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1

Latitudinal Diversity of Sea Anemones (Cnidaria: Actiniaria)  

E-print Network

Latitudinal Diversity of Sea Anemones (Cnidaria: Actiniaria) DAPHNE GAIL FAUTIN*, LACEY MALARKY anemones (cnidarian order Actiniaria) conforms to the classic pattern of biogeography--taxon richness of that inventory. We found the greatest spe- cies richness of sea anemones at 30­40° N and S, with lower numbers

Fautin, Daphne

2

Sea anemones (Cnidaria: Anthozoa: Actiniaria) of Moreton Bay  

E-print Network

Sea anemones (Cnidaria: Anthozoa: Actiniaria) of Moreton Bay Daphne G. FAUTIN Department of Ecology­102 Flinders St, Townsville, Qld, Australia, 4812. ABSTRACT Nineteen species of sea anemones sensu stricto. The sea anemone fauna reported in this paper is predominantly tropical to subtropical, with 14 species

Fautin, Daphne

3

Formation of the Apical Flaps in Nematocysts of Sea Anemones (Cnidaria: Actiniaria)  

E-print Network

Formation of the Apical Flaps in Nematocysts of Sea Anemones (Cnidaria: Actiniaria) ABIGAIL J. REFT formation of the structure at the apical end of sea anemone nematocysts through which the tubule everts at discharge. In anemones of the genus Metridium, we found that each of the three solid triangular apical flaps

Fautin, Daphne

4

Sea Anemone (Cnidaria, Anthozoa, Actiniaria) Toxins: An Overview  

PubMed Central

The Cnidaria phylum includes organisms that are among the most venomous animals. The Anthozoa class includes sea anemones, hard corals, soft corals and sea pens. The composition of cnidarian venoms is not known in detail, but they appear to contain a variety of compounds. Currently around 250 of those compounds have been identified (peptides, proteins, enzymes and proteinase inhibitors) and non-proteinaceous substances (purines, quaternary ammonium compounds, biogenic amines and betaines), but very few genes encoding toxins were described and only a few related protein three-dimensional structures are available. Toxins are used for prey acquisition, but also to deter potential predators (with neurotoxicity and cardiotoxicity effects) and even to fight territorial disputes. Cnidaria toxins have been identified on the nematocysts located on the tentacles, acrorhagi and acontia, and in the mucous coat that covers the animal body. Sea anemone toxins comprise mainly proteins and peptides that are cytolytic or neurotoxic with its potency varying with the structure and site of action and are efficient in targeting different animals, such as insects, crustaceans and vertebrates. Sea anemones toxins include voltage-gated Na+ and K+ channels toxins, acid-sensing ion channel toxins, Cytolysins, toxins with Kunitz-type protease inhibitors activity and toxins with Phospholipase A2 activity. In this review we assessed the phylogentic relationships of sea anemone toxins, characterized such toxins, the genes encoding them and the toxins three-dimensional structures, further providing a state-of-the-art description of the procedures involved in the isolation and purification of bioactive toxins. PMID:23015776

Frazao, Barbara; Vasconcelos, Vitor; Antunes, Agostinho

2012-01-01

5

Sea anemones (Cnidaria: Anthozoa: Actiniaria) of Moreton Bay  

E-print Network

Nineteen species of sea anemones *sensu stricto* (Anthozoa: Zoantharia: Actiniaria) are documented from the Moreton Bay region in eastern Australia, based primarily on specimens observed and collected during the Moreton ...

Fautin, Daphne G.; Crowther, Andrea Louise; Wallace, Carden C.

2008-01-01

6

Environmental sensing and response genes in Cnidaria: the chemical defensome in the sea anemone Nematostella vectensis  

PubMed Central

The starlet sea anemone Nematostella vectensis has been recently established as a new model system for the study of the evolution of developmental processes, as cnidaria occupy a key evolutionary position at the base of the bilateria. Cnidaria play important roles in estuarine and reef communities, but are exposed to many environmental stressors. Here I describe the genetic components of a chemical defensome in the genome of N. vectensis, and review cnidarian molecular toxicology. Gene families that defend against chemical stressors and the transcription factors that regulate these genes have been termed a chemical defensome, and include the cytochromes P450 and other oxidases, various conjugating enyzymes, the ATP-dependent efflux transporters, oxidative detoxification proteins, as well as various transcription factors. These genes account for about 1% (266/27200) of the predicted genes in the sea anemone genome, similar to the proportion observed in tunicates and humans, but lower than that observed in sea urchins. While there are comparable numbers of stress-response genes, the stress sensor genes appear to be reduced in N. vectensis relative to many model protostomes and deuterostomes. Cnidarian toxicology is understudied, especially given the important ecological roles of many cnidarian species. New genomic resources should stimulate the study of chemical stress sensing and response mechanisms in cnidaria, and allow us to further illuminate the evolution of chemical defense gene networks. PMID:18956243

Goldstone, J.V.

2010-01-01

7

Stylobates birtlesi sp. n., a new species of carcinoecium-forming sea anemone (Cnidaria, Actiniaria, Actiniidae) from eastern Australia  

E-print Network

,2,, Daphne G. Fautin1,, Carden C. Wallace2, 1 Department of Ecology and Evolutionary Biology, and Natural History Museum and Biodiversity Institute, University of Kansas, 1200 Sunnyside Ave., Lawrence, Kansas 660457534 USA 2 Museum of Tropical...289DC9 Citation: Crowther AL, Fautin DG, Wallace CC (2011) Stylobates birtlesi sp. n., a new species of carcinoecium-forming sea anemone (Cnidaria, Actiniaria, Actiniidae) from eastern Australia. ZooKeys 89 : 33 48 . doi: 10.3897/zookeys.89...

Crowther, Andrea Louise; Fautin, Daphne G.; Wallace, Carden C.

2014-03-11

8

Sea anemones (Cnidaria: Actiniaria) of the Faroe Islands: a preliminary list and biogeographic context  

E-print Network

We have identified 20 species of sea anemones (order Actiniaria) from BIOFAR material, eight of them new records for the Faroe Islands. This brings the total number of anemone species known thus far from the Faroes to 30. The Faroes shares six (or...

Fautin, Daphne G.; Daly, Marymegan; Cappola, Valerie A.

2005-01-01

9

Prodigies of propagation: the many modes of clonal replication in boloceroidid sea anemones (Cnidaria, Anthozoa, Actiniaria)  

Microsoft Academic Search

Diverse modes of clonal propagation were documented in tiny zooxanthellate sea anemones from the tropical Pacific. All were boloceroidids, as indicated by the tentacles' basal sphincter and the animals' swimming behavior. In one species, single tentacles were pinched off at the sphincter, shed into the coelenteron, and brooded there while regenerating into minute new polyps in ~4 days. Within a

VICKI B. PEARSE

2002-01-01

10

Investigating the origins of triploblasty: 'mesodermal' gene expression in a diploblastic animal, the sea anemone Nematostella vectensis (phylum, Cnidaria; class, Anthozoa).  

PubMed

Mesoderm played a crucial role in the radiation of the triploblastic Bilateria, permitting the evolution of larger and more complex body plans than in the diploblastic, non-bilaterian animals. The sea anemone Nematostella is a non-bilaterian animal, a member of the phylum Cnidaria. The phylum Cnidaria (sea anemones, corals, hydras and jellyfish) is the likely sister group of the triploblastic Bilateria. Cnidarians are generally regarded as diploblastic animals, possessing endoderm and ectoderm, but lacking mesoderm. To investigate the origin of triploblasty, we studied the developmental expression of seven genes from Nematostella whose bilaterian homologs are implicated in mesodermal specification and the differentiation of mesodermal cell types (twist, snailA, snailB, forkhead, mef2, a GATA transcription factor and a LIM transcription factor). Except for mef2, the expression of these genes is largely restricted to the endodermal layer, the gastrodermis. mef2 is restricted to the ectoderm. The temporal and spatial expression of these 'mesoderm' genes suggests that they may play a role in germ layer specification. Furthermore, the predominantly endodermal expression of these genes reinforces the hypothesis that the mesoderm and endoderm of triploblastic animals could be derived from the endoderm of a diploblastic ancestor. Alternatively, we consider the possibility that the diploblastic condition of cnidarians is a secondary simplification, derived from an ancestral condition of triploblasty. PMID:15128674

Martindale, Mark Q; Pang, Kevin; Finnerty, John R

2004-05-01

11

Distribution of sea anemones (Cnidaria, Actiniaria) in Korea analyzed by environmental clustering  

E-print Network

, turbidity, and substratum. The Yellow Sea (YS) and East Sea (ES) are cold-water areas, seasonally influenced by the Yellow Sea Cold and Liman currents, respectively, from the north; the Korea Strait (KS) and Cheju Island

Fautin, Daphne

12

Clownfish in sea anemone  

NSDL National Science Digital Library

The sea anemone allows the clownfish to hide in its tentacles. Sea anemones normally sting organisms that get too close. This is a commensalistic relationship because the clownfish benefits while the anemone is neither harmed nor helped.

Mohammed Al Momany (U.S. National Oceanic and Atmospheric Administration;)

2005-08-29

13

Taxonomy and distribution of sea anemones (Cnidaria: Actiniaria and Corallimorpharia) from deep water of the northeastern Pacific  

E-print Network

Reserve, 505 Guana River Road, Ponte Vedra Beach, FL 32082, USA. Magnolia Press Auckland, New Zealand 3375 WENDY E. EASH-LOUCKS & DAPHNE G. FAUTINEASH-LOUCKS AND FAUTIN2 Zootaxa 3375 2012 Magnolia Press Taxonomy and distribution of sea anemones... published locality is an open symbol with a dot in the center. Depths are in meters: average depth is used if a depth range is provided, and depth is estimated from the ETOPO2 (2'2) bathymetry data set (National Geophysical Data Center 2006) for specimens...

Eash-Loucks, Wendy E.; Fautin, Daphne G.

2012-07-04

14

Hidden among sea anemones: the first comprehensive phylogenetic reconstruction of the order Actiniaria (Cnidaria, Anthozoa, Hexacorallia) reveals a novel group of hexacorals.  

PubMed

Sea anemones (order Actiniaria) are among the most diverse and successful members of the anthozoan subclass Hexacorallia, occupying benthic marine habitats across all depths and latitudes. Actiniaria comprises approximately 1,200 species of solitary and skeleton-less polyps and lacks any anatomical synapomorphy. Although monophyly is anticipated based on higher-level molecular phylogenies of Cnidaria, to date, monophyly has not been explicitly tested and at least some hypotheses on the diversification of Hexacorallia have suggested that actiniarians are para- or poly-phyletic. Published phylogenies have demonstrated the inadequacy of existing morphological-based classifications within Actiniaria. Superfamilial groups and most families and genera that have been rigorously studied are not monophyletic, indicating conflict with the current hierarchical classification. We test the monophyly of Actiniaria using two nuclear and three mitochondrial genes with multiple analytical methods. These analyses are the first to include representatives of all three currently-recognized suborders within Actiniaria. We do not recover Actiniaria as a monophyletic clade: the deep-sea anemone Boloceroides daphneae, previously included within the infraorder Boloceroidaria, is resolved outside of Actiniaria in several of the analyses. We erect a new genus and family for B. daphneae, and rank this taxon incerti ordinis. Based on our comprehensive phylogeny, we propose a new formal higher-level classification for Actiniaria composed of only two suborders, Anenthemonae and Enthemonae. Suborder Anenthemonae includes actiniarians with a unique arrangement of mesenteries (members of Edwardsiidae and former suborder Endocoelantheae). Suborder Enthemonae includes actiniarians with the typical arrangement of mesenteries for actiniarians (members of former suborders Protantheae, Ptychodacteae, and Nynantheae and subgroups therein). We also erect subgroups within these two newly-erected suborders. Although some relationships among these newly-defined groups are still ambiguous, morphological and molecular results are consistent enough to proceed with a new higher-level classification and to discuss the putative functional and evolutionary significance of several morphological attributes within Actiniaria. PMID:24806477

Rodrguez, Estefana; Barbeitos, Marcos S; Brugler, Mercer R; Crowley, Louise M; Grajales, Alejandro; Gusmo, Luciana; Hussermann, Verena; Reft, Abigail; Daly, Marymegan

2014-01-01

15

Hidden among Sea Anemones: The First Comprehensive Phylogenetic Reconstruction of the Order Actiniaria (Cnidaria, Anthozoa, Hexacorallia) Reveals a Novel Group of Hexacorals  

PubMed Central

Sea anemones (order Actiniaria) are among the most diverse and successful members of the anthozoan subclass Hexacorallia, occupying benthic marine habitats across all depths and latitudes. Actiniaria comprises approximately 1,200 species of solitary and skeleton-less polyps and lacks any anatomical synapomorphy. Although monophyly is anticipated based on higher-level molecular phylogenies of Cnidaria, to date, monophyly has not been explicitly tested and at least some hypotheses on the diversification of Hexacorallia have suggested that actiniarians are para- or poly-phyletic. Published phylogenies have demonstrated the inadequacy of existing morphological-based classifications within Actiniaria. Superfamilial groups and most families and genera that have been rigorously studied are not monophyletic, indicating conflict with the current hierarchical classification. We test the monophyly of Actiniaria using two nuclear and three mitochondrial genes with multiple analytical methods. These analyses are the first to include representatives of all three currently-recognized suborders within Actiniaria. We do not recover Actiniaria as a monophyletic clade: the deep-sea anemone Boloceroides daphneae, previously included within the infraorder Boloceroidaria, is resolved outside of Actiniaria in several of the analyses. We erect a new genus and family for B. daphneae, and rank this taxon incerti ordinis. Based on our comprehensive phylogeny, we propose a new formal higher-level classification for Actiniaria composed of only two suborders, Anenthemonae and Enthemonae. Suborder Anenthemonae includes actiniarians with a unique arrangement of mesenteries (members of Edwardsiidae and former suborder Endocoelantheae). Suborder Enthemonae includes actiniarians with the typical arrangement of mesenteries for actiniarians (members of former suborders Protantheae, Ptychodacteae, and Nynantheae and subgroups therein). We also erect subgroups within these two newly-erected suborders. Although some relationships among these newly-defined groups are still ambiguous, morphological and molecular results are consistent enough to proceed with a new higher-level classification and to discuss the putative functional and evolutionary significance of several morphological attributes within Actiniaria. PMID:24806477

Rodriguez, Estefania; Barbeitos, Marcos S.; Brugler, Mercer R.; Crowley, Louise M.; Grajales, Alejandro; Gusmao, Luciana; Haussermann, Verena; Reft, Abigail; Daly, Marymegan

2014-01-01

16

Sea Anemone Genome Reveals Ancestral Eumetazoan Gene Repertoire and Genomic Organization  

Microsoft Academic Search

Sea anemones are seemingly primitive animals that, along with corals, jellyfish, and hydras, constitute the oldest eumetazoan phylum, the Cnidaria. Here, we report a comparative analysis of the draft genome of an emerging cnidarian model, the starlet sea anemone Nematostella vectensis. The sea anemone genome is complex, with a gene repertoire, exon-intron structure, and large-scale gene linkage more similar to

Nicholas H. Putnam; Mansi Srivastava; Uffe Hellsten; Bill Dirks; Jarrod Chapman; Asaf Salamov; Astrid Terry; Harris Shapiro; Erika Lindquist; Vladimir V. Kapitonov; Jerzy Jurka; Grigory Genikhovich; Igor V. Grigoriev; Susan M. Lucas; Robert E. Steele; John R. Finnerty; Ulrich Technau; Mark Q. Martindale; Daniel S. Rokhsar

2007-01-01

17

Purification and characterization of the biological effects of phospholipase A 2 from sea anemone Bunodosoma caissarum  

Microsoft Academic Search

Sea anemones contain a variety of biologically active substances. Bunodosoma caissarum is a sea anemone from the Cnidaria phylum, found only in Brazilian coastal waters. The aim of the present work was to study the biological effects of PLA2 isolated from the sea anemone B. caissarum on the isolated perfused kidney, the arteriolar mesenteric bed and on insulin secretion. Specimens

Ren D. Martins; Renata S. Alves; Alice M. C. Martins; Paulo Sergio F. Barbosa; Janaina S. A. M. Evangelista; Joo Jos F. Evangelista; Rafael M. Ximenes; Marcos H. Toyama; Daniela O. Toyama; Alex Jardelino F. Souza; Diego J. B. Orts; Srgio Marangoni; Dalgimar B. de Menezes; Manasss C. Fonteles; Helena S. A. Monteiro

2009-01-01

18

Sea Anemone: Investigations.  

ERIC Educational Resources Information Center

Several investigations can be undertaken with live sea anemones. A sea anemone's feeding response, fighting power, color, and symbiotic relationships to other invertebrates (such as a marine hermit crab) can be investigated in the high school classroom. Background information and laboratory procedures are provided. (Author/JN)

Hunt, John D.

1982-01-01

19

Stylobates birtlesi sp. n., a new species of carcinoecium-forming sea anemone... 33 Stylobates birtlesi sp. n., a new species of carcinoecium-  

E-print Network

Stylobates birtlesi sp. n., a new species of carcinoecium-forming sea anemone... 33 Stylobates birtlesi sp. n., a new species of carcinoecium- forming sea anemone (Cnidaria,Actiniaria,Actiniidae) from DG, Wallace CC (2011) Stylobates birtlesi sp. n., a new species of carcinoecium-forming sea anemone

Fautin, Daphne

20

A new genus and species of isanthid sea anemone (Cnidaria: Anthozoa: Actiniaria) from Chilean Patagonia, Anthoparactis fossii n. gen. et sp  

NASA Astrophysics Data System (ADS)

We describe a new genus and species of sea anemone from Chilean Patagonia. Anthoparactis fossii n. gen. et sp. adds another acontiate genus and species to the family Isanthidae Carlgren, 1938. Anthoparactis n. gen. differs from the other isanthid genera in having the same number of mesenteries distally and proximally, acontia with basitrichs only, and a column with verrucae distally. Anthoparactis fossii n. sp. differs from the most similar species, Isoparactis fionae Lauretta et al., 2013, in the number of cycles of mesenteries and tentacles, structures of the column, colour pattern of the oral disc, cnidae, and geographical distribution. Isanthidae now includes seven genera and 11 species.

Hussermann, Verena; Rodrguez, Estefana

2014-09-01

21

Sea anemone exposed at low tide  

NSDL National Science Digital Library

Sea anemones are sensitive to drying out. To avoid drying out during low tide and periods of intense sunlight, the anemones roll up to keep their tentacles moist. The outer body of the anemone is thick and tolerant of heat.

Katie Hale (California State University, Fullerton;Student, Biological Sciences)

2007-01-05

22

Genetic study of the extent and consequences of sexual and asexual reproduction in the deep-sea epizoic anemones Amphianthus inornata and Kadosactis commensalis (Cnidaria: Anthozoa)  

Microsoft Academic Search

The anemone Amphianthus inornata is found at bathyal depths living on colonies of the gorgonian Acanella arbuscula. Previous studies of the morphology and reproductive stage of this anemone, during different times of the year, have indicated\\u000a that it reproduces sexually on a seasonal basis. A small proportion of the study population were also reported to be undergoing\\u000a asexual reproduction by

S. K. Bronsdon; A. D. Rogers; P. A. Tyler; J. D. Gage

1997-01-01

23

Origins of Bilateral Symmetry: Hox and Dpp Expression in a Sea Anemone  

Microsoft Academic Search

Over 99% of modern animals are members of the evolutionary lineage Bilateria. The evolutionary success of Bilateria is credited partly to the origin of bilateral symmetry. Although animals of the phylum Cnidaria are not within the Bilateria, some representatives, such as the sea anemone Nematostella vectensis, exhibit bilateral symmetry. We show that Nematostella uses homologous genes to achieve bilateral symmetry:

John R. Finnerty; Kevin Pang; Pat Burton; Dave Paulson; Mark Q. Martindale

2004-01-01

24

Field Guide to Anemone Fishes and their Host Sea Anemones  

NSDL National Science Digital Library

Dr. Daphne G. Fautin of California Academy of Sciences and University of Kansas and Dr. Gerald R. Allen of Western Australian Museum wrote this fascinating field guide to anemone fishes and their sea anemone hosts. The five main chapters of this book cover classification and identification of sea anemones and anemone fishes in addition to their biologies, life histories, and the ecological interactions between them. Species-specific information includes common and scientific name, original description and color features/size, similar species, host species, and distribution. From students to clown fish enthusiasts to research scientists, offers a wealth of practical and intriguing information in this online book.

Allen, Gerald R.; Fautin, Daphne G.

1992-01-01

25

Mitochondrial DNA of the sea anemone, Metridium senile (Cnidaria): prokaryote-like genes for tRNA(f-Met) and small-subunit ribosomal RNA, and standard genetic code specificities for AGR and ATA codons.  

PubMed

The nucleotide sequence of a segment of the mitochondrial DNA (mtDNA) molecule of the sea anemone Metridium senile (phylum Cnidaria, class Anthozoa, order Actiniaria) has been determined, within which have been identified the genes for respiratory chain NADH dehydrogenase subunit 2 (ND2), the small-subunit rRNA (s-rRNA), cytochrome c oxidase subunit II (COII), ND4, ND6, cytochrome b (Cyt b), tRNA(f-Met), and the large-subunit rRNA (1-rRNA). The eight genes are arranged in the order given and are all transcribed from the same strand of the molecule. The overall order of the M. senile mt-genes differs from that of other metazoan mtDNAs. In M. senile mt-protein genes, AGA and AGG codons appear to have the standard genetic code specification of arginine, rather than serine as found for other invertebrate mt-genetic codes. Also, ATA has the standard genetic code specification of isoleucine. TGA occurs in three M. senile mt-protein genes and may specify tryptophan as in other metazoan, protozoan, and some fungal mt-genetic codes. The M. senile mt-rRNA(f-Met) gene has primary and secondary structure features closely resembling those of the Escherichia coli initiator tRNA, including standard dihydrouridine and T psi C loop sequences and a mismatch pair at the top of the aminoacyl stem. Determinations of the 5' and 3' end nucleotides of the M. senile mt-s-rRNAs indicated that these molecules have a homogenous size of 1,081 ntp, larger than any other known metazoan mt-s-rRNAs. Consistent with its larger size, the M. senile mt-s-rRNA can be folded into a secondary structure that more closely resembles that of the E. coli 16S rRNA than can any other metazoan mt-s-rRNA. These findings concerning M. senile mtDNA indicate that most of the unusual features regarding metazoan mt-genetic codes, rRNAs, and probably tRNAs developed after divergence of the Cnidarian line from the ancestral line common to other metazoa. PMID:7966369

Pont-Kingdon, G A; Beagley, C T; Okimoto, R; Wolstenholme, D R

1994-10-01

26

Characterization of Compounds that Induce Symbiosis between Sea Anemone and Anemone Fish  

Microsoft Academic Search

The species-specific partnership between the sea anemone and anemone fish in many parts of the Indo-Pacific region is a well-known phenomenon. Chemicals secreted by the sea anemone to elicit symbiotic behavior of the fish have been studied for two host-guest pairs, Radianthus kuekenthali (sea anemone)--Amphiprion perideraion (anemone fish) and Stoichactis kenti-A. ocellaris. A new pyridinium compound, amphikuemin, which induces characteristic

Michio Murata; Kazuko Miyagawa-Kohshima; Koji Nakanishi; Yoko Naya

1986-01-01

27

Phylum Cnidaria Introduction  

E-print Network

with radially distributed sense organs Neurons serve sensory and motor systems. Epithelial layer of a cnidarian cnidaria (sea anemones and jellyfish) may have two nerve nets. Slow conducting network Fine fibers end cells beneath epithelium Bigger fibers, faster conduction of impulse Enables major responses

Cochran-Stafira, D. Liane

28

Trench warfare on the shore: interclonalaggression in sea anemones  

E-print Network

Trench warfare on the shore: interclonalaggression in sea anemones mpirical research in behavioral surrounded by tentacles. The organism in question is the sea anemoneAnthopleura elegantissima,acon- spicuous- etically distinct groups of anemones are typically separated by an anemone-free zonethat callsto mind

Bermingham, Eldredge

29

Central European Journal of Biology Functional discrimination of sea anemone  

E-print Network

Central European Journal of Biology Functional discrimination of sea anemone neurotoxins using 3D employed isolated neurotoxins from sea anemones with established specific potential to act on voltage relationship between the sequences of amino acids from sea anemone neurotoxins, and the resulting numerical

Gokhman, Dmitry

30

Comprehensive EST analysis of the symbiotic sea anemone, Anemonia viridis  

PubMed Central

Background Coral reef ecosystems are renowned for their diversity and beauty. Their immense ecological success is due to a symbiotic association between cnidarian hosts and unicellular dinoflagellate algae, known as zooxanthellae. These algae are photosynthetic and the cnidarian-zooxanthellae association is based on nutritional exchanges. Maintenance of such an intimate cellular partnership involves many crosstalks between the partners. To better characterize symbiotic relationships between a cnidarian host and its dinoflagellate symbionts, we conducted a large-scale EST study on a symbiotic sea anemone, Anemonia viridis, in which the two tissue layers (epiderm and gastroderm) can be easily separated. Results A single cDNA library was constructed from symbiotic tissue of sea anemones A. viridis in various environmental conditions (both normal and stressed). We generated 39,939 high quality ESTs, which were assembled into 14,504 unique sequences (UniSeqs). Sequences were analysed and sorted according to their putative origin (animal, algal or bacterial). We identified many new repeated elements in the 3'UTR of most animal genes, suggesting that these elements potentially have a biological role, especially with respect to gene expression regulation. We identified genes of animal origin that have no homolog in the non-symbiotic starlet sea anemone Nematostella vectensis genome, but in other symbiotic cnidarians, and may therefore be involved in the symbiosis relationship in A. viridis. Comparison of protein domain occurrence in A. viridis with that in N. vectensis demonstrated an increase in abundance of some molecular functions, such as protein binding or antioxidant activity, suggesting that these functions are essential for the symbiotic state and may be specific adaptations. Conclusion This large dataset of sequences provides a valuable resource for future studies on symbiotic interactions in Cnidaria. The comparison with the closest available genome, the sea anemone N. vectensis, as well as with EST datasets from other symbiotic cnidarians provided a set of candidate genes involved in symbiosis-related molecular crosstalks. Altogether, these results provide new molecular insights that could be used as a starting-point for further functional genomics studies. PMID:19627569

Sabourault, Cecile; Ganot, Philippe; Deleury, Emeline; Allemand, Denis; Furla, Paola

2009-01-01

31

ORIGINAL ARTICLE Ptychodactis aleutiensis, a new species of ptychodactiarian sea  

E-print Network

ORIGINAL ARTICLE Ptychodactis aleutiensis, a new species of ptychodactiarian sea anemone (Cnidaria anemone, Ptychodactis aleutiensis, and redefine the family Ptychodactiidae and the previously monotypic of ptychodactiarian sea anemone from the Aleutian Islands, Alaska. This anemone has been observed by diving ecologists

Fautin, Daphne

32

Micronesica 41(1): 101115, 2009 Neoaiptasia morbilla new species (Cnidaria: Actiniaria), a sea  

E-print Network

anemone symbiont of sand-dwelling gastropods on Saipan, Mariana Islands, with comments on some other -- Very small, cryptic specimens of a new species of sea anemone attach to shells of living gastropods of sea anemones from eastern Asia. Introduction We have found specimens of a small sea anemone attached

Fautin, Daphne

33

Sea Anemone Toxins Affecting Potassium Channels  

NASA Astrophysics Data System (ADS)

The great diversity of K+ channels and their wide distribution in many tissues are associated with important functions in cardiac and neuronal excitability that are now better understood thanks to the discovery of animal toxins. During the past few decades, sea anemones have provided a variety of toxins acting on voltage-sensitive sodium and, more recently, potassium channels. Currently there are three major structural groups of sea anemone K+ channel (SAK) toxins that have been characterized. Radioligand binding and electrophysiological experiments revealed that each group contains peptides displaying selective activities for different subfamilies of K+ channels. Short (35-37 amino acids) peptides in the group I display pore blocking effects on Kv1 channels. Molecular interactions of SAK-I toxins, important for activity and binding on Kv1 channels, implicate a spot of three conserved amino acid residues (Ser, Lys, Tyr) surrounded by other less conserved residues. Long (58-59 amino acids) SAK-II peptides display both enzymatic and K+ channel inhibitory activities. Medium size (42-43 amino acid) SAK-III peptides are gating modifiers which interact either with cardiac HERG or Kv3 channels by altering their voltage-dependent properties. SAK-III toxins bind to the S3C region in the outer vestibule of Kv channels. Sea anemones have proven to be a rich source of pharmacological tools, and some of the SAK toxins are now useful drugs for the diagnosis and treatment of autoimmune diseases.

Diochot, Sylvie; Lazdunski, Michel

34

Reproduction in the Aggregating Sea Anemone, Anthopleura elegantissima  

Microsoft Academic Search

From a sample of 240 specimens of the aggregating sea anemone, Anthopleura elegantissima, collected a few miles north of the Golden Gate, males and females were shown to be distributed as unisexual aggregations on the rocks. The degree of gonadal development was measured by taking the gonad index (the ratio of volume of gonads to wet weight of anemone) every

CHARLES E. FORD

35

EFFECTS OF PHOTOOXIDATIVE STRESS AND ALGAL GROWTH RATES ON ALGAL EXPULSION BY THE SYMBIOTIC SEA ANEMONE ANTHOPLEURA  

E-print Network

ANEMONE ANTHOPLEURA ELEGANTISSIMA By LISA RACHELLE HAINEY A THESIS submitted to WALLA WALLA UNIVERSITY was measured in the symbiotic sea anemone Anthopleura elegantissima. When the anemones were exposed to high...................................................................................................... 15 Anemone collection and maintenance

Cowles, David L.

36

Cytolytic peptide and protein toxins from sea anemones (Anthozoa: Actiniaria)  

Microsoft Academic Search

More than 32 species of sea anemones have been reported to produce lethal cytolytic peptides and proteins. Based on their primary structure and functional properties, cytolysins have been classified into four polypeptide groups. Group I consists of 58kDa peptides, represented by those from the sea anemones Tealia felina and Radianthus macrodactylus. These peptides form pores in phosphatidylcholine containing membranes. The

Gregor Anderluh; Peter Ma?ek

2002-01-01

37

Modeling the Structure of the Sea Anemone, Stomphia Coccinea and the Sea Star, Dermasterias Imbricata Using Implicit Surfaces  

E-print Network

Modeling the Structure of the Sea Anemone, Stomphia Coccinea and the Sea Star, Dermasterias invertebrates, the sea anemone, Stomphia Coccinea, and the sea star, Dermas- terias Imbricata. The sea star arrangement of the sea anemone's tentacles. Using a hierarchical construction of the model, we can re- fine

Wyvill, Brian

38

INTRASPECIFIC AGGRESSION AND ITS EFFECT ON THE DISTRIBUTION OF ANTHOPLEURA ELEGANTISSIMA AND SOME RELATED SEA ANEMONES  

Microsoft Academic Search

Contiguous aggregations of the west coast sea anemone Anthopleura elegan tissima are composed of individuals from a single clone, the products of asexual reproduction. In the field, adjacent clones of anemones are observed to be iso lated from each other by anemone-free spaces ; and in the laboratory a group of anemones of mixed clonal origins will reaggregate into isolated

LISBETH FRANCIS

1973-01-01

39

Differential accumulation of heavy metals in the sea anemone Anthopleura elegantissima as a function of symbiotic state  

E-print Network

Differential accumulation of heavy metals in the sea anemone Anthopleura elegantissima Coast temperate sea anemone Anthopleura elegantissima, and its dinoflagellate-algal symbiont and symbiont-free (aposymbiotic) anemones were used in this study to investigate differences in metal uptake

40

Qualitative shift to indirect development in the parasitic sea anemone Edwardsiella lineata  

E-print Network

Qualitative shift to indirect development in the parasitic sea anemone Edwardsiella lineata Adam M. The lined sea anemone, Edwardsiella lineata, has made a qualitative shift towards indirect development's development with that of a closely related sea anemone, Nematostella vectensis, where the nonfeeding planula

Finnerty, John R.

41

A muscle-specific transgenic reporter line of the sea anemone, Nematostella vectensis  

E-print Network

A muscle-specific transgenic reporter line of the sea anemone, Nematostella vectensis Eduard, and approved November 13, 2009 (received for review August 13, 2009) The sea anemone, Nematostella vectensis networks and developmental processes in the nonbilaterian sea anemone, Nematostella vectensis. meganuclease

Gibson, Matt

42

The nature of the symbiosis between Indo-Pacific anemone fishes and sea anemones  

Microsoft Academic Search

Under the general heading of symbiosis, defined originally to mean a living together of two dissimilar species, exist the sub-categories of mutualism (where both partners benefit), commensalism (where one partner benefits and the other is neutral) and parasitism (where one partner benefits and the other is harmed). The sea anemone-fish (mainly of the genus Amphiprion) symbiosis has generally been considered

R. N. Mariscal

1970-01-01

43

Biochemical and electrophysiological characterization of two sea anemone type 1 potassium toxins from a geographically distant population of Bunodosoma caissarum.  

PubMed

Sea anemone (Cnidaria, Anthozoa) venom is an important source of bioactive compounds used as tools to study the pharmacology and structure-function of voltage-gated K+ channels (KV). These neurotoxins can be divided into four different types, according to their structure and mode of action. In this work, for the first time, two toxins were purified from the venom of Bunodosoma caissarum population from Saint Peter and Saint Paul Archipelago, Brazil. Sequence alignment and phylogenetic analysis reveals that BcsTx1 and BcsTx2 are the newest members of the sea anemone type 1 potassium channel toxins. Their functional characterization was performed by means of a wide electrophysiological screening on 12 different subtypes of KV channels (KV1.1-KV1.6; KV2.1; KV3.1; KV4.2; KV4.3; hERG and Shaker IR). BcsTx1 shows a high affinity for rKv1.2 over rKv1.6, hKv1.3, Shaker IR and rKv1.1, while Bcstx2 potently blocked rKv1.6 over hKv1.3, rKv1.1, Shaker IR and rKv1.2. Furthermore, we also report for the first time a venom composition and biological activity comparison between two geographically distant populations of sea anemones. PMID:23466933

Orts, Diego J B; Peigneur, Steve; Madio, Bruno; Cassoli, Juliana S; Montandon, Gabriela G; Pimenta, Adriano M C; Bicudo, Jos E P W; Freitas, Jos C; Zaharenko, Andr J; Tytgat, Jan

2013-03-01

44

Comparison of developmental trajectories in the starlet sea anemone Nematostella vectensis: embryogenesis, regeneration,  

E-print Network

Comparison of developmental trajectories in the starlet sea anemone Nematostella vectensis Abstract. The starlet sea anemone, Nematostella vectensis, is a small burrowing estuarine animal, native to the Atlantic coast of North America. In recent years, this anemone has emerged as a model system in cnidarian

Finnerty, John R.

45

Free amino acid pool of a sea anemone: exposure and recovery after an oil spill. [Sea Anemones  

SciTech Connect

A number of laboratory studies on marine invertebrates have shown changes in free amino acid (FAA) pools in response to various pollutants. During a nineteen-month field study to determine the effects of natural environmental parameters on the FAA pools to the Gulf Coast sea anemone, Bunodosoma cavernata, an oil tanker collision occurred about 8 miles off Galveston Island. The initial spill from the tanker Burma Agate occurred on November 1, 1979 with large leakages continuing for several weeks. There was no visible sign of oil on the first collection date 13 days after the spill, but 11 days later the anemones were covered with an oil sheen. As a result of this natural exposure to the oil, the authors decided to monitor the sea anemones for changes in the FAA pool during the oil exposure and recovery period.

Kasschau, M.R.; Howard, C.L.

1984-07-01

46

Clone-Specific Cellular Recognition in a Sea Anemone  

Microsoft Academic Search

A highly specific cellular recognition system, capable of distinguishing between syngeneic and allogeneic tissue, exists in Anthopleura elegantissima, a sea anemone that lives in clonal colonies and attacks foreign clones. During the attack, specialized surface protrusions (acrorhagi) are used for stinging. The recognition process was studied by presenting various tissues to the surface of inflated acrorhagi and observing whether nematocyst

Roger Lubbock

1980-01-01

47

Mating systems in the sea anemone genus Epiactis  

Microsoft Academic Search

Four morphologically similar species in the sea anemone genus Epiactis exhibit overlapping distributions on the Pacific coast of North America; E. prolifera, E. lisbethae, E. ritteri and E. fernaldi. All brood their offspring up to the juvenile stage, but each has a different combination of internal versus external brooding and hermaphroditism versus gonochory (separate sexes). Specimens were collected from sites

S. Edmands

1995-01-01

48

Characterization of the Core Elements of the NF-?B Signaling Pathway of the Sea Anemone Nematostella vectensis ?  

PubMed Central

The sea anemone Nematostella vectensis is the leading developmental and genomic model for the phylum Cnidaria, which includes anemones, hydras, jellyfish, and corals. In insects and vertebrates, the NF-?B pathway is required for cellular and organismal responses to various stresses, including pathogens and chemicals, as well as for several developmental processes. Herein, we have characterized proteins that comprise the core NF-?B pathway in Nematostella, including homologs of NF-?B, I?B, Bcl-3, and I?B kinase (IKK). We show that N. vectensis NF-?B (Nv-NF-?B) can bind to ?B sites and activate transcription of reporter genes containing multimeric ?B sites or the Nv-I?B promoter. Both Nv-I?B and Nv-Bcl-3 interact with Nv-NF-?B and block its ability to activate reporter gene expression. Nv-IKK is most similar to human IKK?/TBK kinases and, in vitro, can phosphorylate Ser47 of Nv-I?B. Nv-NF-?B is expressed in a subset of ectodermal cells in juvenile and adult Nematostella anemones. A bioinformatic analysis suggests that homologs of many mammalian NF-?B target genes are targets for Nv-NF-?B, including genes involved in apoptosis and responses to organic compounds and endogenous stimuli. These results indicate that NF-?B pathway proteins in Nematostella are similar to their vertebrate homologs, and these results also provide a framework for understanding the evolutionary origins of NF-?B signaling. PMID:21189285

Wolenski, Francis S.; Garbati, Michael R.; Lubinski, Tristan J.; Traylor-Knowles, Nikki; Dresselhaus, Erica; Stefanik, Derek J.; Goucher, Haley; Finnerty, John R.; Gilmore, Thomas D.

2011-01-01

49

Cereus Ilmoni, 1830 (Cnidaria, Anthozoa): proposed designation of a new type species  

E-print Network

Case 3574 Cereus Ilmoni, 1830 (Cnidaria, Anthozoa): proposed designation of a new type species Pennant, 1777 as the type species of the genus Cereus Ilmoni, 1830. Cereus pedunculatus is a widely-studied member of the order Actiniaria (sea anemones sensu stricto). The type species of Cereus by monotypy

Fautin, Daphne

50

Symbiosis of sea anemones and hermit crabs: different resource utilization patterns in the Aegean Sea  

NASA Astrophysics Data System (ADS)

The small-scale distribution and resource utilization patterns of hermit crabs living in symbiosis with sea anemones were investigated in the Aegean Sea. Four hermit crab species, occupying shells of nine gastropod species, were found in symbiosis with the sea anemone Calliactis parasitica. Shell resource utilization patterns varied among hermit crabs, with Dardanus species utilizing a wide variety of shells. The size structure of hermit crab populations also affected shell resource utilization, with small-sized individuals inhabiting a larger variety of shells. Sea anemone utilization patterns varied both among hermit crab species and among residence shells, with larger crabs and shells hosting an increased abundance and biomass of C. parasitica. The examined biometric relationships suggested that small-sized crabs carry, proportionally to their weight, heavier shells and increased anemone biomass than larger ones. Exceptions to the above patterns are related either to local resource availability or to other environmental factors.

Vafeiadou, Anna-Maria; Antoniadou, Chryssanthi; Chintiroglou, Chariton

2012-09-01

51

Characterization of a novel EF-hand homologue, CnidEF, in the sea anemone Anthopleura elegantissima.  

PubMed

The superfamily of EF-hand proteins is comprised of a large and diverse group of proteins that contain one or more characteristic EF-hand calcium-binding domains. This study describes and characterizes a novel EF-hand cDNA, CnidEF, from the sea anemone Anthopleura elegantissima (Phylum Cnidaria, Class Anthozoa). CnidEF was found to contain two EF-hand motifs near the C-terminus of the deduced amino acid sequence and two regions near the N-terminus that could represent degenerate EF-hand motifs. CnidEF homologues were also identified from two other sea anemone species. A combination of bioinformatic and molecular phylogenetic analyses was used to compare CnidEF to EF-hand proteins in other organisms. The closest homologues identified from these analyses were a luciferin binding protein (LBP) involved in the bioluminescence of the anthozoan Renilla reniformis, and a sarcoplasmic calcium-binding protein (SARC) involved in fluorescence of the annelid worm Nereis diversicolor. Predicted structure and folding analysis revealed a close association with bioluminescent aequorin (AEQ) proteins from the hydrozoan cnidarian Aequorea aequorea. Neighbor-joining analyses grouped CnidEF within the SARC lineage along with AEQ and other cnidarian bioluminescent proteins rather than in the lineage containing calmodulin (CAM) and troponin-C (TNC). PMID:17280859

Hauck, Laura L; Phillips, Wendy S; Weis, Virginia M

2007-04-01

52

vasa and nanos expression patterns in a sea anemone and the evolution of bilaterian germ cell specification mechanisms  

E-print Network

vasa and nanos expression patterns in a sea anemone and the evolution of bilaterian germ cell in the sea anemone Nematostella vectensis, we examined the expression of members of the vasa and nanos gene

Extavour, Cassandra

53

Structural Characterization of a Blue Chromoprotein and Its Yellow Mutant from the Sea Anemone Cnidopus Japonicus*S  

E-print Network

Structural Characterization of a Blue Chromoprotein and Its Yellow Mutant from the Sea Anemone-fluores- cent chromoprotein from the Cnidopus japonicus species of sea anemone that possesses 45% sequence

Ikura, Mitsuhiko

54

Larval settlement and juvenile development of sea anemones that provide habitat for anemonefish  

Microsoft Academic Search

Sea anemones that host obligate symbiotic anemonefish are ecologically important throughout many coral reef regions of the\\u000a Indo-Pacific. This study provides the first quantitative data on larval settlement rates and juvenile development of two species\\u000a of host sea anemone, Heteractis crispa and Entacmaea quadricolor. Larvae were reared from broadcast spawned gametes of sexually reproductive male and female anemones collected from

Anna Scott; Peter Lynton Harrison

2008-01-01

55

Pre-Bilaterian Origins of the Hox Cluster and the Hox Code: Evidence from the Sea Anemone, Nematostella  

E-print Network

Pre-Bilaterian Origins of the Hox Cluster and the Hox Code: Evidence from the Sea Anemone evolution remains obscure. Phylogenetic, developmental, and genomic analyses on the cnidarian sea anemone-Bilaterian Origins of the Hox Cluster and the Hox Code: Evidence from the Sea Anemone, Nematostella vectensis. PLo

Finnerty, John R.

56

J.E. Randall D.G. Fautin Fishes other than anemonefishes that associate with sea anemones  

E-print Network

NOTE J.E. Randall ? D.G. Fautin Fishes other than anemonefishes that associate with sea anemones Accepted: 26 February 2002 / Published online: 14 June 2002 ? Springer-Verlag 2002 Keywords Sea anemones ? Fishes ? Facultative association Introduction The obligatory relationship of sea anemones

Fautin, Daphne

57

Symbiont photosynthesis increases both respiration and photosynthesis in the symbiotic sea anemone Anemonia viridis  

Microsoft Academic Search

Dark respiration of the symbiotic sea anemone Anemonia viridis (Forskl) was observed to increase by ~34% when anemones were exposed to hyperoxic sea water (150% oxygen saturation) overnight, and by 39% after exposure to 6 h in the light at a saturating irradiance of 300 E m-2 s-1 at normoxia (100% oxygen saturation). No increase due to light stimulation was

A. D. Harland; P. S. Davies

1995-01-01

58

Micronesica 41(1): 117130, 2009 A sea anemone symbiotic with gastropods of eight species in the  

E-print Network

Micronesica 41(1): 117­130, 2009 A sea anemone symbiotic with gastropods of eight species University, Columbus, OH 43210 email: daly.66@osu.edu Abstract--Fifty-two specimens of the small sea anemone. The anemones were assoc- iated with gastropods of eight species belonging to five families. Relative abundance

Fautin, Daphne

59

Host feeding and nutrient sufficiency for zooxanthellae in the sea anemone Aiptasia pallida  

Microsoft Academic Search

Nutrient sufficiency of zooxanthellae in the sea anemone Aiptasia pallida cultured in low nutrient seawater depends on the availability of particulate food to the host. Zooxanthellae in anemones unfed for 20 to 30 d exhibited the following characteristics of nutrient deficiency: cell division rates decreased; chlorophyll a content gradually decreased from 2 to -1; and C:N ratios increased from 7.5

C. B. Cook; C. F. D'Elia; G. Muller-Parker

1988-01-01

60

THE ALLOMETRY OF FEEDING, ENERGETICS, AND BODY SIZE IN THREE SEA ANEMONE SPECIES  

Microsoft Academic Search

Three sea anemone species (Anthopleura elegantissima. A. xanthogrammica, and Metridium senile) were used to examine allometric and energetic properties of body size in passive suspension feeders. Photographs of expanded anemones in the field showedthat projectedfeedingsurfacearea(tentacle crown) asa function of body size increased at, or less than, the rate expected for a geometric solid (0.45\\

KENNETH P. SEBENS

1981-01-01

61

Uptake and Assimilation of Dissolved Inorganic Nitrogen by a Symbiotic Sea Anemone  

Microsoft Academic Search

The tropical sea anemone, Aiptasia pulchella, harbours symbiotic dinoflagellates (zooxanthellae). Animals in their natural habitat in Hawaii and those maintained in the laboratory in Los Angeles took up ammonium from nutrient enriched seawater. That the uptake experiment was done in the dark did not influence uptake although prolonged (19 h) dark treatment caused the animals to release ammonium. Aposymbiotic anemones

Frances P. Wilkerson; L. Muscatine

1984-01-01

62

Biogeography of Two Species of Symbiodinium (Freudenthal) Inhabiting the Intertidal Sea Anemone Anthopleura elegantissima (Brandt)  

Microsoft Academic Search

We have analyzed the genetic profiles of dinoflagellate populations obtained from the Pacific coast sea anemone Anthopleura elegantissima(Brandt) at collec- tion sites from Washington to California. Genetic dif- ferences within the symbiont populations of California anemones have been uncovered by restriction length polymorphism (RFLP) analysis of the small subunit (SSU) and large subunit (LSU) ribosomal RNA genes, and by denaturing

T. C. LAJEUNESSE; R. K. TRENCH

2000-01-01

63

Expansion of tandem repeats in sea anemone Nematostella vectensis proteome: A source for gene novelty?  

PubMed Central

Background The complete proteome of the starlet sea anemone, Nematostella vectensis, provides insights into gene invention dating back to the Cnidarian-Bilaterian ancestor. With the addition of the complete proteomes of Hydra magnipapillata and Monosiga brevicollis, the investigation of proteins having unique features in early metazoan life has become practical. We focused on the properties and the evolutionary trends of tandem repeat (TR) sequences in Cnidaria proteomes. Results We found that 11-16% of N. vectensis proteins contain tandem repeats. Most TRs cover 150 amino acid segments that are comprised of basic units of 5-20 amino acids. In total, the N. Vectensis proteome has about 3300 unique TR-units, but only a small fraction of them are shared with H. magnipapillata, M. brevicollis, or mammalian proteomes. The overall abundance of these TRs stands out relative to that of 14 proteomes representing the diversity among eukaryotes and within the metazoan world. TR-units are characterized by a unique composition of amino acids, with cysteine and histidine being over-represented. Structurally, most TR-segments are associated with coiled and disordered regions. Interestingly, 80% of the TR-segments can be read in more than one open reading frame. For over 100 of them, translation of the alternative frames would result in long proteins. Most domain families that are characterized as repeats in eukaryotes are found in the TR-proteomes from Nematostella and Hydra. Conclusions While most TR-proteins have originated from prediction tools and are still awaiting experimental validations, supportive evidence exists for hundreds of TR-units in Nematostella. The existence of TR-proteins in early metazoan life may have served as a robust mode for novel genes with previously overlooked structural and functional characteristics. PMID:20003297

2009-01-01

64

Clone-specific cellular recognition in a sea anemone.  

PubMed Central

A highly specific cellular recognition system, capable of distinguishing between syngeneic and allogeneic tissue, exists in Anthopleura elegantissima, a sea anemone that lives in clonal colonies and attacks foreign clones. During the attack, specialized surface protrusions (acrorhagi) are used for stinging. The recognition process was studied by presenting various tissues to the surface of inflated acrorhagi and observing whether nematocyst discharge occurred. Nematocyte excitation required direct contact of th acrorhagus with foreign tissue and is presumably mediated by cell surface receptors. Most foreign anthozoans were excitatory, but intact syngeneic individuals, organisms other than anthozoans, and inanimate objects consistently failed to elicit discharge. When the intact surface of an excised tentacle from one anemone was presented to the acrorhagus of another, discharge occurred in 101 of 102 allogeneic combinations; more than 50 tests with tentacles from clone mates (i.e., syngeneic combinations) were all negative. No evidence for specific immunological memory was found. It is suggested that clonal recognition depends upon genetically determined chemical markers in the surface membrane of the epithelial cells; these are assumed to differ between clones although, in rare cases, allogeneic clones may have similar markers. PMID:6109283

Lubbock, R

1980-01-01

65

Light Entrained Rhythmic Gene Expression in the Sea Anemone Nematostella vectensis: The Evolution of the Animal Circadian Clock  

PubMed Central

Background Circadian rhythms in behavior and physiology are the observable phenotypes from cycles in expression of, interactions between, and degradation of the underlying molecular components. In bilaterian animals, the core molecular components include Timeless-Timeout, photoreceptive cryptochromes, and several members of the basic-loop-helix-Per-ARNT-Sim (bHLH-PAS) family. While many of core circadian genes are conserved throughout the Bilateria, their specific roles vary among species. Here, we identify and experimentally study the rhythmic gene expression of conserved circadian clock members in a sea anemone in order to characterize this gene network in a member of the phylum Cnidaria and to infer critical components of the clockwork used in the last common ancestor of cnidarians and bilaterians. Methodology/Principal Findings We identified homologs of circadian regulatory genes in the sea anemone Nematostella vectensis, including a gene most similar to Timeout, three cryptochromes, and several key bHLH-PAS transcription factors. We then maintained N. vectensis either in complete darkness or in a 12 hour light: 12 hour dark cycle in three different light treatments (blue only, full spectrum, blue-depleted). Gene expression varied in response to light cycle and light treatment, with a particularly strong pattern observed for NvClock. The cryptochromes more closely related to the light-sensitive clade of cryptochromes were upregulated in light treatments that included blue wavelengths. With co-immunoprecipitation, we determined that heterodimerization between CLOCK and CYCLE is conserved within N. vectensis. Additionally, we identified E-box motifs, DNA sequences recognized by the CLOCK:CYCLE heterodimer, upstream of genes showing rhythmic expression. Conclusions/Significance This study reveals conserved molecular and functional components of the circadian clock that were in place at the divergence of the Cnidaria and Bilateria, suggesting the animal circadian clockwork is more ancient than previous data suggest. Characterizing circadian regulation in a cnidarian provides insight into the early origins of animal circadian rhythms and molecular regulation of environmentally cued behaviors. PMID:20877728

Reitzel, Adam M.; Behrendt, Lars; Tarrant, Ann M.

