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1

Latitudinal diversity of sea anemones (Cnidaria: Actiniaria).  

PubMed

We sought to determine if the global distribution of sea anemones (cnidarian order Actiniaria) conforms to the classic pattern of biogeography--taxon richness at the equator with attenuation toward the poles--a pattern that is derived almost entirely from data on terrestrial plants and animals. We plotted the empirical distribution of species occurrences in 10° bands of latitude based on published information, then, using the Chao2 statistic, inferred the completeness of that inventory. We found the greatest species richness of sea anemones at 30-40° N and S, with lower numbers at tropical latitudes and the fewest species in polar areas. The Chao2 statistic allowed us to infer that the richness pattern we found is not due to particularly poor knowledge of tropical sea anemones. No 10° band of latitude has less than 60% of the theoretical number of species known, but for only about half of them could we reject the null hypothesis (P = 0.05) that information is complete; anemone diversity is best documented at high latitudes. We infer that the 1089 valid species currently known constitute about 70% of the theoretical total of about 1500 species of Actiniaria. The distribution pattern of sea anemone species resembles that of planktonic foraminiferans and benthic marine algae, although planktonic bacteria, marine bivalves, and shallow and deep scleractinian corals show the terrestrial pattern of equatorial richness attenuating with latitude. Sea anemone species richness is complementary to that of scleractinian corals at many scales; our findings affirm it at the global scale. PMID:23677974

Fautin, Daphne Gail; Malarky, Lacey; Soberón, Jorge

2013-04-01

2

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.

Frazao, Barbara; Vasconcelos, Vitor; Antunes, Agostinho

2012-01-01

3

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

Microsoft Academic Search

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

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

2004-01-01

4

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.

Goldstone, J.V.

2010-01-01

5

Sea anemones (Cnidaria, Anthozoa, Actiniaria) from coral reefs in the southern Gulf of Mexico.  

PubMed

Seven sea anemone species from coral reefs in the southern Gulf of Mexico are taxonomically diagnosed and images from living specimens including external and internal features, and cnidae are provided. Furthermore, the known distribution ranges from another 10 species are extended. No species records of sea anemones have been previously published in the primary scientific literature for coral reefs in the southern Gulf of Mexico and thus, this study represents the first inventory for the local actiniarian fauna. PMID:24146599

González-Muñoz, Ricardo; Simões, Nuno; Tello-Musi, José Luis; Rodríguez, Estefanía

2013-10-08

6

Sea anemones (Cnidaria, Anthozoa, Actiniaria) from coral reefs in the southern Gulf of Mexico  

PubMed Central

Abstract Seven sea anemone species from coral reefs in the southern Gulf of Mexico are taxonomically diagnosed and images from living specimens including external and internal features, and cnidae are provided. Furthermore, the known distribution ranges from another 10 species are extended. No species records of sea anemones have been previously published in the primary scientific literature for coral reefs in the southern Gulf of Mexico and thus, this study represents the first inventory for the local actiniarian fauna.

Gonzalez-Munoz, Ricardo; Simoes, Nuno; Tello-Musi, Jose Luis; Rodriguez, Estefania

2013-01-01

7

Evolution of sea anemones (Cnidaria: Actiniaria: Hormathiidae) symbiotic with hermit crabs.  

PubMed

Sea anemones in genera Adamsia, Calliactis and Paracalliactis (family Hormathiidae) engage in a mutualistic symbiosis with hermit crabs in which the anemone gains substrate and food in exchange for defending the crab. Some of the sea anemones also expand the living space of the crab by producing a carcinoecium, a chitinous structure that overlies the initial gastropod shell in which the hermit crab lives. The symbiosis is initiated either by the crab, or by the anemone. Although behavioral and physiological aspects of this symbiosis have been studied, interpretations cannot be generalized without an evolutionary framework. After reconstructing relationships among members of Hormathiidae using DNA sequences, we find that the association has evolved at least twice: Adamsia nests within Calliactis in a single clade, and Paracalliactis belongs to a different clade within the family. The carcinoecium and complex behavioral and anatomical features associated with the symbiosis are interpreted as having evolved at least twice within Hormathiidae and seem to be phylogenetically labile. PMID:20457262

Gusmão, Luciana C; Daly, Marymegan

2010-05-08

8

The Mitochondrial Genome of the Sea Anemone Metridium senile (Cnidaria): Introns, a Paucity of tRNA Genes, and a Near-Standard Genetic Code  

