations against DPPH•, •NO, and O2•− radicals, ferric reducing antioxidant power (FRAP), total phenol, tannin, flavonoid, and proanthocyanidin contents. Permanganate reducing antioxidant capacity (PRAC) was determined using water extracts. Beside, mentioned parameters, soluble proteins, lipid peroxidation (LP), pigments and proline contents were also determined. The data of different procedures were compared and analyzed by multivariate techniques (correlation matrix calculation and principal component analysis (PCA)). PCA found that investigated organs of two different oak tree species possess similar antioxidant characteristics. The superior antioxidant characteristics showed oak leaves over twigs and acorns and seem to be promising source of antioxidants with possible use in industry and pharmacy. PMID:24453789

  6. Influence of pericarp, cotyledon and inhibitory substances on sharp tooth oak (Quercus aliena var. acuteserrata) germination.

    PubMed

    Liu, Yan; Liu, Guangquan; Li, Qingmei; Liu, Yong; Hou, Longyu; Li, Guolei

    2012-01-01

    In order to explore the mechanism of delayed and uneven germination in sharp tooth oak (Quercus aliena var. acuteserrata) (STO), mechanical scarification techniques were used to study STO root and shoot germination and growth. The techniques used were: removing cup scar (RS), removing the pericarp (RP), and cutting off 1/2 (HC) and 2/3 (TC) cotyledons. Germination percentage and root and shoot length for Chinese cabbage (Beassica pekinensis) seeds (CCS) were also investigated for CCS cultivated in a Sanyo growth cabinet watered by distilled water and 80% methanol extracts from the acorn embryo, cotyledon and pericarp with concentrations of 1.0 g, 0.8 g, 0.6 g and 0.4 g dry acorn weight per ml methanol. The results showed that the majority of roots and shoots from acorns with RP and HC treatment emerged two weeks earlier, more simultaneously, and their total emergencies were more than 46% and 28% higher, respectively. TC accelerated root and shoot emergence time and root length, but root and shoot germination rate and shoot height had no significant difference from the control. Positive consequences were not observed on all indices of RS treatment. The germination rates of CCS watered by 1.0 g · ml(-1) methanol extracts from the embryo and cotyledon were significantly lower than those from the pericarp, and all concentrations resulted in decreased growth of root and shoot. Methanol extracts from pericarp significantly reduced root length of CCS, but presented little response in germination percentage and shoot length. The inhibitory effect was gradually increased with the increasing concentration of the methanol extract. We conclude that both the mechanical restriction of the pericarp and the presence of germination inhibitors in the embryo, cotyledon and pericarp are the causes for delayed and asynchronous germination of STO acorns. PMID:23133517

  7. Soil cover by natural trees in agroforestry systems

    NASA Astrophysics Data System (ADS)

    Diaz-Ambrona, C. G. H.; Almoguera Millán, C.; Tarquis Alfonso, A.

    2009-04-01

    The dehesa is common agroforestry system in the Iberian Peninsula. These open oak parklands with silvo-pastoral use cover about two million hectares. Traditionally annual pastures have been grazed by cows, sheep and also goats while acorns feed Iberian pig diet. Evergreen oak (Quercus ilex L.) has other uses as fuelwood collection and folder after tree pruning. The hypothesis of this work is that tree density and canopy depend on soil types. We using the spanish GIS called SIGPAC to download the images of dehesa in areas with different soil types. True colour images were restoring to a binary code, previously canopy colour range was selected. Soil cover by tree canopy was calculated and number of trees. Processing result was comparable to real data. With these data we have applied a dynamic simulation model Dehesa to determine evergreen oak acorn and annual pasture production. The model Dehesa is divided into five submodels: Climate, Soil, Evergreen oak, Pasture and Grazing. The first three require the inputs: (i) daily weather data (maximum and minimum temperatures, precipitation and solar radiation); (ii) the soil input parameters for three horizons (thickness, field capacity, permanent wilting point, and bulk density); and (iii) the tree characterization of the dehesa (tree density, canopy diameter and height, and diameter of the trunk). The influence of tree on pasture potential production is inversely proportional to the canopy cover. Acorn production increase with tree canopy cover until stabilizing itself, and will decrease if density becomes too high (more than 80% soil tree cover) at that point there is competition between the trees. Main driving force for dehesa productivity is soil type for pasture, and tree cover for acorn production. Highest pasture productivity was obtained on soil Dystric Planosol (Alfisol), Dystric Cambisol and Chromo-calcic-luvisol, these soils only cover 22.4% of southwest of the Iberian peninssula. Lowest productivity was

  8. Spatial structure of the meroplankton community along a Patagonian fjord - The role of changing freshwater inputs

    NASA Astrophysics Data System (ADS)

    Meerhoff, Erika; Tapia, Fabián J.; Castro, Leonardo R.

    2014-12-01

    Freshwater inputs are major drivers of circulation, hydrographic structure, and productivity patterns along estuarine systems. We assessed the degree to which meroplankton community structure in the Baker/Martinez fjord complex (Chilean Patagonia, 47.5°S) responds to spatial and temporal changes in hydrographic conditions driven by seasonal changes in Baker river outflow. Zooplankton and hydrographic measurements were conducted along the fjord in early spring (October) and late summer (February), when river outflow was minimal and maximal, respectively. Major meroplankton groups found on these surveys were larval barnacles, crabs, bivalves and gastropods. There was a clear change in community structure between October and February, explained by a switch in the numerically dominant group from barnacle to bivalve larvae. This change in community structure was related to changes in hydrographic structure along the fjord, which are mainly associated with seasonal changes in the Baker river outflow. A variance partition analysis showed no significant spatial trend that could account for the variation in meroplankton along the Martinez channel, whereas temporal variability and environmental variables accounted for 36.6% and 27.6% of the variance, respectively. When comparing meroplankton among the Baker and Martinez channels in October, changes in environmental variables explained 44.9% of total variance, whereas spatial variability accounted for 23.5%. Early and late-stage barnacle larvae (i.e. nauplii and cyprids) were more abundant in water with lower temperature, and higher dissolved oxygen and chlorophyll-a concentration, whereas bivalve larvae were more strongly associated to warmer waters. The seasonal shift in numerical dominance, from barnacle larvae in early spring to bivalve larvae in late summer, suggests that reproduction of these groups is triggered by substantially different sets of conditions, both in terms of hydrography and food availability. The

  9. Kinetic studies of amylase and biomass production by Calvatia gigantea

    SciTech Connect

    Kekos, D.; Macris, B.J.

    1987-01-01

    Production of alpha-amylase (alpha-4, glucan 4-glucanohydrolase, EC 3.2.1.1) by microorganisms has been practiced for many years in small and large scale operations and the literature on this enzyme is voluminous. Aspergillus niger and Aspergillus oryzae have been reported as the main fungal species used for commercial production of the enzyme. On the other hand, large volumes of low-cost agricultural products such as acorn (the perisperm-free dry seed contains approximately 60% starch) are wasted in many countries and provide a challenge to biotechnology to efficiently utilize these rich sources of starch for the production of high added value products like enzymes. C. gigantea is an edible puffball excreting high levels of alpha-amylase when cultivated on different sources of starch containing elevated quantities of toxic tannic compounds. This fungus has been employed for the production of microbial protein from wastes and acorns containing high levels of toxic tannic compounds. The same fungus was also reported to grow on both hydrolyzable and condensed tannins as sole carbon sources. The present work was undertaken to investigate certain kinetic characteristics of alpha-amylase and biomass production by C. gigantea grown on soluble and acorn starch in a lab fermenter. (Refs. 18).

  10. Alveolar targeting of aerosol pentamidine. Toward a rational delivery system

    SciTech Connect

    Simonds, A.K.; Newman, S.P.; Johnson, M.A.; Talaee, N.; Lee, C.A.; Clarke, S.W. )

    1990-04-01

    Nebulizer systems that deposit a high proportion of aerosolized pentamidine on large airways are likely to be associated with marked adverse side effects, which may lead to premature cessation of treatment. We have measured alveolar deposition and large airway-related side effects (e.g., cough, breathlessness, and effect on pulmonary function) after aerosolization of 150 mg pentamidine isethionate labeled with {sup 99m}Tc-Sn-colloid. Nine patients with AIDS were studied using three nebulizer systems producing different droplet size profiles: the Acorn System 22, Respirgard II, and Respirgard II with the inspiratory baffle removed. Alveolar deposition was greatest and side effects least with the nebulizer producing the smallest droplet size profile (Respirgard II), whereas large airway-related side effects were prominent and alveolar deposition lowest with the nebulizer producing the largest droplet size (Acorn System 22). Values for alveolar deposition and adverse airway effects were intermediate using the Respirgard with inspiratory baffle removed, thus indicating the importance of the baffle valve in determining droplet size. Addition of a similar baffle valve to the Acorn System 22 produced a marked improvement in droplet size profile. Selection of a nebulizer that produces an optimal droplet size range offers the advantage of enhancing alveolar targeting of aerosolized pentamidine while reducing large airway-related side effects.

  11. Anatomical and developmental study of petrified Quercus (Fagaceae) fruits from the Middle Miocene, Yakima Canyon, Washington, USA.

    PubMed

    Borgardt, S J; Pigg, K B

    1999-03-01

    The first reported petrified acorns to show internal anatomical structure are here described from Middle Miocene (∼15.6 million years old) chert of the Columbia River Basalt Group in Yakima Canyon, Washington. Quercus hiholensis Borgardt et Pigg sp. nov. is described from anatomical and morphological fruit features, as well as a little recognized anatomical feature, the umbilical complex. Acorns, each comprising a nut and its cupule, are up to 15.3 mm long and 18.8 mm wide with helically arranged, imbricate, tuberculate cupule scales. They show basal aborted ovules, short styles, broad stigmas, and lack grooves in their cotyledons. These characters and the developmental pattern seen in these fossil acorns demonstrate that Q. hiholensis conforms to genus Quercus (Fagaceae), subgenus Quercus, section Quercus (the white oaks). The correspondence of Q. hiholensis to the modern section Quercus reveals that the derived floral and fruit characters that distinguish section Quercus within the genus had evolved by the Middle Miocene. PMID:10077494

  12. Using a Constructed-Response Instrument to Explore the Effects of Item Position and Item Features on the Assessment of Students' Written Scientific Explanations

    NASA Astrophysics Data System (ADS)

    Federer, Meghan Rector; Nehm, Ross H.; Opfer, John E.; Pearl, Dennis

    2015-08-01

    A large body of work has been devoted to reducing assessment biases that distort inferences about students' science understanding, particularly in multiple-choice instruments (MCI). Constructed-response instruments (CRI), however, have invited much less scrutiny, perhaps because of their reputation for avoiding many of the documented biases of MCIs. In this study we explored whether known biases of MCIs—specifically item sequencing and surface feature effects—were also apparent in a CRI designed to assess students' understanding of evolutionary change using written explanation (Assessment of COntextual Reasoning about Natural Selection [ACORNS]). We used three versions of the ACORNS CRI to investigate different aspects of assessment structure and their corresponding effect on inferences about student understanding. Our results identified several sources of (and solutions to) assessment bias in this practice-focused CRI. First, along the instrument item sequence, items with similar surface features produced greater sequencing effects than sequences of items with dissimilar surface features. Second, a counterbalanced design (i.e., Latin Square) mitigated this bias at the population level of analysis. Third, ACORNS response scores were highly correlated with student verbosity, despite verbosity being an intrinsically trivial aspect of explanation quality. Our results suggest that as assessments in science education shift toward the measurement of scientific practices (e.g., explanation), it is critical that biases inherent in these types of assessments be investigated empirically.

  13. Soil and rock 'Yogi'

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Several possible targets of study for rover Sojourner's Alpha Proton X-Ray Spectrometer (APXS) instrument are seen in this image, taken by the Imager for Mars Pathfinder (IMP) on Sol 2. The smaller rock at left has been dubbed 'Barnacle Bill,' while the larger rock at right, approximately 3-4 meters from the lander, is now nicknamed 'Yogi.' Barnacle Bill is scheduled to be the first object of study for the APXS. Portions of a petal and deflated airbag are also visible 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 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.

  14. Multispectral slice of APXS

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Portions of Sojourner's Alpha Proton X-Ray Spectrometer (APXS), a deployment spring, and the rock Barnacle Bill are visible in this color image. The image was taken by Sojourner's rear camera, and shows that the APXS made good contact with 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). 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.

  15. Effects of prolonged entanglement in discarded fishing gear with substantive biofouling on the health and behavior of an adult shortfin mako shark, Isurus oxyrinchus.

    PubMed

    Wegner, Nicholas C; Cartamil, Daniel P

    2012-02-01

    A mature male shortfin mako, Isurus oxyrinchus, was captured with a three-strand twisted natural fiber rope wrapped around the body causing deep abrasions, scoliosis of the back, and undernourishment. Fifty-two pelagic peduculate barnacles from four species were found fouling on the rope. Assuming larval settlement occurred following entanglement, barnacle growth-rate data suggest the rope had been around the shark for at least 150 days. However, the onset of severe scoliosis (likely linked to the increased constriction of the rope with growth and the added drag induced by biofouling) indicates that this rope may have been in place much longer. Following removal of the rope, a pop-up satellite archival tag was attached to the shark to assess post-release health. The resulting 54 days of tag deployment data show that despite its injuries, the shark survived, and following an initial stress period, exhibited movement patterns characteristic of healthy makos. PMID:22172235

  16. Affinity states of biocides determine bioavailability and release rates in marine paints.

    PubMed

    Dahlström, Mia; Sjögren, Martin; Jonsson, Per R; Göransson, Ulf; Lindh, Liselott; Arnebrant, Thomas; Pinori, Emiliano; Elwing, Hans; Berglin, Mattias

    2015-01-01

    A challenge for the next generation marine antifouling (AF) paints is to deliver minimum amounts of biocides to the environment. The candidate AF compound medetomidine is here shown to be released at very low concentrations, ie ng ml(-1) day(-1). Moreover, the release rate of medetomidine differs substantially depending on the formulation of the paint, while inhibition of barnacle settlement is independent of release to the ambient water, ie the paint with the lowest release rate was the most effective in impeding barnacle colonisation. This highlights the critical role of chemical interactions between biocide, paint carrier and the solid/aqueous interface for release rate and AF performance. The results are discussed in the light of differential affinity states of the biocide, predicting AF activity in terms of a high surface affinity and preserved bioavailability. This may offer a general framework for the design of low-release paint systems using biocides for protection against biofouling on marine surfaces. PMID:25775096

  17. Internal bioerosion in dead and live hard corals in intertidal zone of Hormuz Island (Persian Gulf).

    PubMed

    Jafari, Mohammad Ali; Seyfabadi, Jafar; Shokri, Mohammad Reza

    2016-04-30

    Internal macrobioeroders and their erosion rate in three live and dead coral genera (Favia, Platygyra and Porites) from the intertidal zone of the Hormuz Island were studied by collecting five live and five dead colonies from each genus, from which 4 mm cross-sections were cut and photographed. Photos were analyzed using the Coral Point Count with Excel extensions. Totally, 9 taxa were identified: four bivalve species, one sponge, three polychaetes, and one barnacle. Bioerosion rate did not significantly differ among the three live corals, but among the dead ones only Porites was significantly more eroded than Favia. Sponge had the highest role in the erosion of the dead Platygyra, while barnacles were the most effective eroding organism in the live Platygyra. Polychaetes, followed by bivalves, were the most destructive bioeroders on the dead and live Porites. Further, none of the bioeroding organisms had selectively chosen either the dead or live Favia. PMID:26654335

  18. Are Mussels Always the Best Bioindicators? Comparative Study on Biochemical Responses of Three Marine Invertebrate Species to Chronic Port Pollution.

    PubMed

    Laitano, María V; Fernández-Gimenez, Analía V

    2016-07-01

    Bivalves have traditionally been considered good bioindicators due to their sensitivity to pollution, among other features. This characteristic is shared by several other non-bivalve species as well, though studies in this respect remain scarce. This work aims to compare biomarker sensitivity to chronic port pollution among three intertidal invertebrate species with good bioindicator characteristics. Mussels' immunological (phenoloxidase and peroxidases) and biotransformation (glutathione-S-transferase) responses were contrasted against those of limpets and barnacles. The three species under study evidenced activity of all the enzymes measured, although with differences. Barnacle Balanus glandula was the most sensitive species showing pollution modulation of the three enzymes, which suggests that mussels would not always be the best bioindicator species among marine invertebrates depending on the responses that are assessed. PMID:27221210

  19. First 3D reconstruction of the rhizocephalan root system using MicroCT

    NASA Astrophysics Data System (ADS)

    Noever, Christoph; Keiler, Jonas; Glenner, Henrik

    2016-07-01

    Parasitic barnacles (Cirripedia: Rhizocephala) are highly specialized parasites of crustaceans. Instead of an alimentary tract for feeding they utilize a system of roots, which infiltrates the body of their hosts to absorb nutrients. Using X-ray micro computer tomography (MicroCT) and computer-aided 3D-reconstruction, we document the spatial organization of this root system, the interna, inside the intact host and also demonstrate its use for morphological examinations of the parasites reproductive part, the externa. This is the first 3D visualization of the unique root system of the Rhizocephala in situ, showing how it is related to the inner organs of the host. We investigated the interna from different parasitic barnacles of the family Peltogastridae, which are parasitic on anomuran crustaceans. Rhizocephalan parasites of pagurid hermit crabs and lithodid crabs were analysed in this study.

  20. Interspecific variation in patterns of adhesion of marine fouling to silicone surfaces.

    PubMed

    Holm, Eric R; Kavanagh, Christopher J; Meyer, Anne E; Wiebe, Deborah; Nedved, Brian T; Wendt, Dean; Smith, Celia M; Hadfield, Michael G; Swain, Geoff; Wood, Christina Darkangelo; Truby, Kathryn; Stein, Judith; Montemarano, Jean

    2006-01-01

    The adhesion of six fouling organisms: the barnacle Balanus eburneus, the gastropod mollusc Crepidulafornicata, the bivalve molluscs Crassostrea virginica and Ostrea/Dendrostrea spp., and the serpulid tubeworms Hydroides dianthus and H. elegans, to 12 silicone fouling-release surfaces was examined. Removal stress (adhesion strength) varied among the fouling species and among the surfaces. Principal component analysis of the removal stress data revealed that the fouling species fell into two distinct groups, one comprising the bivalve molluscs and tubeworms, and the other the barnacle and the gastropod mollusc. None of the silicone materials generated a minimum in removal stress for all the organisms tested, although several surfaces produced low adhesion strengths for both groups of species. These results suggest that fouling-release materials do not rank (in terms of adhesion strength) identically for all fouling organisms, and thus development of a globally-effective hull coating will continue to require testing against a diversity of encrusting species. PMID:17290867

  1. Monoclonal antibodies to the molluscan small cardioactive peptide SCPB: immunolabeling of neurons in diverse invertebrates.

    PubMed

    Masinovsky, B; Kempf, S C; Callaway, J C; Willows, A O

    1988-07-22

    We reported a development of murine monoclonal antibodies to a molluscan small cardioactive peptide (SCPB) and their application to immunolabeling of neurons in several molluscan and arthropod species. In vitro stimulations of mouse lymphocytes with SCPB conjugated to a carrier protein yielded exclusively IgM class antibodies; in vivo stimulation resulted in generation of both IgM and IgG classes of antibodies. Monoclonal antibodies of the IgM class labeled identified SCP-containing neuron B11 in the frozen sections of the buccal ganglia of Tritonia diomedia. These antibodies failed to stain any neurons in whole mount preparations. A monoclonal antibody of IgG1 subclass selectively labeled neurons in both frozen sections and whole mount preparations of diverse invertebrate species. Thus, neurons B11, B12, and GE1 and several other neurons of the buccal and gastroesophageal ganglia of T. diomedia bound the antibody, and a similar pattern of immunolabeling was found in the closely related gastropod Tritonia festiva. We also observed SCPB-like immunoreactivity in the central neurons of other nudibranch and pulmonate molluscs and in examples of insect (Acheta domesticus and Tehrmobia domestica) and crustacean (Semibalanus cariosus) classes of the Arthropoda. Our results suggest a specific pattern of distribution of SCPB-like immunoreactivity in the gastropod nervous system and a broad occurrence of SCPB-like antigenicity in the diverse invertebrates. PMID:3062048

  2. Ecological investigations of petroleum production platforms in the central Gulf of Mexico: volume II. Final report 1978

    SciTech Connect

    Not Available

    1981-01-01

    Surveys of biofouling macroepibiota and fishes were made in June 1978 at four production platforms offshore Louisiana and were supplemented by limited observations made at an additional 15 platforms in August and September of 1978. Biofouling communities of nearshore platforms were dominated by barnacles in terms of biomass, whereas the communities on offshore platforms were dominated by bivalves. Primary production was largely restricted to surface zones of nearshore platforms but at some offshore platforms primary producers were abundant to depths of 30 m.

  3. Marine plastic litter as an artificial hard bottom fouling ground

    NASA Astrophysics Data System (ADS)

    Harms, J.

    1990-09-01

    20 fouling organisms were observed on plastic litter dredged from the Elbe estuary during July 1990; 60% of the species were typical sessile hard bottom organisms. Most individuals found on this artificial hard bottom were barnacles ( Balanus crenatus, Elminius modestus), the mussel Mytilus edulis and the polychaete Lanice conchilega. All individuals were juveniles which had settled only recently on the plastics. The earliest settlers were not much older than 4 8 weeks.

  4. Marine Bioinspired Underwater Contact Adhesion.

    PubMed

    Clancy, Sean K; Sodano, Antonio; Cunningham, Dylan J; Huang, Sharon S; Zalicki, Piotr J; Shin, Seunghan; Ahn, B Kollbe

    2016-05-01

    Marine mussels and barnacles are sessile biofouling organisms that adhere to a number of surfaces in wet environments and maintain remarkably strong bonds. Previous synthetic approaches to mimic biological wet adhesive properties have focused mainly on the catechol moiety, present in mussel foot proteins (mfps), and especially rich in the interfacial mfps, for example, mfp-3 and -5, found at the interface between the mussel plaque and substrate. Barnacles, however, do not use Dopa for their wet adhesion, but are instead rich in noncatecholic aromatic residues. Due to this anomaly, we were intrigued to study the initial contact adhesion properties of copolymerized acrylate films containing the key functionalities of barnacle cement proteins and interfacial mfps, for example, aromatic (catecholic or noncatecholic), cationic, anionic, and nonpolar residues. The initial wet contact adhesion of the copolymers was measured using a probe tack testing apparatus with a flat-punch contact geometry. The wet contact adhesion of an optimized, bioinspired copolymer film was ∼15.0 N/cm(2) in deionized water and ∼9.0 N/cm(2) in artificial seawater, up to 150 times greater than commercial pressure-sensitive adhesive (PSA) tapes (∼0.1 N/cm(2)). Furthermore, maximum wet contact adhesion was obtained at ∼pH 7, suggesting viability for biomedical applications. PMID:27046671

  5. Differential recruitment of introduced Pacific oysters and native mussels at the North Sea coast: coexistence possible?

    NASA Astrophysics Data System (ADS)

    Diederich, Susanne

    2005-04-01

    Pacific oysters ( Crassostrea gigas Thunberg 1793) have been introduced into the Wadden Sea (North Sea), where they settle on native mussel beds ( Mytilus edulis L.), which represent the only extensive insular hard substrata in this soft-sediment environment. As abundances of C. gigas rose, some mussel beds became increasingly overgrown with oysters, whereas others did not. Field experiments revealed that recruitment of C. gigas was higher in the lower intertidal than in the upper subtidal zone, that it was higher on conspecifics than on mussels, and that it was not affected by barnacle epigrowth except when settling on mussels. Mussel recruitment is known from inter- and subtidal zones. It occurred equally on oyster and mussel shells but showed a clear preference for barnacle epigrowth over clean shells. Assuming that settlement and recruitment are key processes for species abundances on the North Sea coast, it is predicted that the positive feedback in oyster settlement will lead to rapid reef formation of this invader at the expense of mussel beds. Mussels, however, may escape competitive exclusion by settling between or on the larger oysters especially when barnacles are abundant. Experimental patches with mussels were more often covered by fucoid algae ( Fucus vesiculosus forma mytili Nienburg) than patches with oysters, and oyster recruitment was poor underneath such algal canopies. Thus, fucoids may provide the native mussels with a refuge from the invading oysters and the two bivalves may coexist, provided food is not limiting.