2010-01-01

66

Trans -6-hexadecenoic acid and the corresponding alcohol in lipids in the sea anemone Metridium dianthus  

Microsoft Academic Search

Trans-6-hexadecenoic acid was found in polar lipids, triglycerides, was esters and diacylglyceryl ethers of the sea anemoneMetridium dianthus from Passamaquoddy Bay. The corresponding alcomaquoddy Bay. The corresponding alcohol also apparently occurs in the wax esters\\u000a of this species. The long-chain (C20, C22) monoethylenic alcohols reported for other species of sea anemones from neighboring waters were absent and the major alcohol

S. N. Hooper; R. G. Ackman

1971-01-01

67

Continuous drug release by sea anemone Nematostella vectensis stinging microcapsules.  

PubMed

Transdermal delivery is an attractive option for drug delivery. Nevertheless, the skin is a tough barrier and only a limited number of drugs can be delivered through it. The most difficult to deliver are hydrophilic drugs. The stinging mechanism of the cnidarians is a sophisticated injection system consisting of microcapsular nematocysts, which utilize built-in high osmotic pressures to inject a submicron tubule that penetrates and delivers their contents to the prey. Here we show, for the first time, that the nematocysts of the starlet sea anemone Nematostella vectensis can be isolated and incorporated into a topical formulation for continuous drug delivery. We demonstrate quantitative delivery of nicotinamide and lidocaine hydrochloride as a function of microcapsular dose or drug exposure. We also show how the released submicron tubules can be exploited as a skin penetration enhancer prior to and independently of drug application. The microcapsules are non-irritant and may offer an attractive alternative for hydrophilic transdermal drug delivery. PMID:24473172

Tal, Yossi; Ayalon, Ari; Sharaev, Agnesa; Kazir, Zoya; Brekhman, Vera; Lotan, Tamar

2014-02-01

68

Complex functions of Mef2 splice variants in the differentiation of endoderm and of a neuronal cell type in a sea anemone.  

PubMed

In triploblastic animals, mesoderm gives rise to many tissues and organs, including muscle. By contrast, the representatives of the diploblastic phylum Cnidaria (corals, sea anemones, jellyfish and hydroids) lack mesoderm but possess muscle. In vertebrates and insects, the transcription factor Mef2 plays a pivotal role in muscle differentiation; however, it is also an important regulator of neuron differentiation and survival. In the sea anemone Nematostella vectensis, an organism that lacks mesoderm but has muscles and neurons, Mef2 (Nvmef2) has been reported in single ectodermal cells of likely neural origin. To our surprise, we found that Nvmef2 is alternatively spliced, forming differentially expressed variants. Using morpholino-mediated knockdown and mRNA injection, we demonstrate that specific splice variants of Nvmef2 are required for the proliferation and differentiation of endodermal cells and for the development of ectodermal nematocytes, a neuronal cell type. Moreover, we identified a small conserved motif in the transactivation domain that is crucially involved in the endodermal function of Nvmef2. The identification of a crucial and conserved motif in the transactivation domain predicts a similarly important role in vertebrate Mef2 function. This is the first functional study of a determinant of several mesodermal derivatives in a diploblastic animal. Our data suggest that the involvement of alternative splice variants of Mef2 in endomesoderm and neuron differentiation predates the cnidarian-bilaterian split. PMID:22007131

Genikhovich, Grigory; Technau, Ulrich

2011-11-01

69

The Culture Sexual and Asexual Reproduction and Growth of the Sea Anemone Nematostella vectensis  

Microsoft Academic Search

Abstract. Nematostella vectensis, a widely distributed, burrowing sea anemone, was raised through successive sexual generations at room,temperature,in non-circulating seawater. It has separate sexes and,also reproduces,asex- ually by transverse fission. Cultures of animals,were,fed Artemia,sp. nauplii every second,day. Every eight days the culture water was changed, and the anemones were fed pieces,of Mytilus spp. tissue. This led to,regular spawning,by both sexes at

Cadet Hand; Kevin R. Uhlinger

70

Population genetic structure in brooding sea anemones ( Epiactis spp.) with contrasting reproductive modes  

Microsoft Academic Search

Effects of dispersal and mating systems on the genetic structure of populations were evaluated by comparing five sea anemones:\\u000a four Epiactis species that brood their offspring to the juvenile stage and one Anthopleura species that broadcasts gametes and has pelagic, planktotrophic larvae. The anemones were sampled at sites ranging from British\\u000a Columbia to southern California between 1988 and 1992 and

S. Edmands; D. C. Potts

1997-01-01

71

Influence of copper pre-exposure on biochemical responses of the sea anemone Bunodosoma cangicum to changes in oxygen availability.  

PubMed

The influence of copper on the ability of the intertidal sea anemone Bunodosoma cangicum to cope with reactive oxygen species generation associated with changes in oxygen availability was evaluated. Sea anemones were kept under control condition or pre-exposed (96 h) to dissolved copper (6.1 ?g 2.7 ?g/L) and then subjected to a 6-h period of hypoxia (0.5mg O?/L) followed by a 6-h period of re-oxygenation (7.5mg O?/L). Antioxidant capacity against peroxyl radicals (ACAP), superoxide dismutase (SOD) activity, reduced glutathione (GSH) concentration, lipid peroxidation (LPO) level, and ATP concentration were evaluated. Control sea anemones showed variations in SOD and LPO while copper pre-exposed sea anemones displayed changes in ACAP, GSH, LPO and ATP. However, no clear pattern of change over time was observed. ACAP was lower in copper pre-exposed sea anemones than in the control ones during hypoxia and recovery. SOD activity was increased during hypoxia and reduced shortly after recovery in control sea anemones. GSH concentration was higher in copper pre-exposed sea anemones than in the control ones in all experimental conditions. The LPO level increased shortly after recovery in both groups of sea anemones, being higher in control sea anemones than in copper pre-exposed ones. ATP concentration showed transient changes in copper pre-exposed sea anemones, being lower in these sea anemones than in control ones during recovery. These findings suggest that B. cangicum possess mechanisms to prevent oxidative stress generated by changes in oxygen availability associated with the tidal cycle, which can be disturbed by pre-exposure to copper. PMID:24667761

Abujamara, Las Donini; Prazeres, Martina de Freitas; Borges, Vincius Dias; Bianchini, Adalto

2014-05-01

72

Crossota millsae (Cnidaria: Trachymedusae: Rhopalonematidae), a new species of viviparous hydromedusa from the deep sea off California and Hawaii  

Microsoft Academic Search

A new species of deep-sea jellyfish, Crossota millsae (Cnidaria: Hydrozoa: Trachymedusae: Rho- palonematidae), is described from the North Pacific Ocean off California and Hawaii. Discrete depth sampling showed this species lives at depths below 1000 meters in both geographic locations. The species is more abundant off California than off Hawaii. The greatest population densities were found at ~2500 m off

ERIK V. THUESEN

73

Personality and habitat segregation in giant sea anemones (Condylactis gigantea) Nicholai M. Hensley, Taylor C. Cook, Mason Lang, Matthew B. Petelle, Daniel T. Blumstein  

E-print Network

Personality and habitat segregation in giant sea anemones (Condylactis gigantea) Nicholai M May 2012 Accepted 16 May 2012 Available online xxxx Keywords: Sea anemone Animal personality Habitat of giant sea anemone (Condylactis gigantea) responses to disturbance across a continuous habitat gradient

Blumstein, Daniel T.

74

Biogeography of Antarctic sea anemones (Anthozoa, Actiniaria): What do they tell us about the origin of the Antarctic benthic fauna?  

NASA Astrophysics Data System (ADS)

The present study of the biogeography of the Antarctic sea anemone fauna is based on new records and redescriptions of material collected from the Weddell Sea and Peninsula Antarctica, and on an update of the bibliographic data of the Antarctic and sub-Antarctic regions. The faunal compositions at different levels, the geographic and bathymetric distributions of the sea anemone fauna, and the affinities within the continent and with the sub-Antarctic fauna have been studied. Furthermore, the relationships of the sea anemone fauna, of the Southern Ocean, the Mediterranean Sea and Hawaii have been analysed. In this context, the origin of the Antarctic benthic fauna is discussed.

Rodrguez, E.; Lpez-Gonzlez, P. J.; Gili, J. M.

2007-08-01

75

Direct attachment of eggs to the body wall in the externally brooding sea anemone Cnidopus japonicus (Actiniaria; Actiniidae)  

Microsoft Academic Search

. The externally brooding sea anemone Cnidopus japonicus (Verrill) inhabits boulder shores between the mid-intertidal and shallow subtidal zones of Mutsu Bay, northern Japan. The\\u000a anemones usually adhere to the side and under-surfaces of boulders. These anemones keep offspring on the middle part of their\\u000a body wall during the breeding season. Our observations of spawning behavior in an aquarium revealed

Masachika Ishimura; Moritaka Nishihira

2003-01-01

76

Cadherin-23 may be dynamic in hair bundles of the model sea anemone Nematostella vectensis.  

PubMed

Cadherin 23 (CDH23), a component of tip links in hair cells of vertebrate animals, is essential to mechanotransduction by hair cells in the inner ear. A homolog of CDH23 occurs in hair bundles of sea anemones. Anemone hair bundles are located on the tentacles where they detect the swimming movements of nearby prey. The anemone CDH23 is predicted to be a large polypeptide featuring a short exoplasmic C-terminal domain that is unique to sea anemones. Experimentally masking this domain with antibodies or mimicking this domain with free peptide rapidly disrupts mechanotransduction and morphology of anemone hair bundles. The loss of normal morphology is accompanied, or followed by a decrease in F-actin in stereocilia of the hair bundles. These effects were observed at very low concentrations of the reagents, 0.1-10 nM, and within minutes of exposure. The results presented herein suggest that: (1) the interaction between CDH23 and molecular partners on stereocilia of hair bundles is dynamic and; (2) the interaction is crucial for normal mechanotransduction and morphology of hair bundles. PMID:24465885

Tang, Pei-Ciao; Watson, Glen M

2014-01-01

77

Catch-tentacles in sea anemones: occurrence in Haliplanella luciae (Verrill) and a review of current knowledge  

Microsoft Academic Search

The occurrence of catch-tentacles or Fangtentakeln in the sea anemone Haliplanella luciae is reported for the first time, and some aspects of their anatomy and behaviour are noted. Provision is made for this discovery in the diagnoses of the family Haliplanellidae and the genus Haliplanella. The species of acontiarian anemones at present known to possess catch-tentacles are listed. The cnidom

R. B. Williams

1975-01-01

78

Laboratory food choice by the mosshead sculpin, Clinocottus globiceps (Girard) (Teleostei; Cottidae), a predator of sea anemones  

Microsoft Academic Search

Mosshead sculpins, Clinocottus globiceps (Girard), are unique among rocky intertidal fishes of the North American Pacific coast in preying heavily upon sea anemones. We examined food choice by C. globiceps for various food types offered simultaneously in laboratory trials. Both large and small C. globiceps attacked anemones (Anthopleura elegantissima (Brandt) and Epiactis prolifera (Verrill)) more frequently than shrimp or algae,

Ronald M. Yoshiyama; W. David Wallace; Jacqueline L. Burns; Ann L. Knowlton; Jill R. Welter

1996-01-01

79

Effects of starvation, and light and dark on the energy metabolism of symbiotic and aposymbiotic sea anemones, Anthopleura elegantissima  

Microsoft Academic Search

Rates of oxygen and carbon-dioxide exhange were measured in symbiotic and aposymbiotic specimens of the sea anemone Anthopleura elegantissima while fed and starved under light or dark conditions. Respiratory quotients indicated that fed anemones switched from a carbohydrate to a fat catabolism when starved, with the exception that symbiotic individuals starved in the light showed a pronounced carbohydrate catabolism for

W. K. Fitt; R. L. Pardy

1981-01-01

80

Characterization of a potassium channel toxin from the Caribbean sea anemone Stichodactyla helianthus  

Microsoft Academic Search

A peptide toxin, ShK, that blocks voltage-dependent potassium channels was isolated from the whole body extract of the Caribbean sea anemone Stichodactyla helianthus. It competes with dendrotoxin I and ?-dendrotoxin for binding to synaptosomal membranes of rat brain, facilitates acetylcholine release at an avian neuromuscular junction and suppresses K+ currents in rat dorsal root ganglion neurones in culture. Its amino

Olga Castaeda; Vivian Sotolongo; Ana Maria Amor; Reto Stcklin; Amanda J. Anderson; Alan L. Harvey; ke Engstrm; Christer Wernstedt; Evert Karlsson

1995-01-01

81

OBSERVATIONS ON THE SYMBIOSIS OF THE SEA ANEMONE STOICHACTIS AND THE POMACENTRID FISH, AMPHIPRION PERCULA  

Microsoft Academic Search

The partnership between certain tropical damselfishes and sea anemones has excited the interest of students of natural history for almost a century. The most significant investigations of the symbiosis have been those of Sluiter (1888), Ver wey (1930) and Gohar (1948), who have given us some knowledge of the ecology and behavioral characteristics of the animals. In 1947 Gudger reviewed

DEMOREST DAVENPORT; KENNETH S. NORRIS

82

Chemical recognition by hermit crabs of their symbiotic sea anemones and a predatory octopus  

Microsoft Academic Search

The ability of the hermit crabs Dardanus venosus and Pagurus pollicaris to recognize chemically their symbiotic sea anemone Calliactis tricolor and a common octopus predator, Octopus joubini, were studied. The crabs were tested for chemoreceptive responses using a Y-trough olfactometer, which prevented visual cues from being used. Choice tests showed that D. venosus could chemically detect Calliactis. If, however, D.

W. R. Brooks

1991-01-01

83

Genetic evidence of self-fertilization in the sea anemone Epiactis prolifera  

Microsoft Academic Search

Biochemical genetic variation provided evidence for the mode of reproduction of brooded young in the sea anemone Epiactis prolifera Verrill, 1869. Individuals of E. prolifera are female when small but hermaphroditic when large (i.e., gynodioecious); juveniles are brooded externally on the column. Brooding individuals collected from 6 intertidal sites (5 in central California and 1 in Washington State, USA) in

A. Bucklin; D. Hedgecock; C. Hand

1984-01-01

84

Feeding behavior and acquisition of zooxanthellae by planula larvae of the sea anemone Anthopleura elegantissima  

Microsoft Academic Search

Symbiotic associations between cnidarians and photosynthetic dinoflagellates (i.e., zooxanthellae) are common in the marine environment. Many symbiotic cnidarians produce offspring that are initially nonsymbiotic. These new hosts must acquire symbiotic algae from environmental sources. We examined zooxanthella acquisition by laboratory-reared planula larvae of the temperate sea anemone Anthopleura elegantissima. Larvae ingested zooxanthellae while they were feeding. However, the signal that

J. A. Schwarz; V. M. Weis; D. C. Potts

2002-01-01

85

Do reproductive tactics vary with habitat heterogeneity in the intertidal sea anemone Actinia tenebrosa?  

Microsoft Academic Search

Cnidarians display a diverse range of reproductive tactics including sexual and asexual modes of reproduction. Although few studies have looked for intraspecific variation in reproductive tactics, flexible expression of such life-history traits may be favoured in species that occupy a range of habitats. We tested this in the sea anemone Actinia tenebrosa by comparing cycles of reproductive activity and the

Craig D. H. Sherman; Amanda J. Peucker; David J. Ayre

2007-01-01

86

The evolution of mating systems in a group of brooding sea anemones (Epiactis)  

Microsoft Academic Search

The sea anemone genus Epiactis provides an unusually good opportunity to study the evolution of brooding and mating systems. The four Epiactis species on the Pacific coast of North America all brood their offspring up to the juvenile stage, but each has a different combination of internal vs. external brooding and gonochory vs. simultaneous or gynodioecious hermaphroditism. Two of the

SUZANNE EDMANDS

1996-01-01

87

The sea anemone Actinia equina tolerates allogeneic juveniles but alters their phenotype  

Microsoft Academic Search

Actinia equina is a variably coloured sea anemone that broods juveniles within its body cavity. Male, female and non-sexual individuals can produce juveniles, even after periods of isolation, and it has been suggested that this species is capable of reproducing by asexual or parthenogenetic means. Further evidence in favour of this hypothesis has been derived from similarities in coloration and

Roger Lubbock; Catherine Allbut

1981-01-01

88

Chemical biology of the mutualistic relationships of sea anemones with fish and crustaceans  

Microsoft Academic Search

Fish species of the genera Amphiprion and Premnas (Perciformes: Pomacentridae) as well as various crustaceans seek protection from predators among the tentacles of sea anemones, where they live essentially unharmed from stinging by the host's nematocysts. The mucous coats of anemonefish and crustaceans have been suggested as mechanisms that prevent the discharge of the nematocysts upon contact. Whereas some fish

Dietrich Mebs

2009-01-01

89

Cardiovascular effects of equinatoxin III from the sea anemone Actinia equina (L.)  

Microsoft Academic Search

Equinatoxin III is the most hemolytic, and the least lethal of the three basic proteins isolated from the sea anemone Actinia equina (L.). Its LD50 in mice is 83?g\\/kg. Preliminary results on Wistar rats have suggested cardiorespiratory arrest as a putative cause of death, but the mechanism of its action has not yet been studied. So far only equinatoxin II

Duan uput; Robert Frange; Matja Bunc

2001-01-01

90

SOCIAL ORGANIZATION WITHIN CLONES OF THE SEA ANEMONE ANTHOPLEURA ELEGANTISSIMA  

Microsoft Academic Search

The aggregating form of the anemone Anthopleura elegantissinla often lives at tached to large boulders and rocky outcroppings in closely packed groups. These are composed of genetically identical individuals, the products of asexual reproduc tion ( Francis, 1973a) . Contact between the tentacles of genetically different (non clonemate) members of the species elicits aggression in one or both animals, while

LISBETH FRANCIS

1976-01-01

91

Physiological energetics of the intertidal sea anemone Anthopleura elegantissima  

Microsoft Academic Search

Lipid is the major energy storage molecule, and protein is highly conserved when food availability is low in high- and low-intertidal individuals of Anthopleura elegantissima. Under laboratory conditions zooxanthellae were lost from anemones, and tissue carbohydrate was mobilized to support metabolic demands. Routine catabolic requirements for carbohydrate are probably met by translocated photosynthate. Substrate-specific absorption efficiencies were greater than 95%

William E. Zamer; J. Malcolm Shick

1989-01-01

92

RESEARCH ARTICLE Open Access Mutualism with sea anemones triggered the  

E-print Network

documented to promote adaptive radiation in many classic examples. Mutualistic interactions allow species diversification can greatly vary among mutualistic systems. Here, we test whether the development of obligate as rate of morphological evolution compared to their closest relatives without anemone mutualistic

Zimmermann, Niklaus E.

93

Properties of a cytolytic toxin from the sea anemone, Stoichactis kenti.  

PubMed

A cytolytic toxin (kentin) from the Indo-Pacific sea anemone, Stoichactis kenti, was purified to near homogeneity. The toxin is a basic polypeptide of molecular weight approximately 18,000. It broadly resembles cytotoxins from Stoichactis helianthus (helianthin), as well as similar toxins from a number of other anemones, namely Condylactis, Epiactis, Actinia, Pseudactinia, Tealia, Anthopleura, Radianthus and Gyrostoma. The amino acid composition of kentin shows considerable resemblance to that of helianthin, but there are also several significant differences. Neutralization tests indicate that kentin and helianthin are immunologically related but distinguishable. In contrast, no immunological relatedness was found between helianthin and cytolytic toxins from Condylactis gigantea and Epiactis prolifera. PMID:2868547

Bernheimer, A W; Lai, C Y

1985-01-01

94

Taxonomy and distribution of sea anemones (Cnidaria: Actiniaria, Corallimorpharia) from deep water of the northeastern Pacific  

E-print Network

faeculenta (McMurrich, 1893), are widely distributed. In the northeastern Pacific, a naturally occurring oxygen minimum zone (OMZ) off Oregon currently extends from near the shore to at least 1,200 m. It is now expanding and contains areas of virtually...

Eash-Loucks, Wendy Ellyn

2010-12-10

95

Secondary Structure of Sea Anemone Cytolysins in Soluble and Membrane Bound Form by Infrared Spectroscopy  

Microsoft Academic Search

Attenuated total reflection (ATR) Fourier transform infrared spectroscopy (FTIR) was used to investigate the secondary structure of two pore-forming cytolysins from the sea anemoneStichodactyla helianthusand their interaction with lipid membranes. Frequency component analysis of the amide I' band indicated that these peptides are composed predominantly of beta structure, comprising 4450% ?-sheet, 1820% ?-turn, 1215% ?-helix, and 1922% random coil. Upon

Gianfranco Menestrina; Veronique Cabiaux; Mayra Tejuca

1999-01-01

96

LOW TEMPERATURE EVOKES RAPID EXOCYTOSIS OF SYMBIOTIC ALGAE BY A SEA ANEMONE  

Microsoft Academic Search

Darknessevokes expulsion ofzooxanthellae from the sea anemone Aiptasia pu! chella, but brief exposure to low temperature(4°C, 4 h) increasesthe expulsion rate four-fold. Ninety-eight percent of the zooxanthellae are expelled within four days. Low temperature incubation had no detectable effect on host animal survival or be havior, but the effect on zooxanthellae was profound. Low temperaturereduced the rateofphotosynthesis, increasedthe rateofrelease offixed

R. GRANT STEEN; L MUSCATINE

97

Photosynthesis-irradiance responses and photosynthetic periodicity in the sea anemone Aiptasia pulchella and its zooxanthellae  

Microsoft Academic Search

Sea anemones (Aiptasia pulchella) containing zooxanthellae (Symbiodinium microadriaticum) were maintained in a long-term laboratory culture on a 12 h light (100 E m-2 s-1):12 h dark cycle. Photosynthetic oxygen production was measured for the symbiotic association and for freshlyisolated zooxanthellae. Light utilization efficiencies (a) were similar for both sets of zooxanthellae, suggesting negligible shading of zooxanthellae by animal tissue in

G. Muller-Parker

1984-01-01

98

A novel sea anemone peptide that inhibits acid-sensing ion channels.  

PubMed

Sea anemones produce ion channels peptide toxins of pharmacological and biomedical interest. However, peptides acting on ligand-gated ion channels, including acid-sensing ion channel (ASIC) toxins, remain poorly explored. PhcrTx1 is the first compound characterized from the sea anemone Phymanthus crucifer, and it constitutes a novel ASIC inhibitor. This peptide was purified by gel filtration, ion-exchange and reversed-phase chromatography followed by biological evaluation on ion channels of isolated rat dorsal root ganglia (DRG) neurons using patch clamp techniques. PhcrTx1 partially inhibited ASIC currents (IC50?100 nM), and also voltage-gated K(+) currents but the effects on the peak and on the steady state currents were lower than 20% in DRG neurons, at concentrations in the micromolar range. No significant effect was observed on Na(+) voltage-gated currents in DRG neurons. The N-terminal sequencing yielded 32 amino acid residues, with a molecular mass of 3477 Da by mass spectrometry. No sequence identity to other sea anemone peptides was found. Interestingly, the bioinformatic analysis of Cys-pattern and secondary structure arrangement suggested that this peptide presents an Inhibitor Cystine Knot (ICK) scaffold, which has been found in other venomous organisms such as spider, scorpions and cone snails. Our results show that PhcrTx1 represents the first member of a new structural group of sea anemones toxins acting on ASIC and, with much lower potency, on Kv channels. Moreover, this is the first report of an ICK peptide in cnidarians, suggesting that the occurrence of this motif in venomous animals is more ancient than expected. PMID:23764262

Rodrguez, Armando Alexei; Salceda, Emilio; Garateix, Anoland Georgina; Zaharenko, Andr Junqueira; Peigneur, Steve; Lpez, Omar; Pons, Tirso; Richardson, Michael; Daz, Mayln; Hernndez, Yasnay; Stndker, Ludger; Tytgat, Jan; Soto, Enrique

2014-03-01

99

Primary site and initial products of ammonium assimilation in the symbiotic sea anemone Anemonia viridis  

Microsoft Academic Search

Invertebrates containing endosymbiotic dinoflagellate algae (zooxanthellae) retain excretory nitrogen, and many are able\\u000a to take up ammonium from the surrounding seawater. However, the site of assimilation and role of nitrogen recycling between\\u000a symbiont and host remains unclear. In the present study, ammonium uptake by the symbiotic sea anemone Anemonia viridis (Forskl) was examined by following the pathway of assimilation using

J. M. Roberts; P. S. Davies; L. M. Fixter; T. Preston

1999-01-01

100

Cellular Changes Associated with the Acclimation of the Intertidal Sea Anemone Actinia tenebrosa to Ultraviolet Radiation.  

PubMed

To assess the relative importance of long- and short-term cellular defense mechanisms in seasonally UV-R-acclimated Actinia tenebrosa (Anthozoa, Actiniidae), individuals were exposed to summer doses of PAR, UV-A, UV-B and enhanced UV-B (20%) for a period of 4days. Mycosporine-like amino acids (MAAs) and cyclobutane pyrimidine dimer (CPD) concentrations were quantified, while oxidative damage to lipids and proteins, and the activities or levels of the antioxidant enzymes SOD, CAT, GR, GPOX and total glutathione were determined. Our results show that summer UV-R-acclimated individuals had a higher UV-R tolerance, with no significant increases in CPDs levels, than winter-acclimated sea anemones possibly due to higher MAA concentrations. Summer-acclimated individuals showed increased lipid and protein oxidation and GPOX activity only when they were exposed to UV-B at 20% above ambient UV-R levels. In contrast, winter-acclimated sea anemones showed elevated levels of oxidative damage, GPOX and SOD activities after exposure to UV-A or UV-B at ambient and elevated levels. Thus, this study indicates that long-term UV-R acclimation mechanisms such as the accumulation of MAAs could be more important than short-term increases in antioxidant defenses with respect to reducing indirect UV-R damage in intertidal sea anemones. PMID:25041232

Cubillos, Victor M; Lamare, Miles D; Peake, Barrie M; Burritt, David J

2014-11-01

101

The influence of irradiance on the severity of thermal bleaching in sea anemones that host anemonefish  

NASA Astrophysics Data System (ADS)

Entacmaea quadricolor is a geographically widespread species of sea anemone that forms a three-way symbiosis with anemonefish and Symbiodinium. This species dominates the reef substrata at North Solitary Island, Australia, which is located in a region identified as a climate change hot spot. Their geographic location places these anemones under significant threat from rising ocean temperatures, although their upper thermal limit and risk of bleaching are unknown. To address this knowledge gap, anemones were exposed to one of four temperatures (23, 25, 27, or 29C) and one of two irradiance treatments (high or low light) over 6 days. At moderate temperatures (27C, 1C above summer average), anemone bleaching was characterised by symbiont expulsion, while extreme temperatures (29C) resulted in an additional loss of photosynthetic pigments from within symbionts, and in some cases, host mortality. Irradiance influenced the susceptibility to thermal stress with high light promoting the bleaching response, along with significant reductions in the effective quantum yield of anemone symbionts. The long-term loss of photosystem II photochemical efficiency within in hospite symbionts was observed during exposure to temperatures exceeding the summer average, indicating photosynthetic damage. The resident Symbiodinium, identified as clade C using 28S rRNA gene sequences, therefore represents the partner within the symbiosis that is likely to be most vulnerable to rising seawater temperatures. Results suggest that E. quadricolor is living within approximately 1C of the upper thermal maximum at the Solitary Islands, and given the predictions for rising seawater temperature on Australia's east coast, the thermal threshold at which bleaching will occur is expected to be reached and exceeded more frequently in the future.

Hill, R.; Scott, A.

2012-03-01

102

The Expansion Behaviour of Sea Anemones may be Coordinated by Two Inhibitory Neuropeptides, Antho-KAamide and Antho-RIamide  

Microsoft Academic Search

Antho-KAamide (L-3-phenyllactyl-Phe-Lys-Ala-NH2) and Antho-RIamide (L-3-phenyllactyl-Tyr-Arg-Ile-NH2) are novel neuropeptides isolated from the sea anemone Anthopleura elegantissima. They both inhibited spontaneous contractions of isolated muscle preparations from a wide variety of anemone species (threshold around 10-7 M). Their actions were universal in that they inhibited every muscle preparation tested, regardless of whether the muscle group was located in the ectoderm or endoderm,

I. D. McFarlane; D. Hudman; H.-P. Nothacker; C. J. P. Grimmelikhuijzen

1993-01-01

103

Tiny Sea Anemone from the Lower Cambrian of China  

PubMed Central

Background Abundant fossils from the Ediacaran and Cambrian showing cnidarian grade grossly suggest that cnidarian diversification occurred earlier than that of other eumetazoans. However, fossils of possible soft-bodied polyps are scanty and modern corals are dated back only to the Middle Triassic, although molecular phylogenetic results support the idea that anthozoans represent the first major branch of the Cnidaria. Because of difficulties in taxonomic assignments owing to imperfect preservation of fossil cnidarian candidates, little is known about forms ancestral to those of living groups. Methods and Findings We have analyzed the soft-bodied polypoid microfossils Eolympia pediculata gen. et sp. nov. from the lowest Cambrian Kuanchuanpu Formation in southern China by scanning electron microscopy and computer-aided microtomography after isolating fossils from sedimentary rocks by acetic acid maceration. The fossils, about a half mm in body size, are preserved with 18 mesenteries including directives bilaterally arranged, 18 tentacles and a stalk-like pedicle. The pedicle suggests a sexual life cycle, while asexual reproduction by transverse fission also is inferred by circumferential grooves on the body column. Conclusions The features found in the present fossils fall within the morphological spectrum of modern Hexacorallia excluding Ceriantharia, and thus Eolympia pediculata could be a stem member for this group. The fossils also demonstrate that basic features characterizing modern hexacorallians such as bilateral symmetry and the reproductive system have deep roots in the Early Cambrian. PMID:20967244

Han, Jian; Kubota, Shin; Uchida, Hiro-omi; Stanley, George D.; Yao, Xiaoyong; Shu, Degan; Li, Yong; Yasui, Kinya

2010-01-01

104

Biochem. J. (2014) 461, 5159 (Printed in Great Britain) doi:10.1042/BJ20131454 51 The sea anemone toxin AdE-1 modifies both sodium and potassium currents  

E-print Network

Biochem. J. (2014) 461, 51�59 (Printed in Great Britain) doi:10.1042/BJ20131454 51 The sea anemone recently isolated from the sea anemone Aiptasia diaphana, contains 44 amino acids and has a molecular mass of 4907 Da. It was previously found to resemble other sea anemone type 1 and 2 Na+ channel toxins

Hochner, Binyamin

105

Relationships between host and symbiont cell cycles in sea anemones and their symbiotic dinoflagellates.  

PubMed

The processes by which cnidarians and their algal endosymbionts achieve balanced growth and biomass could include coordination of host and symbiont cell cycles. We evaluated this theory with natural populations of sea anemones hosting symbiotic dinoflagellates, focusing on the temperate sea anemone Anthopleura elegantissima symbiotic with Symbiodinium muscatinei in Washington State, USA, and the tropical anemone Stichodactyla helianthus associating with unknown Symbiodinium spp. in Belize. By extruding symbiont-containing gastrodermal cells from the relatively large tentacles of these species and using nuclear staining and flow cytometry, we selectively analyzed cell cycle distributions of the symbionts and the host gastrodermal cells that house them. We found no indications of diel synchrony in host and symbiont G2/M phases, and we observed evidence of diel periodicity only in Symbiodinium spp. associated with S. helianthus but not in the anemone itself. Seasonally, S. muscatinei showed considerable G2/M phase variability among samples collected quarterly over an annual period, while the G2/M phase of its host varied much less. Within samples taken at different times of the year, correlations between host and symbiont G2/M phases ranged from very weakly to very strongly positive, with significant correlations in only half of the samples (two of four A. elegantissima samples and one of two S. helianthus samples). Overall, the G2/M phase relationships across species and sampling periods were positive. Thus, while we found no evidence of close cell cycle coupling, our results suggest a loose, positive relationship between cell cycle processes of the symbiotic partners. PMID:24243963

Dimond, James L; Pineda, Rea R; Ramos-Ascherl, Zullaylee; Bingham, Brian L

2013-10-01

106

Sea anemone toxin:a tool to study molecular mechanisms of nerve conduction and excitation-secretion coupling.  

PubMed Central

The effects of polypeptide neurotoxin from Anemonia sulcata on nerve conduction in crayfish giant axons and on frog myelinated fibers have been analyzed. The main features of toxin action are the following: (i) the toxin acts at very low doses and its action is apparently irreversible. (ii) The toxin selectively affects the closing (inactivation) of the Na+ channel by slowing it down considerably; it does not alter the opening mechanism of the Na+ channel or the steady-state potassium conductance. (iii) The tetrodotoxin-receptor association is unaffected by previous treatment of the axonal membrane with the sea anemone toxin. (iv) Conversely, the sea anemone toxin can only associate with the membrane when the Na+ channel is open for Na+; it does not bind when the channel is previously blocked by tetrodotoxin. (v) Besides its effect on the action potential, the sea anemone toxin displays a veratridine-type depolarizing action at low Ca2+ concentration which can be suppressed by tetrodotoxin. The sea anemone toxin greatly stimulates the release of gamma-[3H]aminobutyric acid from neurotransmitter-loaded rat brain synaptosomes. The apparent dissociation constant of the neurotoxin-receptor complex in this system is 20 nM. The sea anemone toxin effect is antagonized by tetrodotoxin. Images PMID:1087023

Romey, G; Abita, J P; Schweitz, H; Wunderer, G; Lazdunski

1976-01-01

107

Abundance and diversity of anemonefishes and their host sea anemones at two mesophotic sites on the Great Barrier Reef, Australia  

NASA Astrophysics Data System (ADS)

Anemonefishes and their host sea anemones are iconic inhabitants of coral reef ecosystems. While studies have documented their abundance in shallow-water reef habitats in parts of the Indo-Pacific, none have examined these species on mesophotic reefs. In this study, we used autonomous underwater vehicle imagery to examine the abundance and diversity of anemones and anemonefishes at Viper Reef and Hydrographers Passage in the central Great Barrier Reef at depths between 50 and 65 m. A total of 37 host sea anemones (31 Entacmaea quadricolor and 6 Heteractis crispa) and 24 anemonefishes (23 Amphiprion akindynos and 1 A. perideraion) were observed. Densities were highest at Viper Reef, with 8.48 E. quadricolor and A. akindynos per 100 m2 of reef substratum. These results support the hypothesis that mesophotic reefs have many species common to shallow-water coral reefs and that many taxa may occur at depths greater than currently recognised.

Bridge, T.; Scott, A.; Steinberg, D.

2012-12-01

108

Asexual Propagation of Sea Anemones That Host Anemonefishes: Implications for the Marine Ornamental Aquarium Trade and Restocking Programs  

PubMed Central

Anemonefishes and their host sea anemones form an iconic symbiotic association in reef environments, and are highly sought after in the marine aquarium trade. This study examines asexual propagation as a method for culturing a geographically widespread and commonly traded species of host sea anemone, Entacmaea quadricolor. Two experiments were done: the first to establish whether size or colour morph influenced survival after cutting into halves or quarters; and the second to see whether feeding was needed to maximise survival and growth after cutting. Survival rates were high in both experiments, with 89.3 and 93.8% of the anemones cut in half, and 62.5 and 80.4% cut in quarters surviving in experiments 1 and 2, respectively. Anemones that were cut in half were larger in size, and healed and grew quicker than those cut in quarters. However, even though survival was lower when the individuals were cut in quarters, this treatment produced the greatest number of anemones. Feeding increased oral disc diameter growth and reduced wet weight loss, but did not significantly influence pedal disc diameter. Given that the anemones took up to 56 d to form an off-centre mouth, it is highly likely that feeding may have produced greater effect if the experiment was run for longer. This low technology method of propagation could be used to produce individuals throughout the year and the anemones could then be used to supply the aquarium trade or restock depleted habitats, thus supporting biodiversity conservation in coral reef areas. PMID:25314131

Scott, Anna; Hardefeldt, Jannah M.; Hall, Karina C.

2014-01-01

109

Asexual propagation of sea anemones that host anemonefishes: implications for the marine ornamental aquarium trade and restocking programs.  

PubMed

Anemonefishes and their host sea anemones form an iconic symbiotic association in reef environments, and are highly sought after in the marine aquarium trade. This study examines asexual propagation as a method for culturing a geographically widespread and commonly traded species of host sea anemone, Entacmaea quadricolor. Two experiments were done: the first to establish whether size or colour morph influenced survival after cutting into halves or quarters; and the second to see whether feeding was needed to maximise survival and growth after cutting. Survival rates were high in both experiments, with 89.3 and 93.8% of the anemones cut in half, and 62.5 and 80.4% cut in quarters surviving in experiments 1 and 2, respectively. Anemones that were cut in half were larger in size, and healed and grew quicker than those cut in quarters. However, even though survival was lower when the individuals were cut in quarters, this treatment produced the greatest number of anemones. Feeding increased oral disc diameter growth and reduced wet weight loss, but did not significantly influence pedal disc diameter. Given that the anemones took up to 56 d to form an off-centre mouth, it is highly likely that feeding may have produced greater effect if the experiment was run for longer. This low technology method of propagation could be used to produce individuals throughout the year and the anemones could then be used to supply the aquarium trade or restock depleted habitats, thus supporting biodiversity conservation in coral reef areas. PMID:25314131

Scott, Anna; Hardefeldt, Jannah M; Hall, Karina C

2014-01-01

110

Accumulation of glutamate in sea anemones exposed to heavy metals and organic amines  

SciTech Connect

Stress has been reported to accelerate protein catabolism in man and animals and as a result one can expect to observe changes in certain amino acids pools of these organisms. In the present study, the Gulf Coast sea anemone, Bunodosoma cavernata, was used as the test animal and free amino acid levels of whole animals were measured following stressed conditions. Sea anemones were chosen as the test animals since they are sessile and, due to the nature of their morphology, they have few mechanisms by which they can escape environmental stress. The animals were exposed to sublethal concentrations of mercuric chloride and cadmium chloride and the organic amines, aniline, diethanol amine (DEA), and ethylene diamine (EDA). Chloride salts of mercury and cadmium were chosen rather than other anions since chloride is the most abundant anion in seawater. These two particular metals were chosen as challenge compounds due to their high toxicity in aquatic systems. The three organic amines were chosen for their relatively high water solubility and low vapor pressure in an aqueous solution, thus insuring that the toxic compound is retained in the test solution. Since organic amines are used extensively in the Gulf Coast industrial complex, there is a high probability of these compounds contaminating the marine environment. Results indicate that the reaction of B. cavernata to stress from organic amines is similar to the response to heavy metals, only more extensive.

Kasschau, M.R.; Skaggs, M.M.; Chen, E.C.M.

1980-12-01

111

Effects of Lipid Composition on Membrane Permeabilization by Sticholysin I and II, Two Cytolysins of the Sea Anemone Stichodactyla helianthus  

Microsoft Academic Search

Sticholysin I and II (St I and St II), two basic cytolysins purified from the Caribbean sea anemone Stichodactyla helianthus, efficiently permeabilize lipid vesicles by forming pores in their membranes. A general characteristic of these toxins is their preference for membranes containing sphingomyelin (SM). As a consequence, vesicles formed by equimolar mixtures of SM with phosphatidylcholine (PC) are very good

Carlos Alvarez Valcarcel; Mauro Dalla Serra; Cristina Potrich; Ivonne Bernhart; Mayra Tejuca; Diana Martinez; Fabiola Pazos; Maria E. Lanio; Gianfranco Menestrina

2001-01-01

112

Programmed cell death and cell necrosis activity during hyperthermic stress-induced bleaching of the symbiotic sea anemone Aiptasia sp  

Microsoft Academic Search

Different cell death pathways were investigated during bleaching in the sea anemone Aiptasia sp. in response to hyperthermic treatment. Using a suite of techniques, (haematoxylin and eosin staining of paraffin wax-embedded tissue sections, in-situ end labelling (ISEL) of fragmented DNA, agarose gel electrophoresis electron microscopy) both necrotic and programmed cell death (PCD) activity were indicated. After a treatment period of

Simon R Dunn; John C Bythell; Martin D. A Le Tissier; William J Burnett; Jeremy C Thomason

2002-01-01

113

Genetic divergence and isolation by distance in the West Atlantic sea anemone Actinia bermudensis (McMurrich, 1889)  

Microsoft Academic Search

The sea anemone Actinia bermudensis [Proc. Acad. Nat. Sci. Philadelphia 41 (1889) 102] has a widespread distribution over the Western Atlantic, where it has been reported from Bermuda and Bahamas to southern Brazil. Nonetheless, reproductive features of this species, which broods asexually produced offspring, suggest that it has low dispersal capabilities. This raises a question about the specific status of

Paulo Vianna; Renata Schama; Claudia A. M Russo

2003-01-01

114

Increased cell proliferation and mucocyte density in the sea anemone Aiptasia pallida recovering from bleaching.  

PubMed

Recovery of coral after bleaching episodes is a critical period for the health of the reef ecosystem. While events such as symbiont (genus Symbiodinium) shifting/shuffling or tissue apoptosis have been demonstrated to occur following bleaching, little is known concerning tissue recovery or cell proliferation. Here, we studied the sea anemone Aiptasia pallida exposed to a transient elevation of water temperature combined with high illumination (33C and 1900 mol photons x m(-2) x s(-1) for 30 h). Following such treatment bleached anemones showed a significant reduction of their Symbiodinium density. Cell proliferation in the ectodermis and gastrodermis was determined by assessing the densities of cells labeled with a thymidine analogue (EdU). Cell proliferation significantly increased during the first day following stress in both tissue types. This increased cell proliferation returned to pre-stress values after one week. Although cell proliferation was higher in the ectodermis in absence of stress, it was relatively more pronounced in the gastrodermis of stressed anemones. In addition, the ratio of ectodermal mucocytes significantly increased three weeks after induced stress. These results suggest that thermal/photic stress coupled with the loss of the symbionts is able to enhance cell proliferation in both gastrodermis and ectodermis of cnidarians. While new cells formed in the gastrodermis are likely to host new Symbiodinium, the fate of new cells in the ectodermis was only partially revealed. Some new ectodermal cells may, in part, contribute to the increased number of mucocytes which could eventually help strengthen the heterotrophic state until restoration of the symbiosis. PMID:23724115

Fransolet, David; Roberty, Stphane; Herman, Anne-Catherine; Tonk, Linda; Hoegh-Guldberg, Ove; Plumier, Jean-Christophe

2013-01-01

115

Increased Cell Proliferation and Mucocyte Density in the Sea Anemone Aiptasia pallida Recovering from Bleaching  

PubMed Central

Recovery of coral after bleaching episodes is a critical period for the health of the reef ecosystem. While events such as symbiont (genus Symbiodinium) shifting/shuffling or tissue apoptosis have been demonstrated to occur following bleaching, little is known concerning tissue recovery or cell proliferation. Here, we studied the sea anemone Aiptasia pallida exposed to a transient elevation of water temperature combined with high illumination (33C and 1900 molphotons.m?2.s?1 for 30h). Following such treatment bleached anemones showed a significant reduction of their Symbiodinium density. Cell proliferation in the ectodermis and gastrodermis was determined by assessing the densities of cells labeled with a thymidine analogue (EdU). Cell proliferation significantly increased during the first day following stress in both tissue types. This increased cell proliferation returned to pre-stress values after one week. Although cell proliferation was higher in the ectodermis in absence of stress, it was relatively more pronounced in the gastrodermis of stressed anemones. In addition, the ratio of ectodermal mucocytes significantly increased three weeks after induced stress. These results suggest that thermal/photic stress coupled with the loss of the symbionts is able to enhance cell proliferation in both gastrodermis and ectodermis of cnidarians. While new cells formed in the gastrodermis are likely to host new Symbiodinium, the fate of new cells in the ectodermis was only partially revealed. Some new ectodermal cells may, in part, contribute to the increased number of mucocytes which could eventually help strengthen the heterotrophic state until restoration of the symbiosis. PMID:23724115

Fransolet, David; Roberty, Stephane; Herman, Anne-Catherine; Tonk, Linda; Hoegh-Guldberg, Ove; Plumier, Jean-Christophe

2013-01-01

116

Trace element profiles of the sea anemone Anemonia viridis living nearby a natural CO2 vent  

PubMed Central

Ocean acidification (OA) is not an isolated threat, but acts in concert with other impacts on ecosystems and species. Coastal marine invertebrates will have to face the synergistic interactions of OA with other global and local stressors. One local factor, common in coastal environments, is trace element contamination. CO2 vent sites are extensively studied in the context of OA and are often considered analogous to the oceans in the next few decades. The CO2 vent found at Levante Bay (Vulcano, NE Sicily, Italy) also releases high concentrations of trace elements to its surrounding seawater, and is therefore a unique site to examine the effects of long-term exposure of nearby organisms to high pCO2 and trace element enrichment in situ. The sea anemone Anemonia viridis is prevalent next to the Vulcano vent and does not show signs of trace element poisoning/stress. The aim of our study was to compare A. viridis trace element profiles and compartmentalization between high pCO2 and control environments. Rather than examining whole anemone tissue, we analyzed two different body compartmentsthe pedal disc and the tentacles, and also examined the distribution of trace elements in the tentacles between the animal and the symbiotic algae. We found dramatic changes in trace element tissue concentrations between the high pCO2/high trace element and control sites, with strong accumulation of iron, lead, copper and cobalt, but decreased concentrations of cadmium, zinc and arsenic proximate to the vent. The pedal disc contained substantially more trace elements than the anemones tentacles, suggesting the pedal disc may serve as a detoxification/storage site for excess trace elements. Within the tentacles, the various trace elements displayed different partitioning patterns between animal tissue and algal symbionts. At both sites iron was found primarily in the algae, whereas cadmium, zinc and arsenic were primarily found in the animal tissue. Our data suggests that A. viridis regulates its internal trace element concentrations by compartmentalization and excretion and that these features contribute to its resilience and potential success at the trace element-rich high pCO2 vent.

Borell, Esther M.; Fine, Maoz; Shaked, Yeala

2014-01-01

117

Familial strife on the seashore: aggression increases with relatedness in the sea anemone Actinia equina.  

PubMed

Pairwise contests occur when two individuals compete directly over ownership of an indivisible resource. Contests vary in the degree of escalation, some encounters being settled through non-injurious behaviour while others are only resolved after dangerous fighting. Here, we investigate the role of relatedness, assessed using AFLP analysis, on the occurrence of stinging during staged contests in the beadlet sea anemone Actinia equina. Contrary to our expectations, we found that the chance of stinging, and hence the chance of inflicting damage, increased with the degree of relatedness between the two opponents. This result may be explained by the negative relationship between asymmetry in fighting ability and escalation level predicted by theory. We suggest that in order to fully understand how relatedness influences aggression, predictions from kin selection theory should be incorporated with those from contest theory. PMID:24463009

Foster, Nicola L; Briffa, Mark

2014-03-01

118

Computational Insights of the Interaction among Sea Anemones Neurotoxins and Kv1.3 Channel.  

PubMed

Sea anemone neurotoxins are peptides that interact with Na(+) and K(+) channels, resulting in specific alterations on their functions. Some of these neurotoxins (1ROO, 1BGK, 2K9E, 1BEI) are important for the treatment of about 80 autoimmune disorders because of their specificity for Kv1.3 channel. The aim of this study was to identify the common residues among these neurotoxins by computational methods, and establish whether there is a pattern useful for the future generation of a treatment for autoimmune diseases. Our results showed eight new key common residues between the studied neurotoxins interacting with a histidine ring and the selectivity filter of the receptor, thus showing a possible pattern of interaction. This knowledge may serve as an input for the design of more promising drugs for autoimmune treatments. PMID:24812496

Sabogal-Arango, Anglica; Barreto, George E; Ramrez-Snchez, David; Gonzlez-Mendoza, Juan; Barreto, Viviana; Morales, Ludis; Gonzlez, Janneth

2014-01-01

119

Edwardsiella andrillae, a New Species of Sea Anemone from Antarctic Ice  

PubMed Central

Exploration of the lower surface of the Ross Ice Shelf in Antarctica by the Submersible Capable of under-Ice Navigation and Imaging (SCINI) remotely operated vehicle discovered a new species of sea anemone living in this previously undocumented ecosystem. This discovery was a significant outcome of the Coulman High Projects geophysical and environmental fieldwork in 2010-2011 as part of the ANDRILL (ANtarctic geologic DRILLing) program. Edwardsiella andrillae n. sp., lives with most of its column in the ice shelf, with only the tentacle crown extending into the seawater below. In addition to being the only Antarctic representative of the genus, Edwardsiella andrillae is distinguished from all other species of the genus in the number of tentacles and in the size and distribution of cnidae. The anatomy and histology of Edwardsiella andrillae present no features that explain how this animal withstands the challenges of life in such an unusual habitat. PMID:24349517

Daly, Marymegan; Rack, Frank; Zook, Robert

2013-01-01

120

Isolation of DNA, RNA and protein from the starlet sea anemone Nematostella vectensis.  

PubMed

Among marine invertebrates, the starlet sea anemone Nematostella vectensis has emerged as an important laboratory model system. One advantage of working with this species relative to many other marine invertebrates is the ease of isolating relatively pure DNA, RNA and protein. Nematostella can be raised at high densities, under clean culture conditions, and it lacks integumentary or skeletal structures that can impede the recovery of DNA, RNA or protein. Here we describe methods used in our lab to isolate DNA, RNA and protein from Nematostella embryos, larvae and adults. The methods described here are less expensive than commercial kits and are more easily scalable to larger tissue amounts. Preparation of DNA can be completed in ?7 h, RNA preparation in ?1.5 h and protein preparation in ?1 h. PMID:23579778

Stefanik, Derek J; Wolenski, Francis S; Friedman, Lauren E; Gilmore, Thomas D; Finnerty, John R

2013-05-01

121

Characterization of myostatin/gdf8/11 in the starlet sea anemone Nematostella vectensis.  

PubMed

The signaling molecule Myostatin, a member of the TGF-beta superfamily, is crucially involved in the control of muscle growth and development in triploblastic organisms. A homolog to vertebrate myostatin and gdf8/11 was isolated from a diploblastic cnidarian, the starlet sea anemone Nematostella vectensis. Here we provide a detailed characterization of the Nematostella myostatin/gdf8/11 gene and show the first analysis of gene expression in adult polyps. This analysis revealed that myostatin/gdf8/11 is expressed in the mesenteries, which are endodermal folds, and weakly in the body wall endoderm, but largely excluded from the areas of muscle formation, the retractor and the parietal muscle. Contrary to this, in vertebrates the muscle growth inhibitor myostatin is expressed in the muscle tissue. We therefore hypothesize that myostatin/gdf8/11 in Nematostella is involved in regulating nonmuscle cell differentiation, possibly by repressing muscle differentiation. PMID:19533681

Saina, Michael; Technau, Ulrich

2009-11-15

122

Computational Insights of the Interaction among Sea Anemones Neurotoxins and Kv1.3 Channel  

PubMed Central

Sea anemone neurotoxins are peptides that interact with Na+ and K+ channels, resulting in specific alterations on their functions. Some of these neurotoxins (1ROO, 1BGK, 2K9E, 1BEI) are important for the treatment of about 80 autoimmune disorders because of their specificity for Kv1.3 channel. The aim of this study was to identify the common residues among these neurotoxins by computational methods, and establish whether there is a pattern useful for the future generation of a treatment for autoimmune diseases. Our results showed eight new key common residues between the studied neurotoxins interacting with a histidine ring and the selectivity filter of the receptor, thus showing a possible pattern of interaction. This knowledge may serve as an input for the design of more promising drugs for autoimmune treatments. PMID:24812496

Sabogal-Arango, Angelica; Barreto, George E; Ramirez-Sanchez, David; Gonzalez-Mendoza, Juan; Barreto, Viviana; Morales, Ludis; Gonzalez, Janneth

2014-01-01

123

Ancient origins of axial patterning genes: Hox genes and ParaHox genes in the Cnidaria.  