Microsoft Academic Search

The circular, 17,443 nucleotide-pair mitochondrial (mt) DNA molecule of the sea anemone, Metridium senile (class Anthozoa, phylum Cnidaria) is presented. This molecule contains genes for 13 energy pathway proteins and two ribosomal (r) RNAs but, relative to other metazoan mtDNAs, has two unique features: only two transfer RNAs (tRNA f-Met and tRNA Trp ) are encoded, and the cytochrome c

C. Timothy Beagley; Ronald Okimoto; David R. Wolstenholme

9

Edwardsia sojabio sp. n. (Cnidaria: Anthozoa: Actiniaria: Edwardsiidae), a new abyssal sea anemone from the Sea ofJapan  

NASA Astrophysics Data System (ADS)

The paper describes new deep-water edwardsiid sea anemone Edwardsia sojabio sp. n. which is very common on soft muddy bottoms at lower bathyal and upper abyssal depths in the Sea of Japan. It was recorded in high quantity in depths between 2545 and 3550 m and is the second abyssal species of the genus Edwardsia.

Sanamyan, Nadya; Sanamyan, Karen

2013-02-01

10

The mitochondrial genome of the sea anemone Metridium senile (Cnidaria): introns, a paucity of tRNA genes, and a near-standard genetic code.  

PubMed Central

The circular, 17,443 nucleotide-pair mitochondrial (mt) DNA molecule of the sea anemone, Metridium senile (class Anthozoa, phylum Cnidaria) is presented. This molecule contains genes for 13 energy pathway proteins and two ribosomal (r) RNAs but, relative to other metazoan mtDNAs, has two unique features: only two transfer RNAs (tRNA(f-Met) and tRNA(Trp)) are encoded, and the cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 5 (ND5) genes each include a group I intron. The COI intron encodes a putative homing endonuclease, and the ND5 intron contains the molecule's ND1 and ND3 genes. Most of the unusual characteristics of other metazoan mtDNAs are not found in M. senile mtDNA: unorthodox translation initiation codons and partial translation termination codons are absent, the use of TGA to specify tryptophan is the only genetic code modification, and both encoded tRNAs have primary and secondary structures closely resembling those of standard tRNAs. Also, with regard to size and secondary structure potential, the mt-s-rRNA and mt-1-rRNA have the least deviation from Escherichia coli 16S and 23S rRNAs of all known metazoan mt-rRNAs. These observations indicate that most of the genetic variations previously reported in metazoan mtDNAs developed after Cnidaria diverged from the common ancestral line of all other Metazoa.

Beagley, C T; Okimoto, R; Wolstenholme, D R

1998-01-01

11

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

PubMed Central

Abstract We describe a new species of carcinoecium-forming sea anemone, Stylobates birtlesi sp. n., from sites 590–964 m deep in the Coral Sea, off the coast of Queensland, Australia. An anemone of this genus settles on a gastropod shell inhabited by a hermit crab, then covers and extends the shell to produce a chitinous structure termed a carcinoecium. Stylobates birtlesi sp. n. is symbiotic with the hermit crab Sympagurus trispinosus (Balss, 1911). The nature of marginal sphincter muscle and nematocyst size and distribution distinguish Stylobates birtlesi sp. n. from other species in the genus. The four known species of Stylobates are allopatric, each inhabiting a separate ocean basin of the Indo-West Pacific. We also extend the known range of Stylobates loisetteae in the Indian Ocean off the coast of Western Australia.

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

2011-01-01

12

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

PubMed

We describe a new species of carcinoecium-forming sea anemone, Stylobates birtlesisp. n., from sites 590-964 m deep in the Coral Sea, off the coast of Queensland, Australia. An anemone of this genus settles on a gastropod shell inhabited by a hermit crab, then covers and extends the shell to produce a chitinous structure termed a carcinoecium. Stylobates birtlesisp. n. is symbiotic with the hermit crab Sympagurus trispinosus (Balss, 1911). The nature of marginal sphincter muscle and nematocyst size and distribution distinguish Stylobates birtlesi sp. n. from other species in the genus. The four known species of Stylobates are allopatric, each inhabiting a separate ocean basin of the Indo-West Pacific. We also extend the known range of Stylobates loisetteae in the Indian Ocean off the coast of Western Australia. PMID:21594082