  6. Seasonal variability in the recruitment of macrofouling community in Kudankulam waters, east coast of India

    NASA Astrophysics Data System (ADS)

    Satheesh, S.; Godwin Wesley, S.

    2008-09-01

    The seasonal variability in fouling community recruitment on submerged artificial substratum was studied in Kudankulam coastal water, Gulf of Mannar, East coast of India for a period of two years, from May 2003 to April 2005. The results indicated that the fouling community recruitment occurred throughout the year with varying intensities. Barnacles, ascidians, polychaetes, bivalves and seaweeds were the major fouling groups observed from the test panels. Maximum fouling biomass of 9.17 g dm -2 was observed during August 2004 and a minimum value of 0.233 g dm -2 in February 2004. The biomass build-up on test panels was relatively high during the premonsoon season and low during the postmonsoon months. The number of barnacles settled on the panels varied from 1 to 4460 no. dm -2. The maximum percentage of the ascidian coverage (72%) on test panels was observed during March 2005. In general, July-December was the period of intense recruitment for barnacles and March-May was the period for ascidians.

  7. Cochliomycin A inhibits the larval settlement of Amphibalanus amphitrite by activating the NO/cGMP pathway.

    PubMed

    Wang, Kai-Ling; Zhang, Gen; Sun, Jin; Xu, Ying; Han, Zhuang; Liu, Ling-Li; Shao, Chang-Lun; Liu, Qing-Ai; Wang, Chang-Yun; Qian, Pei-Yuan

    2016-01-01

    Cochliomycin A is a compound with anti-barnacle settlement activity and low toxicity, but the molecular mechanism of the compound is unknown. Here, isobaric tags for the relative or absolute quantitation (iTRAQ) labeling proteomic method were applied to analyze changes in the proteome of Amphibalanus (=Balanus) amphitrite cyprids in response to cochliomycin A treatment. Cochliomycin A affected the cytochrome P450, glutathione S-transferase (GST) and NO/cGMP pathways, among which the NO/cGMP pathway was considered to play a key role in barnacle larval settlement, while the cytochrome P450 and the GST pathways are mainly for detoxification. The results of real-time PCR further suggested the NO/cGMP pathway was activated in response to cochliomycin A. Larval settlement assays revealed that S-methylisothiourea sulfate (SMIS) and 1H-(1,2,4)oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) rescued cyprids from cochliomycin A-induced inhibition of larval settlement. The findings supported the hypothesis that cochliomycin A inhibited barnacle larval settlement by stimulating the NO/cGMP pathway. PMID:26732984

  8. Quality assurance and control issues for HF radar wave and current measurements

    NASA Astrophysics Data System (ADS)

    Wyatt, Lucy

    2015-04-01

    HF radars are now widely used to provide surface current measurements over wide areas of the coastal ocean for scientific and operational applications. In general data quality is acceptable for these applications but there remain issues that impact on the quantity and quality of the data. These include problems with calibration and interference which impact on both phased array (e.g. WERA, Pisces) and direction-finding (e.g. SeaSonde) radars. These same issues and others (e.g. signal-to-noise, in-cell current variability, antenna sidelobes) also impact on the quality and quantity of wave data that can be obtained. These issues will be discussed in this paper, illustrated with examples from deployments of WERA, Pisces and SeaSonde radars in the UK, Europe, USA and Australia. These issues involve both quality assurance (making sure the radars perform to spec and the software is fully operational) and in quality control (identifying problems with the data due to radar hardware or software performance issues and flagging these in the provided data streams). Recommendations for the former, and current practice (of the author and within the Australian Coastal Ocean Radar Network, ACORN*) for the latter, will be discussed. The quality control processes for wave measurement are not yet as well developed as those for currents and data from some deployments can be rather noisy. Some new methods, currently under development by SeaView Sensing Ltd and being tested with ACORN data, will be described and results presented. *ACORN is a facility of the Australian Integrated Marine Observing System, IMOS. IMOS is a national collaborative research infrastructure, supported by Australian Government. It is led by University of Tasmania in partnership with the Australian marine and climate science community.

  9. High Rates of Gene Flow by Pollen and Seed in Oak Populations across Europe

    PubMed Central

    Gerber, Sophie; Chadœuf, Joël; Gugerli, Felix; Lascoux, Martin; Buiteveld, Joukje; Cottrell, Joan; Dounavi, Aikaterini; Fineschi, Silvia; Forrest, Laura L.; Fogelqvist, Johan; Goicoechea, Pablo G.; Jensen, Jan Svejgaard; Salvini, Daniela; Vendramin, Giovanni G.; Kremer, Antoine

    2014-01-01

    Gene flow is a key factor in the evolution of species, influencing effective population size, hybridisation and local adaptation. We analysed local gene flow in eight stands of white oak (mostly Quercus petraea and Q. robur, but also Q. pubescens and Q. faginea) distributed across Europe. Adult trees within a given area in each stand were exhaustively sampled (range [239, 754], mean 423), mapped, and acorns were collected ([17,147], 51) from several mother trees ([3], [47], 23). Seedlings ([65,387], 178) were harvested and geo-referenced in six of the eight stands. Genetic information was obtained from screening distinct molecular markers spread across the genome, genotyping each tree, acorn or seedling. All samples were thus genotyped at 5–8 nuclear microsatellite loci. Fathers/parents were assigned to acorns and seedlings using likelihood methods. Mating success of male and female parents, pollen and seed dispersal curves, and also hybridisation rates were estimated in each stand and compared on a continental scale. On average, the percentage of the wind-borne pollen from outside the stand was 60%, with large variation among stands (21–88%). Mean seed immigration into the stand was 40%, a high value for oaks that are generally considered to have limited seed dispersal. However, this estimate varied greatly among stands (20–66%). Gene flow was mostly intraspecific, with large variation, as some trees and stands showed particularly high rates of hybridisation. Our results show that mating success was unevenly distributed among trees. The high levels of gene flow suggest that geographically remote oak stands are unlikely to be genetically isolated, questioning the static definition of gene reserves and seed stands. PMID:24454802

  10. Workshop on seedling physiology and growth problems in oak plantings (5th) (abstracts). Held in Ames, Iowa on March 4-5, 1992. Forest Service general technical report

    SciTech Connect

    Thompson, J.R.; Schultz, R.C.; Van Sambeek, J.W.

    1993-01-01

    The fifth workshop on seedling physiology and growth problems in oak plantings was held at the Holiday Inn Gateway Center in Ames, Iowa on March 4 and 5, 1992 with more than 45 participants. The workshop continues to serve as an informal forum for researchers to exchange ideas and research results. Papers were divided into four general subject areas: (1) field performance of planted oaks, (2) seedling propagation and production, (3) oak physiology and genetics, and (4) natural and acorn germination regeneration. All abstracts prepared for the workshop are included in the technical report.

  11. ESD testing of the 8S actuator (u)

    SciTech Connect

    Mchugh, Douglas C

    2010-12-03

    The 8S actuator is a hot-wire initiated explosive component used to drive the W76-1 2X Acorn 1V valve. It is known to be safe from human electrostatic discharge (ESD) pin-to-pin and all pin-to-cup stimuli as well as 1 amp/1 watt safe. However low impedance (furniture) ESD stimuli applied pin-to-pin has not been evaluated. Components were tested and the results analyzed. The 8S actuator has been shown to be immune to human and severe furniture ESD, whether applied pin-to-pin or pin-to-cup.

  12. New developments in demographic targeting--the implications of 1991.

    PubMed

    Humby, C R

    1989-01-01

    This paper examines benefits that systems such as ACORN, a demographic marketing system that classifies neighborhoods, offer today and monitors some of the trends. It then considers the impact of the 1992 UK census and gives a view of what marketeers can expect in the next 5 years. Neighborhood classifications represent a summary of the consumption patterns of a set of neighbors. If we could reach individuals based on the current life stage the gains to be had would be as great again as that offered by the neighborhood classifications themselves. The greatest weakness of all the neighborhood-based systems is their inability to target at life stage or age. PMID:12342841

  13. Three new species of Glossobalanus (Hemichordata: Enteropneusta: Ptychoderidae) from western North America.

    PubMed

    Cameron, Christopher B; Ostiguy, Angélica

    2013-01-01

    Twenty three enteropneust species have been described from the west coast of North America, including one species from the family Ptychoderidae; Glossobalanus berkeleyi from the Salish Sea, Vancouver Island. Here we use morphology to describe three additional species of acorn worms in the genus Glossobalanus: G. williami from Cape Arago, Oregon; G hartmanae and G. barnharti from La Jolla, California. Notes on the habit and localization of each species as well as a dichotomous key to the genera of the family Ptychoderidae are provided. PMID:26131502

  14. Tree planters` notes, Volume 46, Number 4, Fall 1995. Quarterly report

    SciTech Connect

    Nisley, R.

    1995-12-31

    ;Contents: Bringing Tree Planter`s Note`s (TPNS`) Mission Into Focus ; Our New, Expanded Board of Advisory Editors; The Responsibility To Publish; Technical Update: Field Testing a Modified Duster for Supplemental Mass Pollination in Douglas-fir Seed Orchards; Research Reports: Mexican Conifers Response to Fertilizer Type Indicates Difference Between Value and Cost; Effect of Seed Size on Seedling Growth of a Shade-Tolerant Tropical Tree; Germination of Carolina Silverhell Seed; Effect of Seed Condition, Stratification, and Germination Temperature on the Laboratory Germination of Loblolly Pine Seed; and Test of the Float Method of Assessing Morthern Red Oak Acorn Condition.

  15. Continued development of a detailed model of arc discharge dynamics

    NASA Technical Reports Server (NTRS)

    Beers, B. L.; Pine, V. W.; Ives, S. T.

    1982-01-01

    Using a previously developed set of codes (SEMC, CASCAD, ACORN), a parametric study was performed to quantify the parameters which describe the development of a single electron indicated avalanche into a negative tip streamer. The electron distribution function in Teflon is presented for values of the electric field in the range of four-hundred million volts/meter to four billon volts/meter. A formulation of the scattering parameters is developed which shows that the transport can be represented by three independent variables. The distribution of ionization sites is used to indicate an avalanche. The self consistent evolution of the avalanche is computed over the parameter range of scattering set.

  16. Hemichordate genomes and deuterostome origins.

    PubMed

    Simakov, Oleg; Kawashima, Takeshi; Marlétaz, Ferdinand; Jenkins, Jerry; Koyanagi, Ryo; Mitros, Therese; Hisata, Kanako; Bredeson, Jessen; Shoguchi, Eiichi; Gyoja, Fuki; Yue, Jia-Xing; Chen, Yi-Chih; Freeman, Robert M; Sasaki, Akane; Hikosaka-Katayama, Tomoe; Sato, Atsuko; Fujie, Manabu; Baughman, Kenneth W; Levine, Judith; Gonzalez, Paul; Cameron, Christopher; Fritzenwanker, Jens H; Pani, Ariel M; Goto, Hiroki; Kanda, Miyuki; Arakaki, Nana; Yamasaki, Shinichi; Qu, Jiaxin; Cree, Andrew; Ding, Yan; Dinh, Huyen H; Dugan, Shannon; Holder, Michael; Jhangiani, Shalini N; Kovar, Christie L; Lee, Sandra L; Lewis, Lora R; Morton, Donna; Nazareth, Lynne V; Okwuonu, Geoffrey; Santibanez, Jireh; Chen, Rui; Richards, Stephen; Muzny, Donna M; Gillis, Andrew; Peshkin, Leonid; Wu, Michael; Humphreys, Tom; Su, Yi-Hsien; Putnam, Nicholas H; Schmutz, Jeremy; Fujiyama, Asao; Yu, Jr-Kai; Tagawa, Kunifumi; Worley, Kim C; Gibbs, Richard A; Kirschner, Marc W; Lowe, Christopher J; Satoh, Noriyuki; Rokhsar, Daniel S; Gerhart, John

    2015-11-26

    Acorn worms, also known as enteropneust (literally, 'gut-breathing') hemichordates, are marine invertebrates that share features with echinoderms and chordates. Together, these three phyla comprise the deuterostomes. Here we report the draft genome sequences of two acorn worms, Saccoglossus kowalevskii and Ptychodera flava. By comparing them with diverse bilaterian genomes, we identify shared traits that were probably inherited from the last common deuterostome ancestor, and then explore evolutionary trajectories leading from this ancestor to hemichordates, echinoderms and chordates. The hemichordate genomes exhibit extensive conserved synteny with amphioxus and other bilaterians, and deeply conserved non-coding sequences that are candidates for conserved gene-regulatory elements. Notably, hemichordates possess a deuterostome-specific genomic cluster of four ordered transcription factor genes, the expression of which is associated with the development of pharyngeal 'gill' slits, the foremost morphological innovation of early deuterostomes, and is probably central to their filter-feeding lifestyle. Comparative analysis reveals numerous deuterostome-specific gene novelties, including genes found in deuterostomes and marine microbes, but not other animals. The putative functions of these genes can be linked to physiological, metabolic and developmental specializations of the filter-feeding ancestor. PMID:26580012

  17. In-situ Iberian pig carcass classification using a micro-electro-mechanical system (MEMS)-based near infrared (NIR) spectrometer.

    PubMed

    Zamora-Rojas, E; Pérez-Marín, D; De Pedro-Sanz, E; Guerrero-Ginel, J E; Garrido-Varo, A

    2012-03-01

    Iberian pig (IP) products are gourmet foods highly appreciated at international markets, reaching high prices, because of its exquisite flavors. At present, there aren't practical and affordable analytical methods which can authenticate every single piece put on the market. This paper reports on the performance of a handheld micro-electro-mechanical system (MEMS)-based spectrometer (1600-2400nm) for authentication-classification of individual IP carcasses into different commercial categories. Performance (accuracy and instrumental design) of the instrument was compared with that of high-resolution NIRS monochromators (400-2500nm). A total of 300 carcasses of IPs raised under different feeding regimes ("Acorn", "Recebo" and "Feed") were analyzed in three modes (intact fat in the carcass, skin-free subcutaneous fat samples and melted fat samples). The best classification results for the MEMS instrument were: 93.9% "Acorn" carcasses correctly classified, 96.4% "Feed" and 60.6% "Recebo", respectively. Evaluation of model performance confirmed the suitability of the handheld device for individual, fast, non-destructive, low-cost analysis of IP carcasses on the slaughterhouse line. PMID:22075264

  18. Geographical variation in the spatial synchrony of a forest-defoliating insect: isolation of environmental and spatial drivers.

    PubMed

    Haynes, Kyle J; Bjørnstad, Ottar N; Allstadt, Andrew J; Liebhold, Andrew M

    2013-02-22

    Despite the pervasiveness of spatial synchrony of population fluctuations in virtually every taxon, it remains difficult to disentangle its underlying mechanisms, such as environmental perturbations and dispersal. We used multiple regression of distance matrices (MRMs) to statistically partition the importance of several factors potentially synchronizing the dynamics of the gypsy moth, an invasive species in North America, exhibiting outbreaks that are partially synchronized over long distances (approx. 900 km). The factors considered in the MRM were synchrony in weather conditions, spatial proximity and forest-type similarity. We found that the most likely driver of outbreak synchrony is synchronous precipitation. Proximity played no apparent role in influencing outbreak synchrony after accounting for precipitation, suggesting dispersal does not drive outbreak synchrony. Because a previous modelling study indicated weather might indirectly synchronize outbreaks through synchronization of oak masting and generalist predators that feed upon acorns, we also examined the influence of weather and proximity on synchrony of acorn production. As we found for outbreak synchrony, synchrony in oak masting increased with synchrony in precipitation, though it also increased with proximity. We conclude that precipitation could synchronize gypsy moth populations directly, as in a Moran effect, or indirectly, through effects on oak masting, generalist predators or diseases. PMID:23282993

  19. Morphology and development of a new species of Balanoglossus (Hemichordata: Enteropneusta: Ptychoderidae) from Shimoda, Japan.

    PubMed

    Miyamoto, Norio; Saito, Yasunori

    2007-12-01

    The morphology and development of a new species of the genus Balanoglossus belonging to the family Ptychoderidae are described in detail. This acorn worm was collected from the sandy seashore in the cove near Shimoda Marine Research Center, University of Tsukuba (Shimoda, Shizuoka Prefecture, Japan). This acorn worm is easily distinguished from other balanoglossids by a characteristic hepatic region. There are two kinds of hepatic saccules: large, dark-colored saccules in the anterior region and small, light-colored saccules in the posterior region. Between the two subregions of the hepatic region, there is a small region that has no or tiny saccules. This species does not form distinct burrows or mounds of casts. The breeding season is in winter. The process of embryogenesis from fertilization to metamorphosis was observed. A shift in seawater temperature from about 13 degrees C to about 9 degrees C induced gamete release. Two days after fertilization, embryos hatched and became typical feeding tornaria larvae. Two months after fertilization these larvae metamorphosed into juveniles and began their benthic life. PMID:18271645

  20. Hemichordate genomes and deuterostome origins

    PubMed Central

    Simakov, Oleg; Kawashima, Takeshi; Marlétaz, Ferdinand; Jenkins, Jerry; Koyanagi, Ryo; Mitros, Therese; Hisata, Kanako; Bredeson, Jessen; Shoguchi, Eiichi; Gyoja, Fuki; Yue, Jia-Xing; Chen, Yi-Chih; Freeman, Robert M.; Sasaki, Akane; Hikosaka-Katayama, Tomoe; Sato, Atsuko; Fujie, Manabu; Baughman, Kenneth W.; Levine, Judith; Gonzalez, Paul; Cameron, Christopher; Fritzenwanker, Jens H.; Pani, Ariel M.; Goto, Hiroki; Kanda, Miyuki; Arakaki, Nana; Yamasaki, Shinichi; Qu, Jiaxin; Cree, Andrew; Ding, Yan; Dinh, Huyen H.; Dugan, Shannon; Holder, Michael; Jhangiani, Shalini N.; Kovar, Christie L.; Lee, Sandra L.; Lewis, Lora R.; Morton, Donna; Nazareth, Lynne V.; Okwuonu, Geoffrey; Santibanez, Jireh; Chen, Rui; Richards, Stephen; Muzny, Donna M.; Gillis, Andrew; Peshkin, Leonid; Wu, Michael; Humphreys, Tom; Su, Yi-Hsien; Putnam, Nicholas H.; Schmutz, Jeremy; Fujiyama, Asao; Yu, Jr-Kai; Tagawa, Kunifumi; Worley, Kim C.; Gibbs, Richard A.; Kirschner, Marc W.; Lowe, Christopher J.; Satoh, Noriyuki; Rokhsar, Daniel S.; Gerhart, John

    2015-01-01

    Acorn worms, also known as enteropneust (literally, ‘gut-breathing’) hemichordates, are marine invertebrates that share features with echinoderms and chordates. Together, these three phyla comprise the deuterostomes. Here we report the draft genome sequences of two acorn worms, Saccoglossus kowalevskii and Ptychodera flava. By comparing them with diverse bilaterian genomes, we identify shared traits that were probably inherited from the last common deuterostome ancestor, and then explore evolutionary trajectories leading from this ancestor to hemichordates, echinoderms and chordates. The hemichordate genomes exhibit extensive conserved synteny with amphioxus and other bilaterians, and deeply conserved non-coding sequences that are candidates for conserved gene-regulatory elements. Notably, hemichordates possess a deuterostome-specific genomic cluster of four ordered transcription factor genes, the expression of which is associated with the development of pharyngeal ‘gill’ slits, the foremost morphological innovation of early deuterostomes, and is probably central to their filter-feeding lifestyle. Comparative analysis reveals numerous deuterostome-specific gene novelties, including genes found in deuterostomes and marine microbes, but not other animals. The putative functions of these genes can be linked to physiological, metabolic and developmental specializations of the filter-feeding ancestor. PMID:26580012

  1. [Pyrogallol concentrations in rumen content, liver and kidney of cows at pasture].

    PubMed

    Meiser, H; Hagedorn, H W; Schulz, R

    2000-03-01

    Pyrogallol (1, 2, 3-trihydroxybenzene), the decomposition product of hydrolysable tannins in oak bark, leaves and acorns, is suspected to be poisonous to animals. The aim of our investigations was to correlate clinical signs and pathological findings with pyrogallol concentrations in organs of poisoned and healthy animals. In a field study, pyrogallol concentrations were determined in liver, kidney, and rumen from seven cattle. In a herd of twelve cows, five animals suffered from hemorrhagic diarrhea, anorexia, weakness, rumen stasis, dyspnoea, and colic symptoms. Death was observed in five cows within five weeks after repeated intake of green acorns and oak leaves. Toxicological analyses of rumen content, liver, and kidney specimens of one cattle confirmed the suspicion of pyrogallol contamination. In this animal, values ranged from 6 to 13 ng pyrogallol per gram specimen. In control cattle, concentrations were clearly lower than in perished cattle. Under antioxidative work-up conditions, detection limit was 0.6 ng/g in rumen content and 1.0 ng/g in liver and kidney, respectively. PMID:10763554

  2. Structural evidence for electromagnetic resonance in plant morphogenesis.

    PubMed

    Pietak, Alexis Mari

    2012-09-01

    How a homogeneous collective of cells consistently and precisely establishes long-range tissue patterns remains a question of active research. This work explores the hypothesis of plant organs as resonators for electromagnetic radiation. Long-range structural patterns in the developing ovaries and male flower buds of cucurbit plants (zucchini, acorn, and butternut squash), in addition to mature cucurbit fruits (acorn, butternut, and zucchini squash; watermelon, and cucumber), were investigated. A finite element analysis (FEA) model was used to determine resonant EM modes for models with similar geometric and electrical parameters to those of developing organs. Main features of the developing ovaries (i.e. shape of placental lines, ovum location, definition of distinct tissue regions), male flower buds (i.e. early pollen tube features), and mature fruits (i.e. septa placement, seed location, endocarp and mesocarp) showed distinct correlations with electric and magnetic field components of electromagnetic resonant modes. On account of shared pattern signatures in developing organs and the EM resonant modes supported by a modelled structure with similar geometric and electrical properties to those of cucurbit organs, experimental investigations are warranted. The concept of a developing organ as an EM dielectric resonator may extend to a variety of morphogenetic phenomena in a number of living systems. PMID:22326259

  3. Cache placement, pilfering, and a recovery advantage in a seed-dispersing rodent: Could predation of scatter hoarders contribute to seedling establishment?

    NASA Astrophysics Data System (ADS)

    Steele, Michael A.; Bugdal, Melissa; Yuan, Amy; Bartlow, Andrew; Buzalewski, Jarrod; Lichti, Nathan; Swihart, Robert

    2011-11-01

    Scatter-hoarding mammals are thought to rely on spatial memory to relocate food caches. Yet, we know little about how long these granivores (primarily rodents) recall specific cache locations or whether individual hoarders have an advantage when recovering their own caches. Indeed, a few recent studies suggest that high rates of pilferage are common and that individual hoarders may not have a retriever's advantage. We tested this hypothesis in a high-density (>7 animals/ha) population of eastern gray squirrels ( Sciurus carolinensis) by presenting individually marked animals (>20) with tagged acorns, mapping cache sites, and following the fate of seed caches. PIT tags allowed us to monitor individual seeds without disturbing cache sites. Acorns only remained in the caches for 12-119 h (0.5-5 d). However, when we live-trapped and removed some animals from the site immediately after they stored seeds (thus simulating predation), their seed caches remained intact for significantly longer periods (16-27 d). Cache duration corresponded roughly to the time at which squirrels were returned to the study area. These results suggest that squirrels have a retriever's advantage and may remember specific cache sites longer than previously thought. We further suggest that predation of scatter hoarders who store seeds for long periods and also possess a recovery advantage may be one important mechanism by which seed establishment is achieved.