PubMed

Among the bilaterally symmetrical, triploblastic animals (the Bilateria), a conserved set of developmental regulatory genes are known to function in patterning the anterior-posterior (AP) axis. This set includes the well-studied Hox cluster genes, and the recently described genes of the ParaHox cluster, which is believed to be the evolutionary sister of the Hox cluster (Brooke et al. 1998). The conserved role of these axial patterning genes in animals as diverse as frogs and flies is believed to reflect an underlying homology (i.e., all bilaterians derive from a common ancestor which possessed an AP axis and the developmental mechanisms responsible for patterning the axis). However, the origin and early evolution of Hox genes and ParaHox genes remain obscure. Repeated attempts have been made to reconstruct the early evolution of Hox genes by analyzing data from the triphoblastic animals, the Bilateria (Schubert et al. 1993; Zhang and Nei 1996). A more precise dating of Hox origins has been elusive due to a lack of sufficient information from outgroup taxa such as the phylum Cnidaria (corals, hydras, jellyfishes, and sea anemones). In combination with outgroup taxa, another potential source of information about Hox origins is outgroup genes (e.g., the genes of the ParaHox cluster). In this article, we present cDNA sequences of two Hox-like genes (anthox2 and anthox6) from the sea anemone, Nematostella vectensis. Phylogenetic analysis indicates that anthox2 (= Cnox2) is homologous to the GSX class of ParaHox genes, and anthox6 is homologous to the anterior class of Hox genes. Therefore, the origin of Hox genes and ParaHox genes occurred prior to the evolutionary split between the Cnidaria and the Bilateria and predated the evolution of the anterior-posterior axis of bilaterian animals. Our analysis also suggests that the central Hox class was invented in the bilaterian lineage, subsequent to their split from the Cnidaria. PMID:11324016

Finnerty, J R; Martindale, M Q

1999-01-01

124

Trace element profiles of the sea anemone Anemonia viridis living nearby a natural CO2 vent.  

PubMed

Ocean acidification (OA) is not an isolated threat, but acts in concert with other impacts on ecosystems and species. Coastal marine invertebrates will have to face the synergistic interactions of OA with other global and local stressors. One local factor, common in coastal environments, is trace element contamination. CO2 vent sites are extensively studied in the context of OA and are often considered analogous to the oceans in the next few decades. The CO2 vent found at Levante Bay (Vulcano, NE Sicily, Italy) also releases high concentrations of trace elements to its surrounding seawater, and is therefore a unique site to examine the effects of long-term exposure of nearby organisms to high pCO2 and trace element enrichment in situ. The sea anemone Anemonia viridis is prevalent next to the Vulcano vent and does not show signs of trace element poisoning/stress. The aim of our study was to compare A. viridis trace element profiles and compartmentalization between high pCO2 and control environments. Rather than examining whole anemone tissue, we analyzed two different body compartments-the pedal disc and the tentacles, and also examined the distribution of trace elements in the tentacles between the animal and the symbiotic algae. We found dramatic changes in trace element tissue concentrations between the high pCO2/high trace element and control sites, with strong accumulation of iron, lead, copper and cobalt, but decreased concentrations of cadmium, zinc and arsenic proximate to the vent. The pedal disc contained substantially more trace elements than the anemone's tentacles, suggesting the pedal disc may serve as a detoxification/storage site for excess trace elements. Within the tentacles, the various trace elements displayed different partitioning patterns between animal tissue and algal symbionts. At both sites iron was found primarily in the algae, whereas cadmium, zinc and arsenic were primarily found in the animal tissue. Our data suggests that A. viridis regulates its internal trace element concentrations by compartmentalization and excretion and that these features contribute to its resilience and potential success at the trace element-rich high pCO2 vent. PMID:25250210

Horwitz, Rael; Borell, Esther M; Fine, Maoz; Shaked, Yeala

2014-01-01

125

Mechanism of Membrane Permeabilization by Sticholysin I, a Cytolysin Isolated from the Venom of the Sea Anemone Stichodactyla helianthus  

Microsoft Academic Search

Actinaria cytolysins are very potent basic toxins isolated from the venom of sea anemones, which are supposed to exert their toxic activity through formation of oligomeric pores in the host plasma membrane. To gain insight into their mechanism of action, the interaction of Stichodactyla helianthus sticholysin I (St-I) with lipid bilayers was studied. St-I increased the permeability of calcein-loaded lipid

Mayra Tejuca; Mauro Dalla Serra; Mercedes Ferreras; Maria E. Lanio; Gianfranco Menestrina

1996-01-01

126

Lipid composition of beef brain, beef liver, and the sea anemone: Two approaches to quantitative fractionation of complex lipid mixtures  

Microsoft Academic Search

Two new schemes for fractionation of complex lipid mixtures are presented. Their use for the study of lipids of beef brain,\\u000a beef liver, and the sea anemone are described. Apparatus and techniques for working in an inert atmosphere, evaporation of\\u000a solutions in the cold under nitrogen, use of infrared spectroscopy for examination of lipids and their hydrolysis products,\\u000a preparation and

George Rouser; Gene Kritchevsky; Dorothy Heller; Ellen Lieber

1963-01-01

127

Overproduction in Escherichia coli and purification of the hemolytic protein sticholysin II from the sea anemone Stichodactyla helianthus.  

PubMed

The cDNA coding for the cytolytic toxins sticholysin I and sticholysin II from the sea anemone Stichodactyla helianthus has been isolated, cloned in pUC18, and sequenced. A 6His-tagged version of sticholysin II has been overproduced in Escherichia coli and purified to homogeneity in milligram amounts. Conformational and functional analyses of recombinant sticholysin II do not reveal any significant difference when compared to the natural cytolysin. PMID:10648171

de los Ros, V; Oaderra, M; Martnez-Ruiz, A; Lacadena, J; Mancheo, J M; Martnez del Pozo, A; Gavilanes, J G

2000-02-01

128

Predicting suitable habitat for the gold coral Savalia savaglia (Bertoloni, 1819) (Cnidaria, Zoantharia) in the South Tyrrhenian Sea  

NASA Astrophysics Data System (ADS)

The gold coral Savalia savaglia (Cnidaria, Zoantharia) is a rare component of the mesophotic zone of the Mediterranean Sea and northeastern Atlantic Ocean. During two field campaigns along the Italian coast in the South Tyrrhenian Sea, two populations of this species were discovered. The specimens were filmed and photographed by means of a Remotely Operated Vehicle (ROV). To identify the role of local bathymetry and other derived variables on presence and distribution of S. savaglia we used a Habitat Suitability (HS) modeling technique based on Ecological Niche Factor Analysis (ENFA), utilizing high-resolution multibeam bathymetry and ROV data. Among the set of environmental variables derived from multibeam data, slope, rugosity, eastness and distance to rocks, appear to be the main variables involved in S. savaglia distribution, pointing out that the habitat differs considerably from the mean environmental conditions over the study area, and that S. savaglia ecological niche is significantly narrower than the available habitat. The HS map was developed to differentiate the sea floor into suitability classes. The comparison between suitability classes and presence data showed that the HS map is coherent with the observed spatial distribution of the species. The most suitable habitat for S. savaglia is characterized by a rough sea floor with rocks that is steeply sloped, oriented northeast, and within a water depth range of 34-77 m. Our study suggests that predictive modeling is an approach that can be applied to other deep coral species to locate areas with a suitable habitat. Considering the difficulties to reach the habitats in which these species live, this approach could be essential to planning further studies that help define areas where the species may be present.

Giusti, Michela; Innocenti, Carlo; Canese, Simonepietro

2014-06-01

129

Algal genotype and photoacclimatory responses of the symbiotic alga Symbiodinium in natural populations of the sea anemone Anemonia viridis  

PubMed Central

As an approach to investigate the impact of solar radiation on an algainvertebrate symbiosis, the genetic variation and photosynthetic responses of the dinoflagellate algal symbiosis in an intertidal and a subtidal population of the sea anemone Anemonia viridis were explored. Allozyme analysis of the anemones indicated that the two populations were genetically very similar, with a Nei's index value of genetic identity (I) of 0.998. The algae in all animals examined were identified as Symbiodinium of clade a by PCR-RFLP analysis of the small subunit ribosomal RNA gene. The symbiosis in the two populations did not differ significantly in algal population density, chlorophyll a content per algal cell or any photosynthetic parameter obtained from studies of the relationship between photosynthesis and irradiance. We conclude that there is not necessarily genetic variation or photosynthetic plasticity of the symbiotic algae in Anemonia viridis inhabiting environments characterized by the different solar irradiances of the subtidal and intertidal habitats.

Bythell, J. C.; Douglas, A. E.; Sharp, V. A.; Searle, J. B.; Brown, B. E.

1997-01-01

130

Interactions between the tropical sea anemone Aiptasia pallida and Serratia marcescens, an opportunistic pathogen of corals.  

PubMed

Coral reefs are under increasing stress caused by global and local environmental changes, which are thought to increase the susceptibility of corals to opportunistic pathogens. In the absence of an easily culturable model animal, the understanding of the mechanisms of disease progression in corals remains fairly limited. In the present study, we tested the susceptibility of the tropical sea anemone Aiptasia pallida to an opportunistic coral pathogen (Serratia marcescens). A.?pallida was susceptible to S. marcescens?PDL100 and responded to this opportunistic coral pathogen with darkening of the tissues and retraction of tentacles, followed by complete disintegration of polyp tissues. Histological observations revealed loss of zooxanthellae and structural changes in eosinophilic granular cells in response to pathogen infection. A screen of S.?marcescens mutants identified a motility and tetrathionate reductase mutants as defective in virulence in the A.?pallida infection model. In co-infections with the wild-type strain, the tetrathionate reductase mutant was less fit within the surface mucopolysaccharide layer of the host coral Acropora palmata. PMID:24983533

Krediet, Cory J; Meyer, Julie L; Gimbrone, Nicholas; Yanong, Roy; Berzins, Ilze; Alagely, Ali; Castro, Herman; Ritchie, Kim B; Paul, Valerie J; Teplitski, Max

2014-06-01

131

Outcomes of infections of sea anemone Aiptasia pallida with Vibrio spp. pathogenic to corals.  

PubMed

Incidents of coral disease are on the rise. However, in the absence of a surrogate animal host, understanding of the interactions between coral pathogens and their hosts remains relatively limited, compared to other pathosystems of similar global importance. A tropical sea anemone, Aiptasia pallida, has been investigated as a surrogate model to study certain aspects of coral biology. Therefore, to test whether the utility of this surrogate model can be extended to study coral diseases, in the present study, we tested its susceptibility to common coral pathogens (Vibrio coralliilyticus and Vibrio shiloi) as well as polymicrobial consortia recovered from the Caribbean Yellow Band Disease (CYBD) lesions. A. pallida was susceptible to each of the tested pathogens. A. pallida responded to the pathogens with darkening of the tissues (associated with an increased melanization) and retraction of tentacles, followed by complete disintegration of polyp tissues. Loss of zooxanthellae was not observed; however, the disease progression pattern is consistent with the behavior of necrotizing pathogens. Virulence of some coral pathogens in Aiptasia was paralleled with their glycosidase activities. PMID:24619233

Zaragoza, William J; Krediet, Cory J; Meyer, Julie L; Canas, Gabriela; Ritchie, Kim B; Teplitski, Max

2014-08-01

132

Fast neurotransmission related genes are expressed in non nervous endoderm in the sea anemone Nematostella vectensis.  

PubMed

Cnidarian nervous systems utilize chemical transmission to transfer signals through synapses and neurons. To date, ample evidence has been accumulated for the participation of neuropeptides, primarily RFamides, in neurotransmission. Yet, it is still not clear if this is the case for the classical fast neurotransmitters such as GABA, Glutamate, Acetylcholine and Monoamines. A large repertoire of cnidarian Fast Neurotransmitter related Genes (FNGs) has been recently identified in the genome of the sea anemone, Nematostella vectensis. In order to test whether FNGs are localized in cnidarian neurons, we characterized the expression patterns of eight Nematostella genes that are closely or distantly related to human central and peripheral nervous systems genes, in adult Nematostella and compared them to the RFamide localization. Our results show common expression patterns for all tested genes, in a single endodermal cell layer. These expressions did not correspond with the RFamide expressing nerve cell network. Following these results we suggest that the tested Nematostella genes may not be directly involved in vertebrate-like fast neurotransmission. PMID:24705400

Oren, Matan; Brikner, Itzchak; Appelbaum, Lior; Levy, Oren

2014-01-01

133

Effect of sea anemone toxins on the sodium inactivation process in crayfish axons  

PubMed Central

The effect of sea anemone toxins from Parasicyonis actinostoloides and Anemonia sulcata on the Na conductance in crayfish giant axons was studied under voltage-clamp conditions. The toxin slowed the Na inactivation process without changing the kinetics of Na activation or K activation in an early stage of the toxin effect. An analysis of the Na current profile during the toxin treatment suggested an all-or-none modification of individual Na channels. Toxin-modified Na channels were partially inactivated with a slower time course than that of the normal inactivation. This slow inactivation in steady state decreased in its extent as the membrane was depolarized to above -45 mV, so that practically no inactivation occurred at the membrane potentials as high as +50 mV. In addition to inhibition of the normal Na inactivation, prolonged toxin treatment induced an anomalous closing in a certain population of Na channels, indicated by very slow components of the Na tail current. The observed kinetic natures of toxin-modified Na channels were interpreted based on a simple scheme which comprised interconversions between functional states of Na channels. The voltage dependence of Parasicyonis toxin action, in which depolarization caused a suppression in development of the toxin effect, was also investigated. PMID:6132957

1983-01-01

134

Sexual Plasticity and Self-Fertilization in the Sea Anemone Aiptasia diaphana  

PubMed Central

Traits that influence reproductive success and contribute to reproductive isolation in animal and plant populations are a central focus of evolutionary biology. In the present study we used an experimental approach to demonstrate the occurrence of environmental effects on sexual and asexual reproduction, and provide evidence for sexual plasticity and inter-clonal fertilization in laboratory-cultured lines of the sea anemone Aiptasia diaphana. We showed that in A. diaphana, both asexual reproduction by pedal laceration, and sexual reproduction have seasonal components. The rate of pedal laceration was ten-fold higher under summer photoperiod and water temperature conditions than under winter conditions. The onset of gametogenesis coincided with the rising water temperatures occurring in spring, and spawning occurred under parameters that emulated summer photoperiod and temperature conditions. In addition, we showed that under laboratory conditions, asexually produced clones derived from a single founder individual exhibit sexual plasticity, resulting in the development of both male and female individuals. Moreover, a single female founder produced not only males and females but also hermaphrodite individuals. We further demonstrated that A. diaphana can fertilize within and between clone lines, producing swimming planula larvae. These diverse reproductive strategies may explain the species success as invader of artificial marine substrates. We suggest that these diverse reproductive strategies, together with their unique evolutionary position, make Aiptasia diaphana an excellent model for studying the evolution of sex. PMID:20686700

Schlesinger, Ami; Kramarsky-Winter, Esti; Rosenfeld, Hanna; Armoza-Zvoloni, Rachel; Loya, Yossi

2010-01-01

135

A Taxonomic Approach to Evaluation of the Charge State Model Using Twelve Species of Sea Anemone  

PubMed Central

The charge-state model of electrophoretic variation was tested by comparing the distances between nearest electromorphs of five enzyme loci within polymorphic species and among pooled species of sea anemone. If the charge-state model is generally true, and in particular if it allows linear distance between electromorphs to be used as a measure of genetic distance, then electromorphs of different species should be on the same "mobility ladder". Therefore, distances between adjacent electromorphs should be approximately equal for the two sets of comparisons. It was found that distances between adjacent electromorphs for each locus were significantly smaller for the pooled comparisons than within polymorphic species. Thus, it was concluded that much of the variation detected among different species does not conform to the charge-state model, and therefore that distance between electromorphs per se would not be a good measure of genetic distance. However, the charge-state model does appear to adequately account for most of the variation existing as common polymorphisms within species, or between very closely related species. Possible reasons for this apparent difference in the nature of the variation seen within and among species are discussed. PMID:17246123

McCommas, Steven A.

1983-01-01

136

Extensive genetic divergence between populations of the common intertidal sea anemone Actinia equina from Britain, the Mediterranean and the Cape Verde Islands  

Microsoft Academic Search

Samples of apparently similar red morphs of the common beadlet sea anemone Actinia equina (L.) were collected from rocky shores on the Isle of Man (Irish Sea), on the French Mediterranean coast near Marseille and\\u000a on the Cape Verde Island of Sal (off West Africa). For additional comparison an orange morph and the green A. prasina were also collected from

F. A. Monteiro; A. M. Sol-Cava; J. P. Thorpe

1997-01-01

137

Fatty acid and phospholipid syntheses are prerequisites for the cell cycle of Symbiodinium and their endosymbiosis within sea anemones.  

PubMed

Lipids are a source of metabolic energy, as well as essential components of cellular membranes. Although they have been shown to be key players in the regulation of cell proliferation in various eukaryotes, including microalgae, their role in the cell cycle of cnidarian-dinoflagellate (genus Symbiodinium) endosymbioses remains to be elucidated. The present study examined the effects of a lipid synthesis inhibitor, cerulenin, on the cell cycle of both cultured Symbiodinium (clade B) and those engaged in an endosymbiotic association with the sea anemone Aiptasia pulchella. In the former, cerulenin exposure was found to inhibit free fatty acid (FFA) synthesis, as it does in other organisms. Additionally, while it also significantly inhibited the synthesis of phosphatidylethanolamine (PE), it did not affect the production of sterol ester (SE) or phosphatidylcholine (PC). Interestingly, cerulenin also significantly retarded cell division by arresting the cell cycles at the G0/G1 phase. Cerulenin-treated Symbiodinium were found to be taken up by anemone hosts at a significantly depressed quantity in comparison with control Symbiodinium. Furthermore, the uptake of cerulenin-treated Symbiodinium in host tentacles occurred much more slowly than in untreated controls. These results indicate that FFA and PE may play critical roles in the recognition, proliferation, and ultimately the success of endosymbiosis with anemones. PMID:24009685

Wang, Li-Hsueh; Lee, Hsieh-He; Fang, Lee-Shing; Mayfield, Anderson B; Chen, Chii-Shiarng

2013-01-01

138

Fatty Acid and Phospholipid Syntheses Are Prerequisites for the Cell Cycle of Symbiodinium and Their Endosymbiosis within Sea Anemones  

PubMed Central

Lipids are a source of metabolic energy, as well as essential components of cellular membranes. Although they have been shown to be key players in the regulation of cell proliferation in various eukaryotes, including microalgae, their role in the cell cycle of cnidarian-dinoflagellate (genus Symbiodinium) endosymbioses remains to be elucidated. The present study examined the effects of a lipid synthesis inhibitor, cerulenin, on the cell cycle of both cultured Symbiodinium (clade B) and those engaged in an endosymbiotic association with the sea anemone Aiptasia pulchella. In the former, cerulenin exposure was found to inhibit free fatty acid (FFA) synthesis, as it does in other organisms. Additionally, while it also significantly inhibited the synthesis of phosphatidylethanolamine (PE), it did not affect the production of sterol ester (SE) or phosphatidylcholine (PC). Interestingly, cerulenin also significantly retarded cell division by arresting the cell cycles at the G0/G1 phase. Cerulenin-treated Symbiodinium were found to be taken up by anemone hosts at a significantly depressed quantity in comparison with control Symbiodinium. Furthermore, the uptake of cerulenin-treated Symbiodinium in host tentacles occurred much more slowly than in untreated controls. These results indicate that FFA and PE may play critical roles in the recognition, proliferation, and ultimately the success of endosymbiosis with anemones. PMID:24009685

Wang, Li-Hsueh; Lee, Hsieh-He; Fang, Lee-Shing; Mayfield, Anderson B.; Chen, Chii-Shiarng

2013-01-01

139

Changes of cellular superficial configuration of symbiotic algae during cultivation from two anemones found in the South China Sea  

NASA Astrophysics Data System (ADS)

Symbiotic algae from two anemones, Radianthus macrodactylus and Stichodactyla mertensii, found in the South China Sea, were cultivated in ASP-8A medium in this study. Changes of superficial configuration of symbiotic algae during the cultivation were studied by means of a microscope and a scanning electron microscope (SEM). A number of small cavities appeared on the surfaces of symbiotic algae after they were cultivated for 10 h. The cavities enlarged and the cell contents were lost with extended cultivation. Our data suggested that the presence of cavities on symbiotic algae surfaces may be one of the main reasons for failure to culture symbiotic algae in an artificial medium.

Zhu, Baohua; Pan, Kehou; Wang, Guangce

2008-02-01

140

Effects of sea-anemone toxin (ATX-II) on the frequency of miniature endplate potentials at rat neuromuscular junctions.  

PubMed Central

Soleus and extensor digitorum longus muscles were isolated from rats. The muscles were exposed to ATX-II, a toxin isolated from extracts of the sea-anemone Anemonia sulcata . The toxin caused a dose-dependent increase in the frequency of miniature endplate potentials in both types of muscle. The increase in frequency could be reversed by the application of tetrodotoxin (TTX), and could be prevented by prior exposure of the muscles to TTX. It is concluded that ATX-II causes a sodium-dependent depolarization of the nerve-terminal membrane. PMID:6144341

Harris, J. B.; Tesseraux, I.

1984-01-01

141

The anticancer effects of actinoporin RTX-A from the sea anemone Heteractis crispa (=Radianthus macrodactylus)  

PubMed Central

Four isoforms of actinoporins were isolated in 2002-2004 from the tropical sea anemone Heteractis crispa (=Radianthus macrodactylus). Their potent hemolytic activities and effects on Ehrlich ascites carcinoma bearing mice were also studied. In this study, the individual actinoporin (RTX-A) demonstrated potential cancer-preventive activity at extremely low and non-cytotoxic concentrations. The substance suppressed the malignant transformation of mouse JB6 P+ Cl41 cells stimulated by epidermal growth factor (EGF) in soft agar with the inhibition of number of the colonies C50 (INCC50) = 0.034 nM. Actinoporin RTX-A also was shown to inhibit the phenotype expression of HeLa human cancer cells with an INCC50 = 0.03 nM. The cytotoxic effect of RTX-A against JB6 P+ Cl41 cells and HeLa, THP-1, MDA-MB-231, and SNU-C4 human tumor cell lines was high (IC50 = 0.57, 2.26, 1.11, 30.0 and 4.66 nM), but significantly less than their capacity to suppress tumor cell colony formation or phenotype expression. RTX-A also induced apoptosis and inhibited basal AP-1, NF-?B, and p53-dependent transcriptional activity in JB6 Cl41 cells. These results confirmed that actinoporin RTX-A from H. crispa, at least partially, might exhibit cancer-preventive and anticancer cytotoxic properties through the induction of p53-independent apoptosis and inhibition of the oncogenic AP-1 and NF-?B nuclear factors activity. PMID:19944712

Fedorov, Sergey; Dyshlovoy, Sergey; Monastyrnaya, Margarita; Shubina, Larisa; Leychenko, Elena; Kozlovskaya, Emma; Jin, Jun-O; Kwak, Jong-Young; Bode, Ann M.; Dong, Zigang; Stonik, Valentin

2010-01-01

142

Sea Anemone Peptide with Uncommon ?-Hairpin Structure Inhibits Acid-sensing Ion Channel 3 (ASIC3) and Reveals Analgesic Activity*  

PubMed Central

Three novel peptides were isolated from the venom of the sea anemone Urticina grebelnyi. All of them are 29 amino acid peptides cross-linked by two disulfide bridges, with a primary structure similar to other sea anemone peptides belonging to structural group 9a. The structure of the gene encoding the shared precursor protein of the identified peptides was determined. One peptide, ?-AnmTX Ugr 9a-1 (short name Ugr 9-1), produced a reversible inhibition effect on both the transient and the sustained current of human ASIC3 channels expressed in Xenopus laevis oocytes. It completely blocked the transient component (IC50 10 0.6 ?m) and partially (48 2%) inhibited the amplitude of the sustained component (IC50 1.44 0.19 ?m). Using in vivo tests in mice, Ugr 9-1 significantly reversed inflammatory and acid-induced pain. The other two novel peptides, AnmTX Ugr 9a-2 (Ugr 9-2) and AnmTX Ugr 9a-3 (Ugr 9-3), did not inhibit the ASIC3 current. NMR spectroscopy revealed that Ugr 9-1 has an uncommon spatial structure, stabilized by two S-S bridges, with three classical ?-turns and twisted ?-hairpin without interstrand disulfide bonds. This is a novel peptide spatial structure that we propose to name boundless ?-hairpin. PMID:23801332

Osmakov, Dmitry I.; Kozlov, Sergey A.; Andreev, Yaroslav A.; Koshelev, Sergey G.; Sanamyan, Nadezhda P.; Sanamyan, Karen E.; Dyachenko, Igor A.; Bondarenko, Dmitry A.; Murashev, Arkadii N.; Mineev, Konstantin S.; Arseniev, Alexander S.; Grishin, Eugene V.

2013-01-01

143

Mycosporine-like Amino Acid Content in Four Species of Sea Anemones in the Genus Anthopleura Reflects Phylogenetic but Not Environmental or Symbiotic Relationships  

Microsoft Academic Search

We examine the occurrence of UV-absorbing, mycosporine-like amino acids (MAAs) in four sympatric species of sea anemones in the genus Anthopleura, all collected from intertidal habitats on the Pacific Coast of temperate North America. We compare patterns of MAAs in A. elegantissima of several types: specimens having predominately zooxanthellae (dinoflagellates comprising at least two species) or zoochlorellae as symbionts; those

J. MALCOLM SHICK; WALTER C. DUNLAP; JOHN S. PEARSE; VICKI B. PEARSE

144

Dynamics of external brooding in the sea anemone Epictis Epiactis prolifera  

Microsoft Academic Search

The sexually produced young of the externally brooding actinian Epiactis prolifera Verrill, 1869 are attached to the parent's column just above the base. A transitory brood groove may be formed around the limbus when the parent contracts. In the population studied on the coast of Sonoma County, California, USA, from 27 to 49% of the adult anemones were brooding at

D. F. Dunn; Bodega Bay

1976-01-01

145

Cloning and Aggression among Sea Anemones (Coelenterata: Actiniaria) of the Rocky Shore  

Microsoft Academic Search

Among the common rocky shore anemones of Pacific North America, New Zealand, and Tropical Australia, clonal growth is significantly correlated with other features of the biology including aggressiveness, habitat, and body size. Individual size is more variable among aclonal species and among species living on the lower shore; and aclonal individuals are larger on aver age than clonal individuals. Aclonal

LISBETH FRANCIS

1988-01-01

146

Reproduction of the colonial hydroid Obelia geniculata (L., 1758) (Cnidaria, Hydrozoa) in the White Sea  

Microsoft Academic Search

Populations of the colonial hydroid Obelia geniculata in the White Sea reproduce asexually by frustule formation. Young medusae appear in the plankton during July and August.\\u000a The number of medusae rarely exceeds 36 per m3, and the average number varies every year from 0.4 to 10 per m3. The size of medusae is smaller than reported from other regions. The

Sergei A. Slobodov; Nickolai N. Marfenin

147

The evolution of microRNA pathway protein components in Cnidaria.  

PubMed

In the last decade, it became evident that posttranscriptional regulation of gene expression by microRNAs is a central biological process in both plants and animals. Yet, our knowledge about microRNA biogenesis and utilization in animals stems mostly from the study of Bilateria. In this study, we identified genes encoding the protein components of different parts of the microRNA pathway in Cnidaria, the likely sister phylum of Bilateria. These genes originated from three cnidarian lineages (sea anemones, stony corals, and hydras) that are separated by at least 500 My from one another. We studied the expression and phylogeny of the cnidarian homologs of Drosha and Pasha (DGCR8) that compose the microprocessor, the RNAse III enzyme Dicer and its partners, the HEN1 methyltransferase, the Argonaute protein effectors, as well as members of the GW182 protein family. We further reveal that whereas the bilaterian dicer partners Loquacious/TRBP and PACT are absent from Cnidaria, this phylum contains homologs of the double-stranded RNA-binding protein HYL1, the Dicer partner found in plants. We also identified HYL1 homologs in a sponge and a ctenophore. This finding raises questions regarding the independent evolution of the microRNA pathway in plants and animals, and together with the other results shed new light on the evolution of an important regulatory pathway. PMID:24030553

Moran, Yehu; Praher, Daniela; Fredman, David; Technau, Ulrich

2013-12-01

148

The Evolution of MicroRNA Pathway Protein Components in Cnidaria  

PubMed Central

In the last decade, it became evident that posttranscriptional regulation of gene expression by microRNAs is a central biological process in both plants and animals. Yet, our knowledge about microRNA biogenesis and utilization in animals stems mostly from the study of Bilateria. In this study, we identified genes encoding the protein components of different parts of the microRNA pathway in Cnidaria, the likely sister phylum of Bilateria. These genes originated from three cnidarian lineages (sea anemones, stony corals, and hydras) that are separated by at least 500 My from one another. We studied the expression and phylogeny of the cnidarian homologs of Drosha and Pasha (DGCR8) that compose the microprocessor, the RNAse III enzyme Dicer and its partners, the HEN1 methyltransferase, the Argonaute protein effectors, as well as members of the GW182 protein family. We further reveal that whereas the bilaterian dicer partners Loquacious/TRBP and PACT are absent from Cnidaria, this phylum contains homologs of the double-stranded RNA-binding protein HYL1, the Dicer partner found in plants. We also identified HYL1 homologs in a sponge and a ctenophore. This finding raises questions regarding the independent evolution of the microRNA pathway in plants and animals, and together with the other results shed new light on the evolution of an important regulatory pathway. PMID:24030553

Moran, Yehu; Praher, Daniela; Fredman, David; Technau, Ulrich

2013-01-01

149

Metal accumulation and sublethal effects in the sea anemone, Aiptasia pallida, after waterborne exposure to metal mixtures.  

PubMed

The marine environment is subjected to contamination by a complex mixture of metals from various anthropogenic sources. Measuring the biological responses of organisms to a complex mixture of metals allows for examination of metal-specific responses in an environmentally realistic exposure scenario. To address this issue, the sea anemone, Aiptasia pallida was exposed to a control and a metal mixture (copper, zinc, nickel, and cadmium) at three exposure levels (10, 50, and 100 ?g/L) for 7 days. Anemones were then transferred to metal-free seawater for an additional 7 days after the metal exposure to assess metal depuration and recovery. Metal accumulation, activity of the enzymes catalase, glutathione reductase, and carbonic anhydrase, as well as, cell density of the symbiotic zooxanthellae were measured over 14 days. Metal accumulation in A. pallida occurred in a concentration dependent manner over the 7-day exposure period. Altered enzyme activity and tentacle retraction of the host, as well as decreased zooxanthellae cell density were observed responses over the 7 days, after exposure to a metal concentration as low as 10 ?g/L. Metal depuration and physiological recovery were dependent on both the metal and the exposure concentration. Understanding how A. pallida and their symbionts are affected by metal exposures in the laboratory may allow better understanding about the responses of symbiotic cnidarians in metal polluted aquatic environments. PMID:23845877

Brock, J R; Bielmyer, G K

2013-09-01

150

Digital Marine Bioprospecting: Mining New Neurotoxin Drug Candidates from the Transcriptomes of Cold-Water Sea Anemones  

PubMed Central

Marine bioprospecting is the search for new marine bioactive compounds and large-scale screening in extracts represents the traditional approach. Here, we report an alternative complementary protocol, called digital marine bioprospecting, based on deep sequencing of transcriptomes. We sequenced the transcriptomes from the adult polyp stage of two cold-water sea anemones, Bolocera tuediae and Hormathia digitata. We generated approximately 1.1 million quality-filtered sequencing reads by 454 pyrosequencing, which were assembled into approximately 120,000 contigs and 220,000 single reads. Based on annotation and gene ontology analysis we profiled the expressed mRNA transcripts according to known biological processes. As a proof-of-concept we identified polypeptide toxins with a potential blocking activity on sodium and potassium voltage-gated channels from digital transcriptome libraries. PMID:23170083

Urbarova, Ilona; Karlsen, Bard Ove; Okkenhaug, Siri; Seternes, Ole Morten; Johansen, Steinar D.; Emblem, Ase

2012-01-01

151

Digital marine bioprospecting: mining new neurotoxin drug candidates from the transcriptomes of cold-water sea anemones.  

PubMed

Marine bioprospecting is the search for new marine bioactive compounds and large-scale screening in extracts represents the traditional approach. Here, we report an alternative complementary protocol, called digital marine bioprospecting, based on deep sequencing of transcriptomes. We sequenced the transcriptomes from the adult polyp stage of two cold-water sea anemones, Bolocera tuediae and Hormathia digitata. We generated approximately 1.1 million quality-filtered sequencing reads by 454 pyrosequencing, which were assembled into approximately 120,000 contigs and 220,000 single reads. Based on annotation and gene ontology analysis we profiled the expressed mRNA transcripts according to known biological processes. As a proof-of-concept we identified polypeptide toxins with a potential blocking activity on sodium and potassium voltage-gated channels from digital transcriptome libraries. PMID:23170083

Urbarova, Ilona; Karlsen, Brd Ove; Okkenhaug, Siri; Seternes, Ole Morten; Johansen, Steinar D; Emblem, Ase

2012-10-01

152

The feeding habits of three Mediterranean sea anemone species, Anemonia viridis (Forskl), Actinia equina (Linnaeus) and Cereus pedunculatus (Pennant)  

NASA Astrophysics Data System (ADS)

The feeding habits of the Mediterranean sea anemones Cereus pedunculatus, Actinia equina and Anemonia viridis were examined mainly by analysing their coelenteron contents. The three species are opportunistic omnivorous suspension feeders. Main source of food for A. viridis and C. pedunculatus are crustaceans (mainly amphipods and decapods, respectively), while for the midlittoral species A. equina, it is organic detritus. Using the same method, the temporal and spatial changes in the diet of A. viridis were examined. During the whole year, crustaceans seem to be the main source of food for A. viridis. The diet composition of this species, however, differs remarkably in space, possibly reflecting the different composition of the macrobenthic organismic assemblages in different areas. The data collected are compared with the limited bibliographical information.

Chintiroglou, Ch.; Koukouras, A.

1992-03-01

153

Invasion and Persistence of a Selfish Gene in the Cnidaria  

PubMed Central

Background Homing endonuclease genes (HEGs) are superfluous, but are capable of invading populations that mix alleles by biasing their inheritance patterns through gene conversion. One model suggests that their long-term persistence is achieved through recurrent invasion. This circumvents evolutionary degeneration, but requires reasonable rates of transfer between species to maintain purifying selection. Although HEGs are found in a variety of microbes, we found the previous discovery of this type of selfish genetic element in the mitochondria of a sea anemone surprising. Methods/Principal Findings We surveyed 29 species of Cnidaria for the presence of the COXI HEG. Statistical analyses provided evidence for HEG invasion. We also found that 96 individuals of Metridium senile, from five different locations in the UK, had identical HEG sequences. This lack of sequence divergence illustrates the stable nature of Anthozoan mitochondria. Our data suggests this HEG conforms to the recurrent invasion model of evolution. Conclusions Ordinarily such low rates of HEG transfer would likely be insufficient to enable major invasion. However, the slow rate of Anthozoan mitochondrial change lengthens greatly the time to HEG degeneration: this significantly extends the periodicity of the HEG life-cycle. We suggest that a combination of very low substitution rates and rare transfers facilitated metazoan HEG invasion. PMID:17183657

Goddard, Matthew R.; Leigh, Jessica; Roger, Andrew J; Pemberton, Andrew J

2006-01-01

154

BcsTx3 is a founder of a novel sea anemone toxin family of potassium channel blocker.  

PubMed

Sea anemone venoms have become a rich source of peptide toxins which are invaluable tools for studying the structure and functions of ion channels. In this work, BcsTx3, a toxin found in the venom of a Bunodosoma caissarum (population captured at the Saint Peter and Saint Paul Archipelago, Brazil) was purified and biochemically and pharmacologically characterized. The pharmacological effects were studied on 12 different subtypes of voltage-gated potassium channels (K(V)1.1-K(V)1.6; K(V)2.1; K(V)3.1; K(V)4.2; K(V)4.3; hERG and Shaker IR) and three cloned voltage-gated sodium channel isoforms (Na(V)1.2, Na(V)1.4 and BgNa(V)1.1) expressed in Xenopus laevis oocytes. BcsTx3 shows a high affinity for Drosophila Shaker IR channels over rKv1.2, hKv1.3 and rKv1.6, and is not active on NaV channels. Biochemical characterization reveals that BcsTx3 is a 50 amino acid peptide crosslinked by four disulfide bridges, and sequence comparison allowed BcsTx3 to be classified as a novel type of sea anemone toxin acting on K(V) channels. Moreover, putative toxins homologous to BcsTx3 from two additional actiniarian species suggest an ancient origin of this newly discovered toxin family. PMID:23895459

Orts, Diego J B; Moran, Yehu; Cologna, Camila T; Peigneur, Steve; Madio, Bruno; Praher, Daniela; Quinton, Loic; De Pauw, Edwin; Bicudo, Jos E P W; Tytgat, Jan; de Freitas, Jos C

2013-10-01

155

Isolation of L-3-phenyllactyl-Leu-Arg-Asn-NH sub 2 (Antho-RNamide), a sea anemone neuropeptide containing an unusual amino-terminal blocking group  

SciTech Connect

Using a radioimmunoassay for the carboxyl-terminal sequence Arg-Asn-NH{sub 2}, the authors have purified a peptide from acetic acid extracts of the sea anemone Anthopleura elegantissima. By classical amino acid analyses, mass spectrometry, and {sup 1}H NMR spectroscopy, the structure of this peptide was determined as 3-phenyllactyl-Leu-Arg-Asn-NH{sub 2}. By using reversed-phase HPLC and a chiral mobile phase, it was shown that the 3-phenyllactyl group had the L configuration. Immunocytochemical staining with antiserum against Arg-Asn-NH{sub 2} showed that L-3-phenyllactyl-Leu-Arg-Asn-NH{sub 2} (Antho-RNamide) was localized in neutrons of sea anemones. The L-3-phenyllactyl group has not been found earlier in neuropeptides of vertebrates or higher invertebrates. They propose that this residue renders Antho-RNamide resistant to nonspecific aminopeptidases, thereby increasing the stability of the peptide after neuronal release.

Grimmelikhuijzen, C.J.P.; Jacob, E.; Graff, D.; Reinscheid, R.K.; Nothacker, H.P. (Univ. of Hamburg (West Germany)); Rinehart, K.L.; Staley, A.L. (Univ. of Illinois, Urbana (USA))

1990-07-01

156

Mechanism of action of equinatoxin II, a cytolysin from the sea anemone Actinia equina L. belonging to the family of actinoporins  

Microsoft Academic Search

Actinia equina equinatoxin II (EqT-II) is a representative of a family of pore-forming, basic, polypeptide toxins from sea anemones, now called actinoporins. This family comprises at least 27 members, which are all hemolytic at rather low concentrations. Red blood cell (RBC) hemolysis by EqT-II is the result of a colloid-osmotic shock caused by the opening of toxin- induced pores. Using

Peter Ma?ek; Giovanna Belmonte; Cecilia Pederzolli; Gianfranco Menestrina

1994-01-01

157

Cytotoxicity of equinatoxin II from the sea anemone Actinia equina involves ion channel formation and an increase in intracellular calcium activity  

Microsoft Academic Search

Summary Equinatoxin Il is a 20-kDa basic protein isolated from the sea anemoneActinia equina. The aim of our work was to investigate the primary molecular basis for the cytotoxic effects of equinatoxin II in two model systems: single bovine lactotrophs and planar lipid bilayers. Previous work has shown that equinatoxin II produces rapid changes in cell morphology, which are dependent

R. Zorec; M. TesterS; P. Maeekw; W. T. Mason

1990-01-01

158

The Smallest Oocytes among Broadcast-Spawning Actiniarians and a Unique Lunar Reproductive Cycle in a Unisexual Population of the Sea Anemone, Aiptasia pulchella (Anthozoa: Actiniaria)  

Microsoft Academic Search

Chienhsun Chen, Keryea Soong, and Chaolun Allen Chen (2008) The smallest oocytes among broadcast- spawning actiniarians and a unique lunar reproductive cycle in a unisexual population of the sea anemone, Aiptasia pulchella (Anthozoa: Actiniaria). Zoological Studies 47(1): 37-45. Aiptasia pulchella, an aquarium species and invasive pest, is used as a common model actinarian for laboratory-based experiments to study environmental regulation

Chienhsun Chen; Keryea Soong; Chaolun Allen Chen

2008-01-01

159

Two Alleles of NF-?B in the Sea Anemone Nematostella vectensis Are Widely Dispersed in Nature and Encode Proteins with Distinct Activities  

Microsoft Academic Search

BackgroundNF-?B is an evolutionarily conserved transcription factor that controls the expression of genes involved in many key organismal processes, including innate immunity, development, and stress responses. NF-?B proteins contain a highly conserved DNA-binding\\/dimerization domain called the Rel homology domain.Methods\\/Principal FindingsWe characterized two NF-?B alleles in the sea anemone Nematostella vectensis that differ at nineteen single-nucleotide polymorphisms (SNPs). Ten of these

James C. Sullivan; Francis S. Wolenski; Adam M. Reitzel; Courtney E. French; Nikki Traylor-Knowles; Thomas D. Gilmore; John R. Finnerty

2009-01-01

160

The p53 Tumor Suppressor-Like Protein nvp63 Mediates Selective Germ Cell Death in the Sea Anemone Nematostella vectensis  

Microsoft Academic Search

Here we report the identification and molecular function of the p53 tumor suppressor-like protein nvp63 in a non-bilaterian animal, the starlet sea anemone Nematostella vectensis. So far, p53-like proteins had been found in bilaterians only. The evolutionary origin of p53-like proteins is highly disputed and primordial p53-like proteins are variably thought to protect somatic cells from genotoxic stress. Here we

Sandra Pankow; Casimir Bamberger; Suzannah Rutherford

2007-01-01

161

Sequence-specific H NMR assignments and secondary structure in the sea anemone polypeptide Stichodactyla helianthus neurotoxin I  

SciTech Connect

Sequence-specific assignments are reported for the 500-MHz H nuclear magnetic resonance (NMR) spectrum of the 48-residue polypeptide neurotoxin I from the sea anemone Stichodactyla helianthus (Sh I). Spin systems were first identified by using two-dimensional relayed or multiple quantum filtered correlation spectroscopy, double quantum spectroscopy, and spin lock experiments. Specific resonance assignments were then obtained from nuclear Overhauser enhancement (NOE) connectivities between protons from residues adjacent in the amino acid sequence. Of a total of 265 potentially observable resonances, 248 (i.e., 94%) were assigned, arising from 39 completely and 9 partially assigned amino acid spin systems. The secondary structure of Sh I was defined on the basis of the pattern of sequential NOE connectivities. NOEs between protons on separate strands of the polypeptide backbone, and backbone amide exchange rates. Sh I contains a four-stranded antiparallel {beta}-sheet encompassing residues 1-5, 16-24, 30-33, and 40-46, with a {beta}-bulge at residues 17 and 18 and a reverse turn, probably a type II {beta}-turn, involving residues 27-30. No evidence of {alpha}-helical structure was found.

Fogh, R.H.; Mabbutt, B.C.; Kem, W.R.; Norton, R.S. (Univ. of New South Wales, Kensington (Australia))

1989-02-21

162

The transcriptomic response to thermal stress is immediate, transient and potentiated by ultraviolet radiation in the sea anemone Anemonia viridis.  

PubMed

Among the environmental threats to coral reef health, temperature and ultraviolet increases have been proposed as major agents, although the relative contribution of each in the cnidarian/zooxanthellae symbiosis breakdown has been poorly addressed. We have investigated the transcriptomic response to thermal stress, with and without ultraviolet radiation (UVR), in the symbiotic sea anemone Anemonia viridis. Using the Oligo2K A. viridis microarray, dedicated to genes potentially involved in the symbiosis interaction, we monitored the gene expression profiles after 1, 2 and 5?days of stresses that further lead to massive losses of zooxanthellae. Each stress showed a specific gene expression profile with very little overlap. We showed that the major response to thermal stress is immediate (24?h) but returns to the baseline gene expression profile after 2?days. UVR alone has little effect but potentiates thermal stress, as a second response at 5?days was observed when the two stresses were coupled. Several pathways were highlighted, such as mesoglea loosening, cell death and calcium homeostasis and described in more details. Finally, we showed that the dermatopontin gene family, potentially involved in collagen fibrillogenesis, issued from actinarian-specific duplication events, with one member preferentially expressed in the gastroderm and specifically responding to stress. Anemonia viridis EST sequences have been deposited into GenBank dbEST ([GenBank:FK719875FK759813]. PMID:22288383

Moya, A; Ganot, P; Furla, P; Sabourault, C

2012-03-01

163

Internal brooding favours pre-metamorphic chimerism in a non-colonial cnidarian, the sea anemone Urticina felina.  

PubMed

The concept of intraorganismal genetic heterogeneity resulting from allogeneic fusion (i.e. chimerism) has almost exclusively been explored in modular organisms that have the capacity to reproduce asexually, such as colonial ascidians and corals. Apart from medical conditions in mammals, the natural development of chimeras across ontogenetic stages has not been investigated in any unitary organism incapable of asexual propagation. Furthermore, chimerism was mainly studied among gregarious settlers to show that clustering of genetically similar individuals upon settlement promotes the occurrence of multi-chimeras exhibiting greater fitness. The possible occurrence of chimeric embryos and larvae prior to settlement has not received any attention. Here we document for the first time the presence of natural chimeras in brooded embryos and larvae of a unitary cnidarian, the sea anemone Urticina felina. Rates of visible bi- and multi-chimerism of up to 3.13 per cent were measured in the broods of 16 females. Apart from these sectorial chimeras, monitored fusion events also yielded homogeneous chimeric entities (mega-larvae) suggesting that the actual rates of natural chimerism in U. felina are greater than predicted by visual assessment. In support of this assumption, the broods of certain individuals comprised a dominant proportion (to 90%) of inexplicably large embryos and larvae (relative to oocyte size). Findings of fusion and chimerism in a unitary organism add a novel dimension to the framework within which the mechanisms and evolutionary significance of genetic heterogeneity in animal taxa can be explored. PMID:21508035

Mercier, Annie; Sun, Zhao; Hamel, Jean-Franois

2011-12-01

164

Internal brooding favours pre-metamorphic chimerism in a non-colonial cnidarian, the sea anemone Urticina felina  

PubMed Central

The concept of intraorganismal genetic heterogeneity resulting from allogeneic fusion (i.e. chimerism) has almost exclusively been explored in modular organisms that have the capacity to reproduce asexually, such as colonial ascidians and corals. Apart from medical conditions in mammals, the natural development of chimeras across ontogenetic stages has not been investigated in any unitary organism incapable of asexual propagation. Furthermore, chimerism was mainly studied among gregarious settlers to show that clustering of genetically similar individuals upon settlement promotes the occurrence of multi-chimeras exhibiting greater fitness. The possible occurrence of chimeric embryos and larvae prior to settlement has not received any attention. Here we document for the first time the presence of natural chimeras in brooded embryos and larvae of a unitary cnidarian, the sea anemone Urticina felina. Rates of visible bi- and multi-chimerism of up to 3.13 per cent were measured in the broods of 16 females. Apart from these sectorial chimeras, monitored fusion events also yielded homogeneous chimeric entities (mega-larvae) suggesting that the actual rates of natural chimerism in U. felina are greater than predicted by visual assessment. In support of this assumption, the broods of certain individuals comprised a dominant proportion (to 90%) of inexplicably large embryos and larvae (relative to oocyte size). Findings of fusion and chimerism in a unitary organism add a novel dimension to the framework within which the mechanisms and evolutionary significance of genetic heterogeneity in animal taxa can be explored. PMID:21508035

Mercier, Annie; Sun, Zhao; Hamel, Jean-Francois

2011-01-01

165

In silico assessment of interaction of sea anemone toxin APETx2 and acid sensing ion channel 3.  

PubMed

Acid sensing ion channels (ASICs) are proton-gated cation channels that are expressed throughout the nervous system and have been implicated in mediating sensory perception of noxious stimuli. Amongst the six ASIC isoforms, ASIC1a, 1b, 2a and 3 form proton-gated homomers, which differ in their activation and inactivation kinetics, expression profiles and pharmacological modulation; protons do not gate ASIC2b and ASIC4. As with many other ion channels, structure-function studies of ASICs have been greatly aided by the discovery of some toxins that act in isoform-specific ways. ASIC3 is predominantly expressed by sensory neurons of the peripheral nervous system where it acts to detect acid as a noxious stimulus and thus plays an important role in nociception. ASIC3 is the only ASIC subunit that is inhibited by the sea anemone (Anthopleura elegantissima)-derived toxin APETx2. However, the molecular mechanism by which APETx2 interacts with ASIC3 remains largely unknown. In this study, we made a homology model of ASIC3 and used extensive protein-protein docking to predict for the first time, the probable sites of APETx2 interaction on ASIC3. Additionally, using computational alanine scanning, we also suggest the 'hot-spots' that are likely to be critical for ASIC3-APETx2 interaction. PMID:24942880

Rahman, Taufiq; Smith, Ewan St John

2014-07-18

166

Optimization of preservation and processing of sea anemones for microbial community analysis using molecular tools.  

PubMed

For several years, knowledge on the microbiome associated with marine invertebrates was impaired by the challenges associated with the characterization of bacterial communities. With the advent of culture independent molecular tools it is possible to gain new insights on the diversity and richness of microorganisms associated with marine invertebrates. In the present study, we evaluated if different preservation and processing methodologies (prior to DNA extraction) can affect the bacterial diversity retrieved from snakelocks anemone Anemonia viridis. Denaturing gradient gel electrophoresis (DGGE) community fingerprints were used as proxy to determine the bacterial diversity retrieved (H'). Statistical analyses indicated that preservation significantly affects H'. The best approach to preserve and process A. viridis biomass for bacterial community fingerprint analysis was flash freezing in liquid nitrogen (preservation) followed by the use of a mechanical homogenizer (process), as it consistently yielded higher H'. Alternatively, biomass samples can be processed fresh followed by cell lyses using a mechanical homogenizer or mortar &pestle. The suitability of employing these two alternative procedures was further reinforced by the quantification of the 16S rRNA gene; no significant differences were recorded when comparing these two approaches and the use of liquid nitrogen followed by processing with a mechanical homogenizer. PMID:25384534

Rocha, Joana; Coelho, Francisco J R C; Peixe, Lusa; Gomes, Newton C M; Calado, Ricardo

2014-01-01

167

Intraspecific competition, stealing and placement of the symbiotic sea anemone Calliactis tricolor by the hermit crab Dardanus pedunculatus  

E-print Network

engage in a mutualistic relationship in the et al. 1982). Mutualistic relationships have been associatedrelationship. Although the association of hermit crabs and anemones has usually been found to be mutualistic (

Giraud, Camille

2011-01-01

168

The influence of UV radiation on number and ultrastructure of the endosymbiotic dinoflagellates in the sea anemone Cereus pedunculatus (Anthozoa: Actiniaria)  

NASA Astrophysics Data System (ADS)

The sea anemone Cereus pedunculatus was artificially UV-irradiated to test the effect of UV-light on the number of endosymbiotic dinoflagellates in its gastrodermis and on their ultrastructure. Anemones were kept in the laboratory in a light: dark cycle (LD 12?12; 13 W m-2) at 18 C and briefly (2, 5 and 9 d) exposed to UV radiation at quasisolar intensities, 0.5 or 1 W m-2. Their tentacles were then examined in the electron microscope for qualitative and quantitative changes in the zooxanthellae. There was an intensity-dependent decrease in the number of symbionts, which in some cases were lost altogether (bleaching). Irradiated anemones contained a larger proportion of symbionts with ultrastructural abnormalities, namely diminished starch, some mitochondria with altered matrix and, in particular, characteristic changes in the chloroplasts; instead of being densely stacked, the thylakoids were spread apart and swollen at the ends of their membranes to form vesicle-like structures. Relatively large vesicles also appeared in the cytoplasm. The resulting enlargement of the whole dinoflagellate cell was documented morphometrically. Another intensity-dependent effect was a significant decrease in mitosis rate, established by counting dividing symbiont cells in TEM micrographs. *** DIRECT SUPPORT *** A03B6037 00006

Hannack, K.; Kestler, P.; Sicken, O.; Westheide, W.