Crowther, Andrea L; Fautin, Daphne G; Wallace, Carden C

2011-04-11

13

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

14

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

15

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

16

NAD(P)H-dependent epoxidation of aldrin in vitro by sea anemone microsomes  

Microsoft Academic Search

Previous studies from our laboratory indicated the presence of a functional P450-dependent mixed-function oxidase system (MFO) in the sea anemone (Phylum: Cnidaria). Further catalytic studies have demonstrated that sea anemone microsomes can metabolize aldrin to dieldrin through an epoxidation reaction in the presence of NAD(P)H. Based upon Nickel 63 ECD gas chromatography, dieldrin was the only metabolite detected. Further, the

L. M. Heffernan; H. F. Morris; G. W. Winston

2000-01-01

17

Phylogenetic Relationships among Deep-Sea and Chemosynthetic Sea Anemones: Actinoscyphiidae and Actinostolidae (Actiniaria: Mesomyaria)  

PubMed Central

Sea anemones (Cnidaria, Actiniaria) are present in all marine ecosystems, including chemosynthetic environments. The high level of endemicity of sea anemones in chemosynthetic environments and the taxonomic confusion in many of the groups to which these animals belong makes their systematic relationships obscure. We use five molecular markers to explore the phylogenetic relationships of the superfamily Mesomyaria, which includes most of the species that live in chemosynthetic, deep-sea, and polar sea habitats and to test the monophyly of the recently defined clades Actinostolina and Chemosynthina. We found that sea anemones of chemosynthetic environments derive from at least two different lineages: one lineage including acontiate deep-sea taxa and the other primarily encompassing shallow-water taxa.

Rodriguez, Estefania; Daly, Marymegan

2010-01-01

18

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

19

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

20

Aged Sea Anemones  

Microsoft Academic Search

IN 1904 Dr. J. R. Ashworth and I published in the Proceedings of the Royal Society of Edinburgh (vol. xxv., p. 1) observations on aged individuals of Sagartia troglodytes then and still in the possession of Miss Jessie Nelson in Edinburgh. After eight years these anemones are still in excellent health, having been in captivity for considerably more than half

N. Annandale

1912-01-01

21

Distribution patterns of Chilean shallow-water sea anemones (Cnidaria: Anthozoa: Actiniaria, Corallimorpharia), with a discussion of the taxonomic and zoogeographic relationships between the actinofauna of the South East Pacific, the South West Atlantic and the Antarctic  

Microsoft Academic Search

SUMMARY: The first complete zoogeographical analysis of Chilean shallow water sea anemones (Actiniaria and Coral- limorpharia) and their taxonomic relations with neighbouring faunas is provided, based on extensive recent sampling in combination with a literature review. Between 1994 and 2004, we collected more than 1000 specimens of 32 distinct species of Actiniaria and Corallimorpharia at more than 100 sites along

VERENA HÄUSSERMANN; GÜNTER FÖRSTERRA

22

Mucus antigenicity in sea anemones and corals  

Microsoft Academic Search

The antigenicities of external mucus from the sea anemones Stoichactis haddoni, Radianthus ritteri and Gyrostoma hertwigi and from the coral Trachyphyllia geoffroyi were compared. Marked differences were found between species but not within species. The differences suggested that mucus composition might be species specific, and hence that it might be one of the factors used by sea anemones and corals

Roger Lubbock

1979-01-01

23

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

24

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.

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

2009-01-01

25

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

Microsoft Academic Search

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

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

2007-01-01

26

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

Microsoft Academic Search

BackgroundHox genes were critical to many morphological innovations of bilaterian animals. However, early Hox evolution remains obscure. Phylogenetic, developmental, and genomic analyses on the cnidarian sea anemone Nematostella vectensis challenge recent claims that the Hox code is a bilaterian invention and that no “true” Hox genes exist in the phylum Cnidaria.Methodology\\/Principal FindingsPhylogenetic analyses of 18 Hox-related genes from Nematostella identify

Joseph F. Ryan; Maureen E. Mazza; Kevin Pang; David Q. Matus; Andreas D. Baxevanis; Mark Q. Martindale; John R. Finnerty; Justin Fay

2007-01-01

27

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

28

Sea anemone toxins affecting potassium channels.  