  4. Detoxification and mineral supplementation as functions of geophagy

    SciTech Connect

    Johns, T.; Duquette, M. )

    1991-02-01

    Clays employed historically in the consumption of astringent acorns plus seven edible clays from Africa were examined in relation to the functional significance of human geophagy. On the basis of sorptive maxima for tannic acid ranging from 5.6 to 23.7 mg/g, we conclude that adsorption of tannic acid in traditional acorn preparation methods in California and Sardinia helped make these nuts palatable. Calcium available in solution at pH 2.0 and 0.1 mol NaCl/L was 2.10 and 0.71 mg/g for the Sardinian and Californian clays, respectively. The African clays released calcium, copper, iron, magnesium, manganese, or zinc in amounts of nutritional significance from some clays but not from others. A clay recovered from an archaeological site occupied by Homo erectus and early H. sapiens was indistinguishable mineralogically, in detoxification capacity and in available minerals, from clays used in Africa today. We suggest that the physiological significance of geophagy made it important in the evolution of human dietary behavior.

  5. Migratory herbivorous waterfowl track satellite-derived green wave index.

    PubMed

    Shariatinajafabadi, Mitra; Wang, Tiejun; Skidmore, Andrew K; Toxopeus, Albertus G; Kölzsch, Andrea; Nolet, Bart A; Exo, Klaus-Michael; Griffin, Larry; Stahl, Julia; Cabot, David

    2014-01-01

    Many migrating herbivores rely on plant biomass to fuel their life cycles and have adapted to following changes in plant quality through time. The green wave hypothesis predicts that herbivorous waterfowl will follow the wave of food availability and quality during their spring migration. However, testing this hypothesis is hampered by the large geographical range these birds cover. The satellite-derived normalized difference vegetation index (NDVI) time series is an ideal proxy indicator for the development of plant biomass and quality across a broad spatial area. A derived index, the green wave index (GWI), has been successfully used to link altitudinal and latitudinal migration of mammals to spatio-temporal variations in food quality and quantity. To date, this index has not been used to test the green wave hypothesis for individual avian herbivores. Here, we use the satellite-derived GWI to examine the green wave hypothesis with respect to GPS-tracked individual barnacle geese from three flyway populations (Russian n = 12, Svalbard n = 8, and Greenland n = 7). Data were collected over three years (2008-2010). Our results showed that the Russian and Svalbard barnacle geese followed the middle stage of the green wave (GWI 40-60%), while the Greenland geese followed an earlier stage (GWI 20-40%). Despite these differences among geese populations, the phase of vegetation greenness encountered by the GPS-tracked geese was close to the 50% GWI (i.e. the assumed date of peak nitrogen concentration), thereby implying that barnacle geese track high quality food during their spring migration. To our knowledge, this is the first time that the migration of individual avian herbivores has been successfully studied with respect to vegetation phenology using the satellite-derived GWI. Our results offer further support for the green wave hypothesis applying to long-distance migrants on a larger scale. PMID:25248162

  6. Three classes of Martian rocks

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In this portion of the 360-degree color gallery pan, looking to the northeast, the colors have been exaggerated to highlight the differences between rocks and soils. Visible are the downwind sides of rocks, not exposed to wind scouring like Barnacle Bill (which faces upwind). There is a close correspondence between the shapes and colors of the rocks. Three general classes of rocks are recognized: large rounded rocks with weathered coatings, small gray angular rocks lacking weathered coatings, and flat white rocks. The large rounded rocks in the distance, marked by the red arrows, are comparable to Yogi. Spectral properties show that these rocks have a highly weathered coating in addition to a distinctive shape. A second population of smaller, angular rocks (blue arrows) in the foreground have unweathered surfaces even on the downwind side, except where covered on their tops by drift. These are comparable to Barnacle Bill. They may have been emplaced at the site relatively recently, perhaps as ejecta from an impact crater, so they have not had time to weather as extensively as the larger older rocks. The third kind of rock (white arrows) is white and flat, and includes Scooby Doo in the foreground and a large deposit in the background called Baker's Bank. The age of the white rock relative to the other two classes is still being debated. One representative rock of each class (Yogi, Barnacle Bill, and Scooby Doo) has been measured by the rover.

    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).

  7. Rapid Smothering of Coral Reef Organisms by Muddy Marine Snow

    NASA Astrophysics Data System (ADS)

    Fabricius, K. E.; Wolanski, E.

    2000-01-01

    Estuarine mud, when resuspended in nutrient-rich near-shore water, aggregates to marine snow, and within minutes to hours can exert detrimental or even lethal effects on small coral reef organisms. In a pilot study, estuarine mud was suspended in near-shore and off-shore waters of the Great Barrier Reef to a final concentration of 170 mg l -1. The short-term responses of a coral ( Acropora sp.) and coral-inhabiting barnacles (subfamily Pyrgomatidae), exposed to either near-shore or off-shore water, were microscopically observed and video recorded. In the off-shore water treatment, flocculation was minor, and aggregate sizes were c. 50 μm. The organisms were able to clean themselves from these small settling aggregates at low siltation (<0·5 mg cm -2), and struggled and produced mucus only at high siltation (4-5 mg cm -2). In contrast, in near-shore, nutrient-enriched waters, the suspended mud aggregated into large sticky flocs of marine snow (200-2000 μm diameter). The organisms responded to a thin coat of deposited flocs with vigorous cleaning by cirri and tentacle beating. After 5 min struggle, the barnacle stopped moving, calanoid copepods were entangled in the aggregates, and thick layers of mucus were exuded by the coral polyps. Both barnacle and copepods died after <1 h exposure; a short time compared with natural occurrences of marine snow deposition on coral reefs. Enhanced nutrient concentrations are known to contribute to enhance biologically mediated flocculation. This pilot study suggests that the concentration of suspended mud, and extent of stickiness and flocculation, can synergistically affect reef benthos organisms after short exposure. The enclosed macro video recordings clearly visualize these effects, and help convey the important implications for managers: that inshore reefs of the Great Barrier Reef cannot be sustainably managed without managing the adjacent land.

  8. Migratory Herbivorous Waterfowl Track Satellite-Derived Green Wave Index

    PubMed Central

    Shariatinajafabadi, Mitra; Wang, Tiejun; Skidmore, Andrew K.; Toxopeus, Albertus G.; Kölzsch, Andrea; Nolet, Bart A.; Exo, Klaus-Michael; Griffin, Larry; Stahl, Julia; Cabot, David

    2014-01-01

    Many migrating herbivores rely on plant biomass to fuel their life cycles and have adapted to following changes in plant quality through time. The green wave hypothesis predicts that herbivorous waterfowl will follow the wave of food availability and quality during their spring migration. However, testing this hypothesis is hampered by the large geographical range these birds cover. The satellite-derived normalized difference vegetation index (NDVI) time series is an ideal proxy indicator for the development of plant biomass and quality across a broad spatial area. A derived index, the green wave index (GWI), has been successfully used to link altitudinal and latitudinal migration of mammals to spatio-temporal variations in food quality and quantity. To date, this index has not been used to test the green wave hypothesis for individual avian herbivores. Here, we use the satellite-derived GWI to examine the green wave hypothesis with respect to GPS-tracked individual barnacle geese from three flyway populations (Russian n = 12, Svalbard n = 8, and Greenland n = 7). Data were collected over three years (2008–2010). Our results showed that the Russian and Svalbard barnacle geese followed the middle stage of the green wave (GWI 40–60%), while the Greenland geese followed an earlier stage (GWI 20–40%). Despite these differences among geese populations, the phase of vegetation greenness encountered by the GPS-tracked geese was close to the 50% GWI (i.e. the assumed date of peak nitrogen concentration), thereby implying that barnacle geese track high quality food during their spring migration. To our knowledge, this is the first time that the migration of individual avian herbivores has been successfully studied with respect to vegetation phenology using the satellite-derived GWI. Our results offer further support for the green wave hypothesis applying to long-distance migrants on a larger scale. PMID:25248162

  9. Visitor impact on rocky shore communities of Qeshm Island, the Persian Gulf, Iran.

    PubMed

    Pour, Fatemeh Aghajan; Shokri, Mohammad Reza; Abtahi, Behrooz

    2013-02-01

    The influence of visitors on macroinvertebrates of rocky intertidal shores was investigated in southern coasts of the Qeshm Island, the Persian Gulf, Iran. Qeshm Island located at the Strait of Hormuz, with an area of 1,491 km(2), is the largest island in the region. This island consists of a number of important natural habitat types including creeks, mangroves, corals, and sandy, muddy, and rocky shores that accommodate diverse marine flora and fauna communities. Two rocky shores were selected at the touristic beaches being visited regularly, and further two control locations selected at pristine shores. Intertidal macroinvertebrates were collected from six microhabitats including rock platforms, cobbles, boulders, crevices, sea walls, and rock pools during two different periods representing high and low tourist seasons. Species richness, density, and assemblage structure in heavily visited shores were compared with that of control locations. Striped barnacles (Balanus amphitrite) were present on platforms of all locations, thus the changes in their size were used as the obvious contrast associated with visitor's impact. A total of 70 macroinvertebrate species from 11 phyla were recorded. Significant differences were detected in taxonomic richness, density, and assemblage structure of macroinvertebrates between heavily visited and pristine shores, suggesting that macroinvertebrates were adversely affected by visitors' impact at heavily visited shores. The test of changes in species richness, density, and assemblage structure from high to low seasons yielded mixed results. The significant changes in density and assemblage structure from high to low seasons were only observed in one heavily visited shore. A significant reduction in size of striped barnacles was observed only in one heavily visited shore. The opportunistic or fugitive species (e.g., small macroalgae and barnacles) were dominant macroinvertebrates on heavily visited shores indicating early succession

  10. Rock wall fauna in a deep Newfoundland fiord

    NASA Astrophysics Data System (ADS)

    Haedrich, Richard L.; Gagnon, Jean-Marc

    1991-08-01

    Research dives with PISCES IV in the Bay D'Espoir fiord system of southern Newfoundland revealed a rich and abundant fauna inhabiting the rock walls in the warm deep (790 m) central basin. The giant file clam Acesta excavata, otherwise unknown in the western North Atlantic, was in many places a dominant species. Species otherwise known from continental slope depths quite removed from the fiord included the anemone Actinauge sp., sponges, alcyonarians, the fish Phycis chesteri and Nezumia bairdii and the gooseneck barnacle Arcoscalpellum mitchellotianum. The food source for this abundant fauna is unknown. Nearby cold water basins are impoverished with respect to the fauna.

  11. Crustaceans from antipatharians on banks of the northwestern Gulf of Mexico

    PubMed Central

    Wicksten, Mary K.; Nuttall, Marissa F.; Hickerson, Emma L.

    2014-01-01

    Abstract The stalked barnacle Oxynaspis gracilis, the chirostylid squat lobster Uroptychus sp., and the caridean shrimps Periclimenes cf. antipathophilus and Pseudopontonides principis have been collected at 68–124 m by a remotely operated vehicle (ROV) on banks in the northern Gulf of Mexico. These species inhabited six species of antipatharian hosts. Pseudopontonides principis, Oxynaspis gracilis, and Uroptychus sp. were not confined to a single host species. Except for Oxynaspis gracilis, collected by ROV in 2004–2005, these species have not been reported previously in the northwestern Gulf of Mexico. PMID:25561830

  12. Investigations of belukha whales in coastal waters of western and northern Alaska, 1982-1983: marking and tracking of whales in Bristol Bay

    SciTech Connect

    Frost, K.J.; Lowry, L.F.; Nelson, R.R.

    1983-12-01

    A 2-year study was conducted in Bristol Bay, Alaska, to develop and test techniques for marking belukha whales with visual and radio tags. Information was also gathered on belukha distribution and abundance, foods and feeding, and rates and causes of mortality. Two types of radio packages were developed: an OAR backpack designed to be bolted through the dorsal ridge, and a Telonics barnacle tag with an umbrella-stake attachment. Testing of tags and attachments revealed that the more-powerful OAR radio could be received at longer distances and lower antenna heights, and the the umbrella-stake attachment penetrated too deeply for reliable use on belukhas.

  13. Hydrothermal Vents and Organic Falls in the Heart of the Coral Triangle: Chemosynthetic Communities Discovered via Telepresence in the Sangihe-Talaud Region, Northern Sulawesi, Indonesia

    NASA Astrophysics Data System (ADS)

    Shank, T. M.; Herrera, S.; Bors, E.; Munro, C.; Sibert, E.; Nganro, N.; Makarim, S.; Wirasantosa, S.; Tunnicliffe, V.; Baker, E. T.; Butterfield, D. A.; Holden, J. F.; Hammond, S. R.

    2010-12-01

    From June to August 2010, an international partnership of scientists and engineers from the United States, Canada, and Indonesia utilized the NOAA Ship Okeanos Explorer and HD video from the ROV Little Herc to explore virtually unknown deep seafloor in the heart of the Coral Triangle. The INDEX-SATAL 2010 expedition bathymetrically mapped more than 39,000sq km of the Sangihe-Talaud region, including several discrete volcanic cones on the western flank of the Sangihe Arc. Twenty sites between 275m and 3650m were explored during 27 ROV dives, including the first (and only) known hydrothermally-active site (1850m) in the Indonesian region, Kawio Barat, a volcanically active seamount hosting chemosynthetic ecosystems. The dominant fauna inhabiting hydrothermally-active areas were: 1) three shrimp morpho-species resembling Opaepele sp. and Chorocaris sp., intermingling on the sides of active smokers, amongst stalked barnacles, and scraping mineral surfaces; 2) large (10cm-long) polynoid scale worms (aff Branchinotogluma sp.) meandering through diffuse venting and within barnacle assemblages; 3) discrete patches of tube-dwelling alvinellid polychaetes, and perhaps the most dominant, stalked Vulcanolepas barnacles, densely packed at the base of individual spires, as well as completely carpeting 3 to 4m-tall inactive chimneys on the summit crest of the seamount, particularly above the main group of active chimneys. Brachyuran and galatheid crabs were observed amongst stalked barnacles and in sulfide crevices. Vesicoymid-like clams (5 to 10cm long) were observed on the surface of volcanoclastic and pelagic sediment 50 to 125m down slope of the active venting. Other potentially chemosynthetic habitats were observed at several sites, including wooden logs and coconut shells. For example, the sedimented slopes of Seamount G (1926m) and flats of Memeridge (3600m) contained a notable lack of epibenthic fauna with the notable exception of frequent wood falls inhabited by a

  14. Optical Spectroscopy of Marine Bioadhesive Interfaces

    NASA Astrophysics Data System (ADS)

    Barlow, Daniel E.; Wahl, Kathryn J.

    2012-07-01

    Marine organisms have evolved extraordinarily effective adhesives that cure underwater and resist degradation. These underwater adhesives differ dramatically in structure and function and are composed of multiple proteins assembled into functional composites. The processes by which these bioadhesives cure—conformational changes, dehydration, polymerization, and cross-linking—are challenging to quantify because they occur not only underwater but also in a buried interface between the substrate and the organism. In this review, we highlight interfacial optical spectroscopy approaches that can reveal the biochemical processes and structure of marine bioadhesives, with particular emphasis on macrofoulers such as barnacles and mussels.

  15. Antifouling Compounds from the Marine-Derived Fungus Aspergillus terreus SCSGAF0162.

    PubMed

    Nong, Xu-Hua; Zhang, Xiao-Yong; Xu, Xin-Ya; Qi, Shu-Hua

    2015-06-01

    A new cyclic tetrapeptide, asperterrestide B (1), and 11 known compounds (2-12) were isolated from a marine-derived fungus Aspergillus terreus SCSGAF0162. The structure of 1 was elucidated by spectroscopic analysis, and the absolute configuration of 1 was determined by Mosher ester and Marfey's methods. Compounds 4, 6, and 8 had potent antifouling activity against larvae of the barnacle Balanus amphitrite, with EC50 values of 17.1 ± 1.2, 11.6 ± 0.6, and 17.1 ± 0.8 μg x mL(-1), respectively. PMID:26197544

  16. Industry weapons grow in bifouling battle

    SciTech Connect

    Rittenhouse, R.C.

    1991-10-01

    Macrofouling holds the industry's full attention - again. Thank the zebra mussel for that. Never have the United States' fresh water bodies been more threatened, nor have power plants faced greater challenges from waterborne creatures. Earlier, Asian clams prompted a flurry of preventive activity. Before that, saltwater barnacles and marine blue mussels led the pack of waterborne nuisances. Each still threatens power plant reliability. This paper reports that now joined by the zebra mussel to form a macroinvertebrate gang of four, the group is sending plant operating and maintenance costs sky high.

  17. Crustaceans from antipatharians on banks of the northwestern Gulf of Mexico.

    PubMed

    Wicksten, Mary K; Nuttall, Marissa F; Hickerson, Emma L

    2014-01-01

    The stalked barnacle Oxynaspisgracilis, the chirostylid squat lobster Uroptychus sp., and the caridean shrimps Periclimenescf.antipathophilus and Pseudopontonidesprincipis have been collected at 68-124 m by a remotely operated vehicle (ROV) on banks in the northern Gulf of Mexico. These species inhabited six species of antipatharian hosts. Pseudopontonidesprincipis, Oxynaspisgracilis, and Uroptychus sp. were not confined to a single host species. Except for Oxynaspisgracilis, collected by ROV in 2004-2005, these species have not been reported previously in the northwestern Gulf of Mexico. PMID:25561830

  18. A new species of Leioseius (Acari: Ascidae) from Brazil, redescription of Leioseius basis and a key for separation of the world species of the genus.

    PubMed

    Santos, Jandir C; Moraes, Gilberto J De

    2016-01-01

    Leioseius Berlese is known in South America only from one especies described from Chile. Leioseius cananeiensis n. sp. is described based on the morphology of adult females found in association with barnacles (Crustacea, Cirripedia) on roots of Laguncularia racemosa (L.) (Combretaceae) collected in Cananéia, São Paulo State, Brazil. Leioseius basis Karg is redescribed based on the holotype female, one paratype female and two sparatype males. A key for the separation of females of the 19 recognisable world Leioseius species is provided. PMID:27615869

  19. Learn, how to learn

    NASA Astrophysics Data System (ADS)

    Narayanan, M.

    2002-12-01

    Ernest L. Boyer, in his 1990 book, "Scholarship Reconsidered: Priorities of the Professorate" cites some ground breaking studies and offers a new paradigm that identifies the need to recognize the growing conversation about teaching, scholarship and research in the Universities. The use of `ACORN' model suggested by Hawkins and Winter to conquer and mastering change, may offer some helpful hints for the novice professor, whose primary objective might be to teach students to `learn how to learn'. Action : It is possible to effectively change things only when a teaching professor actually tries out a new idea. Communication : Changes are successful only when the new ideas effectively communicated and implemented. Ownership : Support for change is extremely important and is critical. Only strong commitment for accepting changes demonstrates genuine leadership. Reflection : Feedback helps towards thoughtful evaluation of the changes implemented. Only reflection can provide a tool for continuous improvement. Nurture : Implemented changes deliver results only when nurtured and promoted with necessary support systems, documentation and infrastructures. Inspired by the ACORN model, the author experimented on implementing certain principles of `Total Quality Management' in the classroom. The author believes that observing the following twenty principles would indeed help the student learners how to learn, on their own towards achieving the goal of `Lifelong Learning'. The author uses an acronym : QUOTES : Quality Underscored On Teaching Excellence Strategy, to describe his methods for improving classroom teacher-learner participation. 1. Break down all barriers. 2. Create consistency of purpose with a plan. 3. Adopt the new philosophy of quality. 4. Establish high Standards. 5. Establish Targets / Goals. 6. Reduce dependence on Lectures. 7. Employ Modern Methods. 8. Control the Process. 9. Organize to reach goals. 10. Prevention vs. Correction. 11. Periodic Improvements. 12

  20. Worldwide clinical experience with the CorCap Cardiac Support Device.

    PubMed

    Starling, Randall C; Jessup, Mariell

    2004-12-01

    It has been hypothesized that the mechanical burden associated with LV remodeling leads to increased myocardial wall stress and adverse remodeling, all of which serve to further impair cardiac performance and contribute to disease progression. The CorCap Cardiac Support Device (CSD) (Acorn Cardiovascular, Inc., St. Paul, Minnesota) is a mesh-like device that is surgically implanted around the heart. The device is designed to provide circumferential myocardial wall support, and reduce wall stress and myocyte stretch. Clinical experience with CorCap CSD implants in patients with heart failure can be divided into 3 phases: (1) initial safety studies, (2) randomized controlled trials, and (3) limited marketed release. Initial safety studies were undertaken in 48 patients recruited between April 1999 and April of 2001. In 11 patients with complete follow-up, it was noted that LV size, as measured by LV end-diastolic dimension, significantly decreased as early as 3 months postimplant, with an even greater reduction at 6 months. Most importantly, this benefit was sustained, so that the LV end-diastolic dimension stayed smaller at 1, 2, and 3 years of follow-up. There was also an improvement in LV function, as manifested by changes in LV ejection fraction. Ejection fraction was significantly increased by 3 months and appeared to reach a peak improvement by 6 months. This benefit was likewise maintained at 1, 2, and 3 years postsurgery. Hemodynamic data did not show any evidence of constrictive physiology. These preliminary safety studies had shown that the CorCap CSD could be implanted safely and without excess operative morbidity or mortality. The primary objective of the Acorn Randomized Clinical Trial is to assess the efficacy and safety of the CorCap CSD in patients with advanced heart failure despite optimal medical therapy. A randomized trial with 2 arms (mitral valve surgery randomized to CSD and cardiomyopathy randomized to medical therapy alone or with CSD

  1. Positive and negative effects of mesograzers on early-colonizing species in an intertidal rocky-shore community.

    PubMed

    Tejada-Martinez, Daniela; López, Daniela N; Bonta, César C; Sepúlveda, Roger D; Valdivia, Nelson

    2016-08-01

    The ecological consequences of human-driven overexploitation and loss of keystone consumers are still unclear. In intertidal rocky shores over the world, the decrease of keystone macrograzers has resulted in an increase in the dominance of herbivores with smaller body (i.e., "mesograzers"), which could potentially alter community assembly and structure. Here, we experimentally tested whether mesograzers affect the structure of rocky intertidal communities during the period of early colonization after the occurrence of a disturbance. A manipulative field experiment was conducted to exclude mesograzers (i.e., juvenile chitons, small snails, amphipods, and juvenile limpets) from experimental areas in an ecosystem characterized by the overexploitation of keystone macrograzers and predators. The results of multivariate analyses suggest that mesograzers had significant effects on intertidal community structure through negative and positive effects on species abundances. Mesograzers had negative effects on filamentous algae, but positive effects on opportunistic foliose algae and barnacles. Probably, mesograzers indirectly favored the colonization of barnacles and foliose algae by removing preemptive competitors, as previously shown for other meso- and macrograzer species. These results strongly support the idea that small herbivores exert a firm controlling effect on the assembly process of natural communities. Therefore, changes in functional roles of top-down controllers might have significant implications for the structure of intertidal communities. PMID:27547352

  2. Effects of metals and sediment particle size on the species composition of the epifauna of Pinna bicolor near a lead smelter, Spencer Gulf, South Australia

    NASA Astrophysics Data System (ADS)

    Ward, Trevor J.; Young, Peter C.