1998-02-01

169

BcIV, a new paralyzing peptide obtained from the venom of the sea anemone Bunodosoma caissarum. A comparison with the Na+ channel toxin BcIII.  

PubMed

Sea anemones produce a wide variety of biologically active compounds, such as the proteinaceous neurotoxins and cytolysins. Herein we report a new peptide, purified to homogeneity from the neurotoxic fraction of B. caissarum venom, by using gel filtration followed by rp-HPLC, naming it as BcIV. BcIV is a 41 amino acid peptide (molecular mass of 4669 amu) possessing 6 cysteines covalently linked by three disulfide bonds. This toxin has 45 and 48% of identity when compared to APETx1 and APETx2 from Anthopleura elegantissima, respectively, and 42% of identity with Am-II and BDS-I and-II obtained from Antheopsis maculata and Anemonia sulcata, respectively. This neurotoxin presents only a weak-paralyzing action (minimal Lethal Dose close to 2000 microg/kg) in swimming crabs Callinectes danae. This appears to be a different effect to that caused by the type 1 sea anemone toxin BcIII that is lethal to the same animals at lower doses (LD50=219 microg/kg). Circular dichroism spectra of BcIII and BcIV show a high content of beta-strand secondary structure in both peptides, very similar to type 1 sodium channel toxins from various sea anemones, and to APETx1 and APETx2 from A. elegantissima, a HERG channel modulator and an ASIC3 inhibitor, respectively. Interestingly, BcIII and BcIV have similar effects on the action potential of the crab leg nerves, suggesting the same target in this tissue. As BcIII was previously reported as a Na+ channel effector and BcIV is inactive over Na+ currents of mammalian GH3 cells, we propose a species-specific action for this new molecule. A molecular model of BcIV was constructed using the structure of the APETx1 as template and putative key residues are discussed. PMID:17015047

Oliveira, Joacir Stolarz; Zaharenko, Andr Junqueira; Ferreira, Wilson Alves; Konno, Katsuhiro; Shida, Cludio Saburo; Richardson, Michael; Lcio, Aline Duarte; Beiro, Paulo Srgio Lacerda; de Freitas, Jos Carlos

2006-10-01

170

Employing BAC-reporter constructs in the sea anemone Nematostella vectensis.  

PubMed

Changes in the expression and function of genes drive evolutionary change. Comparing how genes are regulated in different species is therefore becoming an important part of evo-devo studies. A key tool for investigating the regulation of genes is represented by bacterial artificial chromosomes (BAC)-reporter constructs. BACs are large insert libraries, often >100 kb, which thus capture the genomic sequences surrounding a gene of interest, including all, or nearly all, of the elements underpinning regulation. Recombinant BACs, containing a reporter gene in place of the endogenous coding sequence of genes, can be utilized to drive the expression of reporter genes under the regulatory control of the gene of interest while still embedded within its genomic context. Systematic deletions within the BAC-reporter construct can be used to identify the minimal reporter in an unbiased way, avoiding the risk of overlooking regulatory elements that may be many kilobases away from the transcription start-site. Nematostella vectensis (Edwardsiidae, Anthozoa, Cnidaria) has become an important model in regenerative biology, ecology, and especially in studies of evo-devo and gene-regulatory networks due to its interesting phylogenetic position and amenability to molecular techniques. The increasing interest in this rising model system also led to a demand for methods that can be used to study the regulation of genes in Nematostella. Here, we present our progress in employing BAC-reporter constructs to visualize gene-expression in Nematostella. Using a new Nematostella-specific recombination cassette, we made nine different BAC-reporter constructs. Although five BAC recombinants gave variable effects, three constructs, namely Nv-bra:eGFP::L10 BAC, Nv-dpp:eGFP::L10 BAC, and Nv-grm:eGFP::L10 BAC delivered promising results. We show that these three constructs express the reporter gene eGFP in 10.4-17.2% of all analyzed larvae, out of which 26.2-41.9% express GFP in a mosaic fashion within the expected domain. In addition to the expression within the known domains, we also observed cases of misexpression of eGFP and examples that could represent actual expression outside the described domain. Furthermore, we deep-sequenced and assembled five different BACs containing Nv-chordin, Nv-foxa, Nv-dpp, Nv-wnta, and Nv-wnt1, to improve assembly around these genes. The use of BAC-reporter constructs will foster cis-regulatory analyses in Nematostella and thus help to improve our understanding of the regulatory network in this cnidarian system. Ultimately, this will advance the comparison of gene-regulation across species and lead to a much better understanding of evolutionary changes and novelties. PMID:23956207

Fischer, Antje H L; Tulin, Sarah; Fredman, David; Smith, Joel

2013-11-01

171

Nuclear magnetic resonance study of the solution properties of the polypeptide neurotoxin I from the sea anemone Stichodactyla helianthus  

SciTech Connect

The solution properties of the polypeptide neurotoxin I from the sea anemone Stichodactyla helianthus (Sh I) have been investigated by high-resolution H nuclear magnetic resonance (NMR) spectroscopy at 300 MHz. The pH dependence of the spectra has been examined over the range 1.1-12.2 at 27{degree}C. Individual pK{sub a} values have been obtained for the {alpha}-ammonium group of Ala-1 (8.6) and the side chains of Glu-8 (3.7), Tyr-36 (10.9), and Tyr-37 (10.8). For the remaining seven carboxyl groups in the molecule, four pK{sub a} values can be clearly identified. The five Lys residues titrate in the range 10.5-11, but individual pK{sub a} values could not be obtained because of peak overlap. Conformational changes associated with the protonation of carboxylates occur below pH 4, while in the alkaline pH range major unfolding occurs above pH 10. The molecule also unfolds at elevated temperatures. Exchange of the backbone amide protons has been monitored at various values of pH and temperature in the ranges pH 4-5 and 12-27{degree}C. Comparison of these properties of Sh I in solution with those of the related polypeptides anthopleurin A and Anemonia sulcata toxins I and II indicates that Sh I is less stable thermally and that there are some significant differences in the ionic interactions that maintain the tertiary structure. The solvent accessibility of aromatic residues has been probed with photochemically induced dynamic nuclear polarization NMR at 360 MHz.

Norton, R.S.; Cossins, A.I.; Kem, W.R. (Univ. of New South Wales, Kensington (Australia))

1989-02-21

172

Spatial gene expression quantification: a tool for analysis of in situ hybridizations in sea anemone Nematostella vectensis  

PubMed Central

Background Spatial gene expression quantification is required for modeling gene regulation in developing organisms. The fruit fly Drosophila melanogaster is the model system most widely applied for spatial gene expression analysis due to its unique embryonic properties: the shape does not change significantly during its early cleavage cycles and most genes are differentially expressed along a straight axis. This system of development is quite exceptional in the animal kingdom. In the sea anemone Nematostella vectensis the embryo changes its shape during early development; there are cell divisions and cell movement, like in most other metazoans. Nematostella is an attractive case study for spatial gene expression since its transparent body wall makes it accessible to various imaging techniques. Findings Our new quantification method produces standardized gene expression profiles from raw or annotated Nematostella in situ hybridizations by measuring the expression intensity along its cell layer. The procedure is based on digital morphologies derived from high-resolution fluorescence pictures. Additionally, complete descriptions of nonsymmetric expression patterns have been constructed by transforming the gene expression images into a three-dimensional representation. Conclusions We created a standard format for gene expression data, which enables quantitative analysis of in situ hybridizations from embryos with various shapes in different developmental stages. The obtained expression profiles are suitable as input for optimization of gene regulatory network models, and for correlation analysis of genes from dissimilar Nematostella morphologies. This approach is potentially applicable to many other metazoan model organisms and may also be suitable for processing data from three-dimensional imaging techniques. PMID:23039089

2012-01-01

173

Mechanical and electrophysiological effects of sea anemone (Anemonia sulcata) toxins on rat innervated and denervated skeletal muscle.  

PubMed Central

1 Some effects of the sea-anemone toxin ATX-II on mammalian nerve-muscle preparations have been described. 2 When ATX-II (10(-8)-10(-6) M) was applied to rat hemidiaphragm preparations, both directly and indirectly generated twitch responses were potentiated and prolonged. At the same time the resting tension of the preparations increased. 3 The increase in resting tension caused by ATX-II in innervated muscles was not prevented by curarization, but was reversed by exposure to tetrodotoxin. The increase in denervated muscles was not completely reversed by tetrodotoxin. 4 At concentrations exceeding 1 x 10(-7) M, ATX-II caused a sodium-dependent depolarization of both normal and denervated muscles. The depolarization of the denervated muscles was only partially reversed by tetrodotoxin. 5 In the presence of ATX-II repetitive endplate potentials (e.p.ps) were evoked by single shocks to the motor nerves in many fibres, and in those in which a single e.p.p. was still observed, the quantum content (m) was increased. Miniature e.p.p. frequency was not increased by ATX-II, even when muscle fibres were depolarized by 30 mV. 6 The indirectly and directly elicited action potentials of normal and denervated muscle fibres were much prolonged by ATX-II. The action potentials remained sodium-dependent. The sodium-dependent tetrodotoxin-resistant action potential of the denervated muscle fibre was also prolonged by ATX-II. 7 It is concluded that ATX-II both activates, and delays inactivation of, sodium channels in mammalian skeletal muscle fibres, probably in interacting with the channel "gate'. PMID:6115695

Alsen, C.; Harris, J. B.; Tesseraux, I.

1981-01-01

174

Proton nuclear magnetic resonance study of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata: Sequential and stereospecific resonance assignment and secondary structure  

SciTech Connect

The sequential resonance assignment of the {sup 1}H NMR spectrum of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata is presented. This is carried out with two-dimensional NMR techniques to identify through-bond and through-space (< 5{angstrom}) connectivities. Added spectral complexity arises from the fact that the sample is an approximately 1:1 mixture of two BDS-I isoproteins, (Leu-18)-BDS-I and (Phe-18)-BDS-I. Complete assignments, however, are obtained, largely due to the increased resolution and sensitivity afforded at 600 MHz. In addition, the stereospecific assignment of a large number of {beta}-methylene protons is achieved from an analysis of the pattern of {sup 3}J{sub {alpha}{beta}} coupling constants and the relative magnitudes of intraresidue NOEs involving the NH, C{sup {alpha}}H, and C{sup {beta}}H protons. Regular secondary structure elements are deduced from a qualitative interpretation of the nuclear Overhauser enhancement, {sup 3}J{sub HN{alpha}} coupling constant, and amide NH exchange data. A triple-stranded antiparallel {beta}-sheet is found to be related to that found in partially homologous sea anemone polypeptide toxins.

Driscoll, P.C.; Clore, G.M.; Beress, L.; Gronenborn, A.M. (National Institutes of Health, Bethesda, MD (USA))

1989-03-07

175

A new species, *Adamsia obvolva* (Cnidaria: Anthozoa: Actiniaria), from the Gulf of Mexico, and a discussion of the taxonomy of carcinoecium-forming sea anemones  

E-print Network

A ocixeMfofluG.N 835 1791yluJ42 ;003HNMLF;764161SAC 595100MHNUK , MHNUK 695100,495100,395100 MNSU;182743HNMBS 0364001 avlovbo.A :ocixeMfofluG 1292 ' 03 " 1288,N ' 60.84 "W? 2292 ' 24 " 0288,N ' 20 "W 973 ? 034 9891.beF42 HNMBS;095100MHNUK 282743...

Daly, Marymegan; Ardelean, Adorian; Cha, Ha-Rim; Campbell, Andrew C.; Fautin, Daphne G.

2004-01-01

176

Multiple components in ink of the sea hare Aplysia californica are aversive to the sea anemone Anthopleura sola  

Microsoft Academic Search

Sea hares of the genus Aplysia rely on an array of behavioral and chemical defenses, including the release of ink and opaline, to protect themselves from predation. While many studies have demonstrated that ink and opaline are repellent to predators, very little is known about which components of these secretions are active against predators. Ink was previously shown to facilitate

Cynthia E. Kicklighter; Charles D. Derby

2006-01-01

177

Pachyseris inattesa sp. n. (Cnidaria, Anthozoa, Scleractinia): a new reef coral species from the Red Sea and its phylogenetic relationships.  

PubMed

A new scleractinian coral species, Pachyseris inattesa sp. n., is described from the Red Sea. Despite a superficial resemblance with some species in the agariciid genus Leptoseris with which it has been previously confused, P. inattesa sp. n. has micro-morphological characters typical of the genus Pachyseris. This genus, once part of the Agariciidae, is comprised of five extant species and is widely distributed throughout the tropical Indo-Pacific. It is currently incertae sedis as a result of recent molecular analysis and appears to be closely related to the Euphylliidae. A molecular phylogenetic reconstruction including P. inattesa sp. n., the genus type species P. rugosa, and P. speciosa, all present in the Red Sea, was performed using the mitochondrial intergenic spacer between COI and 16S-rRNA. The results confirm that P. inattesa sp. n. is a monophyletic lineage closely related to the other Pachyseris species examined. PMID:25152672

Terraneo, Tullia I; Berumen, Michael L; Arrigoni, Roberto; Waheed, Zarinah; Bouwmeester, Jessica; Caragnano, Annalisa; Stefani, Fabrizio; Benzoni, Francesca

2014-01-01

178

Pachyseris inattesa sp. n. (Cnidaria, Anthozoa, Scleractinia): a new reef coral species from the Red Sea and its phylogenetic relationships  

PubMed Central

Abstract A new scleractinian coral species, Pachyseris inattesa sp. n., is described from the Red Sea. Despite a superficial resemblance with some species in the agariciid genus Leptoseris with which it has been previously confused, P. inattesa sp. n. has micro-morphological characters typical of the genus Pachyseris. This genus, once part of the Agariciidae, is comprised of five extant species and is widely distributed throughout the tropical Indo-Pacific. It is currently incertae sedis as a result of recent molecular analysis and appears to be closely related to the Euphylliidae. A molecular phylogenetic reconstruction including P. inattesa sp. n., the genus type species P. rugosa, and P. speciosa, all present in the Red Sea, was performed using the mitochondrial intergenic spacer between COI and 16S-rRNA. The results confirm that P. inattesa sp. n. is a monophyletic lineage closely related to the other Pachyseris species examined. PMID:25152672

Terraneo, Tullia I.; Berumen, Michael L.; Arrigoni, Roberto; Waheed, Zarinah; Bouwmeester, Jessica; Caragnano, Annalisa; Stefani, Fabrizio; Benzoni, Francesca

2014-01-01

179

Finding of the Hydromedusa Hydractinia minima (Trinci, 1903) (Cnidaria: Hydrozoa: Hydractiniidae) in Peter the Great Bay, Sea of Japan  

Microsoft Academic Search

The first finding of the hydromedusa Hydractinia minima (Trinci, 1903) in plankton of Peter the Great Bay (Sea of Japan) is reported. The hydromedusae are 0.240.51 mm in bell diameter and 0.250.53 mm in height. The size characteristics of the nematocysts of this species (desmonemes and microbasic euryteles) are given. H. minima is present in the plankton of Peter the

S. F. Chaplygina; T. N. Dautova

2005-01-01

180

Evidence for involvement of TRPA1 in the detection of vibrations by hair bundle mechanoreceptors in sea anemones  

Microsoft Academic Search

A homolog of TRPA1 was identified in the genome of the anemone, Nematostella vectensis (nv-TRPA1a), and predicted to possess six ankyrin repeat domains at the N-terminus and an ion channel domain near the C-terminus.\\u000a Transmembrane segments of the ion channel domain are well conserved among several known TRPA1 polypeptides. Inhibitors of\\u000a TRPA1 including ruthenium red decrease vibration-dependent discharge of nematocysts

Janna L. Mahoney; Erin M. Graugnard; Patricia Mire; Glen M. Watson

2011-01-01

181

Behind anemone lines: factors affecting division of labour in the social cnidarian Anthopleura elegantissima  

E-print Network

Behind anemone lines: factors affecting division of labour in the social cnidarian Anthopleura of the sea anemone Anthopleura elegantissima expand and encounter other clones they can form distinctive anemone-free zones, several centimetres across. Contact between isolated pairs of nonclonemate polyps

Grosberg, Rick

182

Genomic survey of candidate stress-response genes in the estuarine anemone Nematostella vectensis.  

PubMed

Salt marshes are challenging habitats due to natural variability in key environmental parameters including temperature, salinity, ultraviolet light, oxygen, sulfides, and reactive oxygen species. Compounding this natural variation, salt marshes are often heavily impacted by anthropogenic insults including eutrophication, toxic contamination, and coastal development that alter tidal and freshwater inputs. Commensurate with this environmental variability, estuarine animals generally exhibit broader physiological tolerances than freshwater, marine, or terrestrial species. One factor that determines an organism's physiological tolerance is its ability to upregulate "stress-response genes" in reaction to particular stressors. Comparative studies on diverse organisms have identified a number of evolutionarily conserved genes involved in responding to abiotic and biotic stressors. We used homology-based scans to survey the sequenced genome of Nematostella vectensis, the starlet sea anemone, an estuarine specialist, to identify genes involved in the response to three kinds of insult-physiochemical insults, pathogens, and injury. Many components of the stress-response networks identified in triploblastic animals have clear orthologs in the sea anemone, meaning that they must predate the cnidarian-triploblast split (e.g., xenobiotic receptors, biotransformative genes, ATP-dependent transporters, and genes involved in responding to reactive oxygen species, toxic metals, osmotic shock, thermal stress, pathogen exposure, and wounding). However, in some instances, stress-response genes known from triploblasts appear to be absent from the Nematostella genome (e.g., many metal-complexing genes). This is the first comprehensive examination of the genomic stress-response repertoire of an estuarine animal and a member of the phylum Cnidaria. The molecular markers of stress response identified in Nematostella may prove useful in monitoring estuary health and evaluating coastal conservation efforts. These data may also inform conservation efforts on other cnidarians, such as the reef-building corals. PMID:18574101

Reitzel, Adam M; Sullivan, James C; Traylor-Knowles, Nikki; Finnerty, John R

2008-06-01

183

Molluscicidal activities of aqueous extract of the sea anemone Parasicyonis actinostoloides against vector snails Bulinus truncatus and Lymnaea natalensis.  

PubMed

The aqueous extract of the sea anemone Parasicyonis actinostoloides showed molluscicidal effect against vector snails of Schistosoma hacematobium and Fasciola gigantica after 24 hours of exposure. LC50) and LC90 values for P. actinostoloides were 40 & 78.6 ppm for B. runcatus and 46.6 & 86.5 ppm for L. natalensis respectively. The effect of continuously exposure of B. truncatits and L. naltlensis to sublethal aqueous extract concentrations (LC0, LC10 & LC25) on survival rate, egg production and on infectivity of miracidia to infection with S. haematobium and F. gigantica were studied. The data showed that no B. truncatus survived more than 42, 32 & 27 days after exposure with a mean life span of 18.5, 13.3 & 11.1 days respectively. The death rate of B. truncatus with LC0 was highly significant as compared to treatment with LC10 & LC25 (p < 0.01). L. natalensis were more susceptible to the effect of aqueous extract than B. truncatus. LC0, LC10 & LC25, extract killed all L. natalensis through 32, 27 & 22 days. The mean life span of those exposed to LC0 was 12.37 days, high significant when compared with treated LC10 & LC25 ones (p < 0.01). The cumulative mortality rates of B. truncatus and L. natalensis in controls during the experimental study (52 days) was 60% & 75%, respectively. Egg production of B. truncatius and L. natalensis was not affected by sublethal concentrations. Control snails layed significantly higher no. of eggs than treated ones. B. truncatus stopped egg laying 17 days after exposure to LC25. those treated with LC10 & LC0 ceased to deposit eggs after 22 & 27 days respectively. The percent reduction in egg laying capacity of B. truncatus treated with LC0, LC10 & LC25 compared to controls was 77.1%, 93.2% & 92.8% respectively (p < 0.01). Similar reduction in egg production of treated L. natalensis cornpared to controls occurred, the percent reduction in egg production of snails treated with LC0, LC10 & LC25 in relation to controls was 78.4%, 92.4% & 94.7% respectively. Sublethal concentrations of aqueous extract of P. actinostoloides affected hatchability of B. truncatus and L. natalensis eggs. The data showed that eggs of B. truncatus and L. natalensis can hatch in all tested concentrations but with different rates. The eggs' hatchability in snails exposed to LC0, LCIo & LC25 extract at 5 days old was 44%, 38% & 30% in B. truncatus respectively. In L. natalensis eggs, the corresponding rates were lower 28%, 24% & 18% respectively. The infection of B. truncatuts and L. natalensis with S. haematobium n and F. giganlica miracidia was greatly reduced by the sublethal concentrations of aqueous extract of P. actinostoloides. The reduction of infection rate increased with the increased of sublethal concentrations. In B. truncatus the reduction was 43.2%, 57.6% & 76.6% compared to controls and in L. natalensis was 56.3%, 70.2% & 77.4%, respectively. PMID:16927866

el-Sayed, Kamelia Abass

2006-08-01

184

Effects of lipid composition on membrane permeabilization by sticholysin I and II, two cytolysins of the sea anemone Stichodactyla helianthus.  

PubMed Central

Sticholysin I and II (St I and St II), two basic cytolysins purified from the Caribbean sea anemone Stichodactyla helianthus, efficiently permeabilize lipid vesicles by forming pores in their membranes. A general characteristic of these toxins is their preference for membranes containing sphingomyelin (SM). As a consequence, vesicles formed by equimolar mixtures of SM with phosphatidylcholine (PC) are very good targets for St I and II. To better characterize the lipid dependence of the cytolysin-membrane interaction, we have now evaluated the effect of including different lipids in the composition of the vesicles. We observed that at low doses of either St I or St II vesicles composed of SM and phosphatidic acid (PA) were permeabilized faster and to a higher extent than vesicles of PC and SM. As in the case of PC/SM mixtures, permeabilization was optimal when the molar ratio of PA/SM was ~1. The preference for membranes containing PA was confirmed by inhibition experiments in which the hemolytic activity of St I was diminished by pre-incubation with vesicles of different composition. The inclusion of even small proportions of PA into PC/SM LUVs led to a marked increase in calcein release caused by both St I and St II, reaching maximal effect at ~5 mol % of PA. Inclusion of other negatively charged lipids (phosphatidylserine (PS), phosphatidylglycerol (PG), phosphatidylinositol (PI), or cardiolipin (CL)), all at 5 mol %, also elicited an increase in calcein release, the potency being in the order CL approximately PA >> PG approximately PI approximately PS. However, some boosting effect was also obtained, including the zwitterionic lipid phosphatidylethanolamine (PE) or even, albeit to a lesser extent, the positively charged lipid stearylamine (SA). This indicated that the effect was not mediated by electrostatic interactions between the cytolysin and the negative surface of the vesicles. In fact, increasing the ionic strength of the medium had only a small inhibitory effect on the interaction, but this was actually larger with uncharged vesicles than with negatively charged vesicles. A study of the fluidity of the different vesicles, probed by the environment-sensitive fluorescent dye diphenylhexatriene (DPH), showed that toxin activity was also not correlated to the average membrane fluidity. It is suggested that the insertion of the toxin channel could imply the formation in the bilayer of a nonlamellar structure, a toroidal lipid pore. In this case, the presence of lipids favoring a nonlamellar phase, in particular PA and CL, strong inducers of negative curvature in the bilayer, could help in the formation of the pore. This possibility is confirmed by the fact that the formation of toxin pores strongly promotes the rate of transbilayer movement of lipid molecules, which indicates local disruption of the lamellar structure. PMID:11371451

Valcarcel, C A; Dalla Serra, M; Potrich, C; Bernhart, I; Tejuca, M; Martinez, D; Pazos, F; Lanio, M E; Menestrina, G

2001-01-01

185

Predator classification by the sea pen Ptilosarcus gurneyi (Cnidaria): role of waterborne chemical cues and physical contact with predatory sea stars  

Microsoft Academic Search

Using laboratory and field experiments we examined the defensive behaviour of the sea pen Ptilosarcus gurneyi (Gray) towards three species of sea stars representing three levels of predatory threat. In the laboratory we first quantified the behaviour of P. gurneyi following physical contact with the sea stars Dermasterias imbricata (specialist predator), Pycnopodia helianthoides (generalist predator), and Pisaster ochraceus (nonpredator). Whereas

Janice O. Weightman; David J. Arsenault

2002-01-01

186

Detrimental effects of host anemone bleaching on anemonefish populations  

NASA Astrophysics Data System (ADS)

Coral bleaching and related reef degradation have caused significant declines in the abundance of reef-associated fishes. Most attention on the effects of bleaching has focused on corals, but bleaching is also prevalent in other cnidarians, including sea anemones. The consequences of anemone bleaching are unknown, and the demographic effects of bleaching on associated fish recruitment, survival, and reproduction are poorly understood. We examined the effect of habitat degradation including host anemone bleaching on fish abundance, egg production, and recruitment of the panda anemonefish ( Amphiprion polymnus) near Port Moresby, Papua New Guinea. Following a high-temperature anomaly in shallow waters of the region, most shallow anemones to a depth of 6 m (approximately 35% of all the anemones in this area) were severely bleached. Anemone mortality was low but bleached anemones underwent a ~34% reduction in body size. Total numbers of A. polymnus were not affected by bleaching and reduction in shelter area. While egg production of females living in bleached anemones was reduced by ~38% in 2009 compared to 2008, egg production of females on unbleached anemones did not differ significantly between years. Total recruitment in 2009 was much lower than in 2008. However, we found no evidence of recruiting larvae avoiding bleached anemones at settlement suggesting that other factors or different chemical cues were more important in determining recruitment than habitat quality. These results provide the first field evidence of detrimental effects of climate-induced bleaching and habitat degradation on reproduction and recruitment of anemonefish.

Saenz-Agudelo, P.; Jones, G. P.; Thorrold, S. R.; Planes, S.

2011-06-01

187

Increasing pCO2 correlates with low concentrations of intracellular dimethylsulfoniopropionate in the sea anemone Anemonia viridis.  

PubMed

Marine anthozoans maintain a mutualistic symbiosis with dinoflagellates that are prolific producers of the algal secondary metabolite dimethylsulfoniopropionate (DMSP), the precursor of the climate-cooling trace gas dimethyl sulfide (DMS). Surprisingly, little is known about the physiological role of DMSP in anthozoans and the environmental factors that regulate its production. Here, we assessed the potential functional role of DMSP as an antioxidant and determined how future increases in seawater pCO2 may affect DMSP concentrations in the anemone Anemonia viridis along a natural pCO2 gradient at the island of Vulcano, Italy. There was no significant difference in zooxanthellae genotype and characteristics (density of zooxanthellae, and chlorophyll a) as well as protein concentrations between anemones from three stations along the gradient, V1 (3232 ?atm CO2), V2 (682 ?atm) and control (463 ?atm), which indicated that A.?viridis can acclimate to various seawater pCO2. In contrast, DMSP concentrations in anemones from stations V1 (33.23??8.30 fmol cell(-1)) and V2 (34.78??8.69 fmol cell(-1)) were about 35% lower than concentrations in tentacles from the control station (51.85??12.96 fmol cell(-1)). Furthermore, low tissue concentrations of DMSP coincided with low activities of the antioxidant enzyme superoxide dismutase (SOD). Superoxide dismutase activity for both host (7.84??1.37?Umg(-1) protein) and zooxanthellae (2.84??0.41?Umg(-1) protein) at V1 was 40% lower than at the control station (host: 13.19??1.42; zooxanthellae: 4.72??0.57?Umg(-1) protein). Our results provide insight into coastal DMSP production under predicted environmental change and support the function of DMSP as an antioxidant in symbiotic anthozoans. PMID:24634728

Borell, Esther M; Steinke, Michael; Horwitz, Rael; Fine, Maoz

2014-02-01

188

Rho participates in chemoreceptor-induced changes in morphology to hair bundle mechanoreceptors of the sea anemone, Nematostella vectensis.  

PubMed

Adjustable hair bundle mechanoreceptors located on anemone tentacles detect movements of nearby, swimming prey. The hair bundles are formed by numerous actin-based stereocilia that converge onto a single, central kinocilium. Interestingly, morphological and functional changes to the hair bundles are induced by activating chemoreceptors that bind prey-derived N-acetylated sugars and proline, respectively. Morphological changes to the hair bundles involve alterations to the actin cytoskeleton of stereocilia. A pharmacological activation of Rho induces hair bundles to elongate to lengths comparable to those normally induced by exposure to N-acetylneuraminic acid (NANA) and prevents shortening of hair bundles normally induced by proline. Rho inhibition prevents NANA-induced elongation, but does not prevent proline-induced shortening of hair bundles. Western blots feature a band similar in mass to that predicted for a Rho homolog in the genome of Nematostella. Immunocytochemistry localizes Rho in stereocilia of the hair bundle. Anemone hair bundles arise from multicellular complexes. Data from experiments using heptanol, a gap junction uncoupler, indicate that cell-cell communication is required in order for activated chemoreceptors to induce morphological changes to the hair bundles. PMID:23474255

Allaire, Kathryn M; Watson, Glen M

2013-06-01

189

Determination of the three-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata: A study using nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing  

Microsoft Academic Search

The three-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata has been determined on the basis of 489 interproton and 24 hydrogen-bonding distance restraints supplemented by 23 backbone and 21 {sub 1} side-chain torsion angle restraints derived from nuclear magnetic resonance (NMR) measurements. A total of 42 structures is calculated by a

Paul C. Driscoll; Angela M. Gronenborn; Laszlo Beress; G. Marius Clore

1989-01-01

190

Prolonged exposure to elevated CO2 promotes growth of the algal symbiont Symbiodinium muscatinei in the intertidal sea anemone Anthopleura elegantissima  

PubMed Central

Summary Some photosynthetic organisms benefit from elevated levels of carbon dioxide, but studies on the effects of elevated PCO2 on the algal symbionts of animals are very few. This study investigated the impact of hypercapnia on a photosynthetic symbiosis between the anemone Anthopleura elegantissima and its zooxanthella Symbiodinium muscatinei. Anemones were maintained in the laboratory for 1 week at 37?Pa PCO2 and pH?8.1. Clonal pairs were then divided into two groups and maintained for 6 weeks under conditions naturally experienced in their intertidal environment, 45?Pa PCO2, pH?8.1 and 231?Pa PCO2, pH?7.3. Respiration and photosynthesis were measured after the 1-week acclimation period and after 6 weeks in experimental conditions. Density of zooxanthellal cells, zooxanthellal cell size, mitotic index and chlorophyll content were compared between non-clonemate anemones after the 1-week acclimation period and clonal anemones at the end of the experiment. Anemones thrived in hypercapnia. After 6 weeks, A. elegantissima exhibited higher rates of photosynthesis at 45?Pa (4.2?mol O2 g?1 h?1) and 231?Pa (3.30?mol O2 g?1 h?1) than at the initial 37?Pa (1.53?mol O2 g?1 h?1). Likewise, anemones at 231?Pa received more of their respiratory carbon from zooxanthellae (CZAR ?=?78.2%) than those at 37?Pa (CZAR ?=?66.6%) but less than anemones at 45?Pa (CZAR ?=?137.3%). The mitotic index of zooxanthellae was significantly greater in the hypercapnic anemones than in anemones at lower PCO2. Excess zooxanthellae were expelled by their hosts, and cell densities, cell diameters and chlorophyll contents were not significantly different between the groups. The response of A. elegantissima to hypercapnic acidification reveals the potential adaptation of an intertidal, photosynthetic symbiosis for high PCO2. PMID:23213455

Towanda, Trisha; Thuesen, Erik V.

2012-01-01

191

Nitric oxide mediates coral bleaching through an apoptotic-like cell death pathway: evidence from a model sea anemone-dinoflagellate symbiosis.  

PubMed

Coral bleaching (involving the loss of symbiotic algae from the cnidarian host) is a major threat to coral reefs and appears to be mediated at the cellular level by nitric oxide (NO). In this study, we examined the specific role of NO in bleaching using the sea anemone Aiptasia pulchella, a model system for the study of corals. Exposure of A. pulchella to high-temperature shock (26-33C over <1 h) or an NO donor (S-nitrosoglutathione) resulted in significant increases in host caspase-like enzyme activity. These responses were reflected in the intensities of bleaching, which were significantly higher in heat- or NO-treated specimens than in controls maintained in seawater at 26C. Notably, the inhibition of caspase-like activity prevented bleaching even in the presence of an NO donor or at elevated temperature. The additional use of an NO scavenger controlled for effects mediated by agents other than NO. We also exposed A. pulchella to a more ecologically relevant treatment (an increase from 26 to 33C over 6-7 d). Again, host NO synthesis correlated with the activation of caspase-like enzyme activity. Therefore, we conclude that NO's involvement in cnidarian bleaching arises through the regulation of host apoptotic pathways. PMID:23934282

Hawkins, Thomas D; Bradley, Benjamin J; Davy, Simon K

2013-12-01

192

Effects of Cd, Co, Cu, Ni and Zn on asexual reproduction and early development of the tropical sea anemone Aiptasia pulchella.  

PubMed

Currently few studies present sub-lethal toxicity data for tropical marine species, and there are no routine toxicity tests using marine cnidarians. The symbiotic sea anemone Aiptasia pulchella has been identified as a useful species for ecotoxicological risk assessment, and would provide a tropical marine cnidarian representative. Chronic sub-lethal toxicity tests assessing the effects of 28-day trace metal exposure on asexual reproduction in A. pulchella were investigated, and concentration-dependant reductions in the number of offspring that were produced were evident for all metal exposures. Metal concentration estimates causing 50% reductions in the numbers of asexually-reproduced juveniles after 28-day exposures (28-day effect concentrations 50%: EC50s) were 14g/L for copper, 63g/L for zinc, 107g/L for cobalt, 145g/L for cadmium, and 369g/L for nickel. Slightly higher 28-day EC50s of 16g/L for copper, 192g/L for zinc, 172g/L for cobalt, 185g/L for cadmium, and 404g/L for nickel exposures and were estimated based on reductions in the total number of live developed and undeveloped offspring. These sensitive and chronic sub-lethal toxicity estimates help fill the knowledge gap related to metal effects on cnidarians over longer exposure periods, and this newly-developed bioassay may provide a much needed tool for ecotoxicological risk assessment relevant to tropical marine environments. PMID:25119449

Howe, Pelli L; Reichelt-Brushett, Amanda J; Clark, Malcolm W

2014-11-01

193

Is boldness a resource-holding potential trait? Fighting prowess and changes in startle response in the sea anemone, Actinia equina  

PubMed Central

Contest theory predicts the evolution of a stable mixture of different strategies for fighting. Here, we investigate the possibility that stable between-individual differences in startle-response durations influence fighting ability or resource-holding potential (RHP) in the beadlet sea anemone, Actinia equina. Both winners and losers showed significant repeatability of pre-fight startle-response durations but mean pre-fight startle-response durations were greater for eventual losers than for eventual winners, indicating that RHP varies with boldness. In particular, individuals with short startle responses inflicted more attacks on their opponent. Both repeatability and mean-level responses were changed by the experience of fighting, and these changes varied with outcome. In losers, repeatability was disrupted to a greater extent and the mean startle-response durations were subject to a greater increase than in winners. Thus, following a fight, this behavioural correlate of RHP behaves in a way similar to post-fight changes in physiological status, which can also vary between winners and losers. Understanding the links between aggression and boldness therefore has the potential to enhance our understanding of both the evolution of animal personality and the winner and loser effects of post-fight changes in RHP. PMID:22171080

Rudin, Fabian S.; Briffa, Mark

2012-01-01

194

Different visible colors and green fluorescence were obtained from the mutated purple chromoprotein isolated from sea anemone.  

PubMed

Green fluorescent protein (GFP)-like proteins have been studied with the aim of developing fluorescent proteins. Since the property of color variation is understudied, we isolated a novel GFP-like chromoprotein from the carpet anemone Stichodactyla haddoni, termed shCP. Its maximum absorption wavelength peak (?(max)) is located at 574 nm, resulting in a purple color. The shCP protein consists of 227 amino acids (aa), sharing 96 % identity with the GFP-like chromoprotein of Heteractis crispa. We mutated aa residues to examine any alteration in color. When E63, the first aa of the chromophore, was replaced by serine (E63S), the ?(max) of the mutated protein shCP-E63S was shifted to 560 nm and exhibited a pink color. When Q39, T194, and I196, which reside in the surrounding 5 of the chromophore's microenvironment, were mutated, we found that (1) the ?(max) of the mutated protein shCP-Q39S was shifted to 518 nm and exhibited a red color, (2) shCP-T194I exhibited a purple-blue color, and (3) an additional mutation at I196H of the mutated protein shCP-E63L exhibited green fluorescence. In contrast, when the aa located neither at the chromophore nor within its microenvironment were mutated, the resultant proteins shCP-L122H, -E138G, -S137D, -T95I, -D129N, -T194V, -E138Q, -G75E, -I183V, and -I70V never altered their purple color, suggesting that mutations at the shCP chromophore and the surrounding 5 microenvironment mostly control changes in color expression or cause fluorescence to develop. Additionally, we found that the cDNAs of shCP and its mutated varieties are faithfully and stably expressed both in Escherichia coli and zebrafish embryos. PMID:24488042

Chiang, Cheng-Yi; Chen, Yi-Lin; Tsai, Huai-Jen

2014-08-01

195

Evolutionary crossroads in developmental biology: Cnidaria  

PubMed Central

There is growing interest in the use of cnidarians (corals, sea anemones, jellyfish and hydroids) to investigate the evolution of key aspects of animal development, such as the formation of the third germ layer (mesoderm), the nervous system and the generation of bilaterality. The recent sequencing of the Nematostella and Hydra genomes, and the establishment of methods for manipulating gene expression, have inspired new research efforts using cnidarians. Here, we present the main features of cnidarian models and their advantages for research, and summarize key recent findings using these models that have informed our understanding of the evolution of the developmental processes underlying metazoan body plan formation. PMID:21389047

Technau, Ulrich; Steele, Robert E.

2011-01-01

196

The specificity of Av3 sea anemone toxin for arthropods is determined at linker DI/SS2-S6in the pore module of target sodium channels.  

PubMed

Av3 is a peptide neurotoxin from the sea anemone Anemonia viridis that shows specificity for arthropod voltage-gated sodium channels (Navs). Interestingly, Av3 competes with a scorpion ?-toxin on binding to insect Navs and similarly inhibits the inactivation process, and thus has been classified as 'receptor site-3 toxin', although the two peptides are structurally unrelated. This raises questions as to commonalities and differences in the way both toxins interact with Navs. Recently, site-3 was partly resolved for scorpion ?-toxins highlighting S1-S2 and S3-S4 external linkers at the DIV voltage-sensor module and the juxtaposed external linkers at the DI pore module. To uncover channel determinants involved in Av3 specificity for arthropods, the toxin was examined on channel chimaeras constructed with the external linkers of the mammalian brain Nav1.2a, which is insensitive to Av3, in the background of the Drosophila DmNav1. This approach highlighted the role of linker DI/SS2-S6, adjacent to the channel pore, in determining Av3 specificity. Point mutagenesis at DI/SS2-S6 accompanied by functional assays highlighted Trp404 and His405 as a putative point of Av3 interaction with DmNav1. His405 conservation in arthropod Navs compared with tyrosine in vertebrate Navs may represent an ancient substitution that explains the contemporary selectivity of Av3. Trp404 and His405 localization near the membrane surface and the hydrophobic bioactive surface of Av3 suggest that the toxin possibly binds at a cleft by DI/S6. A partial overlap in receptor site-3 of both toxins nearby DI/S6 may explain their binding competition capabilities. PMID:25055135

Gur Barzilai, Maya; Kahn, Roy; Regev, Noa; Gordon, Dalia; Moran, Yehu; Gurevitz, Michael

2014-10-15

197

Phyla- and Subtype-Selectivity of CgNa, a Na+ Channel Toxin from the Venom of the Giant Caribbean Sea Anemone Condylactis Gigantea  

PubMed Central

Because of their prominent role in electro-excitability, voltage-gated sodium (NaV) channels have become the foremost important target of animal toxins. These toxins have developed the ability to discriminate between closely related NaV subtypes, making them powerful tools to study NaV channel function and structure. CgNa is a 47-amino acid residue type I toxin isolated from the venom of the Giant Caribbean Sea Anemone Condylactis gigantea. Previous studies showed that this toxin slows the fast inactivation of tetrodotoxin-sensitive NaV currents in rat dorsal root ganglion neurons. To illuminate the underlying NaV subtype-selectivity pattern, we have assayed the effects of CgNa on a broad range of mammalian isoforms (NaV1.2NaV1.8) expressed in Xenopus oocytes. This study demonstrates that CgNa selectively slows the fast inactivation of rNaV1.3/?1, mNaV1.6/?1 and, to a lesser extent, hNaV1.5/?1, while the other mammalian isoforms remain unaffected. Importantly, CgNa was also examined on the insect sodium channel DmNaV1/tipE, revealing a clear phyla-selectivity in the efficacious actions of the toxin. CgNa strongly inhibits the inactivation of the insect NaV channel, resulting in a dramatic increase in peak current amplitude and complete removal of fast and steady-state inactivation. Together with the previously determined solution structure, the subtype-selective effects revealed in this study make of CgNa an interesting pharmacological probe to investigate the functional role of specific NaV channel subtypes. Moreover, further structural studies could provide important information on the molecular mechanism of NaV channel inactivation. PMID:21833172

Billen, Bert; Debaveye, Sarah; Beress, Laszlo; Tytgat, Jan

2010-01-01

198

Characterization and localization of mitochondrial DNA-encoded tRNAs and nuclear DNA-encoded tRNAs in the sea anemone Metridium senile.  

PubMed

The mitochondrial (mt) genome of the sea anemone Metridium senile contains genes for only two transfer RNAs (tRNAs), tRNAf-Met and tRNATrp. Experiments were conducted to seek evidence for the occurrence of functional tRNAs corresponding to these genes and for the participation of nuclear DNA-encoded tRNAs in mt-protein synthesis. RNA sequences corresponding to the two mt-tRNA genes were located in mitochondria and it was shown that 3'-CC (and possibly A, but no other nucleotide) is added post-transcriptionally to the 3' end of at least 50 % of mt-tRNAf-Met molecules and to a small fraction of the mt-tRNATrp molecules. Using specific oligonucleotide primers based on expected nuclear DNA-encoded tRNAs in a series of RACE experiments, we located the nuclear genes for tRNAGln, tRNAIle, tRNAi-Met, tRNAVal and tRNAThr. Data from Northern blot analyses indicated that mtDNA-encoded tRNAf-Met is limited to mitochondria but that nuclear DNA-encoded tRNAVal and tRNAi-Met are present in the cytoplasm and in mitochondria. These data provide direct evidence that in M. senile, mature, functional tRNAs are transcribed from the mtDNA-encoded tRNAf-Met and tRNATrp genes, and are consistent with the interpretation that both nuclear DNA-encoded tRNAVal and tRNAi-Met are utilized in mitochondrial and cytosolic protein synthesis. PMID:23801360

Beagley, C Timothy; Wolstenholme, David R

2013-08-01

199

Two Alleles of NF-?B in the Sea Anemone Nematostella vectensis Are Widely Dispersed in Nature and Encode Proteins with Distinct Activities  

PubMed Central

Background NF-?B is an evolutionarily conserved transcription factor that controls the expression of genes involved in many key organismal processes, including innate immunity, development, and stress responses. NF-?B proteins contain a highly conserved DNA-binding/dimerization domain called the Rel homology domain. Methods/Principal Findings We characterized two NF-?B alleles in the sea anemone Nematostella vectensis that differ at nineteen single-nucleotide polymorphisms (SNPs). Ten of these SNPs result in amino acid substitutions, including six within the Rel homology domain. Both alleles are found in natural populations of Nematostella. The relative abundance of the two NF-?B alleles differs between populations, and departures from Hardy-Weinberg equilibrium within populations indicate that the locus may be under selection. The proteins encoded by the two Nv-NF-?B alleles have different molecular properties, in part due to a Cys/Ser polymorphism at residue 67, which resides within the DNA recognition loop. In nearly all previously characterized NF-?B proteins, the analogous residue is fixed for Cys, and conversion of human RHD proteins from Cys to Ser at this site has been shown to increase DNA-binding ability and increase resistance to inhibition by thiol-reactive compounds. However, the naturally-occurring Nematostella variant with Cys at position 67 binds DNA with a higher affinity than the Ser variant. On the other hand, the Ser variant activates transcription in reporter gene assays more effectively, and it is more resistant to inhibition by a thiol-reactive compound. Reciprocal Cys<->Ser mutations at residue 67 of the native Nv-NF-?B proteins affect DNA binding as in human NF-?B proteins, e.g., a Cys->Ser mutation increases DNA binding of the native Cys variant. Conclusions/Significance These results are the first demonstration of a naturally occurring and functionally significant polymorphism in NF-?B in any species. The functional differences between these alleles and their uneven distribution in the wild suggest that different genotypes could be favored in different environments, perhaps environments that vary in their levels of peroxides or thiol-reactive compounds. PMID:19806194

Sullivan, James C.; Wolenski, Francis S.; Reitzel, Adam M.; French, Courtney E.; Traylor-Knowles, Nikki; Gilmore, Thomas D.; Finnerty, John R.

2009-01-01

200

ANEMONE: An effective minimal ontology negotiation environment  

E-print Network

ANEMONE: An effective minimal ontology negotiation environment Jurriaan van Diggelen, Robbert Jan minimal and effective shared ontologies. We tested our approach, called anemone, on a number anemone: AN Effective Minimal Ontology Negotiation Environment. We illustrate our approach with a case

Dignum, Frank

201

ANEMONE: An Effective Minimal Ontology Negotiation Environment  

E-print Network

ANEMONE: An Effective Minimal Ontology Negotiation Environment Jurriaan van Diggelen, Robbert minimal and effective shared ontologies. We tested our approach, called anemone, on a number anemone: AN Effective Minimal Ontology Negotiation Environment. We illustrate our approach with a case

Diggelen, Jurriaan van

202

Taxonomic, Spatial and Temporal Patterns of Bleaching in Anemones Inhabited by Anemonefishes  

PubMed Central

Background Rising sea temperatures are causing significant destruction to coral reef ecosystems due to coral mortality from thermally-induced bleaching (loss of symbiotic algae and/or their photosynthetic pigments). Although bleaching has been intensively studied in corals, little is known about the causes and consequences of bleaching in other tropical symbiotic organisms. Methodology/Principal Findings This study used underwater visual surveys to investigate bleaching in the 10 species of anemones that host anemonefishes. Bleaching was confirmed in seven anemone species (with anecdotal reports of bleaching in the other three species) at 10 of 19 survey locations spanning the Indo-Pacific and Red Sea, indicating that anemone bleaching is taxonomically and geographically widespread. In total, bleaching was observed in 490 of the 13,896 surveyed anemones (3.5%); however, this percentage was much higher (19100%) during five major bleaching events that were associated with periods of elevated water temperatures and coral bleaching. There was considerable spatial variation in anemone bleaching during most of these events, suggesting that certain sites and deeper waters might act as refuges. Susceptibility to bleaching varied between species, and in some species, bleaching caused reductions in size and abundance. Conclusions/Significance Anemones are long-lived with low natural mortality, which makes them particularly vulnerable to predicted increases in severity and frequency of bleaching events. Population viability will be severely compromised if anemones and their symbionts cannot acclimate or adapt to rising sea temperatures. Anemone bleaching also has negative effects to other species, particularly those that have an obligate relationship with anemones. These effects include reductions in abundance and reproductive output of anemonefishes. Therefore, the future of these iconic and commercially valuable coral reef fishes is inextricably linked to the ability of host anemones to cope with rising sea temperatures associated with climate change. PMID:23951056

Hobbs, Jean-Paul A.; Frisch, Ashley J.; Ford, Benjamin M.; Thums, Michele; Saenz-Agudelo, Pablo; Furby, Kathryn A.; Berumen, Michael L.

2013-01-01

203

Two new species of deep-water Corallimorpharia (Cnidaria: Anthozoa) from the Northeast Pacific, *Corallimorphus denhartogi* and *C. pilatus*  

E-print Network

Corallimorpharia is currently considered an order of hexacorallian anthozoans. Being skeletonless, its members are sometimes referred to as sea anemones, but they are morphologically more similar to members of Scleractinia ...

Fautin, Daphne G.; White, Tracy R.; Pearson, Katherine E.

2002-04-01

204

Looking for long-term changes in hydroid assemblages (Cnidaria, Hydrozoa) in Alboran Sea (South-Western Mediterranean): a proposal of a monitoring point for the global warming  

NASA Astrophysics Data System (ADS)

In the last 20-30 years, the temperature of the Mediterranean Sea has increased and global warming is allowing the establishment of tropical-affinity species into more temperate zones. Sessile communities are particularly useful as a baseline for ecological monitoring; however, a lack of historical data series exists for sessile marine organisms without commercial interest. Hydroids are ubiquitous components of the benthic sessile fauna on rocky shores and have been used as bio-indicators of environmental conditions. In this study on the benthic hydroid assemblages of the Chafarinas Islands (Alboran Sea, South-Western Mediterranean), we characterized the hydroid assemblages, identified the bathymetric gradients, and compared them with a previous study carried out in 1991. Hydroid assemblages showed a significant difference both between year and among depths. Furthermore, eight species not present in 1991 were found, including two possible new species and the tropical and subtropical species Sertularia marginata. Due to its strategic position at the entrance of the Mediterranean and the existence of previous data on hydroid assemblages, the Chafarinas Islands are proposed as a possible monitoring point for entrance of Atlantic tropical species into the Mediterranean Sea.

Gonzlez-Duarte, Manuel Mara; Megina, Cesar; Piraino, Stefano

2014-12-01

205

Accepted by Z.-Q. Zhang: 16 Jan. 2004; published: 30 Jan. 2004 1 ISSN 1175-5326 (print edition)  

E-print Network

.mapress.com/zootaxa/ Anthopleura mariscali, a new species of sea anemone (Cnidaria: Anthozoa: Actiniaria) from the Galápagos mariscali, a new species of sea anemone (Actiniaria) known only from the intertidal zone of islands and endemic species (e.g., Glynn & Wellington 1983; Kay 1991; Zullo 1991). The new species of sea anemone we

Fautin, Daphne

206

Determination of the three-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata: A study using nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing  

SciTech Connect

The three-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata has been determined on the basis of 489 interproton and 24 hydrogen-bonding distance restraints supplemented by 23 {phi} backbone and 21 {sub {chi}1} side-chain torsion angle restraints derived from nuclear magnetic resonance (NMR) measurements. A total of 42 structures is calculated by a hybrid metric matrix distance geometry-dynamical simulated annealing approach. Both the backbone and side-chain atom positions are well defined. The average atomic rms difference between the 42 individual SA structures and the mean structure obtained by averaging their coordinates is 0.67 {plus minus} 0.12 {angstrom} for the backbone atoms and 0.90 {plus minus} 0.17 {angstrom} for all atoms. The core of the protein is formed by a triple-stranded antiparallel {beta}-sheet composed of residues 14-16 (strand 1), 30-34 (strand 2), and 37-41 (strand 3) with an additional mini-antiparallel {beta}-sheet at the N-terminus (residues 6-9). The first and second strands of the triple-stranded antiparallel {beta}-sheet are connected by a long exposed loop. A number of side-chain interactions are discussed in light of the structure.

Driscoll, P.C.; Gronenborn, A.M.; Beress, L.; Clore, G.M. (National Institutes of Health, Bethesda, MD (USA))

1989-03-07

207

Understanding the Molecular Basis of Toxin Promiscuity: The Analgesic Sea Anemone Peptide APETx2 Interacts with Acid-Sensing Ion Channel 3 and hERG Channels via Overlapping Pharmacophores.  