    1984-01-01

    Pinna bicolor (Mollusca: Pelecypoda) were transplanted between four sites near a lead smelter. The species composition of their epifauna (sessile and mobile) was examined in relation to characteristics of both sediments and seston at the sites. Seventy-two taxa were distinguished in the epifaunal community. Substantial differences were found in the short-term sensitivity of some of the species to concentrations of Cd, Pb and Zn in sediments and to sediment particle size. The short-term sensitivity of many species to metals or sediment particle size explained their long-term distribution pattern. Twenty-three taxa were identified as significantly characterizing the faunal differences. Of these, eleven (four molluscs, four bryozoans, two barnacles and one ascidian) were affected by both sediment metal concentration and particle size, and eight (four molluscs, one bryozoan, one polychaete, one hydroid and one barnacle) were affected by metal contamination but not particle size. Of all fauna examined, the Bryozoa were the most metal-sensitive. Four species, Smittina raigii (Bryozoa), Galeolaria sp. 1 (Polychaeta), Epopella simplex (Cirripedia) and Monia ione (Pelecypoda) were identified by their short- and long-term sensitivity to metal contamination, and absence of sensitivity to sediment particle size, as suitable species for monitoring the effects of metal contamination on the epifauna. The implications of the results for toxicity-testing are discussed.

  3. Antifouling effect of bioactive compounds from selected marine organisms in the Obhur Creek, Red Sea

    NASA Astrophysics Data System (ADS)

    Al-Sofyani, Abdulmohsin; Marimuthu, N.; Wilson, J. Jerald; Pugazhendi, Arulazhagan; Dhavamani, Jeyakumar

    2016-06-01

    Three species of sponges and a tunicate were collected from Obhur creek of Jeddah coast for this bioactivity study. In order to assess the antifouling efficacy of selected marine organisms, methanolic extracts of these organisms were tested against different fouling bacterial forms and II-instar stage of the barnacle, Balanus amphitrite. Antibiosis, bioactivity and followed by multivariate analyses were carried out to check the efficacy of antifouling effect of the selected marine organisms. Principal component analysis revealed the exemplary antifouling efficacy of the sponge extracts of Stylissa sp. observed followed by Hyrtios sp. against bacterial forms in the laboratory study. De-trended correspondence analysis confirmed that the contribution of antifouling efficacy of the selected sponge extracts was observed to be more towards Bacillus sp., Vibrio sp. and Alteromonas sp. Moreover, the efficacy of Hyrtios sp. extract (20.430 μg mL-1) followed by Stylissa sp. (30.945 μg mL-1) showed higher against barnacle instar compared with other extracts in the bioactivity assay. Bray-Curtis cluster analysis under paired linkage categorized all the sponge extracts into one major cluster with 75% similarity, and one outlier tunicate. More than 80% similarity observed between Hyrtios sp. and Stylissa sp. Fourier transform infrared spectroscopy (FTIR) showed that the contribution of major peaks found in the marine organisms were towards sulfones, sulfoxides, cyanates and ketones.

  4. Novel antifouling and antimicrobial compound from a marine-derived fungus Ampelomyces sp.

    PubMed

    Kwong, Theresa Fuk Ning; Miao, Li; Li, Xiancui; Qian, Pei Yuan

    2006-01-01

    In this study, using a bioassay-guided isolation and purification procedure, we obtained 3-chloro-2,5-dihydroxybenzyl alcohol from a marine-derived Ampelomyces species that effectively inhibited larval settlement of the tubeworm Hydroides elegans and of cyprids of the barnacle Balanus amphitrite. The inhibitive effect on larval settlement was nontoxic and the EC50 of 3-chloro-2,5-dihydroxybenzyl alcohol ranged from 3.19 microg ml-1 to 3.81 microg ml-1 while the LC50 was 266.68 microg ml-1 for B. amphitrite cyprids; EC50 ranged from 0.67 microg ml-1 to 0.78 microg ml-1, and LC50 was 2.64 microg ml-1 for competent larvae of H. elegans, indicating that inhibitive effect of this compound was nontoxic. At a concentration of 50 mug per disc, this compound showed strong inhibitive effects on the growth of 13 out of 15 marine bacterial species tested in disc diffusion bioassay. Overall, the high inhibitory activities against bacteria and larval settlement as well as the non- or low-toxic nature of this compound to the barnacle and polychaete larvae suggest this compound could be a potent antifoulant and/or antibiotic. PMID:16924374

  5. Characterization of Terpenoids from the Root of Ceriops tagal with Antifouling Activity

    PubMed Central

    Chen, Jun-De; Yi, Rui-Zao; Lin, Yi-Ming; Feng, Dan-Qing; Zhou, Hai-Chao; Wang, Zhan-Chang

    2011-01-01

    One new dimeric diterpenoid, 8(14)-enyl-pimar-2′(3′)-en-4′(18′)-en-15′(16′)-endolabr- 16,15,2′,3′-oxoan-16-one (1) and five known terpenoids: Tagalsin C (2), Tagalsin I (3), lup-20(29)-ene-3β,28-diol (4), 3-oxolup-20(29)-en-28-oic acid (5) and 28-hydroxylup- 20(29)-en-3-one (6) were isolated from the roots of the mangrove plant Ceriops tagal. Their structures and relative stereochemistry were elucidated by means of extensive NMR, IR and MS analysis. The antifouling activity against larval settlement of the barnacle Balanus albicostatus were evaluated using capsaicin as a positive control. All these terpenoids exhibited antifouling activity against cyprid larvae of the barnacle without significant toxicity. The structure-activity relationship results demonstrated that the order of antifouling activity was diterpenoid (Compound 2) > triterpenoid (Compounds 4, 5 and 6) > dimeric diterpenoid (Compounds 1 and 3). The functional groups on the C-28 position of lupane triterpenoid significantly affect the antifouling activity. The diterpenoid dimmer with two identical diterpenoid subunits might display more potent antifouling activity than one with two different diterpenoid subunits. The stability test showed that Compounds 2, 4, 5 and 6 remained stable over 2-month exposure under filtered seawater. PMID:22072902

  6. [Feeding changes for three Sphoeroides species (Tetraodontiformes: Tetraodontidae) after Isidore hurricane impact in Carbonera Inlet, Southeastern Gulf of Mexico].

    PubMed

    Palacios-Sánchez, Sonia Eugenia; Vega-Cendejas, María Eugenia

    2010-12-01

    The coexistence of ecologically similar species may occur because of resources distribution, such as prey and habitat type and segregation time, that minimizes the interspecific competition. The changes brought about by Hurricane Isidore in the distribution of food resources by three coexisting fish species of the family Tetraodontidae (Sphoeroides nephelus, S. spengleri and S testudineus), were analyzed at the Carbonera Inlet. Sphoeroides spp. based their food on benthic organisms; principally, they consume mussels (Brachidontes sp.), barnacles (Balanus sp.) and gastropods (Crepidula sp). Before hurricane impact, the three species share the available food resources in different proportions (bivalves, gastropods, barnacles and decapods), according to different strategies that enabled them to coexist and reduce interspecific competition. After the impact, the abundance of available prey decreased and the interespecific competition for food increased, leading to S. testudines and S. nephelus change their trophic spectrum (xiphosurans, amphipods, isopods and detritus) and displacing S. splengleri of the inlet. The distribution of food resources was conditioned by the abundance and diversity of prey, as well as the adaptive response of each species. PMID:21250477

  7. Chemical defense against fouling in the solitary ascidian Phallusia nigra.

    PubMed

    Mayzel, Boaz; Haber, Markus; Ilan, Micha

    2014-12-01

    The solitary ascidian Phallusia nigra is rarely fouled by epibionts. Here, we tested the antifouling activity of its crude extracts in laboratory and field assays. P. nigra extracts inhibited the growth of all eight tested environmental bacteria and two of four laboratory bacteria. Extracts of the sympatric, but fouled solitary ascidian Herdmania momus inhibited only one test bacterium. Scanning electron microscopy confirmed that the tunic surface of P. nigra is largely bacteria-free. Both ascidian extracts significantly inhibited the larval metamorphosis of the bryozoan Bugula neritina at the tested concentration range of 0.05-2 mg ml(-1). Both crude extracts were toxic to larvae of the brine shrimp Artemia salina at natural volumetric whole-tissue concentrations, but only P. nigra showed activity at 2 mg ml(-1) and below (LC50 = 1.11 mg ml(-1)). P. nigra crude extracts also significantly reduced the settlement of barnacles, polychaetes, and algae in Mediterranean field assays and barnacle settlement in Red Sea trials. Comparisons between control experiments and pH values monitored in all experiments indicate that the observed effects were not due to acidity of the organic extracts. Our results show that P. nigra secondary metabolites have antifouling activities, which may act in synergy with previously proposed physiological antifouling mechanisms. PMID:25572211

  8. Secretory locations of SIPC in Amphibalanus amphitrite cyprids and a novel function of SIPC in biomineralization

    PubMed Central

    Zhang, Gen; Yang, Xiao-Xue; Leung, Pok Man; He, Li-Sheng; Chan, Tat Yin; Yan, Guo-Yong; Zhang, Yu; Sun, Jin; Xu, Ying; Qian, Pei-Yuan

    2016-01-01

    Settlement-inducing protein complex (SIPC) is a pheromone that triggers conspecific larval settlement in the barnacle Amphibalanus amphitrite. In the present study, immunostaining and scanning electron microscopy of SIPC revealed signals in the frontal horn pores and the secretions from carapace pores, suggesting that SIPC might be directly secreted from these organs in A. amphitrite cyprids. Further observations showed that the frontal horn pores could contact surfaces while cyprids were “walking”. Immunostaining for SIPC on the contacted surfaces displayed SIPC signals. These signals were similar to the frontal horn pores in size and morphology, suggesting that frontal horn pores might deposit SIPC. Besides, full-length SIPC was expressed and subsequent assays indicated that recombinant SIPC was able to bind to chitins and induce the precipitation of CaCO3. Furthermore, recombinant SIPC inhibited the formation of vaterites and regulated the morphology of calcite crystals. The crystals that formed with recombinant SIPC were more stable against water erosion. Overall, these results reported a novel function of recombinant SIPC that regulates crystal formation in barnacle shells. PMID:27435340

  9. Evaluation of cationic micropeptides derived from the innate immune system as inhibitors of marine biofouling.

    PubMed

    Trepos, Rozenn; Cervin, Gunnar; Pile, Claire; Pavia, Henrik; Hellio, Claire; Svenson, Johan

    2015-01-01

    A series of 13 short synthetic amphiphilic cationic micropeptides, derived from the antimicrobial iron-binding innate defence protein lactoferrin, have been evaluated for their capacity to inhibit the marine fouling process. The whole biofouling process was studied and microfouling organisms such as marine bacteria and microalgae were included as well as the macrofouling barnacle Balanus improvisus. In total 19 different marine fouling organisms (18 microfoulers and one macrofouler) were included and both the adhesion and growth of the microfoulers were investigated. It was shown that the majority of the peptides inhibited barnacle cyprid settlement via a reversible nontoxic mechanism, with IC50 values as low as 0.5 μg ml(-1). Six peptides inhibited adhesion and growth of microorganisms. Two of these were particularly active against the microfoulers with MIC-values ranging between 0.01 and 1 μg ml(-1), which is comparable with the commercial reference antifoulant SeaNine. PMID:26057499

  10. Polysulfone and polyacrylate-based zwitterionic coatings for the prevention and easy removal of marine biofouling.

    PubMed

    Hibbs, Michael R; Hernandez-Sanchez, Bernadette A; Daniels, Justin; Stafslien, Shane J

    2015-01-01

    A series of polysulfone and polyacrylate-based zwitterionic coatings were prepared on epoxy-primed aluminum substrata and characterized for their antifouling (AF) and fouling-release (FR) properties towards marine bacteria, microalgae and barnacles. The zwitterionic polymer coatings provided minimal resistance against bacterial biofilm retention and microalgal cell attachment, but facilitated good removal of attached microbial biomass by exposure to water-jet apparatus generated hydrodynamic shearing forces. Increasing the ion content of the coatings improved the AF properties, but required a stronger adhesive bond to the epoxy-primed aluminum substratum to prevent coating swelling and dissolution. Grafted poly(sulfobetaine) (gpSBMA), the most promising zwitterionic coating identified from microfouling evaluations, enabled the removal of four out of five barnacles reattached to its surface without incurring damage to their baseplates. This significant result indicated that gpSBMA relied predominately on its surface chemistry for its FR properties since it was very thin (~1-2 µm) relative to commercial coating standards (>200 µm). PMID:26343202

  11. Studies of directed adhesion of bio-organisms on functionalized polydimethylsiloxane elastomer

    NASA Astrophysics Data System (ADS)

    Estes, Thomas G.

    This research involves the adhesion of organisms and cells to polydimethylsiloxane elastomer (PDMSe). This research is accomplished while incorporating surface modification of PDMSe. The surface properties of interest for this research are elastic modulus, chemistry and topography. Organisms that have been studied are Balanus amphitrite barnacles, Ulva spores, Bugula neritina bryozoans, human umbilical vein endothelial cells (HUVECs) and fibroblasts. Applications of this work are focused on preventing the accumulation of spores and barnacles on the hulls of boats, longer lasting synthetic vascular grafts and new diagnostic methods for cardiovascular disease. Currently, organisms on the sides of ship hulls are responsible for increased fuel consumption, increased pollution and greenhouse gasses and increased costs of cleaning. The current paint used saves $3 billion world wide, but is toxic to the environment. This approach is making use of a non toxic surface, PDMSe. PDMSe is modified and then subjected to settlement and release assays in order to further understand the mechanisms that may prevent biofouling. Cardiovascular disease is the leading cause of death in the United States. This research also involves ways to diagnose and prevent cardiovascular disease through investigation of adhesion of the cells that line the inside of our blood vessels. This is accomplished through chemistries to specifically bind endothelial cells to PDMSe. Once this has been accomplished, the cells may be counted and correlated to specific cardiovascular diseases.

  12. Combinatorial materials research applied to the development of new surface coatings XVI: fouling-release properties of amphiphilic polysiloxane coatings.

    PubMed

    Stafslien, Shane J; Christianson, David; Daniels, Justin; VanderWal, Lyndsi; Chernykh, Andrey; Chisholm, Bret J

    2015-01-01

    High-throughput methods were used to prepare and characterize the fouling-release (FR) properties of an array of amphiphilic polysiloxane-based coatings possessing systematic variations in composition. The coatings were derived from a silanol-terminated polydimethylsiloxane, a silanol-terminated polytrifluorpropylmethylsiloxane (CF3-PDMS), 2-[methoxy(polyethyleneoxy)propyl]-trimethoxysilane (TMS-PEG), methyltriacetoxysilane and hexamethyldisilazane-treated fumed silica. The variables investigated were the concentration of TMS-PEG and the concentration of CF3-PDMS. In general, it was found that the TMS-PEG and the CF3-PDMS had a synergist effect on FR properties with these properties being enhanced by combining both compounds into the coating formulations. In addition, reattached adult barnacles removed from coatings possessing both TMS-PEG and relatively high levels of CF3-PDMS displayed atypical base-plate morphologies. The majority of the barnacles removed from these coatings exhibited a cupped or domed base-plate as compared to the flat base-plate observed for the control coating that did not contain TMS-PEG or CF3-PDMS. Coating surface analysis using water contact angle measurements indicated that the presence of CF3-PDMS facilitated migration of TMS-PEG to the coating/air interface during the film formation/curing process. In general, coatings containing both TMS-PEG and relatively high levels of CF3-PDMS possessed excellent FR properties. PMID:25647177

  13. Phylogenetic position of Antarctic Scalpelliformes (Crustacea: Cirripedia: Thoracica)

    NASA Astrophysics Data System (ADS)

    Linse, Katrin; Jackson, Jennifer A.; Fitzcharles, Elaine; Sands, Chester J.; Buckeridge, John S.

    2013-03-01

    The phylogenetic relationships of seven Antarctic barnacle species, one verrucomorph and six scalpelliforms from the Scotia, Weddell and Ross seas were investigated using DNA sequences from two nuclear genes (18 S and 28 S) and one mitochondrial gene (COI), with a combined total length of 3,151 base pairs. Analyses of these new sequences, together with those of previously published ibliform, lepadiform, scalpelliform, balanomorph and verrucomorph species, confirm that the Scalpelliformes are not monophyletic. Bayesian and maximum likelihood analyses consistently recovered a monophyletic group which comprised Ornatoscalpellum stroemii (Sars) and the Southern Ocean scalpellomorphs; Arcoscalpellum sp. from the Weddell Sea, Arcoscalpellum africanum from Elephant Island, A. bouveti from Bouvet Island, the circum-Antarctic Litoscalpellum discoveryi, Litoscalpellum sp. from Shag Rocks and Scalpellum sp. from the Falkland Trough. We also used multiple fossil constraints in a relaxed clock Bayesian framework to estimate divergence times for the 18 S+28 S phylogeny. Our results indicate a mid Cretaceous divergence for the Weddell Sea Arcoscalpellum sp, followed by a late Cretaceous divergence from the North Atlantic O. stroemii. Subsequent to this, the Antarctic scalpellomorphs began to radiate at the Cretaceous-Tertiary boundary. Monophyly within the scalpellid genera Arcoscalpellum, Litoscalpellum and Scalpellum was strongly rejected by all loci. Our results show incongruence between taxonomy and molecular systematics and highlight the need for more species to be sequenced as well as taxonomic revisions to resolve uncertainties in the phylogenetic relationships of the stalked barnacles.

  14. Influence of submersion season on the development of test panel biofouling communities in a tropical coast

    NASA Astrophysics Data System (ADS)

    Satheesh, S.; Wesley, S. G.

    2011-08-01

    The effect of test panel submersion season on the colonization of biofouling communities in a tropical coast revealed that the effects of panel submersion time should be taken into consideration for modelling fouling community recruitment dynamics in coastal systems or during the field trials of antifouling coatings. Wooden test panels fitted onto a raft were submerged during pre-monsoon, monsoon and post-monsoon seasons for the development of the biofouling community. Results showed considerable variation in the colonization of fouling communities on test panels submerged during different seasons. Barnacles, tubeworms, ascidians and seaweeds were the major fouling communities that colonized the test panels. The total biomass of the fouling communities that settled on the post-monsoon season panels varied from the initial value of 2.72 g dm -2 to a maximum of 44.5 g dm -2. On the panels submerged during monsoon season, the total biomass of fouling communities varied between 0.78 g dm -2 and 69.9 g dm -2. The total fouling biomass on the pre-monsoon season panels varied between 2.95 and 33.5 g dm -2. Barnacles were the initial colonizers on the panels submerged during pre-monsoon and post-monsoon seasons. Soft-bodied organisms such as ascidians dominated the monsoon season-initiated panel series during the initial period.

  15. Skeletal and isotopic composition and paleoclimatic significance of late Pleistocene carbonates, Ross Sea, Antarctica

    SciTech Connect

    Taviani, M. ); Reid, D.E.; Anderson, J.B. )

    1993-01-01

    Carbonates cover an extensive area of the northwestern Ross Sea continental shelf. Radiocarbon dates yield late Pleistocene (stage 3) ages for these deposits, hence the carbonates appear to be correlative with widespread tills and glacial marine deposits in the region. Four carbonate facies are recognized on the basis of skeletal composition: a barnacle/foraminifer facies, a muddy bryozoan facies, a bryozoan/barnacle/pelecypod/foraminifer facies, and a planktonic foraminiferal facies. These deposits occur on the shelf and upper slope, while carbonate turbidities derived from them occur on the adjacent continental slope and rise. Compositional analyses of Ross Sea carbonates lend support to previously recognized criteria for identifying cold water carbonates. These include: (1) the presence of an associated ice-rafted component (including dropstones); (2) a dominance of calcite relative to other carbonate minerals (the remaining fraction consists solely of aragonite); (3) allochems that are entirely skeletal; and (4) heavy oxygen isotopic compositions (in the range of +3.0 to +5.1% PDB).

  16. Antifouling coatings based on covalently cross-linked agarose film via thermal azide-alkyne cycloaddition.

    PubMed

    Xu, Li Qun; Pranantyo, Dicky; Neoh, Koon-Gee; Kang, En-Tang; Teo, Serena Lay-Ming; Fu, Guo Dong

    2016-05-01

    Coatings based on thin films of agarose-poly(ethylene glycol) (Agr-PEG) cross-linked systems are developed as environmentally-friendly and fouling-resistant marine coatings. The Agr-PEG cross-linked systems were prepared via thermal azide-alkyne cycloaddition (AAC) using azido-functionalized Agr (AgrAz) and activated alkynyl-containing poly(2-propiolamidoethyl methacrylate-co-poly(ethylene glycol)methyl ether methacrylate) P(PEMA-co-PEGMEMA) random copolymers as the precursors. The Agr-PEG cross-linked systems were further deposited onto a SS surface, pre-functionalized with an alkynyl-containing biomimetic anchor, dopamine propiolamide, to form a thin film after thermal treatment. The thin film-coated SS surfaces can effectively reduce the adhesion of marine algae and the settlement of barnacle cyprids. Upon covalent cross-linking, the covalently cross-linked Agr-PEG films coated SS surfaces exhibit good stability in flowing artificial seawater, and enhanced resistance to the settlement of barnacle cyprids, in comparison to that of the surfaces coated with physically cross-linked AgrAz films. PMID:26836479

  17. Noradrenaline-functionalized hyperbranched fluoropolymer-poly(ethylene glycol) cross-linked networks as dual-mode, anti-biofouling coatings.

    PubMed

    Imbesi, Philip M; Gohad, Neeraj V; Eller, Michael J; Orihuela, Beatriz; Rittschof, Dan; Schweikert, Emile A; Mount, Andrew S; Wooley, Karen L

    2012-02-28

    The strategy of decorating antibiofouling hyperbranched fluoropolymer-poly(ethylene glycol) (HBFP-PEG) networks with a settlement sensory deterrent, noradrenaline (NA), and the results of biofouling assays are presented. This example of a dual-mode surface, which combines both passive and active modes of antibiofouling, works in synergy to improve the overall antibiofouling efficiency against barnacle cyprids. The HBFP-PEG polymer surface, prior to modification with NA, was analyzed by atomic force microscopy, and a significant distribution of topographical features was observed, with a nanoscopic roughness measurement of 110 ± 8 nm. NA attachment to the surface was probed by secondary ion mass spectrometry to quantify the extent of polymer chain-end substitution with NA, where a 3- to 4-fold increase in intensity for a fragment ion associated with NA was observed and 39% of the available sites for attachment were substituted. Cytoskeletal assays confirmed the activity of tethered NA on adhering oyster hemocytes. Settlement assays showed deterrence toward barnacle cyprid settlement, while not compromising the passive biofouling resistance of the surface. This robust strategy demonstrates a methodology for the incorporation of actively antibiofouling moieties onto a passively antibiofouling network. PMID:22276525

  18. Oceanographic and behavioural processes affecting invertebrate larval dispersal and supply in the western Iberia upwelling ecosystem

    NASA Astrophysics Data System (ADS)

    Queiroga, Henrique; Cruz, Teresa; dos Santos, Antonina; Dubert, Jesus; González-Gordillo, Juan Ignácio; Paula, José; Peliz, Álvaro; Santos, A. Miguel P.

    2007-08-01

    The present review addresses recent findings made in the western Iberia ecosystem on the behavioural and physical interactions that regulate dispersal, supply to coastal habitats and settlement of invertebrate larvae. These studies used the barnacle Chthamalus spp. and the crab Carcinus maenas as model organisms. The observations made on the Iberian shelf showed extensive diel vertical migrations along the water column by representatives of both groups that have never been reported before. The interaction of the diel vertical migration with the two-layer flow structure of upwelling/downwelling circulation suggests a mechanism that may help to retain larvae in shelf waters during upwelling conditions. Measurements of daily supply of C. maenas megalopae to estuaries separated by 500 km disclosed a semilunar pattern, with highest supply around highest amplitude tides, indicating that supply of megalopae to estuaries is accomplished by selective tidal stream transport. Relaxation of equatorward winds also played a role in supply, by enhancing translocation of megalopae to the nearshore. Concerning Chthamalus larvae, the observations on daily settlement made at rocky shores also separated by 500 km showed unclear patterns between locations and years. The relationship of settlement with water temperature, tidal range and upwelling indices indicated that supply of barnacle cyprids may be controlled by multiple mechanisms, viz. upwelling/downwelling circulation, internal tidal bores and sea breezes.

  19. Comparison of laboratory and field testing performance evaluations of siloxane-polyurethane fouling-release marine coatings.

    PubMed

    Stafslien, Shane J; Sommer, Stacy; Webster, Dean C; Bodkhe, Rajan; Pieper, Robert; Daniels, Justin; Vander Wal, Lyndsi; Callow, Maureen C; Callow, James A; Ralston, Emily; Swain, Geoff; Brewer, Lenora; Wendt, Dean; Dickinson, Gary H; Lim, Chin-Sing; Teo, Serena Lay-Ming

    2016-09-01

    A series of eight novel siloxane-polyurethane fouling-release (FR) coatings were assessed for their FR performance in both the laboratory and in the field. Laboratory analysis included adhesion assessments of bacteria, microalgae, macroalgal spores, adult barnacles and pseudobarnacles using high-throughput screening techniques, while field evaluations were conducted in accordance with standardized testing methods at three different ocean testing sites over the course of six-months exposure. The data collected were subjected to statistical analysis in order to identify potential correlations. In general, there was good agreement between the laboratory screening assays and the field assessments, with both regimes clearly distinguishing the siloxane-polyurethane compositions comprising monofunctional poly(dimethyl siloxane) (PDMS) (m-PDMS) as possessing superior, broad-spectrum FR properties compared to those prepared with difunctional PDMS (d-PDMS). Of the seven laboratory screening techniques, the Cellulophaga lytica biofilm retraction and reattached barnacle (Amphibalanus amphitrite) adhesion assays were shown to be the most predictive of broad-spectrum field performance. PMID:27494780

  20. Abundance, seasonal patterns and diet of the non-native jellyfish Blackfordia virginica in a Portuguese estuary

    NASA Astrophysics Data System (ADS)

    Marques, F.; Chainho, P.; Costa, J. L.; Domingos, I.; Angélico, M. M.

    2015-12-01

    Blackfordia virginica, a non-indigenous hydrozoan introduced in many systems around the world, has been observed in the Mira estuary, southwest of Portugal, since 1984. Monthly sampling (January 2013-January 2014) at a fixed location with high abundance of the medusae confirmed the occurrence of a seasonal cycle associated with temperature and photoperiod. The beginning of the medusa cycle occurred in May immediately after the spring zooplankton bloom during April. Examination of the gut contents of B. virginica medusae revealed that copepods, the most abundant group in the zooplankton community, were highly predated. Barnacle nauplii, decapod crustacean larvae and anchovy eggs were also identified in the guts. The medusae showed positive selection for copepods, and negative selection for barnacle nauplii, decapod crustacean larvae and anchovy eggs. The mortality rate of copepods (used as a model prey group) induced by medusae predation was estimated and showed the potential impact of this species in the ecosystem, ranging between 2.34 d-1 and 0.02 d-1, with a minimum copepod half-life of 0.30 days.

  1. Secretory locations of SIPC in Amphibalanus amphitrite cyprids and a novel function of SIPC in biomineralization.

    PubMed

    Zhang, Gen; Yang, Xiao-Xue; Leung, Pok Man; He, Li-Sheng; Chan, Tat Yin; Yan, Guo-Yong; Zhang, Yu; Sun, Jin; Xu, Ying; Qian, Pei-Yuan

    2016-01-01

    Settlement-inducing protein complex (SIPC) is a pheromone that triggers conspecific larval settlement in the barnacle Amphibalanus amphitrite. In the present study, immunostaining and scanning electron microscopy of SIPC revealed signals in the frontal horn pores and the secretions from carapace pores, suggesting that SIPC might be directly secreted from these organs in A. amphitrite cyprids. Further observations showed that the frontal horn pores could contact surfaces while cyprids were "walking". Immunostaining for SIPC on the contacted surfaces displayed SIPC signals. These signals were similar to the frontal horn pores in size and morphology, suggesting that frontal horn pores might deposit SIPC. Besides, full-length SIPC was expressed and subsequent assays indicated that recombinant SIPC was able to bind to chitins and induce the precipitation of CaCO3. Furthermore, recombinant SIPC inhibited the formation of vaterites and regulated the morphology of calcite crystals. The crystals that formed with recombinant SIPC were more stable against water erosion. Overall, these results reported a novel function of recombinant SIPC that regulates crystal formation in barnacle shells. PMID:27435340

  2. Grazing effects of the periwinkle Echinolittorina peruviana at a central Peruvian high rocky intertidal

    NASA Astrophysics Data System (ADS)

    Hidalgo, Fernando J.; Firstater, Fausto N.; Fanjul, Eugenia; Bazterrica, M. Cielo; Lomovasky, Betina J.; Tarazona, Juan; Iribarne, Oscar O.

    2008-03-01

    Echinolittorina peruviana is the most common gastropod in the high intertidal zone of Peru, representing more than 80% of the individuals present at that zone. Experimental removal of snails was used to evaluate their effects on (a) abundance of epilithic biofilm, (b) barnacle recruitment, and (c) abundance of macroalgae under “normal” conditions of the El Niño Southern Oscillation (ENSO). Experiments were carried out from October 2005 to April 2007 at two intertidal levels of a semi-protected rocky shore of central Peru. Results demonstrated that E. peruviana is able to control biofilm abundance and barnacle recruitment at both heights investigated, with marked effects in the lower zone. Erect macroalgae ( Ulva spp. and Gelidium spp.) were less affected by grazing; but negative effects were observed on macroalgal crusts. Season and physical stress seem to play a more important role in the abundance of macroalgae in the high intertidal. Our results are similar to those reported elsewhere for high shore littorinids and represent baseline data to understand how the role of intertidal consumers will vary under the cold (La Niña) and warm (El Niño) phases of ENSO on these shores.

  3. Polysulfone and polyacrylate-based zwitterionic coatings for the prevention and easy removal of marine biofouling

    SciTech Connect

    Hibbs, Michael R.; Hernandez-Sanchez, Bernadette A.; Daniels, Justin; Stafslien, Shane J.

    2015-09-07

    A series of polysulfone and polyacrylate-based zwitterionic coatings were prepared on epoxy-primed aluminum substrata and characterized for their antifouling (AF) and fouling-release (FR) properties towards marine bacteria, microalgae and barnacles. The zwitterionic polymer coatings provided minimal resistance against bacterial biofilm retention and microalgal cell attachment, but facilitated good removal of attached microbial biomass by exposure to water-jet apparatus generated hydrodynamic shearing forces. Increasing the ion content of the coatings improved the AF properties, but required a stronger adhesive bond to the epoxy-primed aluminum substratum to prevent coating swelling and dissolution. Grafted poly(sulfobetaine) (gpSBMA), the most promising zwitterionic coating identified from microfouling evaluations, enabled the removal of four out of five barnacles reattached to its surface without incurring damage to their baseplates. As a result, this significant result indicated that gpSBMA relied predominately on its surface chemistry for its FR properties since it was very thin (~1–2 µm) relative to commercial coating standards (>200 µm).

  4. Polysulfone and polyacrylate-based zwitterionic coatings for the prevention and easy removal of marine biofouling

    DOE PAGESBeta

    Hibbs, Michael R.; Hernandez-Sanchez, Bernadette A.; Daniels, Justin; Stafslien, Shane J.

    2015-09-07

    A series of polysulfone and polyacrylate-based zwitterionic coatings were prepared on epoxy-primed aluminum substrata and characterized for their antifouling (AF) and fouling-release (FR) properties towards marine bacteria, microalgae and barnacles. The zwitterionic polymer coatings provided minimal resistance against bacterial biofilm retention and microalgal cell attachment, but facilitated good removal of attached microbial biomass by exposure to water-jet apparatus generated hydrodynamic shearing forces. Increasing the ion content of the coatings improved the AF properties, but required a stronger adhesive bond to the epoxy-primed aluminum substratum to prevent coating swelling and dissolution. Grafted poly(sulfobetaine) (gpSBMA), the most promising zwitterionic coating identified frommore » microfouling evaluations, enabled the removal of four out of five barnacles reattached to its surface without incurring damage to their baseplates. As a result, this significant result indicated that gpSBMA relied predominately on its surface chemistry for its FR properties since it was very thin (~1–2 µm) relative to commercial coating standards (>200 µm).« less

  5. Direct and indirect effects of seastars Asterias rubens on mussel beds ( Mytilus edulis) in the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Saier, Bettina

    2001-08-01

    Near the island of Sylt in the Wadden Sea (German Bight, North Sea), seastars Asterias rubens (L.) co-occur with their preferred prey, mussels Mytilus edulis (L.), which form extensive beds from the intertidal down to the subtidal zone. Mussel density within these beds is significantly lower in the subtidal than the intertidal zone. Laboratory and field experiments were conducted to check if this was due to seastar predation. Feeding experiments did not indicate size refuge of M. edulis from predation by A. rubens, but showed that seastars preferred clean subtidal mussels above barnacle-overgrown intertidal ones. This preference coincided with higher abundances of both large ( arm length >5.5 cm) and smaller seastars in the shallow subtidal, but their abundance was too low to account for the decreased subtidal mussel density in the area studied. However, seastars may indirectly reduce mussel recruitment in the subtidal zone. This is caused by juvenile seastar predation upon the barnacles that grow on mussels, because such epigrowth strongly enhances recruitment in mussels. Such an indirect effect on mussel recruitment may affect mussel density more than adult seastar predation. An exception may be mass invasions of A. rubens on subtidal mussel beds. One such event happened during this study, clearing a large patch of mussels.

  6. The bromotyrosine derivative ianthelline isolated from the arctic marine sponge Stryphnus fortis inhibits marine micro- and macrobiofouling.

    PubMed

    Hanssen, Kine O; Cervin, Gunnar; Trepos, Rozenn; Petitbois, Julie; Haug, Tor; Hansen, Espen; Andersen, Jeanette H; Pavia, Henrik; Hellio, Claire; Svenson, Johan

    2014-12-01

    The inhibition of marine biofouling by the bromotyrosine derivative ianthelline, isolated from the Arctic marine sponge Stryphnus fortis, is described. All major stages of the fouling process are investigated. The effect of ianthelline on adhesion and growth of marine bacteria and microalgae is tested to investigate its influence on the initial microfouling process comparing with the known marine antifoulant barettin as a reference. Macrofouling is studied via barnacle (Balanus improvisus) settlement assays and blue mussel (Mytilus edulis) phenoloxidase inhibition. Ianthelline is shown to inhibit both marine micro- and macrofoulers with a pronounced effect on marine bacteria (minimum inhibitory concentration (MIC) values 0.1-10 μg/mL) and barnacle larval settlement (IC50 = 3.0 μg/mL). Moderate effects are recorded on M. edulis (IC50 = 45.2 μg/mL) and microalgae, where growth is more affected than surface adhesion. The effect of ianthelline is also investigated against human pathogenic bacteria. Ianthelline displayed low micromolar MIC values against several bacterial strains, both Gram positive and Gram negative, down to 2.5 μg/mL. In summary, the effect of ianthelline on 20 different representative marine antifouling organisms and seven human pathogenic bacterial strains is presented. PMID:25051957

  7. Macrofouling control in nuclear power plants

    SciTech Connect

    Ekis, E.W. Jr.; Keoplin-Gall, S.M.; McCarthy, R.E.

    1991-11-01

    Macrofouling of cooling-water systems is one of the more significant and costly problems encountered in the nuclear power industry. Both marine and freshwater macroinvertebrates can be responsible for losses in plant availability because of plugged intakes and heat transfer equipment. There is a greater diversity of macrofouling organisms in marine waters than in fresh waters. Marine macrofouling organisms include barnacles, mollusks, bryozoans, and hydroids. Barnacles are crustaceans with feathery appendages, which allow them to attach to a variety of surfaces. They are a major cause of severe macrofouling because they can remain attached even after death. The major freshwater macrofouling organisms include the Asiatic Clam (Corbicula fluminea) and the newest freshwater macrofouler, the Zebra Mussel (Dreissena polymorpha). The introduction of the Zebra Mussel into the Great Lakes has created economic and ecological problems that will not easily be solved. The threat of intercontinental dispersal of the Zebra Mussel in America is serious. Research programs have been initiated around the country to develop control methods for this macrofouling problem. The various control methodologies can be classified in the following categories: biological, chemical, physical, and mechanical. Laboratory experiments were performed to evaluate the efficacy of Actibrom against mature Zebra Mussels.

  8. Bacteria immobilised in Gels: Improved methodologies for antifouling and biocontrol applications.

    PubMed

    Holmström, C; Steinberg, P; Christov, V; Christie, G; Kjelleberg, S

    2000-01-01

    A range of bacteria, including the marine bacterium Pseudoalteromonas tunicata which produces antifouling compounds, and Escherichia coli were used to investigate methods for immobilising bacteria in gels. Different types of matrices were screened using the survival of barnacle nauplii as a bioassay. A Dupont® polyvinylalcohol (PVOH) 10% gel was found to be the optimal matrix. This non-toxic gel remained stable in seawater while allowing for an outflux of active biological compounds from the bacterial cells. The presence of active bacterial cells in the matrix was tested by CTC-staining, green fluorescent protein (GFP) expressing bacteria and a barnacle larvae bioassay. The Dupont® PVOH 10% gels containing P. tunicata cells were inhibitory against larvae for a period of up to 2 weeks. In further studies using gels containing immobilised bacteria, the E. coli strain C600 was employed based on its cell size, stress resistance and the fact that a plasmid for the expression of GFP could be transferred and maintained in the cells. Immobilised E. Coli cells maintained their viability in the Dupont® PVOH 10% gels for as long as 2 months, and the life-span of these "biologically active"; gels was increased to more than 2 months by the incorporation of small beads into the gels. The results indicate that bacteria can be immobilised in coatings for periods of time consistent with the needs of some antifouling and antibacterial applications. PMID:22115296

  9. Antennulary sensory organs in cyprids of Octolasmis and Lepas (Crustacea: Thecostraca: Cirripedia: Thoracica): a scanning electron microscopic study.

    PubMed

    Blomsterberg, Mikkel; Høeg, Jens T; Jeffries, William B; Lagersson, Niklas C

    2004-05-01

    Cypris larvae of the pedunculate barnacles Octolasmis angulata (Poecilasmatidae), Lepas australis, L. pectinata, and Dosima fascicularis (Lepadidae) were studied with scanning electron microscopy, focusing on the sensory setae and the attachment disc on the antennules. The antennules of O. angulata did not exhibit any remarkable trait, but carry the same number of setae as seen in most other thoracicans. The third segment is bell-shaped and quite distinct from the second and its attachment disc is surrounded by a skirt. We found several potential synapomorphies in antennulary morphology between cyprids of the lepadid species but none of them were shared with the cyprids of Octolasmis; the list of unique lepadid characters includes: one additional, preaxial seta on the second segment; multiple similar (up to eight) postaxial setae (PS3) on the third segment, unlike all other thoracicans, where there is only a single PS3; the third segment consists almost entirely of the attachment disc, which is distended and surrounded by two parallel rows of radial setae; on the fourth segment the terminal seta E is diminutive. We found no traits in cyprids of Octolasmis that seem to be adaptations to their attachment site within the branchial chamber of swimming crabs and, in particular, no similarities with cyprids of rhizocephalan barnacles, many of which also attach in the gill chamber. The synapomorphies between cyprids of the lepadid species may be adaptations to their life in the neuston. PMID:15108154

  10. High frequency (hourly) variation in vertical distribution and abundance of meroplanktonic larvae in nearshore waters during strong internal tidal forcing

    NASA Astrophysics Data System (ADS)

    Liévana MacTavish, A.; Ladah, L. B.; Lavín, M. F.; Filonov, A.; Tapia, Fabian J.; Leichter, J.

    2016-04-01

    We related the vertical distribution and abundance of nearshore meroplankton at hourly time scales with internal tidal wave events. We proposed that significant changes in plankter abundance would occur across internal tidal fronts, and that surface and bottom strata would respond in opposite fashions. First-mode internal tidal bores propagating in the alongshore direction were detected in water-column currents and baroclinic temperature changes. Surface and bottom currents always flowed in opposite directions, and abrupt flow reversals coincided with large temperature changes during arrival of bores. Crab zoeae and barnacle cyprids were more abundant in the bottom strata, whereas barnacle nauplii showed the opposite pattern. Significant changes in vertical distribution and abundance of target meroplankters occurred across internal tidal fronts, especially for crabs at depth, with surface and bottom organisms responding in opposite fashions. Changes in plankter abundance were significantly correlated with current flows in the strata where they were most abundant. The manner in which plankters were affected (increasing or decreasing abundance) appeared to be modulated by their vertical position within the water column. The significant differences found at the high frequencies of this study, maintained across sampling days, suggest that nearshore meroplankton populations may have greater and more consistent temporal and vertical variability than previously considered.

  11. Tree nut allergens.

    PubMed

    Roux, Kenneth H; Teuber, Suzanne S; Sathe, Shridhar K

    2003-08-01

    Allergic reactions to tree nuts can be serious and life threatening. Considerable research has been conducted in recent years in an attempt to characterize those allergens that are most responsible for allergy sensitization and triggering. Both native and recombinant nut allergens have been identified and characterized and, for some, the IgE-reactive epitopes described. Some allergens, such as lipid transfer proteins, profilins, and members of the Bet v 1-related family, represent minor constituents in tree nuts. These allergens are frequently cross-reactive with other food and pollen homologues, and are considered panallergens. Others, such as legumins, vicilins, and 2S albumins, represent major seed storage protein constituents of the nuts. The allergenic tree nuts discussed in this review include those most commonly responsible for allergic reactions such as hazelnut, walnut, cashew, and almond as well as those less frequently associated with allergies including pecan, chestnut, Brazil nut, pine nut, macadamia nut, pistachio, coconut, Nangai nut, and acorn. PMID:12915766

  12. Biomineral ultrastructure, elemental constitution and genomic analysis of biomineralization-related proteins in hemichordates.

    PubMed

    Cameron, C B; Bishop, C D

    2012-08-01

    Here, we report the discovery and characterization of biominerals in the acorn worms Saccoglossus bromophenolosus and Ptychodera flava galapagos (Phylum: Hemichordata). Using electron microscopy, X-ray microprobe analyses and confocal Raman spectroscopy, we show that hemichordate biominerals are small CaCO(3) aragonitic elements restricted to specialized epidermal structures, and in S. bromophenolosus, are apparently secreted by sclerocytes. Investigation of urchin biomineralizing proteins in the translated genome and expressed sequence tag (EST) libraries of Saccoglossus kowalevskii indicates that three members of the urchin MSP-130 family, a carbonic anhydrase and a matrix metaloprotease are present and transcribed during the development of S. kowalevskii. The SM family of proteins is absent from the hemichordate genome. These results increase the number of phyla known to biomineralize and suggest that some of the gene-regulatory 'toolkit', if not mineralized tissue themselves, may have been present in the common ancestor to hemichordates and echinoderms. PMID:22496191

  13. Molecular Identification of Ptychodera flava (Hemichordata: Enteropneusta): Reconsideration in Light of Nucleotide Polymorphism in the 18S Ribosomal RNA Gene.

    PubMed

    Urata, Makoto

    2015-06-01

    Seven nuclear and mitochondrial DNA markers were examined in 12 specimens of Ptychodera flava, a model acorn worm used in molecular biology, collected in Japan from three local populations with different modes of living. A comparison of intraspecific results did not show genetically isolated populations despite the species' enclave habitats and asexual reproduction. Moreover, both the nuclear 18S ribosomal RNA gene and mitochondrial 16S ribosomal RNA gene sequences were identical to those from Moorea in French Polynesia, nearly 10,000 kilometers away from Japan. I also provide the first definitive information regarding polymorphisms in 18S ribosomal RNA gene, the external transcribed spacer (ETS), internal transcribed spacers (ITS), and mitochondrial cytochrome c oxidase subunit 1 (mtCO1) sequence in hemichordates using newly designed primer sets, and I show both high larval vagility and certain criteria for the molecular identification of this species. PMID:26003987

  14. Barnyard grasses were processed with rice around 10000 years ago.

    PubMed

    Yang, Xiaoyan; Fuller, Dorian Q; Huan, Xiujia; Perry, Linda; Li, Quan; Li, Zhao; Zhang, Jianping; Ma, Zhikun; Zhuang, Yijie; Jiang, Leping; Ge, Yong; Lu, Houyuan

    2015-01-01

    Rice (Oryza sativa) is regarded as the only grass that was selected for cultivation and eventual domestication in the Yangtze basin of China. Although both macro-fossils and micro-fossils of rice have been recovered from the Early Neolithic site of Shangshan, dating to more than 10,000 years before present (BP), we report evidence of phytolith and starch microfossils taken from stone tools, both for grinding and cutting, and cultural layers, that indicating barnyard grass (Echinochloa spp.) was a major subsistence resource, alongside smaller quantities of acorn starches (Lithocarpus/Quercus sensu lato) and water chestnuts (Trapa). This evidence suggests that early managed wetland environments were initially harvested for multiple grain species including barnyard grasses as well as rice, and indicate that the emergence of rice as the favoured cultivated grass and ultimately the key domesticate of the Yangtze basin was a protracted process. PMID:26536839

  15. AL-SX (H1616) Container Support: Out-gassing of Polyethylene and Polycarbonate Resins

    SciTech Connect

    G.Cook Story; Leon Seibel and Linda Domeier

    1999-04-01

    Out-gassing tests were carried out on samples of polyethylene and polycarbonate packaging components used within the AL-SX (H1616) shipping container and compared to known samples of high and low density polyethylene and polycarbonate. Polyethylene is used to fabricate the shipping container overpack for the MC3007A/MC4059 and 1X-Acorn; LEXAN{reg_sign} polycarbonate (General Electric) is used to fabricate the lid of the Protective Container utilized to package the MC4213/MC4240 and MC4524 for shipment in the AL-SX (H1616). Pressure was monitored up to about 650 F and all the samples showed similar increases in pressure which were only slightly above those measured for control runs using no resin sample. None of the polymer samples showed out-gassing behavior that would lead to excessive pressure increases in the H1616 within that temperature range.

  16. A squirrel searches for food at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    An Eastern gray squirrel pauses in its daily search for food in the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The Eastern gray squirrel is found in wooded, suburban, and urban areas statewide. It nests in tree hollows or leaf nests in treetops. It forages during the day, mainly early morning and late afternoon, both on the ground and in trees, living on a diet of acorns, nuts, fruits, berries, insects, and bird eggs. Food plants include cypress, buckeyes, elms, grapes, tulip trees, mulberries, and tupelo. It breeds in late winter or early spring and again in late spring or summer, bearing two to six young. The eastern gray squirrel chatters when disturbed. The 92,000-acre wildlife refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles.

  17. Determination of trace elements in soil, leaves and fruits of Quercus brantii grown in southwestern Iran by atomic spectroscopy

    NASA Astrophysics Data System (ADS)

    Mohammadzadeh, A.; Samadi-Maybodi, A.; Khodadoust, S.