PubMed

The sea anemone peptide APETx2 is a potent and selective blocker of acid-sensing ion channel 3 (ASIC3). APETx2 is analgesic in a variety of rodent pain models, but the lack of knowledge of its pharmacophore and binding site on ASIC3 has impeded development of improved analogues. Here we present a detailed structure-activity relationship study of APETx2. Determination of a high-resolution structure of APETx2 combined with scanning mutagenesis revealed a cluster of aromatic and basic residues that mediate its interaction with ASIC3. We show that APETx2 also inhibits the off-target hERG channel by reducing the maximal current amplitude and shifting the voltage dependence of activation to more positive potentials. Electrophysiological screening of selected APETx2 mutants revealed partial overlap between the surfaces on APETx2 that mediate its interaction with ASIC3 and hERG. Characterization of the molecular basis of these interactions is an important first step toward the rational design of more selective APETx2 analogues. PMID:25337890

Jensen, Jonas E; Cristofori-Armstrong, Ben; Anangi, Raveendra; Rosengren, K Johan; Lau, Carus H Y; Mobli, Mehdi; Brust, Andreas; Alewood, Paul F; King, Glenn F; Rash, Lachlan D

2014-11-13

208

Hydralysins, a New Category of -Pore-forming Toxins in Cnidaria*S  

E-print Network

Zlotkin** From the Department of Cell and Animal Biology and §Wolfson Center for Applied Structural Cristalografia, Serrano 119, E-28006 Madrid, Spain Cnidaria are venomous animals that produce diverse protein of the toxins. The importance of these sequence motifs is revealed by the cloning, expression, and mutagenesis

Lebendiker, Mario

209

Characteristics of Anemone Active Regions Appearing in Coronal Holes Observed with the Yohkoh Soft X-Ray Telescope  

NASA Astrophysics Data System (ADS)

Coronal structure of active regions appearing in coronal holes is studied, using data that were obtained with the Soft X-Ray Telescope (SXT) aboard Yohkoh between 1991 November and 1993 March. The following characteristics are found. Many of the active regions (ARs) appearing in coronal holes show a structure that looks like a sea anemone. Such active regions are called anemone ARs. About one-fourth of all active regions that were observed with SXT from their births showed the anemone structure. For almost all the anemone ARs, the order of the magnetic polarities is consistent with the Hale-Nicholson polarity law. These anemone ARs also showed, to a greater or lesser extent, an east-west asymmetry in the X-ray intensity distribution, such that the following (eastern) part of the AR was brighter than its preceding (western) part. This, as well as the anemone shape itself, is consistent with the magnetic polarity distribution around the anemone ARs. These observations also suggest that an active region appearing in coronal holes has a simpler (less sheared) and more preceding-spot-dominant magnetic structure than those appearing in other regions.

Asai, Ayumi; Shibata, Kazunari; Hara, Hirohisa; Nitta, Nariaki V.

2008-02-01

210

Characteristics of Anemone Active Regions Appearing in Coronal Holes Observed with {\\it Yohkoh} Soft X-ray Telescope  

E-print Network

Coronal structure of active regions appearing in coronal holes is studied by using the data obtained with the Soft X-Ray Telescope (SXT) aboard {\\it Yohkoh} from 1991 November to 1993 March. The following characteristics are found; Many of active regions appearing in coronal holes show a structure that looks like a ``sea-anemone''. Such active regions are called {\\it anemone ARs}. About one-forth of all active regions that were observed with SXT from their births showed the anemone structure. For almost all the anemone ARs, the order of magnetic polarities is consistent with the Hale-Nicholson's polarity law. These anemone ARs also showed more or less east-west asymmetry in X-ray intensity distribution, such that the following (eastern) part of the ARs is brighter than its preceding (western) part. This, as well as the anemone shape itself, is consistent with the magnetic polarity distribution around the anemone ARs. These observations also suggest that an active region appearing in coronal holes has simpler ...

Asai, Ayumi; Hara, Hirohisa; Nitta, Nariaki V

2008-01-01

211

Characteristics of Anemone Active Regions Appearing in Coronal Holes Observed with {\\it Yohkoh} Soft X-ray Telescope  

E-print Network

Coronal structure of active regions appearing in coronal holes is studied by using the data obtained with the Soft X-Ray Telescope (SXT) aboard {\\it Yohkoh} from 1991 November to 1993 March. The following characteristics are found; Many of active regions appearing in coronal holes show a structure that looks like a ``sea-anemone''. Such active regions are called {\\it anemone ARs}. About one-forth of all active regions that were observed with SXT from their births showed the anemone structure. For almost all the anemone ARs, the order of magnetic polarities is consistent with the Hale-Nicholson's polarity law. These anemone ARs also showed more or less east-west asymmetry in X-ray intensity distribution, such that the following (eastern) part of the ARs is brighter than its preceding (western) part. This, as well as the anemone shape itself, is consistent with the magnetic polarity distribution around the anemone ARs. These observations also suggest that an active region appearing in coronal holes has simpler (less sheared) and more preceding-spot-dominant magnetic structure than those appearing in other regions.

Ayumi Asai; Kazunari Shibata; Hirohisa Hara; Nariaki V. Nitta

2008-05-29

212

Evolutionary Diversification of Banded Tube-Dwelling Anemones (Cnidaria; Ceriantharia; Isarachnanthus) in the Atlantic Ocean  

PubMed Central

The use of molecular data for species delimitation in Anthozoa is still a very delicate issue. This is probably due to the low genetic variation found among the molecular markers (primarily mitochondrial) commonly used for Anthozoa. Ceriantharia is an anthozoan group that has not been tested for genetic divergence at the species level. Recently, all three Atlantic species described for the genus Isarachnanthus of Atlantic Ocean, were deemed synonyms based on morphological simmilarities of only one species: Isarachnanthus maderensis. Here, we aimed to verify whether genetic relationships (using COI, 16S, ITS1 and ITS2 molecular markers) confirmed morphological affinities among members of Isarachnanthus from different regions across the Atlantic Ocean. Results from four DNA markers were completely congruent and revealed that two different species exist in the Atlantic Ocean. The low identification success and substantial overlap between intra and interspecific COI distances render the Anthozoa unsuitable for DNA barcoding, which is not true for Ceriantharia. In addition, genetic divergence within and between Ceriantharia species is more similar to that found in Medusozoa (Hydrozoa and Scyphozoa) than Anthozoa and Porifera that have divergence rates similar to typical metazoans. The two genetic species could also be separated based on micromorphological characteristics of their cnidomes. Using a specimen of Isarachnanthus bandanensis from Pacific Ocean as an outgroup, it was possible to estimate the minimum date of divergence between the clades. The cladogenesis event that formed the species of the Atlantic Ocean is estimated to have occured around 8.5 million years ago (Miocene) and several possible speciation scenarios are discussed. PMID:22815928

Stampar, Sergio N.; Maronna, Maximiliano M.; Vermeij, Mark J. A.; Silveira, Fabio L. d.; Morandini, Andre C.

2012-01-01

213

PHYLOGENETIC SYSTEMATICS, TAXONOMY, AND BIOGEOGRAPHY OF JELLYFISH (CNIDARIA: MEDUSOZOA)  

E-print Network

The coastal shelf inhabiting box jellyfish (Cubozoa) represent the smallest class within Cnidaria with some 50 described species. A robust phylogenetic framework had been missing for Cubozoa. Herein, a molecular phylogeny ...

Bentlage, Bastian

2012-08-31

214

Mitochondrial DNA of Hydra attenuata (Cnidaria): A Sequence That Includes an End of One Linear Molecule and the Genes for l-rRNA,  

E-print Network

Mitochondrial DNA of Hydra attenuata (Cnidaria): A Sequence That Includes an End of One Linear linear mitochondrial (mt) DNA molecules of Hydra attenuata (phylum Cnidaria, class Hydrozoa, order distinct helical elements. Key words: Hydra attenuata -- Cnidaria -- Mito- chondrial genes -- Nucleotide

Warrior, Rahul

215

Distributed Anemone: Transparent Low-Latency Access to Remote Memory  

E-print Network

Distributed Anemone: Transparent Low-Latency Access to Remote Memory Michael R. Hines, Jian Wang of Distributed Anemone (Adaptive Network Memory Engine) ­ a lightweight and distributed system that pools together the collective memory resources of multiple machines across a gi- gabit Ethernet LAN. Anemone

Wang, Jian

216

Bioindication Potential of Carbonic Anhydrase Activity in Anemones  

E-print Network

Bioindication Potential of Carbonic Anhydrase Activity in Anemones and Corals AUBREY L. GILBERT levels of carbonic anhydrase (CA) were assessed in anemones Condylactis gigantea and Stichodactyla he has been done on CA activity in anemones and corals, two potential candidates for coral reef

Bermingham, Eldredge

217

Cell damage induced by copper: an explant model to study anemone cells.  

PubMed

Sea anemones are benthic organisms, of low mobility and can be directly affected by water pollution. This work studied the defense mechanisms and DNA damage caused by copper toxicity in cells from the anemone Bunodosoma cangicum. For this, exposure of anemones cells were held, kept in primary culture through explant of podal disk to copper (7.8 and 15.6 ?g/L), and the control group, for 6 and 24h. Cytotoxicity was seen through the viability and cell number, MXR phenotype through the accumulation of rhodamine-B, ROS generation by H2DCF-DA and DNA damage by comet assay. The results obtained show that there is a drop in viability and number of cells, especially after exposure of 24h in 15.6 ?g/L. There is an induction of the MXR activity only at 7.8 ?g/L for 24h. As for ROS, there is an increase in the generation of reactive species in greatest concentration of copper for 6h, and in both for 24h, which leads to oxidative stress, which culminates with a DNA damage. What was evidenced by the increase of the tail size, % DNA presented and moment of tail. Therefore, the copper represents an adversity to the anemones cells, being cytotoxic and genotoxic. PMID:24325972

Anjos, Vanessa A; da Silva, Flvio M R; Souza, Marta M

2014-04-01

218

Lipid droplets, medium of energy exchange in the symbiotic anemone Condylactis gigantea : a model coral polyp  

Microsoft Academic Search

The symbiotic sea anemone Condylactis gigantea does not make a CaCO3 skeleton, yet its lipid metabolism appears to be very similar to that of reef-building corals. Like hermatypic corals, it is roughly 1\\/3 lipid on a dry weight basis, its lipid is composed primarily of saturated wax ester and triglyceride, and in the light, its symbiotic algae (zooxanthellae) are the

R. B. Kellogg; J. S. Patton

1983-01-01

219

The European athecate hydroids and their medusae (Hydrozoa, Cnidaria): Filifera Part 3  

E-print Network

belonging to Turritopsis dohrnii (Weismann, 1883). Keywords: Cnidaria - marine - Hydrozoa - Hydractiniidae of Turritopsis polycirrha (Keferstein, 1862). Hydractinia areolata Alder, 1862 is selected as type species

Schuchert, Peter

220

Repetitious DNA in some Anemone Species  

Microsoft Academic Search

The DNA from several Anemone species, which contain different amounts of heterochromatin as revealed by Giemsa staining, was analysed by ultra-centrifugation and renaturation. No satellite band was observed in any of the samples centrifuged in cesium chloride gradients. Renaturation studies showed the presence of repetitive sequences. The proportion of repetitive DNA per genome varied from 53% to 67% and did

C. A. Cullis; D. Schweizer

1974-01-01

221

Biochemical-genetic and ecological evidence that red\\/brown individuals of the anemone Actinia equina comprise two morphs in Britain  

Microsoft Academic Search

A study of the sea anemone Actinia equina L. displaying red to brown column coloration was conducted on British shores in 1981 and 1982 in order to assess the ecological significance of discontinuous variation in pedal disc colour. Two ecologically distinct morphs have been revealed. One is characterised by having a red\\/pink pedal disc, and by being homozygous slow or

D. L. J. Quicke; A. M. Donoghue; R. C. Brace

1983-01-01

222

Buffering role of the intertidal anemone Anthopleura aureoradiata in cercarial transmission from snails to crabs  

E-print Network

Buffering role of the intertidal anemone Anthopleura aureoradiata in cercarial transmission from's infective stages (cercariae). In contrast, the presence of the anemone Anthopleura aureoradiata by anemones. Given the often high densities of anemones on mudflats, they may represent an important regulator

Poulin, Robert

223

Interannual variability in abundance of North Sea jellyfish and links to the North Atlantic Oscillation  

Microsoft Academic Search

Pronounced interannual variability in the abundance of medusae of the jellyfish species Aurelia aurita, Cyanea lamarckii, and Cyanea capillata (Phylum Cnidaria, Class Scyphozoa) in the North Sea was evident in data arising from the International Council for the Exploration of the Seas International 0-group Gadoid Surveys between 1971 and 1986. Possible climatic forcing of jellyfish abundance, via the North Atlantic

Christopher P. Lynam; Stephen J. Hay; Andrew S. Brierley

2004-01-01

224

A dinoflagellate symbiont of the coral Oculina diffusa Lamarck (Cnidaria : Anthozoa)  

E-print Network

A DINOFLAGELLATE SYMBIONT OF THE CORAL Oculina diffusa LAMARCK (CNIDARIA : ANTHOZOA) A Thesis by RALPH ROLAND GOULDY Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE August 1978 Major Subject: Biology A DINOFLAGELLATE SYMBIONT OF THE CORAL Oculina diffusa LAMARCK (CNIDARIA: ANTHOZOA) A Thesis By RALPH ROLAND GOULDY Approved as to style and content by: Chairman of Committee Head of Department Membe Me...

Gouldy, Ralph Roland

2012-06-07

225

Size-dependent dominance hierarchy in the anemone Actinia equina  

Microsoft Academic Search

THERE are many examples of aggression among anthozoan coelenterates: corals show interspecific interaction in which ranking may be obvious1, and inter-clonal aggression occurs in the anemone Anthopleura elegantissima2. Aggressive behaviour is also exhibited by some solitary anemones, such as Actinia equina L. Both these species possess special structures bearing batteries of nematocysts, the acrorhagi which are used solely for offence3.

R. C. Brace; Janis Pavey

1978-01-01

226

The mitochondrial genome of Hydra oligactis (Cnidaria, Hydrozoa) sheds new light on animal mtDNA evolution and cnidarian phylogeny  

E-print Network

The mitochondrial genome of Hydra oligactis (Cnidaria, Hydrozoa) sheds new light on animal mt of Hydra oligactis (Cnidaria, Hydrozoa) ­ the first from the class Hydrozoa ­ has been determined evolution 1. Introduction Hydra is a freshwater member of the Hydrozoa, one of the four traditionally

Lavrov, Dennis V.

227

Populations of Symbiodinium muscatinei Show Strong Biogeographic Structuring in the Intertidal Anemone  

E-print Network

Anemone Anthopleura elegantissima JON G. SANDERS1,2, * AND STEPHEN R. PALUMBI1 1 Stanford University cnidarian symbioses, the partnership between the intertidal anemone Anthopleura elegantissima and its ribosomal gene to characterize the Symbiodinium populations in tentacles clipped from 105 anemones at 14

Palumbi, Stephen

228

Anemone: Transparently Harnessing Cluster-Wide Memory Michael R. Hines1  

E-print Network

Anemone: Transparently Harnessing Cluster-Wide Memory Michael R. Hines1 , Mark Lewandowski2 , Jian, implementation and evaluation of Anemone ­ an Adaptive Network Memory Engine ­ that virtualizes the collective of Anemone and evaluated it using real-world unmodified applications such as ray-tracing and large in

Wang, Jian

229

The effect of light and heterotrophy on carotenoid concentrations in the Caribbean anemone Aiptasia pallida (Verrill)  

E-print Network

The effect of light and heterotrophy on carotenoid concentrations in the Caribbean anemone Aiptasia feeding by the host, or a combination thereof. We used Aiptasia pallida, a common Caribbean anemone), and photosynthetically active radiation (PAR, 400­700 nm) on carotenoid lev- els in zooxanthellate anthozoans. Anemones

Gleason, Daniel F.

230

Palatability of invertebrate larvae to corals and sea anemones  

Microsoft Academic Search

Risk of larval mortality is an underlying theme in debates and models concerning the ecology and evolution of the differing reproductive characteristics among marine benthic invertebrates. In these discussions, predation is often assumed to be a major source of larval mortality. Previous studies, focused primarily on planktotrophic larvae, suggested that marine larvae generally were susceptible to, and poorly defended against,

N. Lindquist

1996-01-01

231

Slideshow: Deep-sea Spiders Have a Snack  

NSDL National Science Digital Library

Three thousand meters below the ocean's surface, a remotely operated vehicle has captured never-before seen images of deep-sea spiders feeding in their natural habitat. These sluggish, long-legged spiders, which occupy a distinct class of arthropods from land spiders, survive on sea anemones in a submarine canyon off the Central California coast.

Janelle Weaver (AAAS;)

2009-12-24

232

Searching for a toxic key to unlock the mystery of anemonefish and anemone symbiosis.  

PubMed

Twenty-six species of anemonefish of the genera Amphiprion and monospecific Premnas, use only 10 species of anemones as hosts in the wild (Families: Actiniidae, Stichodactylidae and Thalassianthidae). Of these 10 anemone species some are used by multiple species of anemonefish while others have only a single anemonefish symbiont. Past studies have explored the different patterns of usage between anemonefish species and anemone species; however the evolution of this relationship remains unknown and has been little studied over the past decade. Here we reopen the case, comparing the toxicity of crude venoms obtained from anemones that host anemonefish as a way to investigate why some anemone species are used as a host more than others. Specifically, for each anemone species we investigated acute toxicity using Artemia francisca (LC50), haemolytic toxicity using ovine erythrocytes (EC50) and neurotoxicity using shore crabs (Ozius truncatus). We found that haemolytic and neurotoxic activity varied among host anemone species. Generally anemone species that displayed greater haemolytic activity also displayed high neurotoxic activity and tend to be more toxic on average as indicated by acute lethality analysis. An overall venom toxicity ranking for each anemone species was compared with the number of anemonefish species that are known to associate with each anemone species in the wild. Interestingly, anemones with intermediate toxicity had the highest number of anemonefish associates, whereas anemones with either very low or very high toxicity had the fewest anemonefish associates. These data demonstrate that variation in toxicity among host anemone species may be important in the establishment and maintenance of anemonefish anemone symbiosis. PMID:24878777

Nedosyko, Anita M; Young, Jeanne E; Edwards, John W; Burke da Silva, Karen

2014-01-01

233

Searching for a Toxic Key to Unlock the Mystery of Anemonefish and Anemone Symbiosis  

PubMed Central

Twenty-six species of anemonefish of the genera Amphiprion and monospecific Premnas, use only 10 species of anemones as hosts in the wild (Families: Actiniidae, Stichodactylidae and Thalassianthidae). Of these 10 anemone species some are used by multiple species of anemonefish while others have only a single anemonefish symbiont. Past studies have explored the different patterns of usage between anemonefish species and anemone species; however the evolution of this relationship remains unknown and has been little studied over the past decade. Here we reopen the case, comparing the toxicity of crude venoms obtained from anemones that host anemonefish as a way to investigate why some anemone species are used as a host more than others. Specifically, for each anemone species we investigated acute toxicity using Artemia francisca (LC50), haemolytic toxicity using ovine erythrocytes (EC50) and neurotoxicity using shore crabs (Ozius truncatus). We found that haemolytic and neurotoxic activity varied among host anemone species. Generally anemone species that displayed greater haemolytic activity also displayed high neurotoxic activity and tend to be more toxic on average as indicated by acute lethality analysis. An overall venom toxicity ranking for each anemone species was compared with the number of anemonefish species that are known to associate with each anemone species in the wild. Interestingly, anemones with intermediate toxicity had the highest number of anemonefish associates, whereas anemones with either very low or very high toxicity had the fewest anemonefish associates. These data demonstrate that variation in toxicity among host anemone species may be important in the establishment and maintenance of anemonefish anemone symbiosis. PMID:24878777

Nedosyko, Anita M.; Young, Jeanne E.; Edwards, John W.; Burke da Silva, Karen

2014-01-01

234

Nucleotide sequence of the histone gene cluster in the coral Acropora formosa (Cnidaria; Scleractinia): features of histone gene structure and organization are common to diploblastic and triploblastic metazoans.  

PubMed

We report the nucleotide sequence of the core histone gene cluster from the Cnidarian Acropora formosa. This is the first histone gene cluster to be sequenced from a diploblastic organism and the predicted amino acid sequences most resemble those of sea urchin equivalents. Each of the Cnidarian histone genes has two conserved regions 3' of the coding sequences and these closely resemble those of the metazoan alpha-class histone genes. In A. formosa the core histone genes are arranged as opposed (H3/H4 and H2A/H2B) pairs, a pattern common to the nondeuterostome metazoa, and tandem repetition is the predominant pattern of organization in the Cnidarian. With the recent identification of several classes of homeobox genes in Cnidarians these features clearly align the Cnidaria with triploblastic metazoans, supporting a monophyletic origin of the metazoa. PMID:7901422

Miller, D J; Harrison, P L; Mahony, T J; McMillan, J P; Miles, A; Odorico, D M; ten Lohuis, M R

1993-09-01

235

@Sea  

NSDL National Science Digital Library

Describes the Harbor Branch Oceanographic Institution's at-sea research expeditions and presents both current and archived expeditions from 1999 to the present. Each expedition is described in a feature story with background, definitions, research technology and sampling equipment, maps, photos, daily logs, some videos and virtual tours, researcher profiles, and related links. HBOI scientists have studied maritime history, pharmaceuticals from the sea, sharks, behavior and physiology of marine life, marine sanctuaries and submersible technology.

236

Putative cross-kingdom horizontal gene transfer in sponge (Porifera) mitochondria  

Microsoft Academic Search

BACKGROUND: The mitochondrial genome of Metazoa is usually a compact molecule without introns. Exceptions to this rule have been reported only in corals and sea anemones (Cnidaria), in which group I introns have been discovered in the cox1 and nad5 genes. Here we show several lines of evidence demonstrating that introns can also be found in the mitochondria of sponges

Chagai Rot; Itay Goldfarb; Micha Ilan; Dorothe Huchon

2006-01-01

237

Statistical Study of Chromospheric Anemone Jets Observed with Hinode/SOT  

NASA Astrophysics Data System (ADS)

The Solar Optical Telescope on board Hinode has revealed numerous tiny jets in all regions of the chromosphere outside of sunspots. A typical chromospheric anemone jet has a cusp-shaped structure and bright footpoint, similar to the shape of an X-ray anemone jet observed previously with the Soft X-ray Telescope on board Yohkoh. The similarity in the shapes of chromospheric and X-ray anemone jets suggests that chromospheric anemone jets are produced as a result of the magnetic reconnection between a small bipole (perhaps a tiny emerging flux) and a pre-existing uniform magnetic field in the lower chromosphere. We examine various chromospheric anemone jets in the solar active region near the solar limb and study the typical features (e.g., length, width, lifetime, and velocity) of the chromospheric anemone jets. Statistical studies show that chromospheric anemone jets have: (1) a typical length ~1.0-4.0 Mm, (2) a width ~100-400 km, (3) a lifetime ~100-500 s, and (4) a velocity ~5-20 km s-1. The velocity of the chromospheric anemone jets is comparable to the local Alfvn speed in the lower solar chromosphere (~10 km s-1). The histograms of chromospheric anemone jets near the limb and near the disk center show similar averages and shapes of distributions, suggesting that the characteristic behavior of chromospheric anemone jets is independent of whether they are observed on the disk or at the limb. The observed relationship between the velocity and length of chromospheric anemone jets shows that the jets do not follow ballistic motion but are more likely accelerated by some other mechanism. This is consistent with numerical simulations of chromospheric anemone jets.

Nishizuka, N.; Nakamura, T.; Kawate, T.; Singh, K. A. P.; Shibata, K.

2011-04-01

238

STATISTICAL STUDY OF CHROMOSPHERIC ANEMONE JETS OBSERVED WITH HINODE/SOT  

SciTech Connect

The Solar Optical Telescope on board Hinode has revealed numerous tiny jets in all regions of the chromosphere outside of sunspots. A typical chromospheric anemone jet has a cusp-shaped structure and bright footpoint, similar to the shape of an X-ray anemone jet observed previously with the Soft X-ray Telescope on board Yohkoh. The similarity in the shapes of chromospheric and X-ray anemone jets suggests that chromospheric anemone jets are produced as a result of the magnetic reconnection between a small bipole (perhaps a tiny emerging flux) and a pre-existing uniform magnetic field in the lower chromosphere. We examine various chromospheric anemone jets in the solar active region near the solar limb and study the typical features (e.g., length, width, lifetime, and velocity) of the chromospheric anemone jets. Statistical studies show that chromospheric anemone jets have: (1) a typical length {approx}1.0-4.0 Mm, (2) a width {approx}100-400 km, (3) a lifetime {approx}100-500 s, and (4) a velocity {approx}5-20 km s{sup -1}. The velocity of the chromospheric anemone jets is comparable to the local Alfven speed in the lower solar chromosphere ({approx}10 km s{sup -1}). The histograms of chromospheric anemone jets near the limb and near the disk center show similar averages and shapes of distributions, suggesting that the characteristic behavior of chromospheric anemone jets is independent of whether they are observed on the disk or at the limb. The observed relationship between the velocity and length of chromospheric anemone jets shows that the jets do not follow ballistic motion but are more likely accelerated by some other mechanism. This is consistent with numerical simulations of chromospheric anemone jets.

Nishizuka, N. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 229-8510 (Japan); Nakamura, T.; Kawate, T.; Singh, K. A. P.; Shibata, K., E-mail: nishizuka.naoto@jaxa.jp [Kwasan and Hida observatories, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)

2011-04-10

239

A new species of Pachycerianthus (Cnidaria, Anthozoa, Ceriantharia) from Tropical Southwestern Atlantic.  

PubMed

A new species of Pachycerianthus (Cnidaria: Ceriantharia) is described from the Brazilian coast of the southwestern Atlantic Ocean. Pachycerianthus schlenzae sp. nov. is found in fine sand or mud in shallow waters of Abrolhos and Royal Charlotte Bank. The new species is only known from this area and is most notably different from other species of the genus Pachycerianthus in mesentery arrangement and cnidome. In addition to the description, we provide some biological data collected from individuals cultivated under laboratory conditions. PMID:25081164

Stampar, Srgio N; Morandini, Andr C; Da Silveira, Fbio Lang

2014-01-01

240

Chromospheric Anemone Jets as Evidence of Ubiquitous Reconnection  

NASA Astrophysics Data System (ADS)

The heating of the solar chromosphere and corona is a long-standing puzzle in solar physics. Hinode observations show the ubiquitous presence of chromospheric anemone jets outside sunspots in active regions. They are typically 3 to 7 arc seconds = 2000 to 5000 kilometers long and 0.2 to 0.4 arc second = 150 to 300 kilometers wide, and their velocity is 10 to 20 kilometers per second. These small jets have an inverted Y-shape, similar to the shape of x-ray anemone jets in the corona. These features imply that magnetic reconnection similar to that in the corona is occurring at a much smaller spatial scale throughout the chromosphere and suggest that the heating of the solar chromosphere and corona may be related to small-scale ubiquitous reconnection.

Shibata, Kazunari; Nakamura, Tahei; Matsumoto, Takuma; Otsuji, Kenichi; Okamoto, Takenori J.; Nishizuka, Naoto; Kawate, Tomoko; Watanabe, Hiroko; Nagata, Shin'ichi; UeNo, Satoru; Kitai, Reizaburo; Nozawa, Satoshi; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu, Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D.; Berger, Thomas E.; Lites, Bruce W.; Shine, Richard A.; Title, Alan M.

2007-12-01

241

Chromospheric Anemone Jets as Evidence of Ubiquitous Reconnection  

E-print Network

The heating of the solar chromosphere and corona is a long-standing puzzle in solar physics. Hinode observations show the ubiquitous presence of chromospheric anemone jets outside sunspots in active regions. They are typically 3 to 7 arc seconds = 2000 to 5000 kilometers long and 0.2 to 0.4 arc second = 150 to 300 kilometers wide, and their velocity is 10 to 20 kilometers per second. These small jets have an inverted Y-shape, similar to the shape of x-ray anemone jets in the corona. These features imply that magnetic reconnection similar to that in the corona is occurring at a much smaller spatial scale throughout the chromosphere and suggest that the heating of the solar chromosphere and corona may be related to small-scale ubiquitous reconnection.

Shibata, Kazunari; Matsumoto, Takuma; Otsuji, Kenichi; Okamoto, Takenori J; Nishizuka, Naoto; Kawate, Tomoko; Watanabe, Hiroko; Nagata, Shin'ichi; UeNo, Satoru; Kitai, Reizaburo; Nozawa, Satoshi; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu, Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D; Berger, Thomas E; Lites, Bruce W; Shine, Richard A; Title, Alan M

2009-01-01

242

Chromospheric Anemone Jets as Evidence of Ubiquitous Reconnection  

E-print Network

The heating of the solar chromosphere and corona is a long-standing puzzle in solar physics. Hinode observations show the ubiquitous presence of chromospheric anemone jets outside sunspots in active regions. They are typically 3 to 7 arc seconds = 2000 to 5000 kilometers long and 0.2 to 0.4 arc second = 150 to 300 kilometers wide, and their velocity is 10 to 20 kilometers per second. These small jets have an inverted Y-shape, similar to the shape of x-ray anemone jets in the corona. These features imply that magnetic reconnection similar to that in the corona is occurring at a much smaller spatial scale throughout the chromosphere and suggest that the heating of the solar chromosphere and corona may be related to small-scale ubiquitous reconnection.

Kazunari Shibata; Tahei Nakamura; Takuma Matsumoto; Kenichi Otsuji; Takenori J. Okamoto; Naoto Nishizuka; Tomoko Kawate; Hiroko Watanabe; Shin'ichi Nagata; Satoru UeNo; Reizaburo Kitai; Satoshi Nozawa; Saku Tsuneta; Yoshinori Suematsu; Kiyoshi Ichimoto; Toshifumi Shimizu; Yukio Katsukawa; Theodore D. Tarbell; Thomas E. Berger; Bruce W. Lites; Richard A. Shine; Alan M. Title

2008-10-22

243

Agent of Whirling Disease Meets Orphan Worm: Phylogenomic Analyses Firmly Place Myxozoa in Cnidaria  

PubMed Central

Myxozoa are microscopic obligate endoparasites with complex live cycles. Representatives are Myxobolus cerebralis, the causative agent of whirling disease in salmonids, and the enigmatic orphan worm Buddenbrockia plumatellae parasitizing in Bryozoa. Originally, Myxozoa were classified as protists, but later several metazoan characteristics were reported. However, their phylogenetic relationships remained doubtful. Some molecular phylogenetic analyses placed them as sister group to or even within Bilateria, whereas the possession of polar capsules that are similar to nematocysts of Cnidaria and of minicollagen genes suggest a close relationship between Myxozoa and Cnidaria. EST data of Buddenbrockia also indicated a cnidarian origin of Myxozoa, but were not sufficient to reject a closer relationship to bilaterians. Phylogenomic analyses of new genomic sequences of Myxobolus cerebralis firmly place Myxozoa as sister group to Medusozoa within Cnidaria. Based on the new dataset, the alternative hypothesis that Myxozoa form a clade with Bilateria can be rejected using topology tests. Sensitivity analyses indicate that this result is not affected by long branch attraction artifacts or compositional bias. PMID:23382916

Nesnidal, Maximilian P.; Helmkampf, Martin; Bruchhaus, Iris; El-Matbouli, Mansour; Hausdorf, Bernhard

2013-01-01

244

Structural rearrangements, including parallel inversions, within the chloroplast genome of Anemone and related genera  

Microsoft Academic Search

Chloroplast DNA cleavage sites for 10 restriction enzymes were mapped for 46 species representing all sections of Anemone, four closely related genera (Clematis, Pulsatilla, Hepatica, and Knowltonia), and three more distantly related outgroups (Caltha, Ranunculus, and Adonis). Comparison of the maps revealed that the chloroplast genomes of Anemone and related genera have sustained an unusual number and variety of rearrangements.

Sara B. Hoot; Jeffrey D. Palmer

1994-01-01

245

The mud flat anemone-cockle association: mutualism in the intertidal zone?  

Microsoft Academic Search

The intertidal cockle Austrovenus stutchburyi exists in a symbiotic relationship with the mud flat anemone Anthopleura aureoradiata, the latter using the shell of buried cockles as the only available hard substrate for attachment. The cockles are also host to a detrimental larval trematode Curtuteria australis that invades the bivalves through the filtration current, and here we demonstrate that the anemones

Kim N. Mouritsen; Robert Poulin

2003-01-01

246

Is dimethylsulfoniopropionate (DMSP) produced by the symbionts or the host in an anemone-zooxanthella symbiosis?  

NASA Astrophysics Data System (ADS)

Many groups of tropical cnidarians including scleractinian corals, octocorals, corallimorphs, and anemones contain the tertiary sulfonium compound dimethylsulfoniopropionate (DMSP). It is not known if the compound is synthesized by the animals, their microalgal symbionts, or derived through their diet. We determined the source of the DMSP in several species of tropical and temperate anemones using three approaches: (1) conducting comparative measurements of DMSP in aposymbiotic and zooxanthellate anemones of three species that harbor zooxanthellae, and similar measurements in one species that can harbor both zooxanthellae and zoochlorellae, (2) manipulating the presence or absence of zooxanthellae by inoculating juvenile aposymbiotic anemones ( Aiptasia pallida) with their symbiont, Symbiodinium bermudense, and (3) manipulating the numbers of S. bermudense by growing aposymbiotic and zooxanthellate A. pallida in the light and the dark. DMSP was present in zooxanthellate anemones in concentrations of 3.4-15 ?mol g-1 fresh mass (FM). In aposymbiotic Aiptasia spp. and Anthopleura elegantissima that lacked large numbers of zooxanthellae, concentrations ranged from being undetectable to 0.43 ?mol g-1 FM. When aposymbiotic A. pallida were inoculated with zooxanthellae, concentrations of DMSP were an average of 4.24 ?mol g-1 FM after 5 weeks; DMSP was undetectable in uninoculated control animals. Aposymbiotic anemones maintained in the light or the dark for 6 weeks contained no DMSP or zooxanthellae. Zooxanthellate anemones in the light contained five times as many zooxanthellae and approximately 7.5 times as much DMSP as zooxanthellate anemones maintained in the dark. Taken together, these data show that the zooxanthellae are the sole source of DMSP in A. pallida. The trends in DMSP concentrations in other species of zooxanthellate anemones suggest that this phenomenon is not limited to A. pallida but may be more generally true for other anemones or even other cnidarians hosting species of Symbiodinium.

van Alstyne, K. L.; Dominique, V. J.; Muller-Parker, G.

2009-03-01

247

Evolution of the anemone AR NOAA 10798 and the related geo-effective flares and CMEs  

NASA Astrophysics Data System (ADS)

We present a detailed examination of the features of the active region (AR) NOAA 10798. This AR generated coronal mass ejections (CMEs) that caused a large geomagnetic storm on 24 August 2005 with the minimum Dst index of -216 nT. We examined the evolution of the AR and the features on/near the solar surface and in the interplanetary space. The AR emerged in the middle of a small coronal hole, and formed a sea anemone like configuration. H? filaments were formed in the AR, which have southward axial field. Three M class flares were generated, and the first two that occurred on 22 August 2005 were followed by Halo-type CMEs. The speeds of the CMEs were fast, and recorded about 1200 and 2400 km s-1, respectively. The second CME was especially fast, and caught up and interacted with the first (slower) CME during their travelings toward Earth. These acted synergically to generate an interplanetary disturbance with strong southward magnetic field of about -50 nT, which was followed by the large geomagnetic storm.

Asai, Ayumi; Shibata, Kazunari; Ishii, Takako T.; Oka, Mitsuo; Kataoka, Ryuho; Fujiki, Ken'ichi; Gopalswamy, Nat

2009-02-01

248

Evolution of Anemone AR NOAA 10798 and the Related Geo-Effective Flares and CMEs  

E-print Network

We present a detailed examination of the features of the Active Region (AR) NOAA 10798. This AR generated coronal mass ejections (CMEs) that caused a large geomagnetic storm on 24 August 2005 with the minimum Dst index of -216 nT. We examined the evolution of the AR and the features on/near the solar surface and in the interplanetary space. The AR emerged in the middle of a small coronal hole, and formed a {\\it sea anemone} like configuration. H$\\alpha$ filaments were formed in the AR, which have southward axial field. Three M-class flares were generated, and the first two that occurred on 22 August 2005 were followed by Halo-type CMEs. The speeds of the CMEs were fast, and recorded about 1200 and 2400 km s$^{-1}$, respectively. The second CME was especially fast, and caught up and interacted with the first (slower) CME during their travelings toward Earth. These acted synergically to generate an interplanetary disturbance with strong southward magnetic field of about -50 nT, which was followed by the large g...

Asai, Ayumi; Ishii, Takako T; Oka, Mitsuo; Kataoka, Ryuho; Fujiki, Ken'ichi; Gopalswamy, Nat

2008-01-01

249

Evolution of Anemone AR NOAA 10798 and the Related Geo-Effective Flares and CMEs  

E-print Network

We present a detailed examination of the features of the Active Region (AR) NOAA 10798. This AR generated coronal mass ejections (CMEs) that caused a large geomagnetic storm on 24 August 2005 with the minimum Dst index of -216 nT. We examined the evolution of the AR and the features on/near the solar surface and in the interplanetary space. The AR emerged in the middle of a small coronal hole, and formed a {\\it sea anemone} like configuration. H$\\alpha$ filaments were formed in the AR, which have southward axial field. Three M-class flares were generated, and the first two that occurred on 22 August 2005 were followed by Halo-type CMEs. The speeds of the CMEs were fast, and recorded about 1200 and 2400 km s$^{-1}$, respectively. The second CME was especially fast, and caught up and interacted with the first (slower) CME during their travelings toward Earth. These acted synergically to generate an interplanetary disturbance with strong southward magnetic field of about -50 nT, which was followed by the large geomagnetic storm.

Ayumi Asai; Kazunari Shibata; Takako T. Ishii; Mitsuo Oka; Ryuho Kataoka; Ken'ichi Fujiki; Nat Gopalswamy

2008-12-11

250

Is dimethylsulfoniopropionate (DMSP) produced by the symbionts or the host in an anemonezooxanthella symbiosis?  

Microsoft Academic Search

Many groups of tropical cnidarians including scleractinian corals, octocorals, corallimorphs, and anemones contain the tertiary\\u000a sulfonium compound dimethylsulfoniopropionate (DMSP). It is not known if the compound is synthesized by the animals, their\\u000a microalgal symbionts, or derived through their diet. We determined the source of the DMSP in several species of tropical and\\u000a temperate anemones using three approaches: (1) conducting comparative

K. L. Van Alstyne; V. J. Dominique; G. Muller-Parker

2009-01-01

251

Corallimorphus profundus in shallow Antarctic habitats: Bionomics, histology, and systematics (Cnidaria: Hexacorallia)  

Microsoft Academic Search

In March 2000 and November\\/December 2001 thirteen specimens of Corallimorphus profundus Moseley, 1877, a conspicuous, anemone-like cnidarian, were hand-sampled by SCUBA diving in 30 to 40 m depth off US Palmer Station, Antarctic Peninsula. Corallimorphus species were formerly recorded only from deep water habitats from where they had been brought up more or less damaged, with most of their epithelia

K. Riemann-Zrneck; K. Iken

2003-01-01

252

National Marine Fisheries Service -1st Quarter 2012 Tables E-G. Other Stocks  

E-print Network

policifera, S. vaginalis, Tethya crypta; Coelenterates: Pale anemone, corkscrew anemone, giant pink-tipped anemone, knobby anemone, staghorn anemone, sun anemone, sea mat, false coral, Florida false coral; Annelid

253

New records of Primnoidae (Cnidaria: Octocorallia) in Brazilian deep waters  

NASA Astrophysics Data System (ADS)

The knowledge of octocorals occurring in Brazilian deep waters is still lacking, with only a few studies conducted so far, most of which focused on large-scale marine habitats characterization. Primnoidae are common and characteristic of seamounts and deepwater coral banks, often providing habitat for other marine species. Although primnoids occur in all ocean basins, only Primnoella and Plumarella species were recorded along the Brazilian coast before this study. Primnoid specimens were obtained through dredging and remotely operated vehicles (ROV) sampling, collected by research projects conducted off the Brazilian coast, between 15 and 34S. Taxonomic assessment resulted in 5 new records of Primnoidae genera in Brazil: Calyptrophora, Candidella, Dasystenella, Narella and Thouarella. The occurrences of Narella-off Salvador and Vitria, and in Campos Basin (935-1700 m), and Calyptrophora-in Campos Basin (1059-1152 m), are herein reported for the first time in the South Atlantic. Calyptrophora microdentata was previously known in Lesser Antilles, New England and Corner Rise Seamounts, between 686 and 2310 m. Candidella imbricata geographical distribution includes Western and Eastern Atlantic (514-2063 m and 815-2139 m, respectively), being registered herein in Campos Basin, between 1059 and 1605 m. Dasystenella acanthina collected off Rio Grande do Sul state (810 m) and occurs also off Argentina and Southern Ocean, between 150 and 5087 m. Plumarella diadema, which type locality is off So Sebastio, Brazil, has its geographical range extended northwards, occurring in Campos Basin (650 m). Thouarella koellikeri previously known for Patagonia and Antartic Peninsula, is registered for the off Brazil for the first time, in Campos Basin and off So Sebastio (609-659 m). There is a lot of work yet to be done in terms of taxonomic knowledge of Brazilian deep-sea octocorals. Research projects focusing on the investigations, including ROV sampling, of other geographical regions and depth ranges along Brazilian coast will certainly reveal other new octocorals occurrences and species.

Arantes, Renata C. M.; Loiola, Livia L.

2014-01-01

254

Isolation and identification of chitin in the black coral Parantipathes larix (Anthozoa: Cnidaria).  

PubMed

Until now, there is a lack of knowledge about the presence of chitin in numerous representatives of corals (Cnidaria). However, investigations concerning the chitin-based skeletal organization in different coral taxa are significant from biochemical, structural, developmental, ecological and evolutionary points of view. In this paper, we present a thorough screening for the presence of chitin within the skeletal formations of a poorly investigated Mediterranean black coral, Parantipathes larix (Esper, 1792), as a typical representative of the Schizopathidae family. Using a wide array variety of techniques ((13)C solid state NMR, Fourier transform infrared (FTIR), Raman, NEXAFS, Morgan-Elson assay and Calcofluor White Staining), we unambiguously show for the first time that chitin is an important component within the skeletal stalks as well as pinnules of this coral. PMID:22546360

Bo, Marzia; Bavestrello, Giorgio; Kurek, Denis; Paasch, Silvia; Brunner, Eike; Born, Ren; Galli, Roberta; Stelling, Allison L; Sivkov, Viktor N; Petrova, Olga V; Vyalikh, Denis; Kummer, Kurt; Molodtsov, Serguei L; Nowak, Dorota; Nowak, Jakub; Ehrlich, Hermann

2012-01-01

255

Phylogenetic placement of the enigmatic parasite, Polypodium hydriforme, within the Phylum Cnidaria  

PubMed Central

Background Polypodium hydriforme is a parasite with an unusual life cycle and peculiar morphology, both of which have made its systematic position uncertain. Polypodium has traditionally been considered a cnidarian because it possesses nematocysts, the stinging structures characteristic of this phylum. However, recent molecular phylogenetic studies using 18S rDNA sequence data have challenged this interpretation, and have shown that Polypodium is a close relative to myxozoans and together they share a closer affinity to bilaterians than cnidarians. Due to the variable rates of 18S rDNA sequences, these results have been suggested to be an artifact of long-branch attraction (LBA). A recent study, using multiple protein coding markers, shows that the myxozoan Buddenbrockia, is nested within cnidarians. Polypodium was not included in this study. To further investigate the phylogenetic placement of Polypodium, we have performed phylogenetic analyses of metazoans with 18S and partial 28S rDNA sequences in a large dataset that includes Polypodium and a comprehensive sampling of cnidarian taxa. Results Analyses of a combined dataset of 18S and partial 28S sequences, and partial 28S alone, support the placement of Polypodium within Cnidaria. Removal of the long-branched myxozoans from the 18S dataset also results in Polypodium being nested within Cnidaria. These results suggest that previous reports showing that Polypodium and Myxozoa form a sister group to Bilateria were an artifact of long-branch attraction. Conclusion By including 28S rDNA sequences and a comprehensive sampling of cnidarian taxa, we demonstrate that previously conflicting hypotheses concerning the phylogenetic placement of Polypodium can be reconciled. Specifically, the data presented provide evidence that Polypodium is indeed a cnidarian and is either the sister taxon to Hydrozoa, or part of the hydrozoan clade, Leptothecata. The former hypothesis is consistent with the traditional view that Polypodium should be placed in its own cnidarian class, Polypodiozoa. PMID:18471296

2008-01-01

256

A comparative analysis of the photobiology of zooxanthellae and zoochlorellae symbiotic with the temperate clonal anemone Anthopleura elegantissima (Brandt)  

Microsoft Academic Search

The temperate anemone Anthopleura elegantissima hosts two phylogenetically different symbiotic microalgae, a dinoflagellate Symbiodinium (zooxanthellae, ZX) and a chlorophyte (zoochlorellae, ZC), throughout certain regions of its latitudinal range. Because of the broad intertidal and geographic range of this anemone, we examined the role of irradiance to ascertain which specific symbiotic parameters are affected and whether light intensity governs the observed

E. A. Verde; L. R. McCloskey

2002-01-01

257

Structural rearrangements, including parallel inversions, within the chloroplast genome of Anemone and related genera.  

PubMed

Chloroplast DNA cleavage sites for 10 restriction enzymes were mapped for 46 species representing all sections of Anemone, four closely related genera (Clematis, Pulsatilla, Hepatica, and Knowltonia), and three more distantly related outgroups (Caltha, Ranunculus, and Adonis). Comparison of the maps revealed that the chloroplast genomes of Anemone and related genera have sustained an unusual number and variety of rearrangements. A single inversion of a 42-kb segment was found in the large single-copy region of Adonis aestivalis. Two types of rearrangements were found in the chloroplast genome of Clematis, Anemone, Pulsatilla, Hepatica, and Knowltonia: An approximately 4-kb expansion of the inverted repeat and four inversions within the large single-copy region. These rearrangements support the monophyletic status of these genera, clearly separating them from Caltha, Ranunculus, and Adonis. Two further inversions were found in two Clematis species and three Anemone species. While appearing to support a monophyletic grouping for these taxa, these two inversions conflict with data from both chloroplast restriction sites and morphology and are better interpreted as having occurred twice independently. These are the first two documented cases of homoplastic inversions in chloroplast DNA. Finally, the second intron of the chloroplast rps 12 gene was shown to have been lost in the common ancestor of the same three Anemone species that feature the two homoplastic inversions. PMID:8006994

Hoot, S B; Palmer, J D

1994-03-01

258

Chromospheric anemone jets and magnetic reconnection in partially ionized solar atmosphere  

NASA Astrophysics Data System (ADS)

The solar optical telescope onboard Hinode with temporal resolution of less than 5 s and spatial resolution of 150 km has observed the lower solar atmosphere with an unprecedented detail. This has led to many important findings, one of them is the discovery of chromospheric anemone jets in the solar chromosphere. The chromospheric anemone jets are ubiquitous in solar chromosphere and statistical studies show that the typical length, life time and energy of the chromospheric anemone jets are much smaller than the coronal events (e.g., jets/flares/CMEs). Among various observational parameters, the apparent length and maximum velocity shows good correlation. The velocity of chromospheric anemone jets is comparable to the local Alfvn speed in the lower solar chromosphere. Since the discovery of chromospheric anemone jets by Hinode, several evidences of magnetic reconnection in chromospheric anemone jets have been found and these observations are summarized in this paper. These observations clearly suggest that reconnection occurs quite rapidly as well as intermittently in the solar chromosphere. In the solar corona (?i > ?SP), anomalous resistivity arises due to various collisionless processes. Previous MHD simulations show that reconnection becomes fast as well as strongly time-dependent due to anomalous resistivity. Such processes would not arise in the solar chromosphere which is fully collisional and partially-ionized. So, it is unclear how the rapid and strongly time-dependent reconnection would occur in the solar chromosphere. It is quite likely that the Hall and ambipolar diffusion are present in the solar chromosphere and they could play an important role in driving such rapid, strongly time-dependent reconnection in the solar chromosphere.

Singh, K. A. P.; Shibata, K.; Nishizuka, N.; Isobe, H.

2011-11-01

259

Chromospheric anemone jets and magnetic reconnection in partially ionized solar atmosphere  

SciTech Connect

The solar optical telescope onboard Hinode with temporal resolution of less than 5 s and spatial resolution of 150 km has observed the lower solar atmosphere with an unprecedented detail. This has led to many important findings, one of them is the discovery of chromospheric anemone jets in the solar chromosphere. The chromospheric anemone jets are ubiquitous in solar chromosphere and statistical studies show that the typical length, life time and energy of the chromospheric anemone jets are much smaller than the coronal events (e.g., jets/flares/CMEs). Among various observational parameters, the apparent length and maximum velocity shows good correlation. The velocity of chromospheric anemone jets is comparable to the local Alfven speed in the lower solar chromosphere. Since the discovery of chromospheric anemone jets by Hinode, several evidences of magnetic reconnection in chromospheric anemone jets have been found and these observations are summarized in this paper. These observations clearly suggest that reconnection occurs quite rapidly as well as intermittently in the solar chromosphere. In the solar corona ({lambda}{sub i} > {delta}{sub SP}), anomalous resistivity arises due to various collisionless processes. Previous MHD simulations show that reconnection becomes fast as well as strongly time-dependent due to anomalous resistivity. Such processes would not arise in the solar chromosphere which is fully collisional and partially-ionized. So, it is unclear how the rapid and strongly time-dependent reconnection would occur in the solar chromosphere. It is quite likely that the Hall and ambipolar diffusion are present in the solar chromosphere and they could play an important role in driving such rapid, strongly time-dependent reconnection in the solar chromosphere.

Singh, K. A. P.; Shibata, K. [Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Nishizuka, N. [Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara-shi, Kanagawa (Japan); Isobe, H. [Unit for Synergetic Studies for Space, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)

2011-11-15

260

Oregon's Rocky Shore Species: Anemones Giant Green Anemones get their bright coloration from symbiotic, single-celled  

E-print Network

" (blobs on rocks that look like paint or tar) is a different stage in the life cycle of this red alga;Oregon's Rocky Shore Species: Sea Stars Rocky shores are home to a diverse group of species including the very colorful ochre sea star Close-up of ochre sea stars illustrating the va- riety of colors

Wright, Dawn Jeannine

261

Similar specificities of symbiont uptake by adults and larvae in an anemone model system for coral biology.  

PubMed

Reef-building corals depend for much of their energy on photosynthesis by symbiotic dinoflagellate algae (genus Symbiodinium) that live within their gastrodermal cells. However, the cellular mechanisms underpinning this ecologically critical symbiosis, including those governing the specificity of symbiont uptake by the host, remain poorly understood, in part because of the difficulties of working with corals in the laboratory. Here, we used the small symbiotic sea anemone Aiptasia as an experimentally tractable model system to analyze the specificity and timing of symbiosis onset in larval and adult animals under controlled laboratory conditions. Using four clonal, axenic Symbiodinium strains, we found no difference in uptake specificity between larvae (even when very young) and adults. Although both compatible and incompatible algal strains were found within the larval guts, only the former appeared to be internalized by gastrodermal cells, and they (but not incompatible algae) proliferated rapidly within the larvae in the absence of detectable exchange with other larvae. Older larvae showed reduced ingestion of both compatible and incompatible algae, and the addition of food failed to promote the uptake of an incompatible algal strain. Thus, Aiptasia adults and larvae appear to have similar mechanisms for discriminating between compatible and incompatible dinoflagellate types prior to phagocytosis by host gastrodermal cells. Whether a particular algal strain is compatible or incompatible appears to be stable during years of axenic culture in the absence of a host. These studies provide a foundation for future analyses of the mechanisms of symbiont-uptake specificity in this emerging model system. PMID:24526722

Hambleton, Elizabeth A; Guse, Annika; Pringle, John R

2014-05-01

262

Giemsa banding: karyotype differences in some species of Anemone and in Hepatica nobilis  

Microsoft Academic Search

Banding patterns were revealed in the karyotypes of six species of Anemone and in Hepatica nobilis using a Giemsa staining technique. There was considerable inter-specific variation both regarding the amount and distribution of bands. Small but significant intra-specific differences in banding patterns were also found. The results are discussed both as they relate to the use of Giemsa banding

G. E. Marks; D. Schweizer

1974-01-01

263

!Yes~igation of the Matina Svstem and Reproduction in The Pasque Flower (Anemone patens)  

Microsoft Academic Search

Klein Anne The buttercup family (Ranunculaceae) exhlbits a lot of variation in pollination methods and breeding strategies, where outcrossing (xenogamy) is typical, but self-fertilization (autogamy) has been observed. This study is an investigation of the breeding system and the pollination biology of Anemone patens, which exhibits both xenogamy and autogamy. Treatment groups were set up and analyzed to look at

Anne Mein

264

Shallow-water zoantharians (Cnidaria, Hexacorallia) from the Central Indo-Pacific  

PubMed Central

Abstract Despite the Central Indo-Pacific (CIP) and the Indonesian Archipelago being a well-known region of coral reef biodiversity, particularly in the Coral Triangle, little published information is available on its zoantharians (Cnidaria: Hexacorallia: Zoantharia). In order to provide a basis for future research on the Indo-Pacific zoantharian fauna and facilitate comparisons between more well-studied regions such as Japan and the Great Barrier Reef, this report deals with CIP zoantharian specimens in the Naturalis collection in Leiden, the Netherlands; 106 specimens were placed into 24 morpho-species and were supplemented with 88 in situ photographic records from Indonesia, the Philippines, and Papua New Guinea. At least nine morpho-species are likely to be undescribed species, indicating that the region needs more research in order to properly understand zoantharian diversity within the CIP. The Naturalis zoantharian specimens are listed by species, as well as all relevant collection information, and in situ images are provided to aid in future studies on zoantharians in the CIP. PMID:25349499

Reimer, James D.; Poliseno, Angelo; Hoeksema, Bert W.

2014-01-01

265

Evolution of box jellyfish (Cnidaria: Cubozoa), a group of highly toxic invertebrates  

PubMed Central

Cubozoa (Cnidaria: Medusozoa) represents a small clade of approximately 50 described species, some of which cause serious human envenomations. Our understanding of the evolutionary history of Cubozoa has been limited by the lack of a sound phylogenetic hypothesis for the group. Here, we present a comprehensive cubozoan phylogeny based on ribosomal genes coding for near-complete nuclear 18S (small subunit) and 28S (large subunit) and partial mitochondrial 16S. We discuss the implications of this phylogeny for our understanding of cubozoan venom evolution, biogeography and life-history evolution. Our phylogenetic hypothesis suggests that: (i) the last common ancestor of Carybdeida probably possessed the mechanism(s) underlying Irukandji syndrome, (ii) deep divergences between Atlantic and Indo-Pacific clades may be explained by ancient vicariant events, and (iii) sexual dimorphism evolved a single time in concert with complex sexual behaviour. Furthermore, several cubozoan taxa are either para- or polyphyletic, and we address some of these taxonomic issues by designating a new family, Carukiidae, a new genus, Copula, and by redefining the families Tamoyidae and Tripedaliidae. Lastly, cubozoan species identities have long been misunderstood and the data presented here support many of the recent scientific descriptions of cubozoan species. However, the results of a phylogeographic analysis of Alatina moseri from Hawai'i and Alatina mordens from Australia indicate that these two nominal species represent a single species that has maintained metapopulation cohesion by natural or anthropogenic dispersal. PMID:19923131

Bentlage, Bastian; Cartwright, Paulyn; Yanagihara, Angel A.; Lewis, Cheryl; Richards, Gemma S.; Collins, Allen G.

2010-01-01

266

Shallow-water zoantharians (Cnidaria, Hexacorallia) from the Central Indo-Pacific.  

PubMed

Despite the Central Indo-Pacific (CIP) and the Indonesian Archipelago being a well-known region of coral reef biodiversity, particularly in the 'Coral Triangle', little published information is available on its zoantharians (Cnidaria: Hexacorallia: Zoantharia). In order to provide a basis for future research on the Indo-Pacific zoantharian fauna and facilitate comparisons between more well-studied regions such as Japan and the Great Barrier Reef, this report deals with CIP zoantharian specimens in the Naturalis collection in Leiden, the Netherlands; 106 specimens were placed into 24 morpho-species and were supplemented with 88 in situ photographic records from Indonesia, the Philippines, and Papua New Guinea. At least nine morpho-species are likely to be undescribed species, indicating that the region needs more research in order to properly understand zoantharian diversity within the CIP. The Naturalis' zoantharian specimens are listed by species, as well as all relevant collection information, and in situ images are provided to aid in future studies on zoantharians in the CIP. PMID:25349499

Reimer, James D; Poliseno, Angelo; Hoeksema, Bert W

2014-01-01

267

Numerical Simulations of Chromospheric Anemone Jets Associated with Moving Magnetic Features  

NASA Astrophysics Data System (ADS)

Observations with the space-based solar observatory Hinode show that small-scale magnetic structures in the photosphere are found to be associated with a particular class of jets of plasma in the chromosphere called anemone jets. The goal of our study is to conduct a numerical experiment of such chromospheric anemone jets related to the moving magnetic features (MMFs). We construct a 2.5 dimensional numerical MHD model to describe the process of magnetic reconnection between the MMFs and the pre-existing ambient magnetic field, which is driven by the horizontal motion of the magnetic structure in the photosphere. We include thermal conduction parallel to the magnetic field and optically thin radiative losses in the corona to account for a self-consistent description of the evaporation process during the heating of the plasma due to the reconnection process. The motion of the MMFs leads to the expected jet and our numerical results can reproduce many observed characteristics of chromospheric anemone jets, topologically and quantitatively. As a result of the tearing instability, plasmoids are generated in the reconnection process that are consistent with the observed bright moving blobs in the anemone jets. An increase in the thermal pressure at the base of the jet is also driven by the reconnection, which induces a train of slow-mode shocks propagating upward. These shocks are a secondary effect, and only modulate the outflow of the anemone jet. The jet itself is driven by the energy input due to the reconnection of the MMFs and the ambient magnetic field.

Yang, Liping; He, Jiansen; Peter, Hardi; Tu, Chuanyi; Zhang, Lei; Feng, Xueshang; Zhang, Shaohua

2013-11-01

268

NUMERICAL SIMULATIONS OF CHROMOSPHERIC ANEMONE JETS ASSOCIATED WITH MOVING MAGNETIC FEATURES  

SciTech Connect

Observations with the space-based solar observatory Hinode show that small-scale magnetic structures in the photosphere are found to be associated with a particular class of jets of plasma in the chromosphere called anemone jets. The goal of our study is to conduct a numerical experiment of such chromospheric anemone jets related to the moving magnetic features (MMFs). We construct a 2.5 dimensional numerical MHD model to describe the process of magnetic reconnection between the MMFs and the pre-existing ambient magnetic field, which is driven by the horizontal motion of the magnetic structure in the photosphere. We include thermal conduction parallel to the magnetic field and optically thin radiative losses in the corona to account for a self-consistent description of the evaporation process during the heating of the plasma due to the reconnection process. The motion of the MMFs leads to the expected jet and our numerical results can reproduce many observed characteristics of chromospheric anemone jets, topologically and quantitatively. As a result of the tearing instability, plasmoids are generated in the reconnection process that are consistent with the observed bright moving blobs in the anemone jets. An increase in the thermal pressure at the base of the jet is also driven by the reconnection, which induces a train of slow-mode shocks propagating upward. These shocks are a secondary effect, and only modulate the outflow of the anemone jet. The jet itself is driven by the energy input due to the reconnection of the MMFs and the ambient magnetic field.

Yang, Liping; He, Jiansen; Tu, Chuanyi; Zhang, Lei [School of Earth and Space Sciences, Peking University, 100871 Beijing (China); Peter, Hardi [Max Planck Institute for Solar System Research, D-37191 Katlenburg-Lindau (Germany); Feng, Xueshang [SIGMA Weather Group, State Key Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, 100871 Beijing (China); Zhang, Shaohua, E-mail: jshept@gmail.com [Institute of Geology and Geophysics, Chinese Academy of Sciences, 100871 Beijing (China)

2013-11-01

269

Internal anatomy of Haliclystus antarcticus (Cnidaria, Staurozoa) with a discussion on histological features used in Staurozoan taxonomy.  

PubMed

Stauromedusae have relatively few macromorphological characters, making both their taxonomy and identification difficult. For this reason, histological characters are also employed in the taxonomy of the group. This study presents a detailed description of the histomorphology of Haliclystus antarcticus Pfeffer, 1889 (Cnidaria, Staurozoa). We make new observations for the species and for the class, and address functional, taxonomical, and evolutionary aspects of staurozoan histo-anatomy. A complete reconstruction of H. antarcticus body plan is used to guide a more detailed observation, based on light microscopy, of structures rarely cited in the literature, such as the intertentacular lobules, the ostia between adjacent perradial pockets, and the male and female gonadal vesicles. Two possible regions of nematocyst formation are hypothesized and discussed. We also provide a review of the current use of histological characters in the taxonomy of the group. Understanding the body plan of stauromedusae is a challenge, because each single individual presents characters found in medusae and in polyps of other medusozoans. Comprehensive histological descriptions are important to establish relations of homology within Staurozoa and Cnidaria, providing crucial data on their evolution. PMID:24072690

Miranda, Luclia S; Collins, Allen G; Marques, Antonio C

2013-12-01

270

Acetate incorporation into the lipids of the anemone Anthopleura elegantissima and its associated zooxanthellae  

Microsoft Academic Search

Anthopleura elegantissima containing zooxanthellae, as well as isolated zooxanthellae, incubated with acetate-1-14C under both light and dark conditions readily incorporate radioactivity into their total lipid pools. In both cases, the specific activity was greatly increased in the light. Dark-incubated anemones and isolated zooxanthellae incorporate activity predominantly into polar lipid; the remainder being present principally in the triglyceride moiety. Light-incubated organisms,

R. S. Blanquet; J. C. Nevenzel; A. A. Benson

1979-01-01

271

Geophytesherbivore interactions: reproduction and population dynamics of Anemone coronaria L  

Microsoft Academic Search

Anemone coronaria, an attractive Mediterranean geophyte, seems to disappear from grazing-protected areas in Israel. We experimentally examined\\u000a the ecological mechanism driving the decline of this geophyte. Ten plot-pairs were established, half we fenced as grazing\\u000a exclosures and half were grazed by beef cattle. Grazing clearly reduced herbaceous biomass, increased relative solar photosynthetic\\u000a active radiation (PAR) at ground level, but had

A. Perevolotsky; R. Schwartz-Tzachor; R. Yonathan; G. Neeman

2011-01-01

272

Multiple origins of Southern Hemisphere Anemone (Ranunculaceae) based on plastid and nuclear sequence data  

Microsoft Academic Search

.?Using two molecular data sets, the plastid atpB-rbcL intergenic spacer region and the nuclear ribosomal internal transcribed spacer regions (ITS), the taxonomic affinities of\\u000a two newly available Anemone species from the Southern Hemisphere were tested. From previous work based on morphology and geographic distribution, it\\u000a was assumed that A. tenuicaulis from New Zealand was most closely related to the Tasmanian

E. Schuettpelz; S. B. Hoot; R. Samuel; F. Ehrendorfer

2002-01-01

273

The Association between the Hermit Crab Dardanus arrosor (Herbst) and the Sea Anemone Calliactis parasitica (Couch)  

Microsoft Academic Search

The association between Calliactis parasitica and the Mediterranean hermit crab, Dardanus arrosor, has been re-examined. It was confirmed that, unlike the Atlantic crab, Pagurus bernhardus, Dardanus arrosor can display an active behaviour pattern which assists the transfer of Calliactis to its shell. Extensive trials showed, however, a marked tendency for crabs to divide into two groups: 'performers', which show this

D. M. Ross; L. Sutton

1961-01-01

274

ADAPTATIONS TO ENVIRONMENTAL OXYGEN LEVELS IN INFATJNAL AND EPIFAUNAL SEA ANEMONES  

Microsoft Academic Search

Numerous investigators have shown correhatioius between various physiological properties of aquatic organisms amidthe chuaracteristic levels of oxygemuin which the aninuals are foumud. Older studies omusurvival timuueumuder how oxygen coiuditions gemuerally imudicate that, withimu closely related groups, burrowimug species are more resistamut to oxygen deprivatiomu thamu epifaunal forms (Packard, 1905). Sinuilarly, animals living imufast-moving streanus are less resistant than those living

CLAY SASSAMAN; CHARLOTTE P. MANGUM

1972-01-01

275

NMR analysis of sequence of toxin II from the sea anemone Radianthus paumotensis  

SciTech Connect

Toxin II from Radianthus paumotensis (Rp/sub II/) has been investigated by high-resolution NMR and chemical sequencing methods. Resonance assignments have been obtained for this protein by the sequential approach. NMR assignments could not be made consistent with the previously reported primary sequence for this protein, and chemical methods have been used to determine a sequence with which the NMR data are consistent. Analysis of the 2D NOE spectra shows that the protein secondary structure is comprised of two sequences of ..beta..-sheet, probably joined into a distorted continuous sheet, connected by turns and extended loops, without any regular ..cap alpha..-helical segments. The residues previously implicated in activity in this class of proteins, D8 and R13, occur in a loop region.

Wemmer, D.E.; Kumar, N.V.; Metrione, R.M.; Lazdunski, M.; Drobny, G.; Kallenbach, N.R.

1986-11-04

276

OXYGEN RADICAL PRODUCTION IN THE SEA ANEMONE ANTHOPLEURA ELEGANTISSIMA AND ITS ENDOSYMBIOTIC ALGAE  

Microsoft Academic Search

Summary Host animals in algal-invertebrate endosymbiotic associations are exposed to photosynthetically generated hyperoxia while in sunlight, conditions conducive to photodynamic excitations and production of cytotoxic oxygen-derived radicals such as the superoxide anion (O 2 T ) and the hydroxyl radical ('OH). All previous evidence of oxyradical production in symbiotic associations has been circumstan- tial. We here present direct evidence, from

JAMES A. DYKENS; J. MALCOLM SHICK; CRAIG BENOIT; GARRY R. BUETTNER; GARY W. WINSTON

1992-01-01

277

Unexpected complexity of the Wnt gene family in a sea anemone  

Microsoft Academic Search

The Wnt gene family encodes secreted signalling molecules that control cell fate in animal development and human diseases. Despite its significance, the evolution of this metazoan-specific protein family is unclear. In vertebrates, twelve Wnt subfamilies were defined, of which only six have counterparts in Ecdysozoa (for example, Drosophila and Caenorhabditis). Here, we report the isolation of twelve Wnt genes from

Arne Kusserow; Kevin Pang; Carsten Sturm; Martina Hrouda; Jan Lentfer; Heiko A. Schmidt; Ulrich Technau; Arndt von Haeseler; Bert Hobmayer; Mark Q. Martindale; Thomas W. Holstein

2005-01-01

278

From Sea Anemone to Homo sapiens: The Evolution of the p53 Family of Genes  

SciTech Connect

Levine, a leading authority on the molecular basis of cancer, gives a lecture on how the genes for p53 (genes that prevent cancer and preserve life) and related proteins have survived through a billion years of evolution.

Arnold Levine

2009-09-14

279

The Response of the Sea Anemone Calliactis parasitica to Shells of the Hermit Crab Pagurus bernhardus  

Microsoft Academic Search

The five stages in the behaviour pattern by which Calliactis parasitica transfers to shells of Buccinum, normally occupied by Pagurus bernhardus, are described. The first of these, the clinging of tentacles to shell, is a trigger for the pattern as a whole; it occurs in Calliactis already settled on glass or plastic, and more consistently, in Calliactis whose pedal disks

D. M. Ross; L. Sutton

1961-01-01

280

Sexual reproduction of two intertidal sea anemones (Coelenteria: Actiniaria) in Malaysia  

E-print Network

Sexual reproduction in the actinians *Anthopleura handi* Dunn and *Haliplanella luciae* (Verrill) was studied through one year at Jeram, on the Malacca Straits. No evidence could be marshalled to support periodicity in gametogenesis of either...

Fautin, Daphne G.

1982-01-01

281

Respiratory response of the sea anemone Bunodosoma cavernata (Bosc) to changes in temperature and salinity  

E-print Network

Lewis & Post ( 1982) McClendon ( 1917) McClendon ( 1917) Table 11. continued ANIMAL REPORTED RATE RATE (as ml Oz/g/h) SOUR CE Cestus veneris Eunicea tourneforti Gorgoni a bentalina Heteroxenia fuscencens Muriceo sis flavida P exaura flexuosa... Lewis & Post ( 1982) McClendon ( 1917) McClendon ( 1917) Table 11. continued ANIMAL REPORTED RATE RATE (as ml Oz/g/h) SOUR CE Cestus veneris Eunicea tourneforti Gorgoni a bentalina Heteroxenia fuscencens Muriceo sis flavida P exaura flexuosa...

Retzer, Kent Arnold

2012-06-07

282

Asexual reproduction and molecular systematics of the sea anemone Anthopleura krebsi(Actiniaria: Actiniidae)  

Microsoft Academic Search

In this paper we use allozyme analyses to demonstrate that individuals in Anthopleura krebsi aggre- gates are monoclonal. Additionally, sympatric samples of the red and the green colour-morphs of A. krebsi from Pernambuco, Brazil were genetically compared and no significant differences were observed between them (gene identity= 0.992), indicating that they do not belong to different biological species. All individuals

Paula Braga Gomes; Mauricio Oscar Zamponi; Antonio Mateo Sol-Cava

2003-01-01

283

The effects of sexual and asexual reproduction on geographic variation in the sea anemone Actinia tenebrosa  

Microsoft Academic Search

Allelic and genotypic frequencies were determined for samples from 35 widely distributed Australasian colonies of Actinia tenebrosa and 2 South African colonies of A. equina. These data provided no evidence of gene flow between Australisian and South African Actinia colonies and indicated that there may be some restriction of gene flow between widely separated Australasian colonies.

D. J. Ayre

1984-01-01

284

Inter-genotype aggression in the solitary sea anemone Actinia tenebrosa  

Microsoft Academic Search

Acrorhagial fighting occurs between some pairs of adult Actinia tenebrosa, and such fighting almost always results in the locomotory withdrawal of the loser. Adults are also able to attack and kill juvenile conspecifics in laboratory conditions. In laboratory trials, 58 of 89 pairs of adults responded aggressively when placed in contact. Conflicts developed disproportionately often when adults were genotypically different,

D. J. Ayre

1982-01-01

285

A sea anemone symbiotic with gastropods of eight species in the Mariana Islands  

E-print Network

. They had been reported predominantly from the north-eastern Atlantic, the Caribean, Japan, and New Zealand in shallow water, and the western Caribean, western Africa, and the south-western Atlantic in deep water. Since then Mercier & Hamel (208) have... is at the center of a recently established marine sanctuary and is now not subject to shell colecting by humans without agency permision. Four transects were perpendicular to the shoreline from the waters edge to a depth of 1 m, and one transect was parallel...

Goodwill, Roger H.; Fautin, Daphne G.; Furey, John; Daly, Marymegan

2009-01-01

286

Chromospheric Anemone Jets Observed with Hinode/SOT and Hida Ca II Spectroheliograph  

NASA Astrophysics Data System (ADS)

We present the first simultaneous observations of chromospheric anemone jets in active regions with the Ca II H broadband filetergram on the Hinode/SOT and with the Ca II K spetroheliogram on the Domeless Solar Telescope (DST) at the Hida Observatory. During coordinated observation period, 9 chromospheric anemone jets were simultaneously observed with the two instruments. These observations revealed: (1) the jets are generated in the low chromosphere because these cannot be seen in Ca II K3, (2) these jets are associated with mixed polarity regions which are either small emerging flux regions or moving magnetic features, (3) the Ca II K line often show red or blue asymmetry in K2/K1 component; the footpoint of the jets associated with emerging flux regions often show red asymmetry (2-16 km s-1), while the one with moving magnetic features show blue asymmetry (5 km s-1). The magnetic cancellations were observed at the footpoint of the jets. The canceling rates are of order of 1016 Mx s-1, and the resulting magnetic energy release rate (1.1-10)1024 erg s-1, with the total energy release (1-13)1026 erg for the duration of the magnetic cancellations, 130 s. These are comparable to the estimated total energy, 1026 erg, in a single chromospheric anemone jet.

Morita, S.; Shibata, K.; Ueno, S.; Ichimoto, K.; Kitai, R.; Otsuji, K.

2012-08-01

287

Observations of Chromospheric Anemone Jets with Hinode SOT and Hida Ca II Spectroheliogram  

E-print Network

We present the first simultaneous observations of chromospheric "anemone" jets in solar active regions with Hinode SOT Ca II H broadband filetergram and Ca II K spetroheliogram on the Domeless Solar Telescope (DST) at Hida Observatory. During the coordinated observation, 9 chromospheric anemone jets were simultaneously observed with the two instruments. These observations revealed three important features, i.e.: (1) the jets are generated in the lower chromosphere, (2) the length and lifetime of the jets are 0.4-5 Mm and 40-320 sec, (3) the apparent velocity of the jets with Hinode SOT are 3-24 km/s, while Ca II K3 component at the jets show blueshifts (in 5 events) in the range of 2- 6 km/s. The chromospheric anemone jets are associated with mixed polarity regions which are either small emerging flux regions or moving magnetic features. It is found that the Ca II K line often show red or blue asymmetry in K2/K1 component: the footpoint of the jets associated with emerging flux regions often show redshift (2-...

Morita, Satoshi; Ueno, Satoru; Ichimoto, Kiyoshi; Kitai, Reizaburo; Otsuji, Ken-ichi

2010-01-01

288

A conserved cluster of three PRD-class homeobox genes (homeobrain, rx and orthopedia) in the Cnidaria and Protostomia  

PubMed Central

Background Homeobox genes are a superclass of transcription factors with diverse developmental regulatory functions, which are found in plants, fungi and animals. In animals, several Antennapedia (ANTP)-class homeobox genes reside in extremely ancient gene clusters (for example, the Hox, ParaHox, and NKL clusters) and the evolution of these clusters has been implicated in the morphological diversification of animal bodyplans. By contrast, similarly ancient gene clusters have not been reported among the other classes of homeobox genes (that is, the LIM, POU, PRD and SIX classes). Results Using a combination of in silico queries and phylogenetic analyses, we found that a cluster of three PRD-class homeobox genes (Homeobrain (hbn), Rax (rx) and Orthopedia (otp)) is present in cnidarians, insects and mollusks (a partial cluster comprising hbn and rx is present in the placozoan Trichoplax adhaerens). We failed to identify this 'HRO' cluster in deuterostomes; in fact, the Homeobrain gene appears to be missing from the chordate genomes we examined, although it is present in hemichordates and echinoderms. To illuminate the ancestral organization and function of this ancient cluster, we mapped the constituent genes against the assembled genome of a model cnidarian, the sea anemone Nematostella vectensis, and characterized their spatiotemporal expression using in situ hybridization. In N. vectensis, these genes reside in a span of 33 kb with the same gene order as previously reported in insects. Comparisons of genomic sequences and expressed sequence tags revealed the presence of alternative transcripts of Nv-otp and two highly unusual protein-coding polymorphisms in the terminal helix of the Nv-rx homeodomain. A population genetic survey revealed the Rx polymorphisms to be widespread in natural populations. During larval development, all three genes are expressed in the ectoderm, in non-overlapping territories along the oral-aboral axis, with distinct temporal expression. Conclusion We report the first evidence for a PRD-class homeobox cluster that appears to have been conserved since the time of the cnidarian-bilaterian ancestor, and possibly even earlier, given the presence of a partial cluster in the placozoan Trichoplax. Very similar clusters comprising these three genes exist in Nematostella and diverse protostomes. Interestingly, in chordates, one member of the ancestral cluster (homeobrain) has apparently been lost, and there is no linkage between rx and orthopedia in any of the vertebrates. In Nematostella, the spatial expression of these three genes along the body column is not colinear with their physical order in the cluster but the temporal expression is, therefore, using the terminology that has been applied to the Hox cluster genes, the HRO cluster would appear to exhibit temporal but not spatial colinearity. It remains to be seen whether the mechanisms responsible for the evolutionary conservation of the HRO cluster are the same mechanisms responsible for cohesion of the Hox cluster and other ANTP-class homeobox clusters that have been widely conserved throughout animal evolution. PMID:20849646

2010-01-01

289

MULTIPLE PLASMA EJECTIONS AND INTERMITTENT NATURE OF MAGNETIC RECONNECTION IN SOLAR CHROMOSPHERIC ANEMONE JETS  

SciTech Connect

The recent discovery of chromospheric anemone jets with the Solar Optical Telescope (SOT) on board Hinode has shown an indirect evidence of magnetic reconnection in the solar chromosphere. However, the basic nature of magnetic reconnection in chromosphere is still unclear. We studied nine chromospheric anemone jets from SOT/Hinode using Ca II H filtergrams, and we found multiple bright, plasma ejections along the jets. In most cases, the major intensity enhancements (larger than 30% relative to the background intensity) of the loop correspond to the timing of the plasma ejections. The typical lifetime and size of the plasma ejecta are about 20-60 s and 0.3-1.5 Mm, respectively. The height-time plot of jet shows many sub-structures (or individual jets) and the typical lifetime of the individual jet is about one to five minutes. Before the onset of the jet activity, a loop appears in Ca II H and gradually increases in size, and after few minutes several jets are launched from the loop. Once the jet activity starts and several individual jets are launched, the loop starts shrinking with a speed of {approx}4 km s{sup -1}. In some events, a downward moving blob with a speed of {approx}35 km s{sup -1} was observed, associated with the upward moving plasma along one of the legs of the loop hosting the jets. The upward moving plasma gradually developed into jets. Multiple plasma ejections in chromospheric anemone jet show the strongly time-dependent as well as intermittent nature of magnetic reconnection in the solar chromosphere.

Singh, K. A. P.; Nishida, K.; Shibata, K. [Kwasan and Hida Observatories, Graduate School of Science, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Isobe, H. [Unit of Synergetic Study for Space, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Nishizuka, N., E-mail: singh@kwasan.kyoto-u.ac.jp, E-mail: nishida@kwasan.kyoto-u.ac.jp, E-mail: shibata@kwasan.kyoto-u.ac.jp, E-mail: isobe@kwasan.kyoto-u.ac.jp, E-mail: nishizuka.naoto@jaxa.jp [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara-shi, Kanagawa 229-8510 (Japan)

2012-11-01

290

Multiple Plasma Ejections and Intermittent Nature of Magnetic Reconnection in Solar Chromospheric Anemone Jets  

NASA Astrophysics Data System (ADS)

The recent discovery of chromospheric anemone jets with the Solar Optical Telescope (SOT) on board Hinode has shown an indirect evidence of magnetic reconnection in the solar chromosphere. However, the basic nature of magnetic reconnection in chromosphere is still unclear. We studied nine chromospheric anemone jets from SOT/Hinode using Ca II H filtergrams, and we found multiple bright, plasma ejections along the jets. In most cases, the major intensity enhancements (larger than 30% relative to the background intensity) of the loop correspond to the timing of the plasma ejections. The typical lifetime and size of the plasma ejecta are about 20-60 s and 0.3-1.5 Mm, respectively. The height-time plot of jet shows many sub-structures (or individual jets) and the typical lifetime of the individual jet is about one to five minutes. Before the onset of the jet activity, a loop appears in Ca II H and gradually increases in size, and after few minutes several jets are launched from the loop. Once the jet activity starts and several individual jets are launched, the loop starts shrinking with a speed of ~4 km s-1. In some events, a downward moving blob with a speed of ~35 km s-1 was observed, associated with the upward moving plasma along one of the legs of the loop hosting the jets. The upward moving plasma gradually developed into jets. Multiple plasma ejections in chromospheric anemone jet show the strongly time-dependent as well as intermittent nature of magnetic reconnection in the solar chromosphere.

Singh, K. A. P.; Isobe, H.; Nishizuka, N.; Nishida, K.; Shibata, K.

2012-11-01

291

Haemolytic activities and adjuvant effect of Anemone raddeana saponins (ARS) on the immune responses to ovalbumin in mice  

Microsoft Academic Search

In this study, saponins (ARS) extracted from the rhizoma of Anemone raddeana were evaluated for their haemolytic activities and its potential ability as adjuvant on the cellular and humoral immune responses of ICR mice against ovalbumin. The haemolytic activity of ARS was determined using 0.5% rabbit red blood cell. ARS showed a slight haemolytic effect, with its haemolytic percents being

Yongxu Sun; Mingquan Li; Jicheng Liu

2008-01-01

292

SEA TURTLES Sea Turtles  

E-print Network

the loggerhead, Kemp's ridley, olive ridley, green, leatherback, and hawks- bill turtles. In the Pacific Ocean317 SEA TURTLES UNIT 24 Sea Turtles Unit 24 PROTECTED RESOURCES STAFF NMFS Office of Protected Center La Jolla, CA INTRODUCTION Sea turtles are highly migratory and widely distributed throughout

293

Beaufort Sea! Chukchi Sea!  

E-print Network

Beaufort Sea! Chukchi Sea! Herald Shoal Hanna Shoal Barrow Canyon Herald Canyon Bering Strait of the Alaska Coastal Current (a) Bering Strait! (b) Central Shelf! (c) BCH! (d) BCC/DBO! (e) BCM! BCC avg the Arctic Ocean through Bering Strait is transported across the shallow and expansive Chukchi Sea through

Pickart, Robert S.

294

The Evolution of the Four Subunits of Voltage-Gated Calcium Channels: Ancient Roots, Increasing Complexity, and Multiple Losses  

PubMed Central

The alpha subunits of voltage-gated calcium channels (Cavs) are large transmembrane proteins responsible for crucial physiological processes in excitable cells. They are assisted by three auxiliary subunits that can modulate their electrical behavior. Little is known about the evolution and roles of the various subunits of Cavs in nonbilaterian animals and in nonanimal lineages. For this reason, we mapped the phyletic distribution of the four channel subunits and reconstructed their phylogeny. Although alpha subunits have deep evolutionary roots as ancient as the split between plants and opistokonths, beta subunits appeared in the last common ancestor of animals and their close-relatives choanoflagellates, gamma subunits are a bilaterian novelty and alpha2/delta subunits appeared in the lineage of Placozoa, Cnidaria, and Bilateria. We note that gene losses were extremely common in the evolution of Cavs, with noticeable losses in multiple clades of subfamilies and also of whole Cav families. As in vertebrates, but not protostomes, Cav channel genes duplicated in Cnidaria. We characterized by in situ hybridization the tissue distribution of alpha subunits in the sea anemone Nematostella vectensis, a nonbilaterian animal possessing all three Cav subfamilies common to Bilateria. We find that some of the alpha subunit subtypes exhibit distinct spatiotemporal expression patterns. Further, all six sea anemone alpha subunit subtypes are conserved in stony corals, which separated from anemones 500 MA. This unexpected conservation together with the expression patterns strongly supports the notion that these subtypes carry unique functional roles. PMID:25146647

Moran, Yehu; Zakon, Harold H.

2014-01-01

295

A Diploblastic Radiate Animal at the Dawn of Cambrian Diversification with a Simple Body Plan: Distinct from Cnidaria?  

PubMed Central

Background Microfossils of the genus Punctatus include developmental stages such as blastula, gastrula, and hatchlings, and represent the most complete developmental sequence of animals available from the earliest Cambrian. Despite the extremely well-preserved specimens, the evolutionary position of Punctatus has relied only on their conical remains and they have been tentatively assigned to cnidarians. We present a new interpretation of the Punctatus body plan based on the developmental reconstruction aided by recent advances in developmental biology. Results Punctatus developed from a rather large egg, gastrulated in a mode of invagination from a coeloblastura, and then formed a mouth directly from the blastopore. Spiny benthic hatchlings were distinguishable from swimming or crawling ciliate larvae found in cnidarians and sponges. A mouth appeared at the perihatching embryonic stage and was renewed periodically during growth, and old mouths transformed into the body wall, thus elongating the body. Growing animals retained a small blind gut in a large body cavity without partitioning by septa and did not form tentacles, pedal discs or holdfasts externally. A growth center at the oral pole was sufficient for body patterning throughout life, and the body patterning did not show any bias from radial symmetry. Conclusions Contrary to proposed cnidarian affinity, the Punctatus body plan has basic differences from that of cnidarians, especially concerning a spacious body cavity separating ectoderm from endoderm. The lack of many basic cnidarian characters in the body patterning of Punctatus leads us to consider its own taxonomic group, potentially outside of Cnidaria. PMID:23840375

Yasui, Kinya; Reimer, James D.; Liu, Yunhuan; Yao, Xiaoyong; Kubo, Daisuke; Shu, Degan; Li, Yong

2013-01-01

296

Cytotoxic oleanane-type triterpenoid saponins from the Rhizomes of Anemone rivularis var. flore-minore.  

PubMed

Phytochemical investigation of the n-BuOH extract of the rhizomes of Anemone rivularis var. flore-minore led to the isolation of five new oleanane-type triterpenoid saponins 1-5, together with five known saponins 6-10. Their structures were determined by the extensive use of 1D and 2D NMR experiments, along with ESIMS analyses and acid hydrolysis. The aglycone of 4 and 5 was determined as 21?-hydroxyoleanolic acid, which was reported in this genus for the first time. The cytotoxicity of these compounds was evaluated against four human cancer cell line, including HL-60 (promyelocytic leukemia), HepG2 (hepatocellular carcinoma), A549 (lung carcinoma) and HeLa (cervical carcinoma). The monodesmosidic saponins 6-8 exhibited cytotoxic activity toward all tested cancer cell lines, with IC50 values in the 7.25-22.38 ?M range. PMID:24552983

Wang, Xiaoyang; Wang, Minchang; Xu, Min; Wang, Yi; Tang, Haifeng; Sun, Xiaoli

2014-01-01

297

Anemone structure of Active Region NOAA 10798 and related geo-effective flares/ CMEs  

NASA Astrophysics Data System (ADS)

Introduction: We report the evolution and the coronal features of an active region NOAA 10798, and the related magnetic storms. Method: We examined in detail the photospheric and coronal features of the active region by using observational data in soft X-rays, in extreme ultraviolet images, and in magnetogram obtained with GOES, SOHO satellites. We also examined the interplanetary disturbances from the ACE data. Results: This active region was located in the middle of a small coronal hole, and generated 3 M-class flares. The flares are associated with high speed CMEs up to 2000 km/s. The interplanetary disturbances also show a structure with southward strong magnetic field. These produced a magnetic storm on 2005 August 24. Conclusions: The anemone structure may play a role for producing the high-speed and geo-effective CMEs even the near limb locations.

Asai, A.; Ishii, T. T.; Shibata, K.; Gopalswamy, N.

2006-08-01

298

Synthesis and biological evaluation of Raddeanin A, a triterpene saponin isolated from Anemone raddeana.  

PubMed

First, Raddeanin A, a cytotoxic oleanane-type triterpenoid saponin isolated from Anemone raddeana REGEL, was synthesized. Stepwise glycosylation was adopted in the synthesis from oleanolic acid, employing arabinosyl, glucosyl and rhamnosyl trichloroacetimidate as donors. The chemical structure of Raddeanin A was confirmed by means of (1)H-NMR, (13)C-NMR, IR, MS and elemental analysis, which elucidated the structure to be 3-O-?-L-rhamnopyranosyl-(1?2)-?-D-glucopyranosyl-(1?2)-?-L-arabinopyranoside oleanolic acid. Biological activity tests showed that in the range of low concentrations, Raddeanin A displayed moderate inhibitory activity against histone deacetylases (HDACs), indicating that the HDACs' inhibitory activity of Raddeanin A may contribute to its cytotoxicity. PMID:25087630

Qian, Shan; Chen, Quan Long; Guan, Jin Long; Wu, Yong; Wang, Zhou Yu

2014-01-01

299

Growth of the Antarctic octocoral Primnoella scotiae and predation by the anemone Dactylanthus antarcticus  

NASA Astrophysics Data System (ADS)

Growth rates in Antarctic marine ectotherms have been demonstrated to be slowed by two to five times compared to shallow-water temperate species, with no previous reports for octocorals. Here growth rates were estimated in the single axis, non-branching Antarctic octocoral Primnoella scotiae using repeated in situ length measures covering both summer and winter periods, for tagged colonies from three sites at Signy Island over a two year period. Mean rates of length increase at the different sites ranged from 0.96 mm yr-1 to 55.3 mm yr-1. The fastest individual colony growth rate at any site ranged from 2.55 mm yr-1 to 175.6 mm yr-1. The mean of the fastest growth rates across all sites was 33.0 mm yr-114.7 (s.e.). Growth was significantly different between sites, and also between seasons and years. The mean overall increase in diameter of the average sized colony in the study (222.5 mm in axis length) was 0.053 mm yr-1. This is the slowest reported growth rate of any octocoral to date, and is five times slower than growth in most cold water octocorals. During the study it was noted that colonies were being attacked and consumed by the anemone Dactylanthus antarcticus. At one of the sites studied, between 5% and 8% of colonies surveyed were attacked each month. Anemone dispersal was via whole body inflation and drifting to new prey colonies that were attached to using tentacle-like column protuberances.

Peck, Lloyd S.; Brockington, Simon

2013-08-01

300

Cnidarian internal stinging mechanism  

PubMed Central

Stinging mechanisms generally deliver venomous compounds to external targets. However, nematocysts, the microscopic stinging organelles that are common to all members of the phylum Cnidaria, occur and act in both external and internal tissue structures. This is the first report of such an internal piercing mechanism. This mechanism identifies prey items within the body cavity of the sea anemone and actively injects them with cytolytic venom compounds. Internal tissues isolated from sea anemones caused the degradation of live Artemia salina nauplii in vitro. When examined, the nauplii were found to be pierced by discharged nematocysts. This phenomenon is suggested to aid digestive phagocytic processes in a predator otherwise lacking the means to masticate its prey. PMID:19129118

Schlesinger, Ami; Zlotkin, Eliahu; Kramarsky-Winter, Esti; Loya, Y.

2008-01-01

301

Pax gene diversity in the basal cnidarian Acropora millepora (Cnidaria, Anthozoa): implications for the evolution of the Pax gene family.  

PubMed

Pax genes encode a family of transcription factors, many of which play key roles in animal embryonic development but whose evolutionary relationships and ancestral functions are unclear. To address these issues, we are characterizing the Pax gene complement of the coral Acropora millepora, an anthozoan cnidarian. As the simplest animals at the tissue level of organization, cnidarians occupy a key position in animal evolution, and the Anthozoa are the basal class within this diverse phylum. We have identified four Pax genes in Acropora: two (Pax-Aam and Pax-Bam) are orthologs of genes identified in other cnidarians; the others (Pax-Cam and Pax-Dam) are unique to Acropora. Pax-Aam may be orthologous with Drosophila Pox neuro, and Pax-Bam clearly belongs to the Pax-2/5/8 class. The Pax-Bam Paired domain binds specifically and preferentially to Pax-2/5/8 binding sites. The recently identified Acropora gene Pax-Dam belongs to the Pax-3/7 class. Clearly, substantial diversification of the Pax family occurred before the Cnidaria/higher Metazoa split. The fourth Acropora Pax gene, Pax-Cam, may correspond to the ancestral vertebrate Pax gene and most closely resembles Pax-6. The expression pattern of Pax-Cam, in putative neurons, is consistent with an ancestral role of the Pax family in neural differentiation and patterning. We have determined the genomic structure of each Acropora Pax gene and show that some splice sites are shared both between the coral genes and between these and Pax genes in triploblastic metazoans. Together, these data support the monophyly of the Pax family and indicate ancient origins of several introns. PMID:10781047

Miller, D J; Hayward, D C; Reece-Hoyes, J S; Scholten, I; Catmull, J; Gehring, W J; Callaerts, P; Larsen, J E; Ball, E E

2000-04-25

302

Observations of Chromospheric Anemone Jets with Hinode CaII Broadband Filtergraph and Hida CaII Spectroheliograph  

NASA Astrophysics Data System (ADS)

We report on the first simultaneous observations of chromospheric ``anemone'' jets in solar active regions with the Hinode Solar Optical Telescope (SOT) CaII H broadband filtergraph and the CaII K spetroheliograph on the Domeless Solar Telescope (DST) at Hida Observatory. During the period of coordinated observations, nine chromospheric anemone jets were simultaneously observed with the two instruments. These observations revealed three important features: (1) the jets are generated in the lower chromosphere; i.e., these cannot be seen in CaII K3; (2) the length and lifetime of the jets are 0.4-5 Mm and 40-320 s, respectively; (3) the apparent velocity of the jets observed with the SOT is 3-24 km s-1, while the CaII K3 component at the jets shows a blueshift (in 5 events) in the range of 2-6 km s-1. The chromospheric anemone jets are associated with mixed polarity regions, which are either small emerging flux regions or moving magnetic features. It is found that the CaII K line often shows red or blue asymmetry in the K2/K1 component; the footpoint of the jets associated with emerging flux regions often shows a redshift (2-16 km s-1), while the one with moving magnetic features shows a blueshift (5 km s-1). A detailed analysis of the magnetic evolution of the jet-forming regions revealed that the reconnection rate (or canceling rate) of the total magnetic flux at the footpoint of the jets is on the order of 1016 Mx s-1, and the resulting magnetic energy release rate is (1.1-10) 1024 erg s-1, with a total energy release of (1-13) 1026 erg for the duration of the magnetic cancellation, 130 s. These are comparable to the estimated total energy, 1026 erg, in a single chromospheric anemone jet. In addition to the DST CaII K spectroheliogram and the SOT CaII H broadband filtergram, we also used for analysis an SOT magnetogram as well as a Hida H? filtergram. We present a physical model of the jet based on the observation, and discuss the relation between chromospheric anemone jets and Ellerman bombs.

Morita, Satoshi; Shibata, Kazunari; Ueno, Satoru; Ichimoto, Kiyoshi; Kitai, Reizaburo; Otsuji, Ken-Ichi

2010-08-01

303

Calcium sulfate hemihydrate is the inorganic mineral in statoliths of Scyphozoan medusae (Cnidaria).  

PubMed

Scyphomedusae use inorganic crystals (statoliths) for gravity sensing. The organs which contain the statoliths are called rhopalia. Rhopalia of five different species of the three different orders of the class Scyphozoa were studied with high-end solid-state chemical methods to elucidate the crystallographic nature of the biomineral: synchrotron powder diffraction, synchrotron single-crystal diffraction, synchrotron microtomography, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Each rhopalium contains a large number of statoliths in an ordered way. The statoliths of all species consist of calcium sulfate hemihydrate, a water-deficient phase. This is remarkable for sea-living organisms consisting mostly of water. The phylogenetic relationships within the class Scyphozoa are discussed. PMID:15824794

Becker, Alexander; Stje, Ilka; Paulmann, Carsten; Beckmann, Felix; Donath, Tilman; Boese, Roland; Prymak, Oleg; Tiemann, Henry; Epple, Matthias

2005-04-21

304

Sea Turtles  

NSDL National Science Digital Library

Sea World informational resource on all eight species of sea turtles. Excellent introduction to sea turtles including information on their classification, habitat, diet, reproduction, and much more. Includes photographs and illustrations throughout. Features two teaching activities for grades K-2.

2012-07-26

305

Spatiotemporal characteristics and mechanisms of intracellular Ca(2+) increases at fertilization in eggs of jellyfish (Phylum Cnidaria, Class Hydrozoa).  

PubMed

We have clarified, for the first time, the spatiotemporal patterns of intracellular Ca(2+) increases at fertilization and the Ca(2+)-mobilizing mechanisms in eggs of hydrozoan jellyfish, which belong to the evolutionarily old diploblastic phylum, Cnidaria. An initial Ca(2+) increase just after fertilization took the form of a Ca(2+) wave starting from one cortical region of the egg and propagating to its antipode in all of four hydrozoan species tested: Cytaeis uchidae, Cladonema pacificum, Clytia sp., and Gonionema vertens. The initiation site of the Ca(2+) wave was restricted to the animal pole, which is known to be the only area of sperm-egg fusion in hydrozoan eggs, and the wave propagating velocity was estimated to be 4.2-5.9 mum/s. After a Ca(2+) peak had been attained by the initial Ca(2+) wave, the elevated Ca(2+) gradually declined and returned nearly to the resting value at 7-10 min following fertilization. Injection of inositol 1,4,5-trisphosphate (IP(3)), an agonist of IP(3) receptors (IP(3)R), was highly effective in inducing a Ca(2+) increase in unfertilized eggs; IP(3) at a final intracellular concentration of 12-60 nM produced a fully propagating Ca(2+) wave equivalent to that observed at fertilization. In contrast, a higher concentration of cyclic ADP-ribose (cADPR), an agonist of ryanodine receptors (RyR), only generated a localized Ca(2+) increase that did not propagate in the egg. In addition, caffeine, another stimulator of RyR, was completely without effect. Sperm-induced Ca(2+) increases in Gonionema eggs were severely affected by preinjection of heparin, an inhibitor of Ca(2+) release from IP(3)R. These results strongly suggest that there is a well-developed IP(3)R-, but not RyR-mediated Ca(2+) release mechanism in hydrozoan eggs and that the former system primarily functions at fertilization. Our present data also demonstrate that the spatial characteristics and mechanisms of Ca(2+) increases at fertilization in hydrozoan eggs resemble those reported in higher triploblastic animals. PMID:15733659

Deguchi, Ryusaku; Kondoh, Eri; Itoh, Junko

2005-03-15

306

Bioactive oleanane-type saponins from the rhizomes of Anemone taipaiensis.  

PubMed

Investigation of the n-BuOH extract of the rhizomes of Anemone taipaiensis led to the isolation of five new oleanane-type triterpenoid saponins (1-5), together with seven known saponins (6-12). Their structures were determined by the extensive use of (1)D and (2)D NMR experiments along with ESIMS analyses and acid hydrolysis. The aglycone of 1, 2 and 4 was determined as siaresinolic acid, which was reported in this genus for the first time. The cytotoxicities of the saponins 1-12, prosapogenins 4a, 5a, 10a-12a and sapogenins siaresinolic acid (SA), oleanolic acid (OA), hederagenin (HE) were evaluated against five human cancer cell lines, including HepG2, HL-60, A549, HeLa and U87MG. The monodesmosidic saponins 6-8, 5a, 10a-12a and sapogenins SA, OA, HE exhibited cytotoxic activity toward all cancer cell lines, with IC50 values ranging from 2.25 to 57.28 ?M. Remarkably, the bisdesmosidic saponins 1-4 and 9 showed selective cytotoxicity against the U87MG cells. PMID:23992864

Wang, Xiao-Yang; Gao, Hui; Zhang, Wei; Li, Yuan; Cheng, Guang; Sun, Xiao-Li; Tang, Hai-Feng

2013-10-15

307

Nanoporous TiO2 nanoparticle assemblies with mesoscale morphologies: nano-cabbage versus sea-anemone.  

PubMed

We report the novel synthesis of nanoporous TiO2 nanoparticle ensembles with unique mesoscale morphologies. Constituent nanoparticles evolved into multifaceted assemblies, exhibiting excellent crystallinity and enhanced photocatalytic activity compared with commercial TiO2. Such materials could be exploited for applications, like organic pollutant degradation. PMID:24760418

Darbandi, Masih; Gebre, Tesfaye; Mitchell, Lucas; Erwin, William; Bardhan, Rizia; Levan, M Douglas; Mochena, Mogus D; Dickerson, James H

2014-06-01

308

Nanoporous TiO2 nanoparticle assemblies with mesoscale morphologies: nano-cabbage versus sea-anemone  

NASA Astrophysics Data System (ADS)

We report the novel synthesis of nanoporous TiO2 nanoparticle ensembles with unique mesoscale morphologies. Constituent nanoparticles evolved into multifaceted assemblies, exhibiting excellent crystallinity and enhanced photocatalytic activity compared with commercial TiO2. Such materials could be exploited for applications, like organic pollutant degradation.We report the novel synthesis of nanoporous TiO2 nanoparticle ensembles with unique mesoscale morphologies. Constituent nanoparticles evolved into multifaceted assemblies, exhibiting excellent crystallinity and enhanced photocatalytic activity compared with commercial TiO2. Such materials could be exploited for applications, like organic pollutant degradation. Electronic supplementary information (ESI) available: Synthesis and characterization procedures, TEM/XRD of samples prepared at different temperature and water content, table of nitrogen adsorption-desorption values of different samples. See DOI: 10.1039/c3nr06154j

Darbandi, Masih; Gebre, Tesfaye; Mitchell, Lucas; Erwin, William; Bardhan, Rizia; Levan, M. Douglas; Mochena, Mogus D.; Dickerson, James H.

2014-05-01

309

Crystal Structure of the Soluble Form of Equinatoxin II, a PoreForming Toxin from the Sea Anemone Actinia equina  

Microsoft Academic Search

Background: Membrane poreforming toxins have a remarkable property: they adopt a stable soluble form structure, which, when in contact with a membrane, undergoes a series of transformations, leading to an active, membrane-bound form. In contrast to bacterial toxins, no structure of a pore-forming toxin from an eukaryotic organism has been determined so far, an indication that structural studies of equinatoxin

Alekos Athanasiadis; Gregor Anderluh; Peter Ma?ek; Duan Turk

2001-01-01

310

Sea Anemone Toxin: A Tool to Study Molecular Mechanisms of Nerve Conduction and Excitation-Secretion Coupling  

Microsoft Academic Search

The effects of a polypeptide neurotoxin from Anemonia sulcata on nerve conduction in crayfish giant axons and on frog myelinated fibers have been analyzed. The main features of toxin action are the following: (i) the toxin acts at very low doses and its action is apparently irreversible. (ii) The toxin selectively affects the closing (inactivation) of the Na+ channel by

G. Romey; J. P. Abita; H. Schweitz; G. Wunderer; M. Lazdunski

1976-01-01

311

Introducing the starlet sea anemone Nematostella vectensis as a model for investigating microbial mediation of health and disease in hexacorals  

E-print Network

All animals in their natural state harbor complex communities of microbes including those that are beneficial (symbionts), neutral, or harmful (pathogens). The dynamic interactions between animals and their microbiota often ...

Har, Jia Yi

2009-01-01

312

Early development of young brooded in the enteron of the beadlet sea anemone Actinia equina (Anthozoa: Actiniaria) from Japan  

Microsoft Academic Search

Histological observations were made to reveal the origin of young brooded in the enteron of adult Actinia equina from Japan. A total of 295 specimens were collected from four rocky intertidal areas of Sagami Bay and eastern Suruga Bay, Pacific coast of Japan, during the period from February 1994 to January 1995. In the enteron of adults, regardless of sex,

KENSUKE YANAGI; SUSUMU SEGAWA; KOTARO TSUCHIYA

1999-01-01

313

Reproductive biology, oogenesis and early development in the brood-caring sea anemone Actinostola spetsbergensis (Anthozoa: Actiniaria)  

Microsoft Academic Search

Kurzfassung Whrend der Fortpflanzungszeit im arktischen Sommer erzeugen die ?? vonA. spetsbergensisCarlgren Oocyten, die durch ihre Hlle aus umfangreicher Mesogloea und histologisch stark verndertem Ovarial-Endoderm auffallen; die Anzahl der sich pro Weibchen entwickelnden Eier ist ungewhnlich gering. Das befruchtete Ei lst sich aus dem Ovar, verlt jedoch das Muttertier nicht, sondern wird mit Hilfe seiner nichtzelligen Hlle im oberen Teil

K. Riemann-Zrneck; Biologische Anstalt Helgoland

1976-01-01

314

Phenotypic selection and characterization of randomly produced non-haemolytic mutants of the toxic sea anemone protein sticholysin II.  