    2013-09-01

    Quercus brantii acorn is rich of some useful mineral elements such as K, Fe and Zn. The content of these mineral elements in Quercus are dependent on their region and environmental conditions. Q. brantii grown naturally in different regions of Iran especially in Kohgiloye va Boyer Ahmad province (southwestern of Iran). In this study total concentration of Fe, Zn and K elements were determined using atomic absorption and emission spectroscopy in fruits, leaves of Q. brantii and also in the soils where this plant was grown. Statistical evaluation (ANOVA test) was employed for all measurements. Results confirmed that the concentration of elements in fruit and leave depended on area which the plant is growth. The transport factor of elements was also considered.

  18. Effect of IGF-II genotype and pig rearing system on the final characteristics of dry-cured Iberian hams.

    PubMed

    Sánchez Del Pulgar, J; Carrapiso, A I; Reina, R; Biasioli, F; García, C

    2013-11-01

    The effect of the IGF-II genotype (AG vs. GG) on the morphological and compositional parameters, the fatty acid composition of intramuscular fat, the odour concentration (analysed by dynamic olfactometry) and the volatile compound profile (analysed by proton transfer reaction time-of-flight mass spectrometry) of dry-cured Iberian ham was studied for the first time, and compared to the effect of pig rearing system (high-oleic concentrated feed vs. acorn and grass). The IGF-II genotype had no effect on most variables. However, it influenced the concentration of some odorants (methanethiol and octanal), although it did not affect odour concentration. Conversely, the rearing system had a significant effect on a large number of ham variables. Results indicate a negligible effect of the IGF-II genotype on the final ham quality and confirm that the rearing system has a marked effect. PMID:23797016

  19. Evolution of multicellular animals as deduced from 5S rRNA sequences: a possible early emergence of the Mesozoa.

    PubMed

    Ohama, T; Kumazaki, T; Hori, H; Osawa, S

    1984-06-25

    The nucleotide sequences of 5S rRNA from a mesozoan Dicyema misakiense and three metazoan species, i.e., an acorn-worm Saccoglossus kowalevskii, a moss-animal Bugula neritina, and an octopus Octopus vulgaris have been determined. A phylogenic tree of multicellular animals has been constructed from 73 5S rRNA sequences available at present including those from the above four sequences. The tree suggests that the mesozoan is the most ancient multicellular animal identified so far, its emergence time being almost the same as that of flagellated or ciliated protozoans. The branching points of planarians and nematodes are a little later than that of the mesozoan but are clearly earlier than other metazoan groups including sponges and jellyfishes. Many metazoan groups seem to have diverged within a relatively short period. PMID:6539911

  20. Biomineral ultrastructure, elemental constitution and genomic analysis of biomineralization-related proteins in hemichordates

    PubMed Central

    Cameron, C. B.; Bishop, C. D.

    2012-01-01

    Here, we report the discovery and characterization of biominerals in the acorn worms Saccoglossus bromophenolosus and Ptychodera flava galapagos (Phylum: Hemichordata). Using electron microscopy, X-ray microprobe analyses and confocal Raman spectroscopy, we show that hemichordate biominerals are small CaCO3 aragonitic elements restricted to specialized epidermal structures, and in S. bromophenolosus, are apparently secreted by sclerocytes. Investigation of urchin biomineralizing proteins in the translated genome and expressed sequence tag (EST) libraries of Saccoglossus kowalevskii indicates that three members of the urchin MSP-130 family, a carbonic anhydrase and a matrix metaloprotease are present and transcribed during the development of S. kowalevskii. The SM family of proteins is absent from the hemichordate genome. These results increase the number of phyla known to biomineralize and suggest that some of the gene-regulatory ‘toolkit’, if not mineralized tissue themselves, may have been present in the common ancestor to hemichordates and echinoderms. PMID:22496191

  1. Passive constraint and new shape-change devices for heart failure.

    PubMed

    Kaplon, Richard; Lombardi, Pierluca

    2002-04-01

    Lessons learned from ventricular remodeling procedures have shown that Laplace mechanics, whereby mural tension is related to ventricular diameter, may be beneficially applied to the left ventricle (LV). Recently developed devices, predicated on the Law of Laplace, are directed at interrupting the heart-failure cascade without removing functioning myocardium. The Acorn cardiac support device is a polyester-mesh jacket placed snugly around the heart to provide end-diastolic support and prevent LV dilation. The Myosplint device uses transmural tension members to bisect the dilated LV to create a bilobed LV with decreased mural tension in each cavity. Preclinical and early clinical data with both devices appears promising and may offer a new surgical alternative for patients with worsening heart failure. PMID:11988954

  2. Left ventricular restoration devices.

    PubMed

    Oliveira, Guilherme H; Al-Kindi, Sadeer G; Bezerra, Hiram G; Costa, Marco A

    2014-04-01

    Left ventricular (LV) remodeling results in continuous cardiac chamber enlargement and contractile dysfunction, perpetuating the syndrome of heart failure. With current exhaustion of the neurohormonal medical paradigm, surgical and device-based therapies have been increasingly investigated as a way to restore LV chamber architecture and function. Left ventricular restoration has been attempted with surgical procedures, such as partial left ventriculectomy, surgical ventricular restoration with or without revascularization, and devices, such as the Acorn CorCap, the Paracor HeartNet, and the Myocor Myosplint. Whereas all these techniques require surgical access, with or without cardiopulmonary bypass, a newer ventricular partitioning device (VPD) called Parachute, can be delivered percutaneously through the aortic valve. Designed to achieve LV restoration from within the ventricle, this VPD partitions the LV by isolating aneurysmal from normal myocardium thereby diminishing the functioning cavity. This review aims to critically appraise the above methods, with particular attention to device-based therapies. PMID:24574107

  3. NAPROS: a semiautomatic user-friendly anaesthetic record system.

    PubMed

    Osswald, P M; Winter, D; Hartung, H J; Gasteiger, P

    1987-01-01

    NAPROS is a semiautomatic, inexpensive, and easy-to-use anaesthetic record system. It is based on an ACORN (BBC-Model B) microcomputer that is linked to a non-invasive arterial pressure monitor (DIN-AMAP 845a) and an inhalation anaesthetic monitor (Engstroem EMMA) for automatic collection of measured data. The following functions have been implemented: Automatic registration of cardiovascular data and concentration of anaesthetic inhalation agents. Graphical or numerical representation of fluid-balances. Possibility to recall dosage information for drugs and drops. Printing of a final anaesthetic report at the end of anaesthesia. Definite advantages of NAPROS are: The number of hours saved by the computer record over manual data entry is 8 hours. - Better acceptance by users. PMID:3681106

  4. Barnyard grasses were processed with rice around 10000 years ago

    PubMed Central

    Yang, Xiaoyan; Fuller, Dorian Q; Huan, Xiujia; Perry, Linda; Li, Quan; Li, Zhao; Zhang, Jianping; Ma, Zhikun; Zhuang, Yijie; Jiang, Leping; Ge, Yong; Lu, Houyuan

    2015-01-01

    Rice (Oryza sativa) is regarded as the only grass that was selected for cultivation and eventual domestication in the Yangtze basin of China. Although both macro-fossils and micro-fossils of rice have been recovered from the Early Neolithic site of Shangshan, dating to more than 10,000 years before present (BP), we report evidence of phytolith and starch microfossils taken from stone tools, both for grinding and cutting, and cultural layers, that indicating barnyard grass (Echinochloa spp.) was a major subsistence resource, alongside smaller quantities of acorn starches (Lithocarpus/Quercus sensu lato) and water chestnuts (Trapa). This evidence suggests that early managed wetland environments were initially harvested for multiple grain species including barnyard grasses as well as rice, and indicate that the emergence of rice as the favoured cultivated grass and ultimately the key domesticate of the Yangtze basin was a protracted process. PMID:26536839

  5. Grazing effects on forage production and botanical composition in a Quercus ithaburensis subs. macrolepis silvopastoral system

    NASA Astrophysics Data System (ADS)

    Pantera, A.; Papanastasis, V. P.

    2009-04-01

    Grazing is considered as a major factor affecting forage production as well as botanical composition of many silvopastoral systems. In order to study these effects, three pairs of grazed and protected plots were established in a Quercus ithaburensis subsp. macrolepis silvopastoral system. The experiment was carried out in western Greece, 15 km west of the city of Agrinion. Data were collected for two continuous years and included the determination of palatable and unpalatable to animals plant species as well as the botanical composition. The results suggest that heavy grazing decreased biomass production approximately threefold. Grazing also affected number of acorns, botanical composition as well as vegetation cover whereas had no effect on natural regeneration in the study period.

  6. KSC-04PD-1286

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. A young wild pig roots in the grass for food in an area near the NASA News Center at KSC. Feral pigs were introduced to Florida in the 1500s and are now found statewide in wooded areas close to water. The pigs have flourished in the environs around KSC, which shares a border with the Merritt Island National Wildlife Refuge, without many predators other than panthers and humans. Pigs are omnivores, foraging on the ground and rooting just beneath the surface, which damages the groundcover. Wild pigs eat almost anything that has nutritional value, including tubers, roots, shoots, acorns, fruits, berries, earthworms, amphibians, reptiles and rodents. Appearance is similar to domestic hogs, but leaner, with a longer, narrower head and a coarser, denser coat. Females may have two litters per year. The piglets are weaned in a few weeks but remain with the mother for several months.

  7. KSC-04PD-1287

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. Three wild pigs a mother and her two offspring root for food in the grass near the NASA News Center at KSC. Feral pigs were introduced to Florida in the 1500s and are now found statewide in wooded areas close to water. The pigs have flourished in the environs around KSC, which shares a border with the Merritt Island National Wildlife Refuge, without many predators other than panthers and humans. Pigs are omnivores, foraging on the ground and rooting just beneath the surface, which damages the groundcover. Wild pigs eat almost anything that has nutritional value, including tubers, roots, shoots, acorns, fruits, berries, earthworms, amphibians, reptiles and rodents. Appearance is similar to domestic hogs, but leaner, with a longer, narrower head and a coarser, denser coat. Females may have two litters per year. The piglets are weaned in a few weeks but remain with the mother for several months.

  8. KSC-04PD-1285

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. Three wild pigs a mother and her two offspring root for food in the grass near the NASA News Center at KSC. Feral pigs were introduced to Florida in the 1500s and are now found statewide in wooded areas close to water. The pigs have flourished in the environs around KSC, which shares a border with the Merritt Island National Wildlife Refuge, without many predators other than panthers and humans. Pigs are omnivores, foraging on the ground and rooting just beneath the surface, which damages the groundcover. Wild pigs eat almost anything that has nutritional value, including tubers, roots, shoots, acorns, fruits, berries, earthworms, amphibians, reptiles and rodents. Appearance is similar to domestic hogs, but leaner, with a longer, narrower head and a coarser, denser coat. Females may have two litters per year. The piglets are weaned in a few weeks but remain with the mother for several months.

  9. Surface-Piercing Activities of the Humpback Whale, Megaptera, Related to Parasites and Mechanics}

    NASA Astrophysics Data System (ADS)

    Galvin, C.

    2006-12-01

    Humpback whales leap out of the water (breach), strike the water surface with their long fins (flipper), strike the water surface with their tail (lobtail), and hold motionless in a vertical position with their heads above water (spyhop). These four surface-piercing activities were known to early whalers, but their explanations remain uncertain. A whale breaches by swimming from depth toward the water surface at an oblique angle, propelling himself into the air at an angle to the water's surface (0 to 70 degrees), rotating about his long axis, and landing on his back, belly up to the sky. Rotation requires applying angular momentum to the whale's trunk, which photographs suggest comes from flinging out the flipper on the side rotating upward, and keeping the downward-rotating flipper closer to the trunk. The humpback has unusually long flippers (long moment arms) up to 30 percent of trunk length. Its generic name, Megaptera, can translate as `long flipper'. Continued use of one flipper as the moment arm raises the possibility of right-handed or left-handed whales, but Whitehead's (1985) data do not support that result. Parasites as a cause of breaching is a hypothesis at least as old as Beale (1839), but in the last half of the 20th century, breaching, flippering, and lobtailing came to be understood as social activities of whales. Whitehead's work in the 1980s provides much data on humpback activities, as well as a prevailing social interpretation of the data. External parasites (loosely defined) include whale lice (fingernail-sized crablike animals) and barnacles (both fixed shell and flexible goosenecked species). Thousands of these animals may inhabit a single whale. Whale lice populate crevices of the jaws and eyes, the pleats in the throat pouch under the jaw, and shelter at fixed barnacles. Fixed barnacles thrive on exposed bumps on the whale's head and flippers. Gooseneck barnacles appear in photos attached to trailing edges of fins and tail. Some parasites

  10. Evolution of the globin gene family in deuterostomes: lineage-specific patterns of diversification and attrition.

    PubMed

    Hoffmann, Federico G; Opazo, Juan C; Hoogewijs, David; Hankeln, Thomas; Ebner, Bettina; Vinogradov, Serge N; Bailly, Xavier; Storz, Jay F

    2012-07-01

    In the Metazoa, globin proteins display an underlying unity in tertiary structure that belies an extraordinary diversity in primary structures, biochemical properties, and physiological functions. Phylogenetic reconstructions can reveal which of these functions represent novel, lineage-specific innovations, and which represent ancestral functions that are shared with homologous globin proteins in other eukaryotes and even prokaryotes. To date, our understanding of globin diversity in deuterostomes has been hindered by a dearth of genomic sequence data from the Ambulacraria (echinoderms + hemichordates), the sister group of chordates, and the phylum Xenacoelomorpha, which includes xenoturbellids, acoelomorphs, and nemertodermatids. Here, we report the results of a phylogenetic and comparative genomic analysis of the globin gene repertoire of deuterostomes. We first characterized the globin genes of the acorn worm, Saccoglossus kowalevskii, a representative of the phylum Hemichordata. We then integrated genomic sequence data from the acorn worm into a comprehensive analysis of conserved synteny and phylogenetic relationships among globin genes from representatives of the eight lineages that comprise the superphylum Deuterostomia. The primary aims were 1) to unravel the evolutionary history of the globin gene superfamily in deuterostomes and 2) to use the estimated phylogeny to gain insights into the functional evolution of deuterostome globins. Results of our analyses indicate that the deuterostome common ancestor possessed a repertoire of at least four distinct globin paralogs and that different subsets of these ancestral genes have been retained in each of the descendant organismal lineages. In each major deuterostome group, a different subset of ancestral precursor genes underwent lineage-specific expansions of functional diversity through repeated rounds of gene duplication and divergence. By integrating results of the phylogenetic analysis with available

  11. Mid-winter food use and body weights of mallards and wood ducks in Mississippi

    USGS Publications Warehouse

    Delnicki, D.; Reinecke, K.J.

    1986-01-01

    We obtained esophageal food samples from 311 mallards (Anas platyrhynchos) and 94 wood ducks (Aix sponsa) and body weights from 2,118 mallards and 315 wood ducks in western Mississippi during December and January 1979-83. On average, mallards ingested 3.0% animal food, principally aquatic invertebrates, and 97.0% plant food. Rice, soybeans, and seeds of 'moist soil' plants provided 41.3, 41.6, and 10-11% of the total food intake. Wood ducks ingested nearly 100% plant food, of which 23.4% was soybeans and 74.3% was acorns from Nuttall (Quercus nuttallii), water (Q. nigra), and willow oaks (Q. phellos). Mallard food use varied with water conditions; the use of rice decreased and soybeans increased during 1980-81 when cumulative November-January precipitation was < 50% of normal. Wood duck food use varied with habitat; the diet included more acorns at sites having larger acreages of intact bottomland hardwood forest. Mallard and wood duck body weights varied within and among winters. Mallard weights decreased by about 2% from December to January each year. We considered this a regulated loss, whereas we attributed increases and decreases of 4-5% in average weights during wet and dry winters to changes in feeding opportunities associated with winter precipitation. Wood duck weights followed similar trends. We concluded that continued drainage in the Mississippi Delta will adversely affect waterfowl foraging opportunities, and that research on winter feeding ecology will progress more rapidly if we develop an understanding of the foraging efficiencies associated with alternate food resources.

  12. The Comparative Effectiveness of Rodents and Dung Beetles as Local Seed Dispersers in Mediterranean Oak Forests

    PubMed Central

    Pérez-Ramos, Ignacio M.; Verdú, José R.; Numa, Catherine; Marañón, Teodoro; Lobo, Jorge M.

    2013-01-01

    The process of seed dispersal of many animal-dispersed plants is frequently mediated by a small set of biotic agents. However, the contribution that each of these dispersers makes to the overall recruitment may differ largely, with important ecological and management implications for the population viability and dynamics of the species implied in these interactions. In this paper, we compared the relative contribution of two local guilds of scatter-hoarding animals with contrasting metabolic requirements and foraging behaviours (rodents and dung beetles) to the overall recruitment of two Quercus species co-occurring in the forests of southern Spain. For this purpose, we considered not only the quantity of dispersed seeds but also the quality of the seed dispersal process. The suitability for recruitment of the microhabitats where the seeds were deposited was evaluated in a multi-stage demographic approach. The highest rates of seed handling and predation occurred in those microhabitats located under shrubs, mostly due to the foraging activity of rodents. However, the probability of a seed being successfully cached was higher in microhabitats located beneath a tree canopy as a result of the feeding behaviour of beetles. Rodents and beetles showed remarkable differences in their effectiveness as local acorn dispersers. Quantitatively, rodents were much more important than beetles because they dispersed the vast majority of acorns. However, they were qualitatively less effective because they consumed a high proportion of them (over 95%), and seeds were mostly dispersed under shrubs, a less suitable microhabitat for short-term recruitment of the two oak species. Our findings demonstrate that certain species of dung beetles (such as Thorectes lusitanicus), despite being quantitatively less important than rodents, can act as effective local seed dispersers of Mediterranean oak species. Changes in the abundance of beetle populations could thus have profound implications

  13. Protein Aggregation Formed by Recombinant cp19k Homologue of Balanus albicostatus Combined with an 18 kDa N-Terminus Encoded by pET-32a(+) Plasmid Having Adhesion Strength Comparable to Several Commercial Glues.

    PubMed

    Liang, Chao; Li, Yunqiu; Liu, Zhiming; Wu, Wenjian; Hu, Biru

    2015-01-01

    The barnacle is well known for its tenacious and permanent attachment to a wide variety of underwater substrates, which is accomplished by synthesizing, secreting and curing a mixture of adhesive proteins termed "barnacle cement". In order to evaluate interfacial adhesion abilities of barnacle cement proteins, the cp19k homologous gene in Balanus albicostatus (Balcp19k) was cloned and expressed in Escherichia coli. Here, we report an intriguing discovery of a gel-like super adhesive aggregation produced by Trx-Balcp19k, a recombinant Balcp19k fusion protein. The Trx-Balcp19k consists of an 18 kDa fragment at the N-terminus, which is encoded by pET-32a(+) plasmid and mainly comprised of a thioredoxin (Trx) tag, and Balcp19k at the C-terminus. The sticky aggregation was designated as "Trx-Balcp19k gel", and the bulk adhesion strength, biochemical composition, as well as formation conditions were all carefully investigated. The Trx-Balcp19k gel exhibited strong adhesion strength of 2.10 ± 0.67 MPa, which was approximately fifty folds higher than that of the disaggregated Trx-Balcp19k (40 ± 8 kPa) and rivaled those of commercial polyvinyl acetate (PVA) craft glue (Mont Marte, Australia) and UHU glue (UHU GmbH & Co. KG, Germany). Lipids were absent from the Trx-Balcp19k gel and only a trace amount of carbohydrates was detected. We postulate that the electrostatic interactions play a key role in the formation of Trx-Balcp19k gel, by mediating self-aggregation of Trx-Balcp19k based on its asymmetric distribution pattern of charged amino acids. Taken together, we believe that our discovery not only presents a promising biological adhesive with potential applications in both biomedical and technical fields, but also provides valuable paradigms for molecular design of bio-inspired peptide- or protein-based materials. PMID:26317205

  14. Protein Aggregation Formed by Recombinant cp19k Homologue of Balanus albicostatus Combined with an 18 kDa N-Terminus Encoded by pET-32a(+) Plasmid Having Adhesion Strength Comparable to Several Commercial Glues

    PubMed Central

    Liang, Chao; Li, Yunqiu; Liu, Zhiming; Wu, Wenjian; Hu, Biru

    2015-01-01

    The barnacle is well known for its tenacious and permanent attachment to a wide variety of underwater substrates, which is accomplished by synthesizing, secreting and curing a mixture of adhesive proteins termed “barnacle cement”. In order to evaluate interfacial adhesion abilities of barnacle cement proteins, the cp19k homologous gene in Balanus albicostatus (Balcp19k) was cloned and expressed in Escherichia coli. Here, we report an intriguing discovery of a gel-like super adhesive aggregation produced by Trx-Balcp19k, a recombinant Balcp19k fusion protein. The Trx-Balcp19k consists of an 18 kDa fragment at the N-terminus, which is encoded by pET-32a(+) plasmid and mainly comprised of a thioredoxin (Trx) tag, and Balcp19k at the C-terminus. The sticky aggregation was designated as “Trx-Balcp19k gel”, and the bulk adhesion strength, biochemical composition, as well as formation conditions were all carefully investigated. The Trx-Balcp19k gel exhibited strong adhesion strength of 2.10 ± 0.67 MPa, which was approximately fifty folds higher than that of the disaggregated Trx-Balcp19k (40 ± 8 kPa) and rivaled those of commercial polyvinyl acetate (PVA) craft glue (Mont Marte, Australia) and UHU glue (UHU GmbH & Co. KG, Germany). Lipids were absent from the Trx-Balcp19k gel and only a trace amount of carbohydrates was detected. We postulate that the electrostatic interactions play a key role in the formation of Trx-Balcp19k gel, by mediating self-aggregation of Trx-Balcp19k based on its asymmetric distribution pattern of charged amino acids. Taken together, we believe that our discovery not only presents a promising biological adhesive with potential applications in both biomedical and technical fields, but also provides valuable paradigms for molecular design of bio-inspired peptide- or protein-based materials. PMID:26317205

  15. Environmentally Benign and Permanent Modifications to Prevent Biofouling on Marine and Hydrokinetic Devices

    SciTech Connect

    Zheng Zhang

    2012-04-19

    Semprus Biosciences is developing environmentally benign and permanent modifications to prevent biofouling on Marine and Hydrokinetic (MHK) devices. Biofouling, including growth on external surfaces by bacteria, algae, barnacles, mussels, and other marine organisms, accumulate quickly on MHK devices, causing mechanical wear and changes in performance. Biofouling on crucial components of hydrokinetic devices, such as rotors, generators, and turbines, imposes substantial mass and hydrodynamic loading with associated efficiency loss and maintenance costs. Most antifouling coatings leach toxic ingredients, such as copper and tributyltin, through an eroding process, but increasingly stringent regulation of biocides has led to interest in the development of non-biocidal technologies to control fouling. Semprus Biosciences research team is developing modifications to prevent fouling from a broad spectrum of organisms on devices of all shapes, sizes, and materials for the life of the product. The research team designed and developed betaine-based polymers as novel underwater coatings to resist the attachment of marine organisms. Different betaine-based monomers and polymers were synthesized and incorporated within various coating formulations. The formulations and application methods were developed on aluminum panels with required adhesion strength and mechanical properties. The coating polymers were chemically stable under UV, hydrolytic and oxidative environments. The sulfobetaine formulations are applicable as nonleaching and stable underwater coatings. For the first time, coating formulations modified with highly packed sulfobetaine polymers were prepared and demonstrated resistance to a broad spectrum of marine organisms. Assays for comparing nonfouling performance were developed to evaluate protein adsorption and bacteria attachment. Barnacle settlement and removal were evaluated and a 60-day field test was performed. Silicone substrates including a commercial

  16. Dominance of blue mussels versus consumer-mediated enhancement of benthic diversity

    NASA Astrophysics Data System (ADS)

    Enderlein, Peter; Wahl, Martin

    2004-03-01

    In the shallow subtidal of Kiel Fjord (western Baltic Sea), the blue mussel Mytilus edulis is the dominant competitor for space. Vertically suspended settlement substrata in the upper 6 m of the water column almost invariably become dominated by M. edulis within a few summer months. However, not all naturally available hard substrata bear mussel monocultures. In three in situ experiments we investigated the dominance of mussels and the influence of local consumers on establishment and dynamics of a benthic community: (a) the natural course of succession in the absence of benthic consumers was followed on vertically suspended settlement substrata, (b) settling plates were exposed to natural recruitment being either accessible or inaccessible to all benthic consumers, and (c) the three major local consumer species, viz. the shore crab Carcinus maenas, the starfish Asterias rubens and the periwinkle Littorina littorea, were enclosed separately in cages containing a settling panel to assess species-specific consumer effects on recruitment. The results illustrate that in this region of the Baltic Sea mussels do have the potential to dominate ungrazed substrata within a few weeks and that top-down effects (predation and grazing) may control community structure. While some species - mussels in particular - were suppressed by consumption, others seemed to benefit from the presence of consumers. Thus, barnacles and algae thrived when consumers were present. Blue mussels being the locally dominant competitor, the beneficial effects of consumers on barnacles and algae were presumably indirect ones through consumer-caused release from asymmetrical competition. The isolated effects of C. maenas, A. rubens and L. littorea, on recruitment differed in quality (positive vs. negative), quantity (strength of effect) and specificity. Barnacle recruitment was significantly reduced in the presence of both starfish and shore crabs. Diatom recruitment was significantly reduced by snails

  17. Investigation into the hydrodynamic performance of fouling-release surfaces

    NASA Astrophysics Data System (ADS)

    Quinn, Ronan Declan

    diameter, when subject to these flow conditions using a simple point load adhesion measurement such as ASTM D5618. It has also been shown that creep could play a key role in the self cleaning of these surfaces and this may allow the use of such coatings in conditions previously thought unsuitable. In order to study the applicability of this data to fouling organisms, a preliminary investigation into the methods of adhesion of barnacles to fouling release surfaces was also undertaken. It was found that barnacles adhere to surfaces in a manner that is different to epoxy and perhaps other synthetic adhesive. Although much insight was gained into the interaction of barnacles and silicones, the implications of this, remain unanswered.