PubMed

A rapid screening method for haemolytic activity, using blood agar plates, has been developed to analyze randomly produced mutant variants of the pore-forming protein sticholysin II (Stn II). Those exhibiting a reduced activity were selected and the DNA corresponding to each Stn II variant sequenced. Once the mutation produced was determined, protein variants were isolated and characterized in terms of structure (circular dichroism spectra and thermal stability) and haemolytic activity. Three single mutation protein variants, at residues K19, F106 and Y111, showed a significantly decreased haemolytic activity while their thermostability was identical to that of the wild-type protein. Considering the obtained data and based on the three-dimensional structure of the protein, the role of these residues on the mechanism of haemolysis has been analyzed. PMID:15388326

Alegre-Cebollada, Jorge; Lacadena, Valle; Oaderra, Mercedes; Mancheo, Jos M; Gavilanes, Jos G; del Pozo, Alvaro Martnez

2004-09-24

315

Modeling habitat distribution from organism occurrences and environmental data: case study using anemonefishes and their sea anemone hosts  

E-print Network

We demonstrate the KGSMapper (Kansas Geological Survey Mapper), a straightforward, web-based biogeographic tool that uses environmental conditions of places where members of a taxon are known to occur to find other places ...

Guinotte, J. M.; Bartley, J. D.; Iqbal, A.; Fautin, Daphne G.; Buddemeier, Robert W.

2006-07-03

316

Character evolution in light of phylogenetic analysis and taxonomic revision of the zooxanthellate sea anemone families Thalassianthidae and Aliciidae  

E-print Network

are involved in a symbiosis with zooxanthellae (intracellular photosynthetic algae), which is implicated in the evolution of these morphological structures to increase surface area available for zooxanthellae and to provide protection against predation. Both...

Crowther, Andrea Louise

2013-05-31

317

Anemone-like nanostructures for non-lithographic, reproducible, large-area, and ultra-sensitive SERS substrates.  

PubMed

The melt-infiltration technique enables the fabrication of complex nanostructures for a wide range of applications in optics, electronics, biomaterials, and catalysis. Here, anemone-like nanostructures are produced for the first time under the surface/interface principles of melt-infiltration as a non-lithographic method. Functionalized anodized aluminum oxide (AAO) membranes are used as templates to provide large-area production of nanostructures, and polycarbonate (PC) films are used as active phase materials. In order to understand formation dynamics of anemone-like structures finite element method (FEM) simulations are performed and it is found that wetting behaviour of the polymer is responsible for the formation of cavities at the caps of the structures. These nanostructures are examined in the surface-enhanced-Raman-spectroscopy (SERS) experiment and they exhibit great potential in this field. Reproducible SERS signals are detected with relative standard deviations (RSDs) of 7.2-12.6% for about 10?000 individual spots. SERS measurements are demonstrated at low concentrations of Rhodamine 6G (R6G), even at the picomolar level, with an enhancement factor of ?10(11). This high enhancement factor is ascribed to the significant electric field enhancement at the cavities of nanostructures and nanogaps between them, which is supported by finite difference time-domain (FDTD) simulations. These novel nanostructured films can be further optimized to be used in chemical and plasmonic sensors and as a single molecule SERS detection platform. PMID:25220106

Daglar, Bihter; Demirel, Gokcen Birlik; Khudiyev, Tural; Dogan, Tamer; Tobail, Osama; Altuntas, Sevde; Buyukserin, Fatih; Bayindir, Mehmet

2014-10-01

318

Anemone-like nanostructures for non-lithographic, reproducible, large-area, and ultra-sensitive SERS substrates  

NASA Astrophysics Data System (ADS)

The melt-infiltration technique enables the fabrication of complex nanostructures for a wide range of applications in optics, electronics, biomaterials, and catalysis. Here, anemone-like nanostructures are produced for the first time under the surface/interface principles of melt-infiltration as a non-lithographic method. Functionalized anodized aluminum oxide (AAO) membranes are used as templates to provide large-area production of nanostructures, and polycarbonate (PC) films are used as active phase materials. In order to understand formation dynamics of anemone-like structures finite element method (FEM) simulations are performed and it is found that wetting behaviour of the polymer is responsible for the formation of cavities at the caps of the structures. These nanostructures are examined in the surface-enhanced-Raman-spectroscopy (SERS) experiment and they exhibit great potential in this field. Reproducible SERS signals are detected with relative standard deviations (RSDs) of 7.2-12.6% for about 10 000 individual spots. SERS measurements are demonstrated at low concentrations of Rhodamine 6G (R6G), even at the picomolar level, with an enhancement factor of ~1011. This high enhancement factor is ascribed to the significant electric field enhancement at the cavities of nanostructures and nanogaps between them, which is supported by finite difference time-domain (FDTD) simulations. These novel nanostructured films can be further optimized to be used in chemical and plasmonic sensors and as a single molecule SERS detection platform.The melt-infiltration technique enables the fabrication of complex nanostructures for a wide range of applications in optics, electronics, biomaterials, and catalysis. Here, anemone-like nanostructures are produced for the first time under the surface/interface principles of melt-infiltration as a non-lithographic method. Functionalized anodized aluminum oxide (AAO) membranes are used as templates to provide large-area production of nanostructures, and polycarbonate (PC) films are used as active phase materials. In order to understand formation dynamics of anemone-like structures finite element method (FEM) simulations are performed and it is found that wetting behaviour of the polymer is responsible for the formation of cavities at the caps of the structures. These nanostructures are examined in the surface-enhanced-Raman-spectroscopy (SERS) experiment and they exhibit great potential in this field. Reproducible SERS signals are detected with relative standard deviations (RSDs) of 7.2-12.6% for about 10 000 individual spots. SERS measurements are demonstrated at low concentrations of Rhodamine 6G (R6G), even at the picomolar level, with an enhancement factor of ~1011. This high enhancement factor is ascribed to the significant electric field enhancement at the cavities of nanostructures and nanogaps between them, which is supported by finite difference time-domain (FDTD) simulations. These novel nanostructured films can be further optimized to be used in chemical and plasmonic sensors and as a single molecule SERS detection platform. Electronic supplementary information (ESI) available: SEM images of the AAO membrane and bare polymer film, FEM simulations of anemone-like polymeric nanopillars depending on the time and pressure, and detailed calculation of the enhancement factor both including experimental and theoretical approaches. See DOI: 10.1039/c4nr03909b

Daglar, Bihter; Demirel, Gokcen Birlik; Khudiyev, Tural; Dogan, Tamer; Tobail, Osama; Altuntas, Sevde; Buyukserin, Fatih; Bayindir, Mehmet

2014-10-01

319

Vol. 12(50), pp. 6922-6930, 11 December, 2013 DOI: 10.5897/AJB2013.12956  

E-print Network

anemone equistatin overexpression Mahmood Valizadeh1,2 , Celine Deraison3 , Seyed Kamal Kazemitabar4 and infestations can lower quality and cause transmission of viruses. The protease inhibitor Sea Anemone Equistatin, sea anemone equistatin, agrobacterium transformation. INTRODUCTION Cultivated chrysanthemum

Paris-Sud XI, Université de

320

Cnidarian phylogenetic relationships as revealed by mitogenomics  

PubMed Central

Background Cnidaria (corals, sea anemones, hydroids, jellyfish) is a phylum of relatively simple aquatic animals characterized by the presence of the cnidocyst: a cell containing a giant capsular organelle with an eversible tubule (cnida). Species within Cnidaria have life cycles that involve one or both of the two distinct body forms, a typically benthic polyp, which may or may not be colonial, and a typically pelagic mostly solitary medusa. The currently accepted taxonomic scheme subdivides Cnidaria into two main assemblages: Anthozoa (Hexacorallia?+?Octocorallia) cnidarians with a reproductive polyp and the absence of a medusa stage and Medusozoa (Cubozoa, Hydrozoa, Scyphozoa, Staurozoa) cnidarians that usually possess a reproductive medusa stage. Hypothesized relationships among these taxa greatly impact interpretations of cnidarian character evolution. Results We expanded the sampling of cnidarian mitochondrial genomes, particularly from Medusozoa, to reevaluate phylogenetic relationships within Cnidaria. Our phylogenetic analyses based on a mitochogenomic dataset support many prior hypotheses, including monophyly of Hexacorallia, Octocorallia, Medusozoa, Cubozoa, Staurozoa, Hydrozoa, Carybdeida, Chirodropida, and Hydroidolina, but reject the monophyly of Anthozoa, indicating that the Octocorallia?+?Medusozoa relationship is not the result of sampling bias, as proposed earlier. Further, our analyses contradict Scyphozoa [Discomedusae?+?Coronatae], Acraspeda [Cubozoa?+?Scyphozoa], as well as the hypothesis that Staurozoa is the sister group to all the other medusozoans. Conclusions Cnidarian mitochondrial genomic data contain phylogenetic signal informative for understanding the evolutionary history of this phylum. Mitogenome-based phylogenies, which reject the monophyly of Anthozoa, provide further evidence for the polyp-first hypothesis. By rejecting the traditional Acraspeda and Scyphozoa hypotheses, these analyses suggest that the shared morphological characters in these groups are plesiomorphies, originated in the branch leading to Medusozoa. The expansion of mitogenomic data along with improvements in phylogenetic inference methods and use of additional nuclear markers will further enhance our understanding of the phylogenetic relationships and character evolution within Cnidaria. PMID:23302374

2013-01-01

321

Sea urchin  

NSDL National Science Digital Library

The sea urchin is a type of echinoderm. It is a consumer because it cannot make its own food and must eat other organisms to get energy. Sea urchins are omnivores, meaning they eat both plants and other animals to gain energy. Sea urchins have been known to eat algae, mussels, and sponges.

N/A N/A (NOAA;Channel Islands National Marine Sanctuary)

2004-12-23

322

Increase of litter at the Arctic deep-sea observatory HAUSGARTEN.  

PubMed

Although recent research has shown that marine litter has made it even to the remotest parts of our planet, little information is available about temporal trends on the deep ocean floor. To quantify litter on the deep seafloor over time, we analysed images from the HAUSGARTEN observatory (79N) taken in 2002, 2004, 2007, 2008 and 2011 (2500 m depth). Our results indicate that litter increased from 3635 to 7710 items km? between 2002 and 2011 and reached densities similar to those reported from a canyon near the Portuguese capital Lisboa. Plastic constituted the majority of litter (59%) followed by a black fabric (11%) and cardboard/paper (7%). Sixty-seven percent of the litter was entangled or colonised by invertebrates such as sponges (41%) or sea anemones (15%). The changes in litter could be an indirect consequence of the receding sea ice, which opens the Arctic Ocean to the impacts of man's activities. PMID:23083926

Bergmann, Melanie; Klages, Michael

2012-12-01

323

Reproduction of Cnidaria  

E-print Network

Empirical and experimental data on cnidarian reproduction show it to be more variable than had been thought, and many patterns that had previously been deduced hold up poorly or not at all in light of additional data. The ...

Fautin, Daphne G.

2002-01-01

324

Reproductive strategy of the jellyfish Aurelia aurita (Cnidaria Scyphomedusae) in the Suez Canal and its migration between the Red Sea and Mediterranean  

Microsoft Academic Search

The life history of the common jellyfish A. aurita (Linnaeus) in the Suez Canal was investigated by monthly sampling over a 28 month period from September 2006 to December 2008. Young medusae of 23 cm diameter appeared during February\\/March. Growth was rapid. Some specimens of this cohort reached 16 cm and spawned by March\\/May and then decreased in size or

Hamed A. El-Serehy; Khaled A. Al-Rasheid

2011-01-01

325

Sea Chest  

NSDL National Science Digital Library

By exploring life at sea for sailors and passengers, the Maritime Museum of San Diego offers insight into the history of maritime exploration, emigration, and commerce. Background and classroom activities are applicable to history, geography, social studies, science, art and other subjects. Emphasis on 19th Century sea travel and sailing ships, with topics including navigation techniques and technology, sailor's crafts, health and medicine at sea, shipboard life and social interactions.

326

Sea Stars  

NSDL National Science Digital Library

At first glance, starfish, more properly called sea stars, arent doing much of anything. In this video, Jonathans investigations reveal a slow-motion predator that hunts and attacks its prey. Traveling the world, Jonathan investigates sea stars from the tropics to the Antarctic and uses time-lapse photography to reveal an amazing complexity to the world of the sea star. Please see the accompanying study guide for educational objectives and discussion points.

Productions, Jonathan B.

2010-10-06

327

Association of a luminous Vibrio sp ., taxonomically related to Vibrio harveyi, with Clytia linearis (Thornely, 1900) (Hydrozoa, Cnidaria)  

Microsoft Academic Search

A previously unknown association between a luminous Vibrio sp., taxonomically related to the species Vibrio harveyi and a common member of the shallow\\/mid water communities of the Mediterranean Sea, the hydrozoan Clytia linearis is described. All the specimens of C. linearis observed under blue light excitation showed both a natural luminescence appearing as a series of fine dots due to

Loredana Stabili; Cinzia Gravili; Salvatore Maurizio Tredici; Ferdinando Boero; Pietro Alifano

2011-01-01

328

Biomass of Scyphozoan Jellyfish, and Its Spatial Association with 0-Group Fish in the Barents Sea  

PubMed Central

An 0-group fish survey is conducted annually in the Barents Sea in order to estimate fish population abundance. Data on jellyfish by-catch have been recorded since 1980, although this dataset has never been analysed. In recent years, however, the ecological importance of jellyfish medusae has become widely recognized. In this paper the biomass of jellyfish (medusae) in 060 m depths is calculated for the period 19802010. During this period the climate changed from cold to warm, and changes in zooplankton and fish distribution and abundance were observed. This paper discusses the less well known ecosystem component; jellyfish medusae within the Phylum Cnidaria, and their spatial and temporal variation. The long term average was ca. 9108 kg, with some years showing biomasses in excess of 5109 kg. The biomasses were low during 1980s, increased during 1990s, and were highest in early 2000s with a subsequent decline. The bulk of the jellyfish were observed in the central parts of the Barents Sea, which is a core area for most 0-group fishes. Jellyfish were associated with haddock in the western area, with haddock and herring in the central and coastal area, and with capelin in the northern area of the Barents Sea. The jellyfish were present in the temperature interval 1CSea jellyfish medusae; however their biomass has showed a recent moderate decline during years with record high temperatures in the Barents Sea. Jellyfish are undoubtedly an important component of the Barents Sea ecosystem, and the data presented here represent the best summary of jellyfish biomass and distribution yet published for the region. PMID:22457732

Eriksen, Elena; Prozorkevich, Dmitry; Trofimov, Aleksandr; Howell, Daniel

2012-01-01

329

Biomass of scyphozoan jellyfish, and its spatial association with 0-group fish in the Barents Sea.  

PubMed

An 0-group fish survey is conducted annually in the Barents Sea in order to estimate fish population abundance. Data on jellyfish by-catch have been recorded since 1980, although this dataset has never been analysed. In recent years, however, the ecological importance of jellyfish medusae has become widely recognized. In this paper the biomass of jellyfish (medusae) in 0-60 m depths is calculated for the period 1980-2010. During this period the climate changed from cold to warm, and changes in zooplankton and fish distribution and abundance were observed. This paper discusses the less well known ecosystem component; jellyfish medusae within the Phylum Cnidaria, and their spatial and temporal variation. The long term average was ca. 910? kg, with some years showing biomasses in excess of 510? kg. The biomasses were low during 1980s, increased during 1990s, and were highest in early 2000s with a subsequent decline. The bulk of the jellyfish were observed in the central parts of the Barents Sea, which is a core area for most 0-group fishes. Jellyfish were associated with haddock in the western area, with haddock and herring in the central and coastal area, and with capelin in the northern area of the Barents Sea. The jellyfish were present in the temperature interval 1CSea jellyfish medusae; however their biomass has showed a recent moderate decline during years with record high temperatures in the Barents Sea. Jellyfish are undoubtedly an important component of the Barents Sea ecosystem, and the data presented here represent the best summary of jellyfish biomass and distribution yet published for the region. PMID:22457732

Eriksen, Elena; Prozorkevich, Dmitry; Trofimov, Aleksandr; Howell, Daniel

2012-01-01

330

Sea Turtles  

NSDL National Science Digital Library

In Malaysia there is an island known for more sea turtles than virtually anywhere on Earth. In this video, Jonathan visits this amazing ecosystem to learn about the life cycle of sea turtles. He is surprised to discover an amazingly complex and competitive environment. Please see the accompanying study guide for educational objectives and discussion points.

Productions, Jonathan B.

2010-03-29

331

Nutritional exchange in a tropical tripartite symbiosis: direct evidence for the transfer of nutrients from anemonefish to host anemone and zooxanthellae  

Microsoft Academic Search

The relationship between anemones and anemonefishes is an oft-cited and endearing example of a mutualistic symbiosis. Current\\u000a research on mutualistic symbioses suggests these relationships are more commonplace and have greater importance at the ecosystem\\u000a level on nutrient dynamics and evolutionary processes than previously thought. Using stable isotopes 15N and 13C, both field and laboratory experiments were designed to investigate whether

Ann Cleveland; E. Alan Verde; Raymond W. Lee

2011-01-01

332

Sea Level  

NSDL National Science Digital Library

This problem provides an opportunity to increase familiarity with negative and positive numbers on a number line. The vertical number line is presented as black markings every one meter all the way up a lighthouse and on the underwater support going down to the sea bed, with sea level being "0". In answering the nine questions, children begin to calculate with negative numbers in the context of the distances between the sea creatures. The Teachers' Notes page offers suggestions for implementation, discussion questions, ideas for extension and support, and a link to a related resource, Swimming Pool (cataloged separately).

2008-01-01

333

Student Experiments at Sea (SEAS)  

NSDL National Science Digital Library

Interdisciplinary curriculum introduces the scientific process, experimental design and data analysis. Units on plate tectonics, hydrothermal vents, ridge visualization, surveying deep sea organisms. Students become the scientists, developing proposals for at-sea investigations, teacher coordinates submission to researchers studying the East Pacific Rise. Students retrieve, organize, analyze and report data from their experiment. Past experimental journals are posted. Free registration required to access curriculum and submit proposal.

2010-12-23

334

Sea level trends in South East Asian Seas (SEAS)  

NASA Astrophysics Data System (ADS)

Southeast Asian Seas (SEAS) span the largest archipelago in the global ocean and provide a complex oceanic pathway connecting the Pacific and Indian Oceans. The SEAS regional sea level trends are some of the highest observed in the modern satellite altimeter record that now spans almost two decades. Initial comparisons of global sea level reconstructions find that 17 year sea level trends over the past 60 years exhibit good agreement in areas and at times of strong signal to noise associated decadal variability forced by low frequency variations in Pacific trade winds. The SEAS region exhibits sea level trends that vary dramatically over the studied time period. This historical variation suggests that the strong regional sea level trends observed during the modern satellite altimeter record will abate as trade winds fluctuate on decadal and longer time scales. Furthermore, after removing the contribution of the Pacific Decadal Oscillation (PDO) to sea level trends in the past twenty years, the rate of sea level rise is greatly reduced in the SEAS region. As a result of the influence of the PDO, the SEAS regional sea level trends during 2010s and 2020s are likely to be less than the global mean sea level (GMSL) trend if the observed oscillations in wind forcing and sea level persist. Nevertheless, long-term sea level trends in the SEAS will continue to be affected by GMSL rise occurring now and in the future.

Strassburg, M. W.; Hamlington, B. D.; Leben, R. R.; Manurung, P.; Lumban Gaol, J.; Nababan, B.; Vignudelli, S.; Kim, K.-Y.

2014-10-01

335

SaponinB, a novel cytostatic compound purified from Anemone taipaiensis, induces apoptosis in a human glioblastoma cell line.  

PubMed

Glioblastoma multiforme (GBM) is one of the most common malignant brain tumors. Saponin B, a novel compound isolated from the medicinal plant, Anemone taipaiensis, has been found to have a strong time- and dose-dependent cytostatic effect on human glioma cells and to suppress the growth of U87MG GBM cells. In this study, we investigated whether saponin B induces the apoptosis of glioblastoma cells and examined the underlying mechanism(s) of action of saponin B. Saponin B signi?cantly suppressed U87MG cell proliferation. Flow cytometric analysis of DNA in the U87MG cells con?rmed that saponin B blocked the cell cycle at the S phase. Furthermore, treatment of the U87MG cells with saponin B induced chromatin condensation and led to the formation of apoptotic bodies, as observed under a ?uorescence microscope, and Annexin V/PI assay further suggested that phosphatidylserine (PS) externalization was apparent at higher drug concentrations. Treatment with saponin B activated the receptor-mediated pathway of apoptosis, as western blot analysis revealed the activation of Fas-l. Saponin B increased the Bax and caspase-3 ratio and decreased the protein expression of Bcl-2. The results from the present study demonstrate that the novel compound, saponin B, effectively induces the apoptosis of GBM cells and inhibits glioma cell growth and survival. Therefore, saponin B may be a potential candidate for the development of novel cancer therapeutics with antitumor activity against gliomas. PMID:24048272

Wang, Yuangang; Tang, Haifeng; Zhang, Yun; Li, Juan; Li, Bo; Gao, Zhenhui; Wang, Xiaoyang; Cheng, Guang; Fei, Zhou

2013-11-01

336

The impact of invasive grasses on the population growth of Anemone patens, a long-lived native forb.  

PubMed

Negative impacts of invasive plants on natives have been well documented, but much less is known about whether invasive plants can cause population level declines. We used demographic models to investigate the effects of two invasive grasses on the demography and population growth of Anemone patens, a long-lived native perennial of North American grasslands. Demographic data of A. patens growing in patches characterized by Bromus inermis, Poa pratensis, or native grasses were used to parameterize integral projection models. Models based on both average conditions and those allowing for environmental stochasticity indicate that A. patens is slowly increasing in patches of native grass (lambda = 1.02) and declining in patches of invasive grasses, particularly those dominated by B. inermis (lambda = 0.93). Extinction probabilities indicate that A. patens should persist in native grass patches, but has a much higher probability of extinction in Bromus patches compared to Poa patches. While sensitivity analyses showed that survival had the biggest effect on population growth rates in all habitats, results of a Life Table Response Experiment (LTRE) revealed that slower individual growth rates in patches of invasive grasses contributed the most to the observed reduction in population growth. These results suggest that invasive grasses may cause slow declines in A. patens, despite short-term coexistence, and that controlling B. inermis only would not be sufficient to ensure A. patens persistence. PMID:17249243

Williams, Jennifer L; Crone, Elizabeth E

2006-12-01

337

Savage Seas  

NSDL National Science Digital Library

This companion site to the new PBS series offers a collection of informative pieces and activities centered around the world's oceans. The site is divided into four principal sections, each of which features an article, brief sidebars, video clips, and in some cases, animations. The first, The Captain's Bridge, explores shipwrecks, stormy seas, and ocean rescues. The second, The Crow's Nest, dives into the power of waves. The Deep Sea section takes users to the nether regions of the ocean, while The Weather Factory touches on cyclones, ice and icebergs, and El Nino. Additional features at the site include Ask the Expert, Facts from the Sea, an annotated collection of related sites, and information about the series.

338

THE JELLYFISH AURELIA AURITA (CNIDARIA: SCYPHOMEDUSAE): ITS LIFE HISTORY STRATEGY, MIGRATION ACTIVITY AND ITS IMPACT ON THE ZOOPLANKTON COMMUNITY OF SUEZ CANAL, EGYPT  

Microsoft Academic Search

Suez Canal is the main connecting link between the Red Sea in the south and the Mediterranean in the north. It crosses different lakes on its route from Port Said on the Mediterranean Sea to Port Suez on the Red Sea. Jellyfishes form a major part of the macro- plankton of the canal. The role of jellyfishes in general and

HAMED A. EL-SEREHY

339

Sea Launch  

NSDL National Science Digital Library

Sea Launch is an international satellite launch service company that has a unique way of delivering payloads into space. With the launch platform situated on the equator in the middle of the Pacific Ocean, a specially designed rocket propels satellites into orbit with very good accuracy. The Sea Launch home page has plenty of information about its operation, including an overview of the technology, statistics about its successes and failures, and Webcasts of many of its launches. A 200+ page user's guide goes into detail about all the various stages of a mission; everything from design considerations for the spacecraft to transportation to the launch site is mentioned in the document.

340

Aral Sea  

NASA Technical Reports Server (NTRS)

This series of MODIS images shows the dwindling Aral Sea. Once one of the world's largest freshwater lakes, the Aral Sea has decreased by as much as 60% over the past few decades due to diversion of the water to grow cotton and rice. These diversion have dropped the lake levels, increased salinity, and nearly decimated the fishing industry. The previous extent of the lake is clearly visible as a whitish perimeter in these image from April 16, May 18, and June 3, 2002. s. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

2002-01-01

341

Sea ice in the China Sea  

SciTech Connect

In every winter, sea ice occurring in Bohai Sea and the North Yellow Sea is the first-year ice which is going through generating, developing and thawing processes. Therefore, it is necessary to spatially and temporally describe ice period, freezing range, thickness variations and general motion of sea ice. The purpose of this paper is to provide initial general situation and features of sea ice for forecasting and researching sea ice.

Deng Shuqi [National Research Center for Marine Environmental Forecasts, Beijing (China)

1993-12-31

342

Celtic Sea  

... carbonate. The plates, or coccoliths, give the ocean a milky white or turquoise appearance during intense blooms. The long-term flux of ... Sea for several weeks in summer. The coccoliths backscatter light from the water column to create a bright optical effect. Other algal ...

2013-04-17

343

Triterpenoid saponins from the rhizomes of Anemone flaccida and their inhibitory activities on LPS-induced NO production in macrophage RAW264.7 cells.  

PubMed

A new ursane-type triterpenoid saponin, flaccidoside IV (1), and three new oleanane-type triterpenoid saponins, flaccidosides V-VII (2-4), along with 17 known saponins (5-21), were isolated from the rhizomes of Anemone flaccida. The structures of the new triterpenoid saponins were determined based on spectroscopic analyses and chemical methods. All the isolated saponins were tested for their inhibitory activities on lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophages, and several bisdesmosidic oleanane-type triterpenoid saponins (2, 7, and 10) showed significant inhibitory activities, which indicated they had potential anti-inflammatory activities under their noncytotoxic concentrations in vitro. PMID:25236706

Huang, Xiao-Jun; Tang, Jing-Qun; Li, Man-Mei; Liu, Qing; Li, Yao-Lan; Fan, Chun-Lin; Pei, Hong; Zhao, Hui-Nan; Wang, Ying; Ye, Wen-Cai

2014-09-01

344

Sea World  

NSDL National Science Digital Library

Excellent resource for information and teaching activities on marine life, designed primarily for elementary level. Teachers can sign up for a monthly e-newsletter (or access archived newsletters) filled with classroom activities, current information, and special links. Also features a searchable database of Sea World education materials and information on camps, marine science careers, and Shamu TV, an award-winning series broadcast around the country via satellite and cable.

345

Sea World  

NSDL National Science Digital Library

This is an excellent resource for information and teaching activities on marine life, designed primarily for elementary level. Teachers can sign up for a monthly e-newsletter (or access archived newsletters) filled with classroom activities, current information, and special links. Also features a searchable database of Sea World education materials and information on camps, marine science careers, and Shamu TV, an award-winning series broadcast around the country via satellite and cable.

2012-09-07

346

Systematic Motion of Fine-scale Jets and Successive Reconnection in Solar Chromospheric Anemone Jet Observed with the Solar Optical Telescope/Hinode  

NASA Astrophysics Data System (ADS)

The Solar Optical Telescope (SOT) on board Hinode allows observations with high spatiotemporal resolution and stable image quality. A ?-shaped chromospheric anemone jet was observed in high resolution with SOT/Hinode. We found that several fine-scale jets were launched from one end of the footpoint to the other. These fine-scale jets (~1.5-2.5 Mm) gradually move from one end of the footpoint to the other and finally merge into a single jet. This process occurs recurrently, and as time progresses the jet activity becomes more and more violent. The time evolution of the region below the jet in Ca II H filtergram images taken with SOT shows that various parts (or knots) appear at different positions. These bright knots gradually merge into each other during the maximum phase. The systematic motion of the fine-scale jets is observed when different knots merge into each other. Such morphology would arise due to the emergence of a three-dimensional twisted flux rope in which the axial component (or the guide field) appears in the later stages of the flux rope emergence. The partial appearance of the knots could be due to the azimuthal magnetic field that appears during the early stage of the flux rope emergence. If the guide field is strong and reconnection occurs between the emerging flux rope and an ambient magnetic field, this could explain the typical feature of systematic motion in chromospheric anemone jets.

Singh, K. A. P.; Isobe, H.; Nishida, K.; Shibata, K.

2012-11-01

347

SYSTEMATIC MOTION OF FINE-SCALE JETS AND SUCCESSIVE RECONNECTION IN SOLAR CHROMOSPHERIC ANEMONE JET OBSERVED WITH THE SOLAR OPTICAL TELESCOPE/HINODE  

SciTech Connect

The Solar Optical Telescope (SOT) on board Hinode allows observations with high spatiotemporal resolution and stable image quality. A {lambda}-shaped chromospheric anemone jet was observed in high resolution with SOT/Hinode. We found that several fine-scale jets were launched from one end of the footpoint to the other. These fine-scale jets ({approx}1.5-2.5 Mm) gradually move from one end of the footpoint to the other and finally merge into a single jet. This process occurs recurrently, and as time progresses the jet activity becomes more and more violent. The time evolution of the region below the jet in Ca II H filtergram images taken with SOT shows that various parts (or knots) appear at different positions. These bright knots gradually merge into each other during the maximum phase. The systematic motion of the fine-scale jets is observed when different knots merge into each other. Such morphology would arise due to the emergence of a three-dimensional twisted flux rope in which the axial component (or the guide field) appears in the later stages of the flux rope emergence. The partial appearance of the knots could be due to the azimuthal magnetic field that appears during the early stage of the flux rope emergence. If the guide field is strong and reconnection occurs between the emerging flux rope and an ambient magnetic field, this could explain the typical feature of systematic motion in chromospheric anemone jets.

Singh, K. A. P.; Nishida, K.; Shibata, K. [Kwasan and Hida Observatories, Graduate School of Science, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Isobe, H., E-mail: singh@kwasan.kyoto-u.ac.jp [Unit for Synergetic Study for Space, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)

2012-11-20

348

Sea Cucumbers  

NSDL National Science Digital Library

What reef animal comes in a rainbow of crazy colors, can throw out its innards to immobilize predators, then creep away and regrow a brand-new stomach? Its the sea cucumber, prized as a gastronomic delight by some cultures and beginning to yield some of its secrets to scientists. Follow host Ari Daniel Shapiro from a Chinatown market to the reefs of Fiji to learn more about this amazing creature. Also included is a Learn More section that provides background information on the scientists recorded in the podcast, lessons, images, and cool facts.

2009-01-01

349

Methodological approaches for nanotoxicology using cnidarian models.  

PubMed

The remarkable amenability of aquatic invertebrates to laboratory manipulation has already made a few species belonging to the phylum Cnidaria as attracting systems for exploring animal development. The proliferation of molecular and genomic tools, including the whole genomic sequence of the freshwater polyp Hydra vulgaris and the starlet sea anemone Nematostella vectensis, further enhances the promise of these species to investigate the evolution of key aspects of development biology. In addition, the facility with which cnidarian population can be investigated within their natural ecological context suggests that these models may be profitably expanded to address important questions in ecology and toxicology. In this review, we explore the traits that make Hydra and Nematostella exceptionally attractive model organisms in context of nanotoxicology, and highlight a number of methods and developments likely to further increase that utility in the near future. PMID:23193991

Ambrosone, Alfredo; Tortiglione, Claudia

2013-03-01

350

[Land and marine fauna constituting a threat for recreational divers in the tropics].  

PubMed

Due to intensively growing international tourism, increasing numbers of people leave for countries with hot climates, where various threats for human health and life exist. Besides climatic and sanitary conditions, a rich fauna, represented by predators and venomous animals, can be included. Based on available world literature and their own observations, the authors present the threats that a tourist can possibly encounter whilst relaxing on the beach or during recreational diving in tropical waters. When staying in water, a large threat is posed by marine fish of prey (sharks, barracuda, muraena), Cnidaria (jellyfish, corals, anemones) and venomous animals (fish, sea snakes). On land, on the other hand, a threat can be posed by venomous arthropods (scorpions, spiders) and Hymenoptera insects. The study presents the most important representatives of fauna present in coastal areas frequently visited by diving enthusiasts. Also, clinical image and conduct in the case of body injures are discussed. PMID:19112854

Korzeniewski, Krzysztof

2008-09-01

351

Sea Ice  

NASA Technical Reports Server (NTRS)

Sea ice covers vast areas of the polar oceans, with ice extent in the Northern Hemisphere ranging from approximately 7 x 10(exp 6) sq km in September to approximately 15 x 10(exp 6) sq km in March and ice extent in the Southern Hemisphere ranging from approximately 3 x 10(exp 6) sq km in February to approximately 18 x 10(exp 6) sq km in September. These ice covers have major impacts on the atmosphere, oceans, and ecosystems of the polar regions, and so as changes occur in them there are potential widespread consequences. Satellite data reveal considerable interannual variability in both polar sea ice covers, and many studies suggest possible connections between the ice and various oscillations within the climate system, such as the Arctic Oscillation, North Atlantic Oscillation, and Antarctic Oscillation, or Southern Annular Mode. Nonetheless, statistically significant long-term trends are also apparent, including overall trends of decreased ice coverage in the Arctic and increased ice coverage in the Antarctic from late 1978 through the end of 2003, with the Antarctic ice increases following marked decreases in the Antarctic ice during the 1970s. For a detailed picture of the seasonally varying ice cover at the start of the 21st century, this chapter includes ice concentration maps for each month of 2001 for both the Arctic and the Antarctic, as well as an overview of what the satellite record has revealed about the two polar ice covers from the 1970s through 2003.

Parkinson, Claire L.; Cavalieri, Donald J.

2005-01-01

352

Melting Ice, Rising Seas  

NASA Video Gallery

Sea level rise is an indicator that our planet is warming. Much of the world's population lives on or near the coast, and rising seas are something worth watching. Sea level can rise for two reason...

353

Tracking Sea Otters  

USGS Multimedia Gallery

USGS sea otter researcher Tim Tinker drives the boat on an expedition to track and observe sea otters in Monterey Bay, California. USGS scientists study sea otters in efforts to help the threatened species continue to recover from near extinction....

354

A vertical wall dominated by Acesta excavata and Neopycnodonte zibrowii, part of an undersampled group of deep-sea habitats.  

PubMed

We describe a novel biotope at 633 to 762 m depth on a vertical wall in the Whittard Canyon, an extensive canyon system reaching from the shelf to the deep sea on Ireland's continental margin. We explored this wall with an ROV and compiled a photomosaic of the habitat. The assemblage contributing to the biotope was dominated by large limid bivalves, Acesta excavata (mean shell height 10.4 cm), and deep-sea oysters, Neopycnodonte zibrowii, at high densities, particularly at overhangs. Mean density of N. zibrowii increased with depth, with densities of the most closely packed areas of A. excavata also increasing with depth. Other taxa associated with the assemblage included the solitary coral Desmophyllum dianthus, cerianthid anemones, comatulid crinoids, the trochid gastropod Margarites sp., the portunid crab Bathynectes longispina and small fish of the family Bythitidae. The scleractinian coral Madrepora oculata, the pencil urchin Cidaris cidaris and a species of Epizoanthus were also common. Prominent but less abundant species included the flytrap anemone Actinoscyphia saginata, the carrier crab Paramola cuvieri, and the fishes Lepidion eques and Conger conger. Observations of the hydrography of the canyon system identified that the upper 500 m was dominated by Eastern North Atlantic Water, with Mediterranean Outflow Water beneath it. The permanent thermocline is found between 600 and 1000 m depth, i.e., in the depth range of the vertical wall and the dense assemblage of filter feeders. Beam attenuation indicated nepheloid layers present in the canyon system with the greatest amounts of suspended material at the ROV dive site between 500 and 750 m. A cross-canyon CTD transect indicated the presence of internal waves between these depths. We hypothesise that internal waves concentrate suspended sediment at high concentrations at the foot of the vertical wall, possibly explaining the large size and high density of filter-feeding molluscs. PMID:24260319

Johnson, Mark P; White, Martin; Wilson, Annette; Wrzberg, Laura; Schwabe, Enrico; Folch, Helka; Allcock, A Louise

2013-01-01

355

A Vertical Wall Dominated by Acesta excavata and Neopycnodonte zibrowii, Part of an Undersampled Group of Deep-Sea Habitats  

PubMed Central

We describe a novel biotope at 633 to 762 m depth on a vertical wall in the Whittard Canyon, an extensive canyon system reaching from the shelf to the deep sea on Irelands continental margin. We explored this wall with an ROV and compiled a photomosaic of the habitat. The assemblage contributing to the biotope was dominated by large limid bivalves, Acesta excavata (mean shell height 10.4 cm), and deep-sea oysters, Neopycnodonte zibrowii, at high densities, particularly at overhangs. Mean density of N. zibrowii increased with depth, with densities of the most closely packed areas of A. excavata also increasing with depth. Other taxa associated with the assemblage included the solitary coral Desmophyllum dianthus, cerianthid anemones, comatulid crinoids, the trochid gastropod Margarites sp., the portunid crab Bathynectes longispina and small fish of the family Bythitidae. The scleractinian coral Madrepora oculata, the pencil urchin Cidaris cidaris and a species of Epizoanthus were also common. Prominent but less abundant species included the flytrap anemone Actinoscyphia saginata, the carrier crab Paramola cuvieri, and the fishes Lepidion eques and Conger conger. Observations of the hydrography of the canyon system identified that the upper 500 m was dominated by Eastern North Atlantic Water, with Mediterranean Outflow Water beneath it. The permanent thermocline is found between 600 and 1000 m depth, i.e., in the depth range of the vertical wall and the dense assemblage of filter feeders. Beam attenuation indicated nepheloid layers present in the canyon system with the greatest amounts of suspended material at the ROV dive site between 500 and 750 m. A cross-canyon CTD transect indicated the presence of internal waves between these depths. We hypothesise that internal waves concentrate suspended sediment at high concentrations at the foot of the vertical wall, possibly explaining the large size and high density of filter-feeding molluscs. PMID:24260319

Johnson, Mark P.; White, Martin; Wilson, Annette; Wurzberg, Laura; Schwabe, Enrico; Folch, Helka; Allcock, A. Louise

2013-01-01

356

The effects of asexual reproduction and inter-genotypic aggression on the genotypic structure of populations of the sea anemone Actinia tenebrosa  

Microsoft Academic Search

Genotype frequencies of adult and juvenile Actinia tenebrosa from 2 populations showed that settlement and recruitment predominantly involved the localised asexual (ameiotic) proliferation of established genotypes. However, there is strong indirect evidence that the genotypic variation was generated by sexual reproduction. Genotypic structuring of these populations was detected at 2 levels. First, coarse clumping of genotypically identical adults and juveniles

D. J. Ayre

1983-01-01

357

Venom present in sea anemone (Heteractis magnifica) induces apoptosis in non-small-cell lung cancer A549 cells through activation of mitochondria-mediated pathway.  

PubMed

Lung cancer is a major cause of cancer deaths throughout the world and the complexity of apoptosis resistance in lung cancer is apparent. Venom from Heteractis magnifica caused dose-dependent decreases in survival of the human non-small-cell lung cancer cell line, as determined by the MTT and Crystal Violet assays. The H. magnifica venom induced cell cycle arrest and induced apoptosis of A549 cells, as confirmed by annexin V/propidium iodide staining. The venom-induced apoptosis in A549 cells was characterized by cleavage of caspase-3 and a reduction in the mitochondrial membrane potential. Interestingly, crude extracts from H. magnifica had less effect on the survival of non-cancer cell lines. In the non-cancer cells, the mechanism via which cell death occurred was through necrosis not apoptosis. These findings are important for future work using H. magnifica venom for pharmaceutical development to treat human lung cancer. PMID:24190482

Ramezanpour, Mahnaz; da Silva, Karen Burke; Sanderson, Barbara J S

2014-03-01

358

Ion and nonelectrolyte permeability properties of channels formed in planar lipid bilayer membranes by the cytolytic toxin from the sea anemone, Stoichactis helianthus  

Microsoft Academic Search

Summary When present at nanomolar concentrations on one side of a lipid bilayer membrane,helianthus toxin (a protein of mol wt?16,000) increases enormously membrane permeability to ions and nonelectrolytes by forming channels in the membrane. Membranes containing sphingomyelin are especially sensitive to toxin, but sphingomyelin isnot required for toxin action. Conductance is proportional to about the 4th power of toxin concentration.

Wamberto Varanda; Alan Finkelstein

1980-01-01

359

Immunochemistry of sea anemone toxins: structure-antigenicity relationships and toxin-receptor interactions probed by antibodies specific for one antigenic  

SciTech Connect

Two antibody subpopulations directed against Anemonia sulcata toxin I or II have been purified by immunoaffinity chromatography. These antibodies are specific for a single antigenic region and were used in a structure-antigenicity relationship study using homologous toxins and chemically modified derivatives of A. sulcata toxin II. Asp-7 and/or Asp=9 and Gln-47 of toxin II were found to be implicated in the antigenic region recognized by the two antibody subpopulations. On the contrary, Arg-14, Lys-35, -36, and -46, and ..cap alpha..-NH/sub 2/ of the glycine residue of A. sulcata toxin II are not involved in the corresponding antigenic region. When assayed for interaction with the sodium channel, the antigenic region of toxin II, including Asp-9 and Gln-47, appeared fully accessible to its specific antibodies, suggesting that it is not involved in the binding of the toxin to its receptor.

Ayeb, M.E.; Bahraoui, E.M.; Granier, C.; Beress, L.; Rochat, H.

1986-11-04

360

Carbonic Anhydrase Expression and Synthesis in the Sea Anemone [ITAL]Anthopleura elegantissima[\\/ITAL] Are Enhanced by the Presence of Dinoflagellate Symbionts  

Microsoft Academic Search

Endosymbiotic dinoflagellates resident within cnidarian hosts are extremely productive primary producers. This high pro- ductivity may be due in part to an inorganic carbon transport system, present in host tissue, that accelerates carbon delivery to the algae. The enzyme carbonic anhydrase (CA; EC 4.2.1.1) has been shown to be important in this transport system in a variety of tropical symbiotic

Virginia M. Weis; Wendy S. Reynolds

1999-01-01

361

Nme Gene Family Evolutionary History Reveals Pre-Metazoan Origins and High Conservation between Humans and the Sea Anemone, Nematostella vectensis  

Microsoft Academic Search

BackgroundThe Nme gene family is involved in multiple physiological and pathological processes such as cellular differentiation, development, metastatic dissemination, and cilia functions. Despite the known importance of Nme genes and their use as clinical markers of tumor aggressiveness, the associated cellular mechanisms remain poorly understood. Over the last 20 years, several non-vertebrate model species have been used to investigate Nme

Thomas Desvignes; Pierre Pontarotti; Julien Bobe; Sergios-Orestis Kolokotronis

2010-01-01

362

Beaufort Sea: information update  

SciTech Connect

The report is based on a multi-disciplinary meeting held March 6-7, 1985, as part of preparations for the Beaufort Sea Sale 97. The chapters are based on presentations given: The causeway effect: Modification of nearshore thermal regime resulting from causeways; Summertime sea ice intrusions in the Chukchi Sea; The deepwater limit of ice gouging on the Beaufort Sea shelf; Distribution, abundance, migration, harvest, and stock identity of Belukha Whales in the Beaufort Sea; Ringed seals in the Beaufort Sea; Beaufort Sea socioeconomics; The Baffin Island Oil Spill, (BIOS) Project.

Becker, P.R.

1988-04-01

363

Cnidarian Diversity Classes of Cnidaria  

E-print Network

of carnivorous colonial hydrozoans · About 175 species known ­ Most live in deep ocean, so more are being · Polyps usually colonial · Habitat ­ Mostly marine ­ A few freshwater #12;3 sperm Young polyp male female;4 Siphonophores · Siphonophores have elaborated on coloniality ­ Unique form of individuality that has led many

Cochran-Stafira, D. Liane

364

Adhesion networks of cnidarians: a postgenomic view.  

PubMed

Cell-extracellular matrix (ECM) and cell-cell adhesion systems are fundamental to the multicellularity of metazoans. Members of phylum Cnidaria were classified historically by their radial symmetry as an outgroup to bilaterian animals. Experimental study of Hydra and jellyfish has fascinated zoologists for many years. Laboratory studies, based on dissection, biochemical isolations, or perturbations of the living organism, have identified the ECM layer of cnidarians (mesoglea) and its components as important determinants of stem cell properties, cell migration and differentiation, tissue morphogenesis, repair, and regeneration. Studies of the ultrastructure and functions of intercellular gap and septate junctions identified parallel roles for these structures in intercellular communication and morphogenesis. More recently, the sequenced genomes of sea anemone Nematostella vectensis, Hydra magnipapillata, and coral Acropora digitifera have opened up a new frame of reference for analyzing the cell-ECM and cell-cell adhesion molecules of cnidarians and examining their conservation with bilaterians. This chapter integrates a review of literature on the structure and functions of cell-ECM and cell-cell adhesion systems in cnidarians with current analyses of genome-encoded repertoires of adhesion molecules. The postgenomic perspective provides a fresh view on fundamental similarities between cnidarian and bilaterian animals and is impelling wider adoption of species from phylum Cnidaria as model organisms. PMID:24411175

Tucker, Richard P; Adams, Josephine C

2014-01-01

365

Mortality is associated with social rank in the clown anemonefish (Amphiprion percula)  

E-print Network

. percula, because these fish are well protected from predators by their close association with sea anemones predators afforded by the anemone. Six factors (reef, depth, anemone diameter, number of individuals explanation for this pattern was that competition for rank, amongst individuals within an anemone, resulted

Buston, Peter

366

Photoconversion in orange and red fluorescent  

E-print Network

and mTagRFP-T (a variant with increased photostability)10 are all derived from the same sea anemone that had been originally developed from a sea anemone chromoprotein11. For this protein, we observed minor

Cai, Long

367

Anthozoa -Corals and Anemones  

E-print Network

matrix that allows for calcium carbonate deposits to form · Localized removal of dissolved phosphates for photosynthesis · Therefore silty deposits from land can suffocate a reef · Zooxanthellae are very sensitive (nutrient for algae) which can inhibit formation of calcium carbonate · Generate extra oxygen through

Cochran-Stafira, D. Liane

368

Nucleotide sequence of the histone gene cluster in the coral acropora formosa (cnidaria; scleractinia): Features of histone gene structure and organization are common to diploblastic and triploblastic metazoans  

Microsoft Academic Search

We report the nucleotide sequence of the core histone gene cluster from the Cnidarian Acropora formosa. This is the first histone gene cluster to be sequenced from a diploblastic organism and the predicted amino acid sequences most resemble those of sea urchin equivalents. Each of the Cnidarian histone genes has two conserved regions 3' of the coding sequences and these

D. J. Miller; P. L. Harrison; T. J. Mahony; J. P. McMillan; A. Miles; D. M. Odorico; M. R. ten Lohuis

1993-01-01

369

The discovery of new deep-sea hydrothermal vent communities in the southern ocean and implications for biogeography.  

PubMed

Since the first discovery of deep-sea hydrothermal vents along the Galpagos Rift in 1977, numerous vent sites and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting hydrothermal vents in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR) in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea hydrothermal vents hosting high-temperature black smokers up to 382.8C and diffuse venting. The chemosynthetic ecosystems hosted by these vents are dominated by a new yeti crab (Kiwa n. sp.), stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in vent ecosystems in other oceans, including polychaete worms (Siboglinidae), bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR vents. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for vent taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic vent ecosystems represent a new vent biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea hydrothermal vents globally indicate that vent biogeography is more complex than previously recognised. PMID:22235194

Rogers, Alex D; Tyler, Paul A; Connelly, Douglas P; Copley, Jon T; James, Rachael; Larter, Robert D; Linse, Katrin; Mills, Rachel A; Garabato, Alfredo Naveira; Pancost, Richard D; Pearce, David A; Polunin, Nicholas V C; German, Christopher R; Shank, Timothy; Boersch-Supan, Philipp H; Alker, Belinda J; Aquilina, Alfred; Bennett, Sarah A; Clarke, Andrew; Dinley, Robert J J; Graham, Alastair G C; Green, Darryl R H; Hawkes, Jeffrey A; Hepburn, Laura; Hilario, Ana; Huvenne, Veerle A I; Marsh, Leigh; Ramirez-Llodra, Eva; Reid, William D K; Roterman, Christopher N; Sweeting, Christopher J; Thatje, Sven; Zwirglmaier, Katrin

2012-01-01

370

The Discovery of New Deep-Sea Hydrothermal Vent Communities in the Southern Ocean and Implications for Biogeography  

PubMed Central

Since the first discovery of deep-sea hydrothermal vents along the Galpagos Rift in 1977, numerous vent sites and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting hydrothermal vents in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR) in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea hydrothermal vents hosting high-temperature black smokers up to 382.8C and diffuse venting. The chemosynthetic ecosystems hosted by these vents are dominated by a new yeti crab (Kiwa n. sp.), stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in vent ecosystems in other oceans, including polychaete worms (Siboglinidae), bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR vents. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for vent taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic vent ecosystems represent a new vent biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea hydrothermal vents globally indicate that vent biogeography is more complex than previously recognised. PMID:22235194

Rogers, Alex D.; Tyler, Paul A.; Connelly, Douglas P.; Copley, Jon T.; James, Rachael; Larter, Robert D.; Linse, Katrin; Mills, Rachel A.; Garabato, Alfredo Naveira; Pancost, Richard D.; Pearce, David A.; Polunin, Nicholas V. C.; German, Christopher R.; Shank, Timothy; Boersch-Supan, Philipp H.; Alker, Belinda J.; Aquilina, Alfred; Bennett, Sarah A.; Clarke, Andrew; Dinley, Robert J. J.; Graham, Alastair G. C.; Green, Darryl R. H.; Hawkes, Jeffrey A.; Hepburn, Laura; Hilario, Ana; Huvenne, Veerle A. I.; Marsh, Leigh; Ramirez-Llodra, Eva; Reid, William D. K.; Roterman, Christopher N.; Sweeting, Christopher J.; Thatje, Sven; Zwirglmaier, Katrin

2012-01-01

371

Diversity, Distribution and Nature of Faunal Associations with Deep-Sea Pennatulacean Corals in the Northwest Atlantic  

PubMed Central

Anthoptilum grandiflorum and Halipteris finmarchica are two deep-sea corals (Octocorallia: Pennatulacea) common on soft bottoms in the North Atlantic where they are believed to act as biogenic habitat. The former also has a worldwide distribution. To assist conservation efforts, this study examines spatial and temporal patterns in the abundance, diversity, and nature of their faunal associates. A total of 14 species were found on A. grandiflorum and 6 species on H. finmarchica during a multi-year and multi-site sampling campaign in eastern Canada. Among those, 7 and 5 species, respectively, were attached to the sea pens and categorized as close associates or symbionts. Rarefaction analyses suggest that the most common associates of both sea pens have been sampled. Biodiversity associated with each sea pen is analyzed according to season, depth and region using either close associates or the broader collection of species. Associated biodiversity generally increases from northern to southern locations and does not vary with depth (?1001400 m). Seasonal patterns in A. grandiflorum show higher biodiversity during spring/summer due to the transient presence of early life stages of fishes and shrimps whereas it peaks in fall for H. finmarchica. Two distinct endoparasitic species of highly modified copepods (families Lamippidae and Corallovexiidae) commonly occur in the polyps of A. grandiflorum and H. finmarchica, and a commensal sea anemone frequently associates with H. finmarchica. Stable isotope analyses (?13C and ?15N) reveal potential trophic interactions between the parasites and their hosts. Overall, the diversity of obligate/permanent associates of sea pens is moderate; however the presence of mobile/transient associates highlights an ecological role that has yet to be fully elucidated and supports their key contribution to the enhancement of biodiversity in the Northwest Atlantic. PMID:25369515

Baillon, Sandrine; Hamel, Jean-Franois; Mercier, Annie

2014-01-01

372

Diversity, distribution and nature of faunal associations with deep-sea pennatulacean corals in the northwest atlantic.  

PubMed

Anthoptilum grandiflorum and Halipteris finmarchica are two deep-sea corals (Octocorallia: Pennatulacea) common on soft bottoms in the North Atlantic where they are believed to act as biogenic habitat. The former also has a worldwide distribution. To assist conservation efforts, this study examines spatial and temporal patterns in the abundance, diversity, and nature of their faunal associates. A total of 14 species were found on A. grandiflorum and 6 species on H. finmarchica during a multi-year and multi-site sampling campaign in eastern Canada. Among those, 7 and 5 species, respectively, were attached to the sea pens and categorized as close associates or symbionts. Rarefaction analyses suggest that the most common associates of both sea pens have been sampled. Biodiversity associated with each sea pen is analyzed according to season, depth and region using either close associates or the broader collection of species. Associated biodiversity generally increases from northern to southern locations and does not vary with depth (?100-1400 m). Seasonal patterns in A. grandiflorum show higher biodiversity during spring/summer due to the transient presence of early life stages of fishes and shrimps whereas it peaks in fall for H. finmarchica. Two distinct endoparasitic species of highly modified copepods (families Lamippidae and Corallovexiidae) commonly occur in the polyps of A. grandiflorum and H. finmarchica, and a commensal sea anemone frequently associates with H. finmarchica. Stable isotope analyses (?13C and ?15N) reveal potential trophic interactions between the parasites and their hosts. Overall, the diversity of obligate/permanent associates of sea pens is moderate; however the presence of mobile/transient associates highlights an ecological role that has yet to be fully elucidated and supports their key contribution to the enhancement of biodiversity in the Northwest Atlantic. PMID:25369515

Baillon, Sandrine; Hamel, Jean-Franois; Mercier, Annie

2014-01-01

373

7 CFR 1437.310 - Sea grass and sea oats.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture...Coverage Using Value 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss crops and eligibility will...

2010-01-01

374

7 CFR 1437.310 - Sea grass and sea oats.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture...Coverage Using Value 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss crops and eligibility will...

2012-01-01

375

7 CFR 1437.310 - Sea grass and sea oats.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture...Coverage Using Value 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss crops and eligibility will...

2011-01-01

376

7 CFR 1437.310 - Sea grass and sea oats.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture...Coverage Using Value 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss crops and eligibility will...

2013-01-01

377

7 CFR 1437.310 - Sea grass and sea oats.  

...2014-01-01 2014-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture...Coverage Using Value 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss crops and eligibility will...

2014-01-01

378

All That Unplowed Sea  

ERIC Educational Resources Information Center

Hunting and gathering at sea may fast be approaching their productive limits. Aquaculture - farming at sea - linked to conservation represents the sea's promise. If the system works, it might prove to be the key to supplying large amounts of food and fresh water at no cost in nonrenewable energy resources. (BT)

MOSAIC, 1975

1975-01-01

379

Deep-Sea Technology  

NSDL National Science Digital Library

In this lesson plan students will learn about special vehicles used in recent Black Sea research and the theory that the Black Sea during the Ice Age was an isolated freshwater lake surrounded by farmland that was eventually flooded. Students will describe the purpose of the research vehicles by writing newspaper articles pretending they have just returned from the Black Sea expedition.

380

Deep sea waste disposal  

SciTech Connect

The book presents papers on the marine disposal of wastes. Topics considered include incineration at sea, the modelling and biological effects of industrial wastes, microbial studies of ocean dumping, deep-sea mining wastes, the chemical analysis of ferromanganese nodules, and economic aspects of deep-sea disposal.

Kester, D.R.; Burt, W.V.; Capuzzo, J.M.; Park, P.K.; Ketchum, B.W.; Duedall, I.W.

1985-01-01

381

Sea Education Association  

NSDL National Science Digital Library

Headquartered in Woods Hole, Massachusetts, SEA offers a variety of science programs at sea for high school and college students. Site features information on the vessels, the crew, current voyages, admissions information, and a wealth of photographs from past expeditions. Also includes a section where you can track the progress of the SEA boats and hear daily, and archived, audio reports.

382

Sea Level Rise  

NSDL National Science Digital Library

In this activity, students will learn the difference between sea ice and glaciers in relation to sea level rise. They will create and explore topographic maps as a means of studying sea level rise and how it will affect Alaska's coastline.

Fairbanks, Geophysical I.

383

Tracking Sea Otters  

USGS Multimedia Gallery

Sea otter researchers Michelle Staedler, Monterey Bay Aquarium, and Tim Tinker, USGS, work together to locate sea otters in their study project. USGS scientists and their partners study sea otters in efforts to help the threatened species continue to recover from near extinction....

384

Hydra (whole mount) Cl. Hydrozoa, A-tentacle, B-hypostome, C-body column,  

E-print Network

as you have observed in the aquarium. #12;9 Metridium Metridium Oral surface of the sea anemone showing opening - shows complete and incomplete septa. Detail of the oral opening of the sea anemone showing the position of the siphonoglyphs. Internal anatomy of the sea anemone - showing the body wall Cross section

Cochran-Stafira, D. Liane

385

Chemical defense of common antarctic shallow-water nudibranch Tritoniella belli eliot (Mollusca: Tritonidae) and its prey, Clavularia frankliniana rouel (Cnidaria: Octocorallia)  

Microsoft Academic Search

Extracts of the dorid nudibranchTritoniella belli and stoloniferan coralClavularia frankliniana were chromatographed and analyzed by1H NMR and thin-layer chromatography. Three glycerol ethers were detected inT. belli, primarily 1-O-hexadecyl glycerol (chimyl alcohol). Chimyl alcohol was also detected after gradient flash chromatography and reverse-phase HPLC purification in the tissues ofC. frankliniana. The common omnivorous predatory Antarctic sea starOdontaster validus, a likely predator

J. B. McClintock; B. J. Baker; M. Slattery; J. N. Heine; P. J. Bryan; W. Yoshida; M. T. Davies-Coleman; D. J. Faulkner

1994-01-01

386

Regulation of intracellular pH in cnidarians: response to acidosis in Anemonia viridis.  

PubMed

The regulation of intracellular pH (pHi) is a fundamental aspect of cell physiology that has received little attention in studies of the phylum Cnidaria, which includes ecologically important sea anemones and reef-building corals. Like all organisms, cnidarians must maintain pH homeostasis to counterbalance reductions in pHi, which can arise because of changes in either intrinsic or extrinsic parameters. Corals and sea anemones face natural daily changes in internal fluids, where the extracellular pH can range from 8.9 during the day to 7.4 at night. Furthermore, cnidarians are likely to experience future CO?-driven declines in seawater pH, a process known as ocean acidification. Here, we carried out the first mechanistic investigation to determine how cnidarian pHi regulation responds to decreases in extracellular and intracellular pH. Using the anemone Anemonia viridis, we employed confocal live cell imaging and a pH-sensitive dye to track the dynamics of pHi after intracellular acidosis induced by acute exposure to decreases in seawater pH and NH?Cl prepulses. The investigation was conducted on cells that contained intracellular symbiotic algae (Symbiodinium sp.) and on symbiont-free endoderm cells. Experiments using inhibitors and Na?-free seawater indicate a potential role of Na?/H? plasma membrane exchangers (NHEs) in mediating pHi recovery following intracellular acidosis in both cell types. We also measured the buffering capacity of cells, and obtained values between 20.8 and 43.8 mM per pH unit, which are comparable to those in other invertebrates. Our findings provide the first steps towards a better understanding of acid-base regulation in these basal metazoans, for which information on cell physiology is extremely limited. PMID:24256552

Laurent, Julien; Venn, Alexander; Tambutt, ric; Ganot, Philippe; Allemand, Denis; Tambutt, Sylvie

2014-02-01

387

Dust Storm, Aral Sea  

NASA Technical Reports Server (NTRS)

The Aral Sea has shrunk to less than half its size since 1985. The Aral Sea receives little water (sometimes no water) from the two major rivers that empty into it-the Syr Darya and Amu Darya. Instead, the river water is diverted to support irrigation for the region's extensive cotton fields. Recently, water scarcity has increased due to a prolonged drought in Central Asia. As the Aral Sea recedes, its former sea bed is exposed. The Aral's sea bed is composed of fine sediments-including fertilizers and other agricultural chemicals-that are easily picked up by the region's strong winds, creating thick dust storms. The International Space Station crew observed and recorded a large dust storm blowing eastward from the Aral Sea in late June 2001. This image illustrates the strong coupling between human activities (water diversions and irrigation), and rapidly changing land, sea and atmospheric processes-the winds blow across the

2002-01-01

388

the East Sea Sea of Japan  

Microsoft Academic Search

Sediment cores collected from the deep basins of the East Sea Sea of Japan provide an ongoing and historical record of artificial radionuclides contamination into one of the most highly publicized radioactive waste dumping areas in the world ocean. The depth distributions of 90Sr, 137Cs and 239,240Pu in sediment cores were investigated with 210 . the aid of Pb-derived sediment

Gi-Hoon Hong; Sang-Han Lee; Suk-Hyun Kim; Chang-Soo Chung; M. Baskaran

389

Numerical Investigation of a Coronal Mass Ejection from an Anemone Active Region: Reconnection and Deflection of the 2005 August 22 Eruption  

E-print Network

We present a numerical investigation of the coronal evolution of a coronal mass ejection (CME) on 2005 August 22 using a 3-D thermodynamics magnetohydrodynamic model, the SWMF. The source region of the eruption was anemone active region (AR) 10798, which emerged inside a coronal hole. We validate our modeled corona by producing synthetic extreme ultraviolet (EUV) images, which we compare to EIT images. We initiate the CME with an out-of-equilibrium flux rope with an orientation and chirality chosen in agreement with observations of a H-alpha filament. During the eruption, one footpoint of the flux rope reconnects with streamer magnetic field lines and with open field lines from the adjacent coronal hole. It yields an eruption which has a mix of closed and open twisted field lines due to interchange reconnection and only one footpoint line-tied to the source region. Even with the large-scale reconnection, we find no evidence of strong rotation of the CME as it propagates. We study the CME deflection and find t...

Lugaz, N; Shibata, K; Roussev, I I; Asai, A; Gombosi, T

2011-01-01

390

Natural selection and neutral evolution jointly drive population divergence between alpine and lowland ecotypes of the allopolyploid plant Anemone multifida (Ranunculaceae).  

PubMed

Population differentiation can be driven in large part by natural selection, but selectively neutral evolution can play a prominent role in shaping patters of population divergence. The decomposition of the evolutionary history of populations into the relative effects of natural selection and selectively neutral evolution enables an understanding of the causes of population divergence and adaptation. In this study, we examined heterogeneous genomic divergence between alpine and lowland ecotypes of the allopolyploid plant, Anemone multifida. Using peak height and dominant AFLP data, we quantified population differentiation at non-outlier (neutral) and outlier loci to determine the potential contribution of natural selection and selectively neutral evolution to population divergence. We found 13 candidate loci, corresponding to 2.7% of loci, with signatures of divergent natural selection between alpine and lowland populations and between alpine populations (Fst ?=?0.074-0.445 at outlier loci), but neutral population differentiation was also evident between alpine populations (FST ?=?0.041-0.095 at neutral loci). By examining population structure at both neutral and outlier loci, we determined that the combined effects of selection and neutral evolution are associated with the divergence of alpine populations, which may be linked to extreme abiotic conditions and isolation between alpine sites. The presence of outlier levels of genetic variation in structured populations underscores the importance of separately analyzing neutral and outlier loci to infer the relative role of divergent natural selection and neutral evolution in population divergence. PMID:23874801

McEwen, Jamie R; Vamosi, Jana C; Rogers, Sean M

2013-01-01

391

East Siberian Sea, Russia  

NASA Technical Reports Server (NTRS)

The winter sea ice in the east Siberian Sea is looking a bit like a cracked windshield in these true-color Moderate Resolution Imaging Spectroradiometer (MODIS) images from June 16 and 23, 2002. North of the thawing tundra, the sea ice takes on its cracked, bright blue appearance as it thins, which allows the reflection of the water to show through. Numerous still-frozen lakes dot the tundra. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

2002-01-01

392

National Sea Grant Library  

NSDL National Science Digital Library

The National Sea Grant Library (NSGL) is the digital library and official archive for NOAA Sea Grant documents. It is the only comprehensive collection of Sea Grant funded documents from over 30 programs and projects across the country. This collection encompasses a wide variety of subjects, including oceanography, marine education, aquaculture, fisheries, aquatic nuisance species, coastal hazards, seafood safety, limnology, coastal zone management, marine recreation, and law.

393

Age, Growth, Reproduction and Feeding of the Spurdog ( Squalus acanthias Linnaeus, 1758) in the South-eastern Black Sea  

NASA Astrophysics Data System (ADS)

Life-history parameters and diet of spurdog ( Squalus acanthias) sampled from the SE Black Sea were studied. Spurdog from age classes I to XIV were identified, with a dominance of age class VIII for both sexes. The length-weight relationship was W=00040*L 295and the mean annual growth rates in length and weight were 72 cm and 5401 g, respectively. The estimated von Bertalanffy growth parameters were: W ?=12021 (g), L ?=157 (cm), K=012 (year -1) and t 0=-130 (year). The size at first maturity was 82 cm for males and 88 cm for females. Mean biennial fecundity was also found to be 8 pups/female. The relationships between fecundity-length, fecundity-weight and fecundity-age were found to be: F=-170842+02369*L (R=093), F=03780+00018*W (R=089) and F =-07859+11609*A (R=094) respectively. The spurdog can be considered an opportunistic feeder. Their natural diet was composed mainly of teleost fishes, followed by Crustaceans, Nematodes and Actinarians (=sea anemones). Whiting ( Merlangius merlangus euxinus) was the predominant prey item among their fish prey. Demersal teleosts formed the majority of the diet, and there was no difference ( P>005) among the food items of immature, maturing and mature individuals of both sexes.

Avsar, D.

2001-02-01

394

Sea level extremes in the Caribbean Sea  

NASA Astrophysics Data System (ADS)

level extremes in the Caribbean Sea are analyzed on the basis of hourly records from 13 tide gauges. The largest sea level extreme observed is 83 cm at Port Spain. The largest nontidal residual in the records is 76 cm, forced by a category 5 hurricane. Storm surges in the Caribbean are primarily caused by tropical storms and stationary cold fronts intruding the basin. However, the seasonal signal and mesoscale eddies also contribute to the creation of extremes. The five stations that have more than 20 years of data show significant trends in the extremes suggesting that flooding events are expected to become more frequent in the future. The observed trends in extremes are caused by mean sea level rise. There is no evidence of secular changes in the storm activity. Sea level return periods have also been estimated. In the south Colombian Basin, where large hurricane-induced surges are rare, stable estimates can be obtained with 30 years of data or more. For the north of the basin, where large hurricane-induced surges are more frequent, at least 40 years of data are required. This suggests that the present data set is not sufficiently long for robust estimates of return periods. ENSO variability correlates with the nontidal extremes, indicating a reduction of the storm activity during positive ENSO events. The period with the highest extremes is around October, when the various sea level contributors' maxima coincide.

Torres, R. Ricardo; Tsimplis, Michael N.

2014-08-01

395

Pelagic sea snakes dehydrate at sea.  

PubMed

Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans. PMID:24648228

Lillywhite, Harvey B; Sheehy, Coleman M; Brischoux, Franois; Grech, Alana

2014-05-01

396

Hawksbill Sea Turtle (Eretmochelys imbricata)  

USGS Multimedia Gallery

Hawksbill Sea Turtles (Eretmochelys imbricata), such as the one hiding here under a boulder, and Green Sea Turtles (Chelonia mydas) are occasionally seen in Hurricane Hole. Hawksbills feed mostly on sponges while Greens eat mostly sea grasses....

2010-05-03

397

Migrations in the Sea  

Microsoft Academic Search

THE terms ``anadromous'' and ``catadromous'' are employed to distinguish fish which leave the sea to spawn in fresh water and fish which migrate from fresh water to the sea when they reach maturity. Gilson, in his paper, ``L'Anguille'' (1908, Ann. d. I. Spc. toy, Zool. et Malacca, d Belgique, T. 43), proposed that the words should be used to define

A. Meek

1915-01-01

398

Sea Level Viewer  

NSDL National Science Digital Library

Video and animations of sea level from NASA's Climate website. Since 1992, NASA and CNES have studied sea surface topography as a proxy for ocean temperatures. NASA Missions TOPEX/Poseidon, Jason 1 and Jason 2 have been useful in predicting major climate, weather, and geologic events including El Nino, La Nina, Hurricane Katrina, and the Indian Ocean Tsunami.

Jackson, Randall; Nasa, For

399

Bering Sea Expedition  

NSDL National Science Digital Library

In this investigation learners research the effects of melting sea ice in the Bering Sea Ecosystem. They create research proposals to earn a place on the scientific research vessel Healy and present their findings and proposals to a Research Board committee.

Curriculum, Alaska S.; Grant, Alaska S.

400

White Sea - Russia  

NASA Technical Reports Server (NTRS)

At bottom center of this true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from April 13, 2001, the White Sea in western Russia is becoming free of ice in its southern extent. Meanwhile, the blue-green waters along the coast of the peninsula jutting out into the Barents Sea to the northeast could be due to a phytoplankton bloom.

2002-01-01

401

Kara Sea radioactivity assessment  

Microsoft Academic Search

Investigations following five international expeditions to the Kara Sea have shown that no radiologically significant contamination has occurred outside of the dumping sites in Novaya Zemlya bays. Increased levels of radionuclides in sediment have only been observed in Abrosimov and Stepovoy Bays very close to dumped containers. Evaluations of radionuclide inventories in water and sediment of the open Kara Sea

Iolanda Osvath; Pavel P Povinec; Murdoch S Baxter

1999-01-01

402

Getting Your Sea Legs  

PubMed Central

Sea travel mandates changes in the control of the body. The process by which we adapt bodily control to life at sea is known as getting one's sea legs. We conducted the first experimental study of bodily control as maritime novices adapted to motion of a ship at sea. We evaluated postural activity (stance width, stance angle, and the kinematics of body sway) before and during a sea voyage. In addition, we evaluated the role of the visible horizon in the control of body sway. Finally, we related data on postural activity to two subjective experiences that are associated with sea travel; seasickness, and mal de debarquement. Our results revealed rapid changes in postural activity among novices at sea. Before the beginning of the voyage, the temporal dynamics of body sway differed among participants as a function of their (subsequent) severity of seasickness. Body sway measured at sea differed among participants as a function of their (subsequent) experience of mal de debarquement. We discuss implications of these results for general theories of the perception and control of bodily orientation, for the etiology of motion sickness, and for general phenomena of perceptual-motor adaptation and learning. PMID:23840560

Stoffregen, Thomas A.; Chen, Fu-Chen; Varlet, Manuel; Alcantara, Cristina; Bardy, Benoit G.

2013-01-01

403

Sea Lion Skeleton - Nostrils  

NSDL National Science Digital Library

The carnivorous sea lion uses its sharp pointed teeth and large mouth to shred and tear its prey. The large nose and large eyes on either side of the skull help the sea lion to detect prey. The skull protects the brain from damage and injury.

Ketan Patel (California State University, Fullerton;Student, Biological Sciences)

2007-07-26

404

Sea Lion Skeleton - Skull  

NSDL National Science Digital Library

The carnivorous sea lion uses its sharp pointed teeth and large mouth to shred and tear its prey. The large nose and large eyes on either side of the skull help the sea lion to detect prey. The skull protects the brain from damage and injury.

Ketan Patel (California State University, Fullerton;Student, Biological Sciences)

2007-07-26

405

Tracking Sea Otters  

USGS Multimedia Gallery

USGS wildlife biologist Alisha Kage holds out a VHF receiver, hoping to hear the tell-tale beep that helps her locate sea otters that are part of study to monitor and learn more about the species. USGS scientists study sea otters in efforts to help the threatened species continue to recover from nea...

406

Black Sea in Bloom  

NASA Technical Reports Server (NTRS)

This true-color image shows bright, turquoise-colored swirls across the surface of the Black Sea, signifying the presence of a large phytoplankton bloom. Scientists have observed similar blooms recurring annually, roughly this same time of year. The Sea of Azov, which is the smaller body of water located just north of the Black Sea in this image, also shows a high level of biological activity currently ongoing. The brownish pixels in the Azov are probably sediments carried in from high waters upstream. This scene was acquired by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), flying aboard the OrbView-2 satellite, on May 4, 2002. According to the Black Sea Environment Programme's Marine Hydrophysical Institute, the Black Sea is 'one of the marine areas of the world most damaged by human activities.' The coastal zone around these Eastern European inland water bodies is densely populated-supporting a permanent population of roughly 16 million people and another 4 million tourists each year. Six countries border with the Black Sea, including Ukraine to the north, Russia and Georgia to the east, Turkey to the south, and Bulgaria and Romania to the west. Because it is isolated from the world's oceans, and because there is an extensive drainage network of rivers that empty into it, the Black Sea has a unique and delicate water balance which is very important for supporting its marine ecosystem. Of particular concern to scientists is the salinity, water level, and nutrient levels of the Black Sea's waters, all of which are, unfortunately, being impacted by human activities. Within the last three decades the combination of increased nutrient loads from human sources together with pollution and over-harvesting of fisheries has resulted in a sharp decline in water quality. Scientists from each of the Black Sea's bordering nations are currently working together to study the issues and formulate a joint, international strategy for saving this unique marine ecosystem. Working with a spirit of placing more emphasis on joint ownership of the Black Sea's resources, and less emphasis on blame, it is hoped that the cooperating countries can strike an effective balance between both enjoying and preserving the Black Sea. Image courtesy the SeaWiFS Project, NASA GSFC, and ORBIMAGE

2002-01-01

407

2188 Biochemistry 1989, 28, 2188-2 198 Determination of the Three-Dimensional Solution Structure of the  

E-print Network

of the Antihypertensive and Antiviral Protein BDS-I from the Sea Anemone Anemonia Geometry-Dynamical Simulated Annealing-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia anemone Anemonia sulcata with both antihypertensive and antiviral properties (Beress et al., 1985

Clore, G. Marius

408

Behav Ecol Sociobiol (1 982) 10:289-292 BehavioralEcology  

E-print Network

territorially defends the sea anemone it occupies, using as a weap- on its large, specially modified `snapping), an obligate symbiont of the Ca- ribbean sea anemone Bartholomea annulata, is an ex- cellent subject for studies of symmetric contests. The shrimp territorially defend individuals or clusters of this anemone

Bermingham, Eldredge

409

NIKKI GEORGINA TRAYLOR-KNOWLES ntk1717@gmail.com (410) 905-5107  

E-print Network

into the stress response of cnidarians with a focus on wound healing in the sea anemone Nematostella vectensis-kB signaling pathway in the sea anemone, Nematostella vectensis. Molecular and Cellular Biology. doi:10 anemone Nematostella vectensis are widely distributed in natural populations and encode proteins

Palumbi, Stephen

410

NOTE / NOTE Why is group size correlated with the size  

E-print Network

NOTE / NOTE Why is group size correlated with the size of the host sea anemone in the false clown- lenciennes, 1830) and that of the host sea anemone Stichodactyla gigantea (Forskål, 1775). We argue that some consequence of a positive relationship be- tween anemone size and the length of the dominant group member

Dill, Lawrence M.

411

Early origins and evolution of microRNAs and Piwi-interacting RNAs in animals  

E-print Network

Nematostella vectensis (starlet sea anemone), a close relative to the Bilateria, possesses an extensive have emerged earlier in metazoan evolution. Diverse microRNAs of the starlet sea anemone EumetazoaCnidariaisrepresentedbythestarletsea anemone, Nematostella vectensis13 . To explore whether cnidarians have miRNAs, we sequenced complementary

Bartel, David

412

THE ANOMURAN COLLECTIONS MADE BY THE FISH HAWK EXPEDITION TO PORTO RICO.  

E-print Network

with polyzoa or anemones. The great majority live in the dead shells of mollusks, changing from one shell. A hydroid envelops the shell and grows with the crab, or a sea anemone plants itself on the shell and covers, and we often find the sea anemone and crab in close contact; the shell having, as it were, fitted

413

Numerical Investigation of a Coronal Mass Ejection from an Anemone Active Region: Reconnection and Deflection of the 2005 August 22 Eruption  

NASA Astrophysics Data System (ADS)

We present a numerical investigation of the coronal evolution of a coronal mass ejection (CME) on 2005 August 22 using a three-dimensional thermodynamic magnetohydrodynamic model, the space weather modeling framework. The source region of the eruption was anemone active region (AR) 10798, which emerged inside a coronal hole. We validate our modeled corona by producing synthetic extreme-ultraviolet (EUV) images, which we compare to EIT images. We initiate the CME with an out-of-equilibrium flux rope with an orientation and chirality chosen in agreement with observations of an H? filament. During the eruption, one footpoint of the flux rope reconnects with streamer magnetic field lines and with open field lines from the adjacent coronal hole. It yields an eruption which has a mix of closed and open twisted field lines due to interchange reconnection and only one footpoint line-tied to the source region. Even with the large-scale reconnection, we find no evidence of strong rotation of the CME as it propagates. We study the CME deflection and find that the effect of the Lorentz force is a deflection of the CME by about 3 R -1 sun toward the east during the first 30 minutes of the propagation. We also produce coronagraphic and EUV images of the CME, which we compare with real images, identifying a dimming region associated with the reconnection process. We discuss the implication of our results for the arrival at Earth of CMEs originating from the limb and for models to explain the presence of open field lines in magnetic clouds.

Lugaz, N.; Downs, C.; Shibata, K.; Roussev, I. I.; Asai, A.; Gombosi, T. I.

2011-09-01

414

NUMERICAL INVESTIGATION OF A CORONAL MASS EJECTION FROM AN ANEMONE ACTIVE REGION: RECONNECTION AND DEFLECTION OF THE 2005 AUGUST 22 ERUPTION  

SciTech Connect

We present a numerical investigation of the coronal evolution of a coronal mass ejection (CME) on 2005 August 22 using a three-dimensional thermodynamic magnetohydrodynamic model, the space weather modeling framework. The source region of the eruption was anemone active region (AR) 10798, which emerged inside a coronal hole. We validate our modeled corona by producing synthetic extreme-ultraviolet (EUV) images, which we compare to EIT images. We initiate the CME with an out-of-equilibrium flux rope with an orientation and chirality chosen in agreement with observations of an H{alpha} filament. During the eruption, one footpoint of the flux rope reconnects with streamer magnetic field lines and with open field lines from the adjacent coronal hole. It yields an eruption which has a mix of closed and open twisted field lines due to interchange reconnection and only one footpoint line-tied to the source region. Even with the large-scale reconnection, we find no evidence of strong rotation of the CME as it propagates. We study the CME deflection and find that the effect of the Lorentz force is a deflection of the CME by about 3{sup 0} R{sup -1}{sub sun} toward the east during the first 30 minutes of the propagation. We also produce coronagraphic and EUV images of the CME, which we compare with real images, identifying a dimming region associated with the reconnection process. We discuss the implication of our results for the arrival at Earth of CMEs originating from the limb and for models to explain the presence of open field lines in magnetic clouds.

Lugaz, N.; Shibata, K. [Kwasan Observatory, Kyoto University, Kyoto (Japan); Downs, C.; Roussev, I. I. [Institute for Astronomy, University of Hawaii, Honolulu, HI (United States); Asai, A. [Unit of Synergetic Studies for Space, Kyoto University, Kyoto (Japan); Gombosi, T. I. [Center for Space Environment Modeling, University of Michigan, MI (United States)

2011-09-10

415

The Bering Sea  

NASA Technical Reports Server (NTRS)

Over the past several years, dense clouds of phytoplankton (microscopic plants that live in water) have appeared in the Bering Sea each summer. One class of phytoplankton are particularly easy to spot from overhead. Called coccolithophores, these phytoplankton grow calcium-rich shells. These shells are bright white and turn the water where they grow a milky blue. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) captured this image of coccolithophores off the coast of Alaska on September 13 and 14, 2000. (The Bering Sea straddles the International Dateline, so the left side of the image is the 14th while the right is the 13th.) The bloom covers approximately 400,000 square kilometers (154,000 square miles). Swirls of water with varying shades show ocean currents and eddies. In general, the brighter the water, the higher the concentration of coccolithophores. SeaWiFS has been taking pictures of this area since 1997. Follow these links to see more images: June 27, 2000 April 29, 2000 Changing Currents Color the Bering Sea a new Shade of Blue (several images from 1998) Image provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE.

2002-01-01

416

STELLER SEA LIONS AND FISHERIES: COMPETITION AT SEA?  

E-print Network

STELLER SEA LIONS AND FISHERIES: COMPETITION AT SEA? by TABITHA CHENG YEE HUI B.Sc., The University the decline of Steller sea lions (Eumetopias jubatus) in western Alaska is the reduction of prey abundance that attempted to assess competition between sea lions and fisheries by estimating the local amounts of prey

417

Arctic Sea Ice  

NSDL National Science Digital Library

In this activity, learners explore how the area of Arctic sea ice has changed over recent years. First, learners graph the area of Arctic sea ice over time from 1979 to 2007. Then, learners use this information to extrapolate what the area will be in 2018 and graph their predictions. In part two of the activity, learners make a flip book to simulate the sea changes they just graphed. This resource includes background information related to the Northwest Passage and questions for learners to answer after completing this activity.

Meier, Beverly L.

2012-06-26

418

Jellyfish as Prey: Frequency of Predation and Selective Foraging of Boops boops (Vertebrata, Actinopterygii) on the Mauve Stinger Pelagia noctiluca (Cnidaria, Scyphozoa)  

PubMed Central

In recent years, jellyfish blooms have attracted considerable scientific interest for their potential impacts on human activities and ecosystem functioning, with much attention paid to jellyfish as predators and to gelatinous biomass as a carbon sink. Other than qualitative data and observations, few studies have quantified direct predation of fish on jellyfish to clarify whether they may represent a seasonally abundant food source. Here we estimate predation frequency by the commercially valuable Mediterranean bogue, Boops boops on the mauve stinger jellyfish, Pelagia noctiluca, in the Strait of Messina (NE Sicily). A total of 1054 jellyfish were sampled throughout one year to quantify predation by B. boops from bite marks on partially eaten jellyfish and energy density of the jellyfish. Predation by B. boops in summer was almost twice that in winter, and they selectively fed according to medusa gender and body part. Calorimetric analysis and biochemical composition showed that female jellyfish gonads had significantly higher energy content than male gonads due to more lipids and that gonads had six-fold higher energy content than the somatic tissues due to higher lipid and protein concentrations. Energetically, jellyfish gonads represent a highly rewarding food source, largely available to B. boops throughout spring and summer. During the remainder of the year, when gonads were not very evident, fish predation switched towards less-selective foraging on the somatic gelatinous biomass. P. noctiluca, the most abundant jellyfish species in the Mediterranean Sea and a key planktonic predator, may represent not only a nuisance for human leisure activities and a source of mortality for fish eggs and larvae, but also an important resource for fish species of commercial value, such as B. boops. PMID:24727977

Fuentes, Veronica L.; Boero, Ferdinando; Guglielmo, Letterio; Purcell, Jennifer E.; Piraino, Stefano

2014-01-01

419

Dead Sea Scrolls  

NASA Technical Reports Server (NTRS)

A consortium of researchers from Jet Propulsion Laboratory and three other organizations used charged coupled devices (CCDs) and other imaging enhancement technology to decipher previously unreadable portions of the Dead Sea Scrolls. The technique has potentially important implications for archeology.

1994-01-01

420

Record Sea Ice Minimum  

NASA Technical Reports Server (NTRS)

Arctic sea ice reached a record low in September 2007, below the previous record set in 2005 and substantially below the long-term average. This image shows the Arctic as observed by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) aboard NASA's Aqua satellite on September 16, 2007. In this image, blue indicates open water, white indicates high sea ice concentration, and turquoise indicates loosely packed sea ice. The black circle at the North Pole results from an absence of data as the satellite does not make observations that far north. Three contour lines appear on this image. The red line is the 2007 minimum, as of September 15, about the same time the record low was reached, and it almost exactly fits the sea ice observed by AMSR-E. The green line indicates the 2005 minimum, the previous record low. The yellow line indicates the median minimum from 1979 to 2000.

2007-01-01

421

Sea ice ecosystems.  

PubMed

Polar sea ice is one of the largest ecosystems on Earth. The liquid brine fraction of the ice matrix is home to a diverse array of organisms, ranging from tiny archaea to larger fish and invertebrates. These organisms can tolerate high brine salinity and low temperature but do best when conditions are milder. Thriving ice algal communities, generally dominated by diatoms, live at the ice/water interface and in recently flooded surface and interior layers, especially during spring, when temperatures begin to rise. Although protists dominate the sea ice biomass, heterotrophic bacteria are also abundant. The sea ice ecosystem provides food for a host of animals, with crustaceans being the most conspicuous. Uneaten organic matter from the ice sinks through the water column and feeds benthic ecosystems. As sea ice extent declines, ice algae likely contribute a shrinking fraction of the total amount of organic matter produced in polar waters. PMID:24015900

Arrigo, Kevin R

2014-01-01

422

Purple sea urchin swarm  

NSDL National Science Digital Library

Sea urchins live in low tide regions and eat seaweed. Urchins have no arms but have five rows of tube feet for movement. They are found in holes and use their spines for protection and to burrow into the rocks.

Katie Hale (California State University, Fullerton;Student, Biological Sciences)

2007-01-04

423

2011 Sea Ice Minimum  

NASA Video Gallery

This video shows Arctic sea ice from March 7, 2011, to Sept. 9, 2011, ending with a comparison of the 30-year average minimum extent, shown in yellow, and the Northwest Passage, in red. (no audio) ...

424

Smart Sea Lions  

NSDL National Science Digital Library

This video segment adapted from NOVA scienceNOW explores whether animals and humans are more similar than we think. Meet Rio, a sea lion who demonstrates to researchers reasoning skills once thought limited to humans.

Foundation, Wgbh E.

2009-08-31

425

Stellar Sea Lion Research  

NSDL National Science Digital Library

The phenomenon is the decline in population of western Stellar Sea Lions from 1969 to 1986, shown in a series of three images. The accompanying text describes the possible factors that may be contributing to the change in population.

426

Sea Raiders of Acadia  

ERIC Educational Resources Information Center

One of the French allies, the Micmac, waged much of the war against the English on the sea. This article discusses the determined stand by the Micmac seamen of the eastern coasts for their lands and way of life. (NQ)

Dickason, Olive Patricia

1976-01-01

427

Sea Floor Spreading I  

NSDL National Science Digital Library

In this introductory Excel tutorial (Activity I) students use Excel to explore the geodynamics model equation for ocean depth around a sea-floor spreading center. For students with no prior Excel experience.

Activity And Starting Point Page By R.m. Mackay. Clark College, Physics A.

428

Black Sea Becomes Turquoise  

NASA Technical Reports Server (NTRS)

This true-color image shows bright, turquoise-colored swirls across the surface of the Black Sea, signifying the presence of a large phytoplankton bloom. Scientists have observed similar blooms recurring annually, roughly this same time of year. The Sea of Azov, which is the smaller body of water located just north of the Black Sea in this image, also shows a high level of color variance. The brownish pixels in the Azov are probably due to sediments carried in from high waters and snowmelt from upstream. This scene was acquired by the Moderate Resolution Imaging Spectroradiometer, flying aboard NASA's Terra satellite, on May 14, 2002. According to the Black Sea Environment Programme's Marine Hydrophysical Institute, the Black Sea is ?one of the marine areas of the world most damaged by human activities.? The coastal zone around these Eastern European inland water bodies is densely populated'supporting a permanent population of roughly 16 million people and another 4 million tourists each year. Six countries border with the Black Sea, including Ukraine to the north, Russia and Georgia to the east, Turkey to the south, and Bulgaria and Romania to the west. Because it is isolated from the world's oceans, and because there is an extensive drainage network of rivers that empty into it, the Black Sea has a unique and delicate water balance which is very important for supporting its marine ecosystem. Of particular concern to scientists is the salinity, water level, and nutrient levels of the Black Sea's waters, all of which are, unfortunately, being impacted by human activities. Within the last three decades the combination of increased nutrient loads from human sources together with pollution and over-harvesting of fisheries has resulted in a sharp decline in water quality. Scientists from each of the Black Sea's bordering nations are currently working together to study the issues and formulate a joint, international strategy for saving this unique marine ecosystem. Working with a spirit of placing more emphasis on joint ownership of the Black Sea's resources, and less emphasis on blame, it is hoped that the cooperating countries can strike an effective balance between both enjoying and preserving the Black Sea.

2002-01-01

429

Sea bed mechanics  

SciTech Connect

This book provides a discussion on sea bed processes with engineering applications. It brings together the material currently available only in technical reports of research papers. It provides formulae and background references necessary for design calculation of problems such as sea bed or coastal erosion, and sub-marine pipeline stability. It also covers dissipation of wave energy, formation of ripples and dunes, and the transportation of sediments.

Sleath, J.F.A.

1984-01-01

430

Sea Level Viewer  

NSDL National Science Digital Library

This website presents ocean topography as measured by sea surface heights taken from space by NASA and CNES. Ocean heat circulation impacts weather and causes events such as Large El Nino, Hurricane Katrina, Indian Ocean Tsunami and La Nina. These events and the latest view of sea surface height are depicted with this 3D interactive viewer. Objectives of NASA missions TOPEX/Poseiden, Jason 1, and Jason 2/OSTM are charted. Closed Captioning is available.

431

Sea Urchin Embryology  

NSDL National Science Digital Library

Advanced high school level laboratory activities using sea urchins to observe fertilization and early developmental stages. This is a comprehensive site complete with multiple labs, support lessons, background information, animated graphics illustrating lab techniques, printable overheads (also available in Spanish and French), and a glossary of terms. A one-stop site for sea urchin information, experiments, suppliers, and research. Links to additional resources are available.

432

Global sea level rise  

Microsoft Academic Search

Published values for the long-term, global mean sea level rise determined from tide gauge records exhibit considerable scatter, from about 1 mm to 3 mm\\/yr. This disparity is not attributable to instrument error; long-term trends computed at adjacent sites often agree to within a few tenths of a millimeter per year. Instead, the differing estimates of global sea level rise

Bruce C. Douglas

1991-01-01

433

The genesis of sea level variability in the Barents Sea  

NASA Astrophysics Data System (ADS)

The regional variability of sea level is an integral indicator of changing oceanographic conditions due to different processes of oceanic, atmospheric, and terrestrial origin. The present study explores the nature of sea level variability in the Barents Sea-a marginal shelf sea of the Arctic Ocean. A characteristic feature that distinguishes this sea from other Arctic shelf seas is that it is largely ice free throughout the year. This allows continuous monitoring of sea level by space-borne altimeters. In this work we combine satellite altimetry, ocean gravity measurements by GRACE satellites, available hydrography data, and a high-resolution ocean data synthesis product to estimate the steric and mass-related components of sea level in the Barents Sea. We present one of the first observational evidence of the local importance of the mass-related sea level changes. The observed 1-3 month phase lag between the annual cycles of sea level in the Barents Sea and in the Nordic seas (Norwegian, Iceland, Greenland seas) is explained by the annual mass-related changes. The analysis of the barotropic vorticity budget shows that the mass-related sea level variability in the central part of the Barents Sea is determined by the combined effect of wind stress, flow over the varying bottom topography, and dissipation, while the impact of vorticity fluxes is negligible. Overall, the steric sea level has smaller amplitudes and mainly varies on the seasonal time scale. The thermosteric sea level is the main contributor to the steric sea level along the pathways of the Atlantic inflow into the Barents Sea. The relative contribution of the halosteric sea level is dominant in the southeastern, eastern, and northern parts of the Barents Sea, modulated by the seasonal sea ice formation/melt as well as by continental runoff. The variability of the thermosteric sea level in the Barents Sea is mostly driven by variations in the net surface heat flux, whereas the contribution of heat advection becomes as important as the ocean-atmosphere heat exchange at interannual time scales.

Volkov, Denis L.; Landerer, Felix W.; Kirillov, Sergey A.

2013-09-01

434

Semi-automated image analysis for the assessment of megafaunal densities at the Arctic deep-sea observatory HAUSGARTEN.  

PubMed

Megafauna play an important role in benthic ecosystem function and are sensitive indicators of environmental change. Non-invasive monitoring of benthic communities can be accomplished by seafloor imaging. However, manual quantification of megafauna in images is labor-intensive and therefore, this organism size class is often neglected in ecosystem studies. Automated image analysis has been proposed as a possible approach to such analysis, but the heterogeneity of megafaunal communities poses a non-trivial challenge for such automated techniques. Here, the potential of a generalized object detection architecture, referred to as iSIS (intelligent Screening of underwater Image Sequences), for the quantification of a heterogenous group of megafauna taxa is investigated. The iSIS system is tuned for a particular image sequence (i.e. a transect) using a small subset of the images, in which megafauna taxa positions were previously marked by an expert. To investigate the potential of iSIS and compare its results with those obtained from human experts, a group of eight different taxa from one camera transect of seafloor images taken at the Arctic deep-sea observatory HAUSGARTEN is used. The results show that inter- and intra-observer agreements of human experts exhibit considerable variation between the species, with a similar degree of variation apparent in the automatically derived results obtained by iSIS. Whilst some taxa (e. g. Bathycrinus stalks, Kolga hyalina, small white sea anemone) were well detected by iSIS (i. e. overall Sensitivity: 87%, overall Positive Predictive Value: 67%), some taxa such as the small sea cucumber Elpidia heckeri remain challenging, for both human observers and iSIS. PMID:22719868

Schoening, Timm; Bergmann, Melanie; Ontrup, Jrg; Taylor, James; Dannheim, Jennifer; Gutt, Julian; Purser, Autun; Nattkemper, Tim W

2012-01-01

435

Semi-Automated Image Analysis for the Assessment of Megafaunal Densities at the Arctic Deep-Sea Observatory HAUSGARTEN  

PubMed Central

Megafauna play an important role in benthic ecosystem function and are sensitive indicators of environmental change. Non-invasive monitoring of benthic communities can be accomplished by seafloor imaging. However, manual quantification of megafauna in images is labor-intensive and therefore, this organism size class is often neglected in ecosystem studies. Automated image analysis has been proposed as a possible approach to such analysis, but the heterogeneity of megafaunal communities poses a non-trivial challenge for such automated techniques. Here, the potential of a generalized object detection architecture, referred to as iSIS (intelligent Screening of underwater Image Sequences), for the quantification of a heterogenous group of megafauna taxa is investigated. The iSIS system is tuned for a particular image sequence (i.e. a transect) using a small subset of the images, in which megafauna taxa positions were previously marked by an expert. To investigate the potential of iSIS and compare its results with those obtained from human experts, a group of eight different taxa from one camera transect of seafloor images taken at the Arctic deep-sea observatory HAUSGARTEN is used. The results show that inter- and intra-observer agreements of human experts exhibit considerable variation between the species, with a similar degree of variation apparent in the automatically derived results obtained by iSIS. Whilst some taxa (e. g. Bathycrinus stalks, Kolga hyalina, small white sea anemone) were well detected by iSIS (i. e. overall Sensitivity: 87%, overall Positive Predictive Value: 67%), some taxa such as the small sea cucumber Elpidia heckeri remain challenging, for both human observers and iSIS. PMID:22719868

Schoening, Timm; Bergmann, Melanie; Ontrup, Jorg; Taylor, James; Dannheim, Jennifer; Gutt, Julian; Purser, Autun; Nattkemper, Tim W.

2012-01-01

436

Evolution of the tetraploid Anemone multifida (2n = 32) and hexaploid A. baldensis (2n = 48) (Ranunculaceae) was accompanied by rDNA loci loss and intergenomic translocation: evidence for their common genome origin  

PubMed Central

Background and Aims In the genus Anemone two small groups of taxa occur with the highest ploidy levels 2n = 6x = 48, belonging to the closely related clades: the montane/alpine Baldensis clade and the more temperate Multifida clade. To understand the formation of polyploids within these groups, the evolution of allohexaploid A. baldensis (AABBDD, 2n = 6x = 48) from Europe and allotetraploid Anemone multifida (BBDD, 2n = 4x = 32) from America was analysed. Methods Internal transcribed spacer and non-transcribed spacer sequences were used as molecular markers for phylogenetic analyses. Cytogenetic studies, including genomic in situ hybridization with genomic DNA of potential parental species as probe, fluorescence in situ hybridization with 5S and 18S rDNA as probes and 18S rDNA restriction analyses, were used to identify the parental origin of chromosomes and to study genomic changes following polyploidization. Key Results This study shows that A. multifida (BBDD, 2n= 4x = 32) and A. baldensis (AABBDD, 2n = 6x = 48) are allopolyploids originating from the crosses of diploid members of the Multifida (donor of the A and B subgenomes) and Baldensis groups (donor of the D subgenome). The A and B subgenomes are closely related to the genomes of A. sylvestris, A. virginiana and A. cylindrica, indicating that these species or their progeny might be the ancestral donors of the B subgenome of A. multifida and A and B subgenomes of A. baldensis. Both polyploids have undergone genomic changes such as interchromosomal translocation affecting B and D subgenomes and changes at rDNA sites. Anemone multifida has lost the 35S rDNA loci characteristic of the maternal donor (B subgenome) and maintained only the rDNA loci of the paternal donor (D subgenome). Conclusions It is proposed that A. multifida and A. baldensis probably had a common ancestor and their evolution was facilitated by vegetation changes during the Quaternary, resulting in their present disjunctive distribution. PMID:22711694

Mlinarec, J.; Satovic, Z.; Malenica, N.; Ivancic-Bace, I.; Besendorfer, V.

2012-01-01

437

The Dead Sea  

NASA Technical Reports Server (NTRS)

The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea.

With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Size: 18.5 by 48.1 kilometers (11.5 by 29.8 miles) Location: 31.4 degrees North latitude, 35.4 degrees East longitude Orientation: North at top Image Data: ASTER bands 3, 2, and 1 Original Data Resolution: 15 meters (49.2 feet) Dates Acquired: May 3, 2005

2006-01-01

438

Bioprospecting / Deep Sea Research  

NSDL National Science Digital Library

The first portion of the radio broadcast discusses the relatively new field of bioprospecting, the exploration of the sea floor for novel compounds and processes that may have industrial or medical applications. Bioprospectors are trying to collect samples of deep-sea organisms which may yield new pharmaceutical compounds, as in the case of Conus magnus, a sea snail whose venom has yielded a painkiller 1000 times more potent than morphine. There is also discussion of who owns these resources and what can be done to protect them. This segment is 12 minutes in length. The second segment of the broadcast traces the history of undersea exploration, including methods of measuring ocean depth, the bathysphere used by William Beebe and Otis Barton, the modern Alvin submersible, and remotely operated vehicles. There is also discussion of the motives and inspiration for ocean exploration; the deep sea knowledge of whalers; and comparisons of deep sea research with space exploration. This segment is 34 minutes and 40 seconds in length.

439

Sustainable Seas Student Intertidal Monitoring Project, Duxbury Reef, Bolinas, CA  

NASA Astrophysics Data System (ADS)

The Sustainable Seas Student Monitoring Project at the Branson School in Ross, CA has monitored Duxbury Reef in Bolinas, CA since 1999, in cooperation with the Farallones Marine Sanctuary Association and the Gulf of Farallones National Marine Sanctuary. Goals of the project include: 1) To monitor the rocky intertidal habitat and develop a baseline database of invertebrates and algal density and abundance; 2) To contribute to the conservation of the rocky intertidal habitat through education of students and visitors about intertidal species and requirements for maintaining a healthy, diverse intertidal ecosystem; 3) To increase stewardship in the Gulf of the Farallones National Marine Sanctuary; and 4) To contribute abundance and population data on key algae and invertebrate species to the national database, LiMPETS (Long Term Monitoring Program and Experiential Training for Students). Student volunteers complete an intensive training course on the natural history of intertidal invertebrates and algae, identification of key species, rocky intertidal ecology, interpretation and monitoring techniques, and history of the sanctuary. Students identify and count key invertebrate and algae species along two permanent transects (A and B), and using randomly determined points within a permanent 100 m2 area, three times per year (fall, winter, and late spring). Using the data collected since 2004, we will analyze the population densities of aggregating anemones, Anthopleura elegantissima, for seasonal abundance variations as well as long-term population trends. We will also follow the seasonal and long-term population fluctuations of red algal turf, Endocladia muricata and Gelidium coulteri, and black turban snails, Tegula funebralis. Comparing populations of turf algae and the herbivorous black turban snails gathered before and after the November 7, 2007 San Francisco Bay oil spill shows very little impact on the Duxbury Reef intertidal inhabitants. Future analyses will include intertidal abiotic factors to enhance insights into the workings of the Duxbury Reef ecosystem. Kathy Soave The Branson School 39 Fernhill Rd. Ross, CA 94957 (415) 454-3612 x 323 Amy Dean Farallones Marine Sanctuary Association, PO Box 29386 San Francisco, CA 94129, 415-561-6625 x 303 AGU Sponsor, Ines Cifuentes, AGU membership number 10189667

Soave, K.; Dean, A.; Prescutti, K.; Ball, O.; Chang, E.; Darakananda, K.; Jessup, K.; Poutian, J.; Schwalbe, H.; Storm, E.

2008-12-01

440

Sea Slug Forum  

NSDL National Science Digital Library

Produced by the Australian Museum and maintained by Dr. Bill Rudman, the recently redesigned Sea Slug Forum is an excellent resource for information on nudibranchs and related sea slugs such as bubble-shells, sea hares, and side-gilled slugs. One of the chief features of the site is a lengthy species list that links to lovely photos, brief descriptions, distribution information, and related messages from the site's Forum. The site also offers a sizable collection of short pieces and archived forum messages on a variety of general topics, arranged alphabetically. Users can send their own questions and review messages sent to the site along with Dr. Rudman's replies by date or via a keyword search engine. Additional resources include suggested reading, related annotated links, and information on forum participants.

441

Mountains in the Sea  

NSDL National Science Digital Library

In this 6-7 day investigation, learners begin with an introduction to seamounts that are present in the Gulf of Alaska. They learn how seamounts were formed and look at a bathymetric map of a seamount. In Activity 3A, learners explore sea floor mapping techniques as they participate in an activity to create a map of a sea feature they have molded out of clay. In Activity 3B, learners watch a short animated presentation, "Who cares about Sea Floor Mapping?" and create a model of a seamount found in Alaska. They use pre-sonar techniques to collect data and create a graph of their seamount using Excel. This detailed lesson plan includes learner hand-outs, evaluation questions, curricular connections, and tips.

Grant, Alaska S.

2011-01-01

442

Geology of Barents Sea  

SciTech Connect

The Barents Sea is situated on the continental shelf between Norway, the Spitsbergen Islands, and Novaya Zemlya. The main structural framework of the area was formed during the Caledonian and Hercynian orogenies, whereas the western parts were reactivated by the Kimmerian and Alpine orogenies. Because of the complex opening of the Greenland Norwegian Sea, important tertiary reactivation of Mesozoic normal faults occurred along southwest-northeast-trending systems of wrench faults. Owing to substantial erosion in the late Tertiary, the subsidence history and thermal development are more difficult to unravel in this area than in other places along the Norwegian Shelf. The erosion products were deposited in a huge sedimentary wedge extending onto the oceanic crust. The hydrocarbon discoveries in the Troms area in the southern part of the Barents Sea are encouraging for further exploration. However, the petroleum potential for large areas is not well known at this stage.

Riis, F.; Vollset, J.