  18. Cytotoxic Polyketides from the Deep-Sea-Derived Fungus Engyodontium album DFFSCS021

    PubMed Central

    Yao, Qifeng; Wang, Jie; Zhang, Xiaoyong; Nong, Xuhua; Xu, Xinya; Qi, Shuhua

    2014-01-01

    Eight new chromones, engyodontiumones A–H (1–8), and three new phenol derivatives (9–11) together with eight known polyketides (12–19) were isolated from the deep-sea-derived fungus Engyodontium album DFFSCS021. Their structures were identified by extensive spectroscopic analysis. Compounds 8 and 16 showed significant selective cytotoxicity against human histiocytic lymphoma U937 cell line with IC50 values of 4.9 and 8.8 μM, respectively. In addition, this is the first time to report that 8, 15 and 16 had mild antibacterial activity against Escherichia coli and Bacillus subtilis, and 15 showed potent antilarval activity against barnacle Balanus amphitrite larval settlement. PMID:25501793

  19. Drowned forests and archaeology on the continental shelf of British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Fedje, Daryl W.; Josenhans, Heiner

    2000-02-01

    We have used high-resolution digital terrain imaging and sea-floor sampling to reveal drowned late glacial to early postglacial terrestrial landscapes at water depths as great as 150 m. In situ tree stumps and shellfish-rich paleobeaches are present on these drowned landscapes. A stone tool encrusted with barnacles and bryozoa was recovered from a drowned delta flood plain now 53 m below mean sea level. This is the first tangible evidence that the formerly subaerial broad banks of the western North American Continental Shelf may have been occupied by humans in earliest Holocene and possibly late-glacial time. Analyses (14C) of the drowned terrestrial and intertidal deposits were used to refine the local sea-level curve, which shows very rapid change within this glacio-isostatically dynamic region.

  20. Sinularones A–I, New Cyclopentenone and Butenolide Derivatives from a Marine Soft Coral Sinularia sp. and Their Antifouling Activity

    PubMed Central

    Shi, Haiyan; Yu, Shanjiang; Liu, Dong; van Ofwegen, Leen; Proksch, Peter; Lin, Wenhan

    2012-01-01

    Nine new compounds, namely sinularones A–I (1–9), characterized as cyclopentenone and butenolide-type analogues, were isolated from a soft coral Sinularia sp., together with a known butenolide (10). Their structures were elucidated by means of spectroscopic (IR, MS, 1D and 2D NMR, CD) analysis. The absolute configurations were determined on the basis of CD and specific rotation data in association with the computed electronic circular dichroism (ECD) by time dependent density functional theory (TD DFT) at 6-31+G(d,p)//DFT B3LYP/6-31+G(d,p) level. Compounds 1–2 and 7–10 showed potent antifouling activities against the barnacle Balanus amphitrite. PMID:22822376

  1. Salesclerks, sexual danger, and national identity in Egypt, 1920s-1950s.

    PubMed

    Reynolds, Nancy Y

    2011-01-01

    This article investigates change and continuity in anxieties about shopping during the first half of the twentieth century in Egypt to argue that department stores and their salesclerks became critical sites for enacting and challenging new notions of sexuality and citizenship. Retail innovations, such as commission pay, display, free entry, and large commercial staffs, became understood as sexual and moral problems because department stores blurred the boundaries between classes and were public spaces where unrelated men and women could mix. These concerns about sexuality in the 1920s were recycled and amplified in the late 1940s and early 1950s when salesclerks again came under scrutiny during debates over citizenship and ethnicity. I argue that the particular way this latter debate was barnacled by the concerns of the 1920s helped to delineate the broader society's reaction to the challenges of defining Egyptian nationality. PMID:22145182

  2. Malaclemys terrapin rhizophorarum (mangrove diamond-backed terrapin)

    USGS Publications Warehouse

    Denton, Mathew J.; Hart, Kristen M.; Oelinik, Anton; Wood, Roger; Baldwin, John N.

    2015-01-01

    MALACLEMYS TERRAPIN RHIZOPHORARUM (Mangrove Diamond-backed Terrapin). DIET. Malaclemys terrapin rhizophorarum, one of seven subspecies of M. terrapin, inhabits subtropical mangrove habitats in South Florida, USA. In temperate climates M. terrapin is largely carnivorous, feeding primarily on gastropods, bivalves, and decapod crustaceans (Tucker et. al. 1995. Herpetologica 51:167–181; Butler et. al. 2012. Chelon. Conserv. Biol. 11:124–128). In addition to its preferred prey, M. t. rhizophorarum has also been reported to consume barnacles, fish, and vegetation (Tucker et. al. 1995, op. cit.; Butler et. al. 2012, op. cit.; Tulipani 2013. Ph.D. Dissertation. The College of William and Mary, Williamsburg, Virginia. 224 pp.). Herein, we report observations regarding the diet of M. t. rhizophorarum from the southernmost extent of their range in the Florida Keys, USA.

  3. Pathfinder Rear Ramp

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Mars Pathfinder's rear rover ramp can be seen successfully unfurled in this image, taken at the end of Sol 2 by the Imager for Mars Pathfinder (IMP). This ramp was later used for the deployment of the microrover Sojourner, which occurred at the end of Sol 2. Areas of a lander petal and deflated airbag are visible at left. The image helped Pathfinder scientists determine that the rear ramp was the one to use for rover deployment. At upper right is the rock dubbed 'Barnacle Bill,' which Sojourner will later study.

    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.

  4. Sojourner & Yogi

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A close up of Sojourner as it placed its Alpha Proton X-Ray Spectrometer (APXS) upon the surface of the rock Yogi was taken by the Imager for Mars Pathfinder (IMP) over sols 8, 9 and 10. Distortion in the background is due to parallax. Early results of Yogi show it to be low in quartz content, and more primitive than the rock Barnacle Bill, and appeared more like the common basalts found on Earth.

    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.

  5. Efficacy and toxicity of self-polishing biocide-free antifouling paints.

    PubMed

    Löschau, Margit; Krätke, Renate

    2005-11-01

    The ban on harmful substances in antifouling paints requires the development of new antifouling strategies. Alternatives should be as effective as conventional paints but of lower toxicity. In the present study two commercially available, self-polishing antifouling paints were examined in order to get information on their antifouling properties and toxicological potential. Efficacy was shown in settlement assays with the marine barnacle species Balanus amphitrite, however, efficacy was related to toxic effects observed on target and non-target organisms. Toxicity of the paint extracts was concentration-dependent and differed according to the paint and the species investigated. Toxicity could at least partially be attributed to zinc leached from the paints. Effects of a water-soluble paint were more pronounced in larvae of B. amphitrite, Artemia salina and in the green algae Dunaliella tertiolecta. Embryos of the freshwater species Danio rerio and Vibrio fisheri were more affected by a paint based on organic solvents. PMID:15955603

  6. Effects of the Exxon Valdez oil spill on migrant shorebirds using rocky intertidal habitats of Prince William Sound, Alaska, during spring, 1989. Exxon Valdez oil spill state/federal natural resource damage assessment final report

    SciTech Connect

    Martin, P.D.

    1993-12-01

    A minimum of a few 10,000`s of surfbirds (Aphriza virgata) and black turnstones (Arenaria melanocephala) used rocky intertidal habitats of southwestern Prince William sound in spring 1989. Virtually all the shorebirds were found using shorelines, primarily on northern Montague Island, subjectively classified in the field as lightly oiled or unoiled. Surfbirds and black turnstones preyed mainly on herring eggs, blue mussels, and barnacles. Samples of these prey items from oiled areas contained petroleum-derived hydrocarbons, as did at some of the samples from the relatively clean portions of Montague Island. The results of chemical analysis of a small sample of shorebird liver tissues provided only limited support for the hypothesis that shorebirds had ingested significant quantities of petroleum-derived hydrocarbons. Surfbirds and black turnstones probably escaped significant population impacts as a result of the EVOs because shorelines which received heavy use by these species were largely spared contamination.

  7. Herring Bay experimental and monitoring studies. Restoration study number 102. Exxon Valdez oil spill state/federal natural resource damage assessment final report

    SciTech Connect

    Highsmith, R.C.; Stekoll, M.S.; van Tamelen, P.; Hooten, A.J.; Deysher, L.

    1993-10-01

    Intertidal studies were established in 1990 in Herring Bay, Prince William Sound in response to the T/V Exxon Valdez oil spill and have continued through the 1992 field season. Examination of the dominant intertidal alga, Fucus gardneri, has shown that larger plants were removed from the intertidal in areas affected by the spill/clean-up. Where Fucus cover was reduced, an increase in the abundance of ephemeral alage often occurred. Populations of intertidal grazing invertebrates, such as limpets and periwinkles showed reduced densities at oiled sites. Initially, barnacle recruitment was lower in quadrats on tar-covered rocks, compared to scraped quadrats, but differences disappeared at most sites over time. However, Fucus germlings and filamentous algae contineud to have lower densities and percent cover on oiled than non-oiled substrates. Recovery is taking place in lower and middle intertidal zones and normal community interactions are returning.

  8. Invaders eating invaders: Exploitation of novel alien prey by the alien shimofuri goby in the San Francisco Estuary, California

    USGS Publications Warehouse

    Matern, S.A.; Brown, L.R.

    2005-01-01

    The shimofuri goby (Tridentiger bifasciatus), which is native to Asian estuaries, was recently introduced to the San Francisco Estuary, California, USA. We conducted gut content analyses to examine the goby's feeding ecology in this highly invaded estuary. Shimofuri gobies were generalist predators on benthic invertebrates, consuming seasonally abundant prey, especially amphipods (Corophium spp.). In addition, shimofuri goby utilized two novel prey items not exploited by other resident fishes - hydroids (Cordylophora caspia) and barnacle (Balanus improvisus) cirri, both of which are alien. The shimofuri goby's feeding ecology appears well-suited to the fluctuating environment of the San Francisco Estuary and may partially explain observed increases in shimofuri goby abundance compared with declines in populations of some native species. ?? Springer 2005.

  9. Hydrogen embrittlement: Prevention and control; ASTM Special Technical Publication, No. 962

    SciTech Connect

    Raymond, L.

    1988-01-01

    The control and prevention of hydrogen embrittlement in metals are discussed, with a focus on test methods, in reviews and reports presented at the ASTM national symposium held in Los Angeles in May 1985. Sections are devoted to current standards and projections, hydrogen in steel and Ti, relative susceptibility, hydrogen in welding, case histories of prevention and control, and ongoing research. Topics addressed include electrochemical aspects, accelerated acceptance testing methods, the barnacle electrode method, the disk pressure test, a bent-beam test for H2S stress corrosion cracking, diffusible hydrogen testing by gas chromatography, surface films for embrittlement prevention, the effects of strain on hydrogen entry and transport in ferrous alloys, and the temperature dependence of fatigue crack propagation in Nb-H alloys.

  10. Antifouling bastadin congeners target mussel phenoloxidase and complex copper(II) ions.

    PubMed

    Bayer, Mirko; Hellio, Claire; Maréchal, Jean-Philippe; Frank, Walter; Lin, Wenhan; Weber, Horst; Proksch, Peter

    2011-12-01

    Synthetically prepared congeners of sponge-derived bastadin derivatives such as 5,5'-dibromohemibastadin-1 (DBHB) that suppress the settling of barnacle larvae were identified in this study as strong inhibitors of blue mussel phenoloxidase that is involved in the firm attachment of mussels to a given substrate. The IC₅₀ value of DBHB as the most active enzyme inhibitor encountered in this study amounts to 0.84 μM. Inhibition of phenoloxidase by DBHB is likely due to complexation of copper(II) ions from the catalytic centre of the enzyme by the α-oxo-oxime moiety of the compound as shown here for the first time by structure activity studies and by X-ray structure determination of a copper(II) complex of DBHB. PMID:21547349

  11. Effect of silver nanoparticles on marine organisms belonging to different trophic levels.

    PubMed

    Gambardella, Chiara; Costa, Elisa; Piazza, Veronica; Fabbrocini, Adele; Magi, Emanuele; Faimali, Marco; Garaventa, Francesca

    2015-10-01

    Silver nanoparticles (Ag-NPs) are increasingly used in a wide range of consumer products and such an extensive use raises questions about their safety and environmental toxicity. We investigated the potential toxicity of Ag-NPs in the marine ecosystem by analyzing the effects on several organisms belonging to different trophic levels. Algae (Dunaliella tertiolecta, Skeletonema costatum), cnidaria (Aurelia aurita jellyfish), crustaceans (Amphibalanus amphitrite and Artemia salina) and echinoderms (Paracentrotus lividus) were exposed to Ag-NPs and different end-points were evaluated: algal growth, ephyra jellyfish immobilization and frequency of pulsations, crustaceans mortality and swimming behavior, and sea urchin sperm motility. Results showed that all the end-points were able to underline a dose-dependent effect. Jellyfish were the most sensitive species, followed by barnacles, sea urchins, green algae, diatoms and brine shrimps. In conclusion, Ag-NPs exposure can influence different trophic levels within the marine ecosystem. PMID:26065810

  12. Cirripedia of Madeira

    NASA Astrophysics Data System (ADS)

    Wirtz, Peter; Araújo, Ricardo; Southward, Alan J.

    2006-09-01

    We give a list of Cirripedia from Madeira Island and nearby deep water, based on specimens in the collection of the Museu Municipal do Funchal (História Natural) (MMF), records mentioned in the literature, and recent collections. Tesseropora atlantica Newman and Ross, 1976 is recorded from Madeira for the first time. The Megabalanus of Madeira is M. azoricus. There are 20 genera containing 27 species, of which 22 occur in depths less than 200 m. Of these shallow water species, eight are wide-ranging oceanic forms that attach to other organisms or to floating objects, leaving just 13 truly benthic shallow water barnacles. This low diversity is probably a consequence of the distance from the continental coasts and the small area of the available habitat. No endemic species have been found.

  13. Bioactive steroid derivatives and butyrolactone derivatives from a gorgonian-derived Aspergillus sp. fungus.

    PubMed

    Chen, Min; Wang, Kai-Ling; Liu, Min; She, Zhi-Gang; Wang, Chang-Yun

    2015-09-01

    Six steroid derivatives, 1-6, and five butyrolactone derivatives, 7-11, were isolated from the fermentation broth of a gorgonian-derived Aspergillus sp. fungus. Their structures were elucidated on the basis of NMR and MS spectral data. Compound 1 is a new, highly conjugated steroid. The NMR and MS data of 7 and 8 are reported for the first time, as their structures were listed in SciFinder Scholar with no associated reference. Compounds 1, 4, 5, and 8-11 inhibited the larval settlement of barnacle Balanus amphitrite with EC50 values ranging from 0.63 to 18.4 μg ml(-1) . Butyrolactone derivatives 7 and 8 showed pronounced antibacterial activities against Staphylococcus aureus with the same MIC values as the positive control ciprofloxacin (MIC 1.56 μM for all three compounds). PMID:26363883

  14. Bioactive diphenyl ether derivatives from a gorgonian-derived fungus Talaromyces sp.

    PubMed

    Chen, Min; Han, Lei; Shao, Chang-Lun; She, Zhi-Gang; Wang, Chang-Yun

    2015-03-01

    Three new diphenyl ether derivatives, talaromycins A-C (1-3, resp.), together with six known analogs, 4-9, were isolated from a gorgonian-derived fungus, Talaromyces sp. The structures of the new compounds were determined by analysis of extensive NMR spectroscopic data. All of the isolated metabolites, 1-9, were evaluated for their cytotoxic and antifouling activities. Compound 4 exhibited pronounced cytotoxicity against the tested human cell lines with the IC50 values ranging from 4.3 to 9.8 μM. Compounds 3, 5, 8, and 9 showed potent antifouling activities against the larval settlement of the barnacle Balanus amphitrite with the EC50 values ranging from 2.2 to 4.8 μg/ml. PMID:25766917

  15. Evidence for a Chemoautotrophically Based Food Web at Inactive Hydrothermal Vents (Manus Basin)

    NASA Astrophysics Data System (ADS)

    van Dover, C. L.; Erickson, K.; Macko, S.

    2008-12-01

    Hydrothermal vents are ephemeral systems. When venting shuts down, sulfide-dependent taxa die off, and non-vent taxa can colonize the hard substrata. In Manus Basin (Papua New Guinea), where active and inactive sulfide mounds are interspersed, hydroids, cladorhizid sponges, barnacles, and bamboo sponges, and other invertebrate types may occupy inactive sulfide mounds. Carbon and nitrogen isotopic compositions of animals occupying inactive sulfide mounds are consistent with nutritional dependence on either chemoautotrophically or photosynthetically produced organic material, but sulfur isotopic compositions of these animals point to a chemoautotrophic source of sulfur from dissolved sulfide in vent fluids rather than sulfur derived from seawater sulfate through photosynthesis. Given that suspension-feeding and micro- carnivorous invertebrates are the biomass dominants at inactive sulfide mounds, the primary source of chemoautotrophic nutrition is likely suspended particulates and organisms delivered from nearby active vents.

  16. Trace element and stable isotope analysis of fourteen species of marine invertebrates from the Bay of Fundy, Canada.

    PubMed

    English, Matthew D; Robertson, Gregory J; Mallory, Mark L

    2015-12-15

    The Bay of Fundy, Canada, is a macrotidal bay with a highly productive intertidal zone, hosting a large abundance and diversity of marine invertebrates. We analysed trace element concentrations and stable isotopic values of δ(15)N and δ(13)C in 14 species of benthic marine invertebrates from the Bay of Fundy's intertidal zone to investigate bioaccumulation or biodilution of trace elements in the lower level of this marine food web. Barnacles (Balanus balanus) consistently had significantly greater concentrations of trace elements compared to the other species studied, but otherwise we found low concentrations of non-essential trace elements. In the range of trophic levels that we studied, we found limited evidence of bioaccumulation or biodilution of trace elements across species, likely due to the species examined occupying similar trophic levels in different food chains. PMID:26490410

  17. Evidence for a chemoautotrophically based food web at inactive hydrothermal vents (Manus Basin)

    NASA Astrophysics Data System (ADS)

    Erickson, K. L.; Macko, S. A.; Van Dover, C. L.

    2009-09-01

    Hydrothermal vents are ephemeral systems. When venting shuts down, sulfide-dependent taxa die off, and non-vent taxa can colonize the hard substrata. In Manus Basin (Papua New Guinea), where hydrothermally active and inactive sites are interspersed, hydroids, cladorhizid sponges, barnacles, bamboo corals, and other invertebrate types may occupy inactive sites. Carbon and nitrogen isotopic compositions of animals occupying inactive sites are consistent with nutritional dependence on either chemoautotrophically or photosynthetically produced organic material, but sulfur isotopic compositions of these animals point to a chemoautotrophic source of sulfur from dissolved sulfide in vent fluids rather than sulfur derived from seawater sulfate through photosynthesis. Given that suspension-feeding and micro-carnivorous invertebrates are the biomass dominants at inactive sites, the primary source of chemoautotrophic nutrition is likely suspended particulates and organisms delivered from nearby active vents.

  18. Identification and counteraction of microbe-induced corrosion in metallic systems

    SciTech Connect

    Stein, A.A.

    1986-11-01

    Biological attack of metallic systems is a longstanding problem that affects all structural materials in a variety of environment and systems. Corrosion of buried pipelines by sulfate-reducing bacteria has been studied by the petrochemical industry for years. In the power industry, corrosion studies have focused on condensers and service water systems where slime, barnacles, clams, and other macro-organisms are easily detected. Efforts have been made to eliminate the effect of these organisms through the use of chlorination, back-flushing, organic coatings, or thermal shock. The objective was to maintain component performance by eliminating biofouling and reducing metallic corrosion. Recently, it has been recognized that corrosion caused by micro-organisms can occur even in very clean systems. This article gives guidelines for the identification and counteraction of microbe-induced corrosion in metallic systems.

  19. Alkanes in benthic organisms from the Buccaneer oil field

    SciTech Connect

    Middleditch, B.S.; Basile, B.

    1980-06-01

    About 200 g per day of alkanes are present in brine discharged from each of two production platforms in the Buccaneer oil field in the NW Gulf of Mexico. These alkanes disperse rapidly in the water column, so that seawater concentrations of petroleum alkanes in this region are generally very low. They can be taken up to some extent by plankton, fish, and barnacles, but the petroleum alkane concentrations in these organisms are also relatively low. The largest pool of petroleum alkanes is in the surficial sediments, where concentrations of up to 25 ppM are observed, with concentration gradients extending more than 20 m from the production platforms. Organisms are examined which are exposed to these sediments and, for comparison, other specimens from control sites around structures from which there are no discharges.

  20. Hard foulers induced crevice corrosion of HSLA steel in the coastal waters of the Gulf of Mannar (Bay of Bengal), India

    NASA Astrophysics Data System (ADS)

    Palanichamy, S.; Subramanian, G.

    2014-03-01

    In the present study an attempt has been made to investigate the relationship between the variations in the fouling assemblage and corrosion behaviour of HSLA steel at three coastal locations in the Gulf of Mannar, India, over a period of 24 months. Oyster fouling was dominant in the Tuticorin open sea, while barnacles were the major foulants in the Tuticorin harbour and Mandapam. The fouling load in the Tuticorin waters was higher when compared to the Mandapam waters. The corrosion rates decreased progressively with the immersion time at all three test locations. In the Tuticorin open sea, the corrosion rates were higher when compared to the other two locations throughout the study period. The surface of the coupons was characterized by crevices beneath the hard foulers in the Tuticorin harbour and Mandapam, whereas in the Tuticorin open sea, the coupons experienced crevices of a tunneling nature. The percentage of the loss of the tensile strength increased with time at all the test locations.

  1. The impact of the hydrodynamic conditions in aquatic areas on the red king crab fouling communities of the Barents Sea

    NASA Astrophysics Data System (ADS)

    Dvoretsky, A. G.; Dvoretsky, V. G.

    2014-03-01

    A comparative analysis of the species composition and indices of associated organisms for the red king crab Paralithodes camtschaticus has been carried out at two aquatic areas of the Barents Sea that differ based on the intensity of their water exchange with the open sea areas. In Dolgaya Bay, a typical fjord of the Barents Sea with low water circulation, such common fouling organisms as the barnacles Balanus crenatus dominated on the crabs, while, in Dalnezelenetskaya Bay, a semiopen coastal area, the most common mobile symbionts on the red king crab were the amphipods Ischyrocerus commensalis and I. anguipes. In Dolgaya Bay, the hydrodynamic conditions promote the settlement of larval foulers, whose colonization leads to a decrease of the crab infestation with the mobile symbionts and changes in their distribution along the host body if compared to the more open coastal areas of Eastern Murman.

  2. Sources of organic matter for intertidal consumers on Ascophyllum-shores (SW Iceland): a multi-stable isotope approach

    NASA Astrophysics Data System (ADS)

    Sarà, G.; de Pirro, M.; Romano, C.; Rumolo, P.; Sprovieri, M.; Mazzola, A.

    2007-12-01

    Stable isotopes were used to examine the origin of organic matter in Icelandic Ascophyllum-based habitats, the role of different organic matters in filling intertidal food webs and the food preferences of the most abundant suspension feeders, grazers and predators. We selected three intertidal sites on the SW coast of Iceland where we sampled in early September 2004, organic matter sources (POM, SOM and most abundant primary producers, A. nodosum and F. vesciculosus) and the most abundant macrofauna species (barnacles, mussels, gastropods, sponge and crabs). Even though the primary production ( Ascophyllum-based) was the same at the three study sites, the isotopic composition of common-among-sites organisms varied due to local differences in the origin of available POM and SOM and in food web structures.

  3. Contaminant cocktails: Interactive effects of fertiliser and copper paint on marine invertebrate recruitment and mortality.

    PubMed

    Lawes, Jasmin C; Clark, Graeme F; Johnston, Emma L

    2016-01-15

    Understanding interactive effects of contaminants is critical to predict how human activities change ecosystem structure and function. We examined independent and interactive effects of two contaminants (fertiliser and copper paint) on the recruitment, mortality, and total abundance of developing invertebrate communities in the field, 2, 4, 6, and 8 weeks after substrate submersion. Contaminants affected community structure differently, and produced an intermediate community in combination. Fertiliser increased recruitment and decreased mortality of active filter feeders (ascidians and barnacles), while copper paint decreased recruitment and increased mortality of some taxa. Contaminants applied together affected some taxa (e.g. Didemnid ascidians) antagonistically, as fertiliser mitigated adverse effects of copper paint. Recruitment of active filter feeders appears to be indicative of nutrient enrichment, and their increased abundance may reduce elevated nutrients in modified waterways. This study demonstrates the need to consider both independent and interactive effects of contaminants on marine communities in the field. PMID:26632524

  4. Macrofouling control technology update

    SciTech Connect

    Tsou, J.L.; Armor, A.F.

    1996-12-31

    Macrofouling of condenser systems with debris, fish, clams, barnacles, mussels, algae, and other marine organisms can significantly affect power plant availability and performance. Typical difficulties include increased condenser back pressure due to reduced cooling-water flow, malfunctioning of on-line tube-cleaning equipment, and accelerated corrosion and erosion of tubing. In some severe cases, condenser back pressure increased to a point that the turbine had to be tripped. In 1981 EPRI initiated a research project to develop utility industry guidelines for reducing macrofouling problems. In 1987 EPRI published the Guidelines on Macrofouling Control Technology. Since then significant progress has been made by EPRI, utility members, equipment manufacturers, and others. The purpose of this paper is to update the macrofouling control technology. Control technology covered will include thermal treatment, mechanical removal devices, antifouling coatings, and chemical treatment.

  5. Combinatorial materials research applied to the development of new surface coatings: VIII: Overview of the high-throughput measurement systems developed for a marine coating workflow

    NASA Astrophysics Data System (ADS)

    Chisholm, Bret J.; Stafslien, Shane J.; Christianson, David A.; Gallagher-Lein, Christy; Daniels, Justin W.; Rafferty, Crystal; Wal, Lyndsi Vander; Webster, Dean C.

    2007-11-01

    A combinatorial workflow has been produced for the development of novel, environmental-friendly marine coatings. A particularly challenging aspect of the workflow development was the selection and development of high-throughput screening methods that allow for some degree of prediction of coating performance in the aquatic environment of interest. The high-throughput screening methods currently in place include measurements of surface energy, viscoelastic properties, pseudobarnacle adhesion, and a suite of biological assays based on various marine organisms. An experiment involving a series of fouling-release coatings was used to correlate high-throughput screening data to data obtained from ocean site immersion testing. The results of the experiment showed that both bacterial biofilm surface coverage and storage modulus at 30 °C showed a good correlation with barnacle adhesion strength and a fair correlation with fouling rating, but surface energy and pseudobarnacle adhesion did not correlate with the results from ocean site testing.

  6. Antifouling leaching technique for optical lenses

    USGS Publications Warehouse

    Strahle, William J.; Perez, C. L.; Martini, Marinna A.

    1994-01-01

    The effectiveness of optical lenses deployed in water less than 100 m deep is significantly reduced by biofouling caused by the settlement of macrofauna, such as barnacles, hydroids, and tunicates. However, machineable porous plastic rings can be used to dispense antifoulant into the water in front of the lens to retard macrofaunal growth without obstructing the light path. Unlike coatings which can degrade the optical performance, antifouling rings do not interfere with the instrument optics. The authors have designed plastic, reusable cup-like antifouling rings to slip over the optical lenses of a transmissometer. These rings have been used for several deployments on shallow moorings in Massachusetts Bay, MA and have increased the time before fouling degrades optical characteristics

  7. Field experimental evaluation of secondary metabolites from marine invertebrates as antifoulants.

    PubMed

    Pereira, R C; Carvalho, A G V; Gama, B A P; Coutinho, R

    2002-05-01

    The crude organic extracts of the endemic gorgonian Phyllogorgia dilatata and two sponge species Aplysina fulva and Mycale microsigmatosa were evaluated for anti-fouling properties through field experiments. To investigate this property in ecologically meaningful conditions, crude extracts from these invertebrates were incorporated at concentrations naturally found in these marine organisms into a stable gel used as a substratum for fouling settlement. Crude extract from A. fulva showed no significant anti-fouling property at the natural concentrations used in the field experiments. In fact, fouling organisms settled significantly more on gels treated with A. fulva extract than on the control gel. On the other hand, both M. microsigmatosa and P. dilatata yielded crude extracts that exhibited a selective action inhibiting only the settlement of barnacles. The evidences obtained here by means of field experiments can provide a basis for future development of one kind of natural antifoulant technology to prevent marine biofouling. PMID:12489403

  8. Monitoring and manipulation of a sublittoral hard bottom biocoenosis in Balsfjord, northern Norway

    NASA Astrophysics Data System (ADS)

    Sandnes, O. K.; Gulliksen, B.

    1980-03-01

    Sublittoral hard bottom biocoenoses in Balsfjord, Norway (69°31' N, 19°1' E), were monitored using underwater stereophotogrammetry. The study includes manipulation of natural densities of organisms and testing the importance of biological interactions and “key species ” for the structure of biocoenoses. Underwater photography has the advantages of being a non-destructive method, but it is selective because small or hidden organisms cannot always be observed. Field experiments with exclusion of organisms from cages seem suitable for testing hypotheses concerning which animals are “key species ” in certain biocoenoses. Sea-urchins (Strongylocentrotus droebachiensis, S. pallidus) were suspected to be “key species ” in the present study, and their removal from cages caused an increase in abundance of barnacles (Balanus balanoides), the limpet Acmaea testudinalis and algal cover.

  9. Foods of Spectacled Eiders Somateria fischeri in the Bering Sea, Alaska

    USGS Publications Warehouse

    Petersen, M.R.; Piatt, J.F.; Trust, K.A.

    1998-01-01

    The winter diet of Spectacled Eiders living in marine habitats is known only from two individuals described by Cottam (1939). Here we examine marine diets from 36 stomachs collected near St. Lawrence Island, Bering Sea, Alaska, during May-June in 1987 and 1992. All Spectacled Eiders ate Mollusca, including Gastropoda (snails; frequency of occurrence 20.0%; sole taxon 0.0%) and Bivalvia (bivalves; 80.0%; 48.0%), and Crustacea (barnacles, amphipods and crabs; 30.6%; 0.0%). One bird ate a cod. The predominant species group eaten was Macoma Clams (72.0%; 36.0%). Prey species of Spectacled Eiders occur predominantly in waters 25-60 m deep in the Bering Sea. To obtain these prey, especially the bivalves, on the winter area Spectacled Eiders must forage in waters exceeding 40 m. We speculate that Spectacled Eiders regularly forage at depths of 45-70 m throughout winter.

  10. Parasites and commensals of the West Indian manatee from Puerto Rico

    USGS Publications Warehouse

    Mignucci-Giannoni, A. A.; Beck, C.A.; Montoya-Ospina, R. A.; Williams, E.H., Jr.

    1999-01-01

    Metazoan parasites and commensals were collected from dead manatees salvaged in Puerto Rico. Thirty-five manatees were examined between 1980 and 1998. Parasites and commensals were identified in 20 (57%) manatees and included 3 species of helminths, 1 nematode (Heterocheilus tunicatus) and 2 digeneans (Chiorchis fabaceus and Cochleotrema cochleotrema). Two species of commensals were also associated with manatees: a barnacle (Chelonibia manati) and a fish (whitefin remora, Echeneis neucratoides). The 3 species of helminths found in manatees constitute the first records of these parasite-host relationships for the study area. The record of C. manati is the first for the Caribbean, and thus the species is not endemic to the Gulf of Mexico as previously described. The speculation that West Indian manatees closer to the center of their geographic distribution would have a greater diversity of parasites was found not true for these insular specimens but perhaps could be true for continental South American specimens.

  11. Fouling in your own nest: vessel noise increases biofouling.

    PubMed

    Stanley, Jenni A; Wilkens, Serena L; Jeffs, Andrew G

    2014-01-01

    Globally billions of dollars are spent each year on attempting to reduce marine biofouling on commercial vessels, largely because it results in higher fuel costs due to increased hydrodynamic drag. Biofouling has been long assumed to be primarily due to the availability of vacant space on the surface of the hull. Here, it is shown that the addition of the noise emitted through a vessel's hull in port increases the settlement and growth of biofouling organisms within four weeks of clean surfaces being placed in the sea. More than twice as many bryozoans, oysters, calcareous tube worms and barnacles settled and established on surfaces with vessel noise compared to those without. Likewise, individuals from three species grew significantly larger in size in the presence of vessel noise. The results demonstrate that vessel noise in port is promoting biofouling on hulls and that underwater sound plays a much wider ecological role in the marine environment than was previously considered possible. PMID:25115518

  12. Influence of fouling assemblage on the corrosion behaviour of mild steel in the coastal waters of the Gulf of Mannar, India

    NASA Astrophysics Data System (ADS)

    Subramanian, G.; Palanichamy, S.

    2013-12-01

    Corrosion behaviour and biofouling characteristics of mild steel in three different coastal locations in the Gulf of Mannar, India have been studied over a period of 24 months. Oyster fouling was predominant at Open sea — Tuticorin, while barnacle fouling was dominant at both Mandapam and Harbour — Tuticorin. The rate of corrosion for 24 months exposure period was highest at Mandapam, where fouling was minimal. The surface of the mild steel was characterized by etchings & crevices beneath the hard foulers attached on it, at all the test locations. The depth of crevice caused by hard foulers was higher at Open sea — Tuticorin followed by Harbour — Tuticorin and Mandapam. The loss in ultimate tensile strength was more in Open sea — Tuticorin than the other two locations. Corrosion behaviour of mild steel is discussed based on the variation in the biofouling assemblage at the three test locations.

  13. Cytotoxic polyketides from the deep-sea-derived fungus Engyodontium album DFFSCS021.

    PubMed

    Yao, Qifeng; Wang, Jie; Zhang, Xiaoyong; Nong, Xuhua; Xu, Xinya; Qi, Shuhua

    2014-12-01

    Eight new chromones, engyodontiumones A-H (1-8), and three new phenol derivatives (9-11) together with eight known polyketides (12-19) were isolated from the deep-sea-derived fungus Engyodontium album DFFSCS021. Their structures were identified by extensive spectroscopic analysis. Compounds 8 and 16 showed significant selective cytotoxicity against human histiocytic lymphoma U937 cell line with IC50 values of 4.9 and 8.8 μM, respectively. In addition, this is the first time to report that 8, 15 and 16 had mild antibacterial activity against Escherichia coli and Bacillus subtilis, and 15 showed potent antilarval activity against barnacle Balanus amphitrite larval settlement. PMID:25501793

  14. Study of propagation along nonuniform excitable fibers

    SciTech Connect

    Zhou, Y.

    1992-01-01

    Two related reaction diffusion systems which support traveling wave solutions when parameters are constant are studied when there are jump discontinuities in the diffusion coefficient. The first system represents a classical axon model where the fiber has a jump in diameter at discrete locations, and the membrane dynamics represents that of barnacle muscle (which we call Morris-Lecar dynamics). The second model represents a passive cable with a uniform density of spines which have Morris-Lecar dynamics. Use of a conditional comparison principle establishes conditions where a traveling wave solution can be blocked from propagating beyond the change in fiber diameter. The authors then examine numerically for both models conditions on physical parameters which show that traveling wave solutions are blocked by changes in the fiber diameter, when propagation is successful, and when there is both forward propagation and the formation of a reflecting (echo) wave.

  15. NASA Lewis' Icing Research Tunnel Works With Small Local Company to Test Coatings

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Dynamic Coatings, Inc., wanted to test coating products that would enable the company to approach new markets. A Space Act Agreement with NASA Lewis Research Center afforded them this opportunity. They used Lewis' Icing Research Tunnel to test coating products for reduced ice adhesion, industrial and aerospace lubrication applications, a tiremold release coating now used in the production of tires for the Boeing 777, and a product that solidifies asbestos fibers (which is being tested as an insulator in a power plant in Iowa). Not only was the testing a success, but during these activities, Dynamic Coatings met another coating company with whom they now have a joint venture offering a barnacle-repellent coating for marine applications, now on the market in Florida.

  16. Using catenas for GIS-based mapping of NW Mediterranean littoral habitats

    NASA Astrophysics Data System (ADS)

    Mariani, Simone; Cefalì, Maria Elena; Terradas, Marc; Chappuis, Eglantine; Ballesteros, Enric

    2014-06-01

    Studies aimed at describing habitats and mapping their distributions are pivotal to implementing management plans and to effectively guide conservation measures. We developed a novel approach of data collection and entry (CAT-LIT) to establish a detailed cartography of the littoral habitats found along the Catalan coast (Spain). Field data were recorded using coded, two-digit hierarchical lists (e.g. Aa, Ab, etc.) of horizons found at each point along the coast, called catenas. The horizons were either dominated by species (on the rocky bottoms) or sediment types (on the beaches) and corresponded to LPRE, EUNIS and CORINE habitats. Catenas were transferred into a database and calculations about the extent of bottom types, habitats, and catenas themselves along the coast were carried out with GIS tools. In addition, habitat link richness was calculated and represented using network analysis programs. The application of CAT-LIT to the Catalan coast showed that the habitats dominated by the lichen Verrucaria amphibia and the flattened barnacle Euraphia depressa and those dominated by the barnacle Chthamalus spp. were almost ubiquitous. Those dominated by the red alga Corallina elongata, the mussel Mytilus galloprovincialis and the red alga Rissoella verruculosa were also common. Because of the frequency of their connections, those habitats formed a huge hub of links in the networks. By using catenas, the habitats can be viewed using GIS based programs keeping the catena as the main informational and ecological unit. The catenas allow maximum compactness when vertically distributed habitats are to be shown on a 2D map. The complete cartography and dataset on the spatial distribution of the littoral habitats from Catalonia is valuable for coastal management and conservation to study changes in the habitat distribution and relate such changes to anthropogenic pressures. Furthermore, the CAT-LIT can be easily adapted to shores of other seas and oceans to obtain accurate

  17. Towards a solution to the goose-agriculture conflict in North Norway, 1988-2012: the interplay between policy, stakeholder influence and goose population dynamics.

    PubMed

    Tombre, Ingunn M; Eythórsson, Einar; Madsen, Jesper

    2013-01-01

    This paper presents results from a multidisciplinary study of a negotiation process between farmers and wildlife authorities which led to an agricultural subsidy scheme to alleviate conflicts between agriculture and geese in Norway. The Svalbard-breeding population of pink-footed geese Anser brachyrhynchus has increased considerably over the last decades and conflicts with farmers have escalated, especially at stopover sites in spring when geese feed on newly sprouted pasture grass. In Vesterålen, an important stopover site for geese in North Norway, farmers deployed scaring of geese at varying intensity dependent on the level of conflict during 1988-2012. We assessed the efficiency of a subsidy scheme established in 2006, in terms of its conflict mitigation, reflected in a near discontinuation of scaring activities. The presence of pink-footed geese was analysed in relation to scaring intensity, the total goose population size and the increasing occurrence of another goose species, the barnacle goose Branta leucopsis. Scaring significantly affected the number of geese staging in Vesterålen, both in absolute and relative terms (controlling for total population size). The geese responded immediately to an increased, and reduced, level of scaring. Despite the establishment of the subsidy scheme, the number of pink-footed geese has recently declined which is probably caused by the increasing number of barnacle geese. For the farmers, the subsidy scheme provides funding that reduces the economic costs caused by the geese. Sustaining a low level of conflict will require close monitoring, dialogue and adaptation of the subsidy scheme to cater for changes in goose population dynamics. PMID:23977175

  18. Raised Holocene paleo-shorelines along the Capo Schisò coast, Taormina: New evidence of recent co-seismic deformation in northeastern Sicily (Italy)

    NASA Astrophysics Data System (ADS)

    Spampinato, Cecilia Rita; Scicchitano, Giovanni; Ferranti, Luigi; Monaco, Carmelo

    2012-04-01

    Detailed mapping of geomorphological, biological and archaeological sea-level markers around the Capo Schisò volcanic headland, a few kilometers south of Taormina, north-eastern Sicily, has documented the occurrence of three Holocene paleo-shorelines raised at different altitudes. The uppermost shoreline (PS1) is represented by a fossiliferous beach deposit that is heavily eroded and only few small sections, at elevations ranging between ˜3 and ˜5 m above the present sea-level, are visible. The middle shoreline (PS2) was found at a maximum altitude of ˜3 m and is represented by algal rims, remnants of barnacle bands and vermetid concretions, and by a fossiliferous beach deposit. The lowermost shoreline (PS3) includes remnants of algal rims, vermetid concretions, fossil barnacle bands and a beachrock, and reaches an elevation of 1.60-1.80 m. New radiocarbon dating results, integrated with published ages from nearby paleo-shoreline outcrops, constrains for the Taormina region an average uplift rate of 1.7-1.8 mm/yr in the last 5 ka, and the occurrence of three co-seismic uplift events at 4.4-3.9 ka, 2.1-1.8 ka and ≤1.0 ka ago. Abrupt displacements are tentatively attributed to footwall uplift along an offshore normal fault, but further investigations are needed to better constrain the causative source of past earthquakes. Notwithstanding, based on coastal tectonic analysis, this paper provides a new assessment of age and recurrence time of Holocene earthquakes in a historically strong seismogenic area.

  19. Probing biofouling resistant polymer brush surfaces by atomic force microscopy based force spectroscopy.

    PubMed

    Schön, Peter; Kutnyanszky, Edit; ten Donkelaar, Bas; Santonicola, M Gabriella; Tecim, Tugba; Aldred, Nick; Clare, Anthony S; Vancso, G Julius

    2013-02-01

    The protein repellency and biofouling resistance of zwitterionic poly(sulfobetaine methacrylate)(pSBMA) brushes grafted via surface initiated polymerization (SIP) from silicon and glass substrata was assessed using atomic force microscopy (AFM) adherence experiments. Laboratory settlement assays were conducted with cypris larvae of the barnacle Balanus amphitrite. AFM adherence includes the determination of contact rupture forces when AFM probe tips are withdrawn from the substratum. When the surface of the AFM tip is modified, adherence can be assessed with chemical specifity using a method known as chemical force microscopy (CFM). In this study, AFM tips were chemically functionalized with (a) fibronectin- here used as model for a nonspecifically adhering protein - and (b) arginine-glycine-aspartic acid (RGD) peptide motifs covalently attached to poly(methacrylic acid) (PMAA) brushes as biomimics of cellular adhesion receptors. Fibronectin functionalized tips showed significantly reduced nonspecific adhesion to pSBMA-modified substrata compared to bare gold (2.3±0.75 nN) and octadecanethiol (ODT) self-assembled monolayers (1.3±0.75 nN). PMAA and PMAA-RGD modified probes showed no significant adhesion to pSBMA modified silicon substrata. The results gathered through AFM protein adherence studies were complemented by laboratory fouling studies, which showed no adhesion of cypris larvae of Balanus amphitrite on pSBMA. With regard to its unusually high non-specific adsorption to a wide variety of materials the behavior of fibronectin is analogous to the barnacle cyprid temporary adhesive that also binds well to surfaces differing in polarity, charge and free energy. The antifouling efficacy of pSBMA may, therefore, be directly related to the ability of this surface to resist nonspecific protein adsorption. PMID:23138001

  20. Altitude matters: differences in cardiovascular and respiratory responses to hypoxia in bar-headed geese reared at high and low altitudes.

    PubMed

    Lague, Sabine L; Chua, Beverly; Farrell, Anthony P; Wang, Yuxiang; Milsom, William K

    2016-07-01

    Bar-headed geese (Anser indicus) fly at high altitudes during their migration across the Himalayas and Tibetan plateau. However, we know relatively little about whether rearing at high altitude (i.e. phenotypic plasticity) facilitates this impressive feat because most of what is known about their physiology comes from studies performed at sea level. To provide this information, a comprehensive analysis of metabolic, cardiovascular and ventilatory responses to progressive decreases in the equivalent fractional composition of inspired oxygen (FiO2 : 0.21, 0.12, 0.09, 0.07 and 0.05) was made on bar-headed geese reared at either high altitude (3200 m) or low altitude (0 m) and on barnacle geese (Branta leucopsis), a low-altitude migrating species, reared at low altitude (0 m). Bar-headed geese reared at high altitude exhibited lower metabolic rates and a modestly increased hypoxic ventilatory response compared with low-altitude-reared bar-headed geese. Although the in vivo oxygen equilibrium curves and blood-oxygen carrying capacity did not differ between the two bar-headed goose study groups, the blood-oxygen carrying capacity was higher than that of barnacle geese. Resting cardiac output also did not differ between groups and increased at least twofold during progressive hypoxia, initially as a result of increases in stroke volume. However, cardiac output increased at a higher FiO2  threshold in bar-headed geese raised at high altitude. Thus, bar-headed geese reared at high altitude exhibited a reduced oxygen demand at rest and a modest but significant increase in oxygen uptake and delivery during progressive hypoxia compared with bar-headed geese reared at low altitude. PMID:27385754