PubMed

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. PMID:19184586

Diochot, Sylvie; Lazdunski, Michel

2009-01-01

29

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

30

NF-?B is required for cnidocyte development in the sea anemone Nematostella vectensis.  

PubMed

The sea anemone Nematostella vectensis (Nv) is a leading model organism for the phylum Cnidaria, which includes anemones, corals, jellyfishes and hydras. A defining trait across this phylum is the cnidocyte, an ectodermal cell type with a variety of functions including defense, prey capture and environmental sensing. Herein, we show that the Nv-NF-?B transcription factor and its inhibitor Nv-I?B are expressed in a subset of cnidocytes in the body column of juvenile and adult anemones. The size and distribution of the Nv-NF-?B-positive cnidocytes suggest that they are in a subtype known as basitrichous haplonema cnidocytes. Nv-NF-?B is primarily cytoplasmic in cnidocytes in juvenile and adult animals, but is nuclear when first detected in the 30-h post-fertilization embryo. Morpholino-mediated knockdown of Nv-NF-?B expression results in greatly reduced cnidocyte formation in the 5 day-old animal. Taken together, these results indicate that NF-?B plays a key role in the development of the phylum-specific cnidocyte cell type in Nematostella, likely by nuclear Nv-NF-?B-dependent activation of genes required for cnidocyte development. PMID:23063796

Wolenski, Francis S; Bradham, Cynthia A; Finnerty, John R; Gilmore, Thomas D

2012-10-12

31

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 5–8kDa 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

32

Characterizing the spatiotemporal expression of RNAs and proteins in the starlet sea anemone, Nematostella vectensis.  

PubMed

In an effort to reconstruct the early evolution of animal genes and proteins, there is an increasing focus on basal animal lineages such as sponges, cnidarians, ctenophores and placozoans. Among the basal animals, the starlet sea anemone Nematostella vectensis (phylum Cnidaria) has emerged as a leading laboratory model organism partly because it is well suited to experimental techniques for monitoring and manipulating gene expression. Here we describe protocols adapted for use in Nematostella to characterize the expression of RNAs by in situ hybridization using either chromogenic or fluorescence immunohistochemistry (?1 week), as well as to characterize protein expression by whole-mount immunofluorescence (?3 d). We also provide a protocol for labeling cnidocytes (?3 h), the phylum-specific sensory-effector cell type that performs a variety of functions in cnidarians, including the delivery of their venomous sting. PMID:23579779

Wolenski, Francis S; Layden, Michael J; Martindale, Mark Q; Gilmore, Thomas D; Finnerty, John R

2013-04-11

33

High In Situ Repeatability of Behaviour Indicates Animal Personality in the Beadlet Anemone Actinia equina (Cnidaria)  

PubMed Central

‘Animal personality’ means that individuals differ from one another in either single behaviours or suites of related behaviours in a way that is consistent over time. It is usually assumed that such consistent individual differences in behaviour are driven by variation in how individuals respond to information about their environment, rather than by differences in external factors such as variation in microhabitat. Since behavioural variation is ubiquitous in nature we might expect ‘animal personality’ to be present in diverse taxa, including animals with relatively simple nervous systems. We investigated in situ startle responses in a sea anemone, Actinia equina, to determine whether personalities might be present in this example of an animal with a simple nervous system. We found very high levels of repeatability among individuals that were re-identified in the same locations over a three week sampling period. In a subset of the data, where we used tide-pool temperature measurements to control for a key element of variation in microhabitat, these high levels of repeatability remained. Although a range of other consistent differences in micro-habitat features could have contributed to consistent differences between the behaviour of individuals, these data suggest the presence of animal personality in A. equina. Rather than being restricted to certain groups, personality may be a general feature of animals and may be particularly pronounced in species with simple nervous systems.

Briffa, Mark; Greenaway, Julie

2011-01-01

34

Effects of anemonefish on giant sea anemones: expansion behavior, growth, and survival  

Microsoft Academic Search

The symbiosis between giant sea anemones and anemonefish on coral reefs is well known, but little information exists on impacts\\u000a of this interaction on the sea anemone host. On a coral reef at Eilat, northern Red Sea, individuals of the sea anemone Entacmaea quadricolor that possessed endemic anemonefish Amphiprion bicinctus expanded their tentacles significantly more frequently than did those lacking

D. Porat; N. E. Chadwick-Furman

35

Effects of anemonefish on giant sea anemones: expansion behavior, growth, and survival  

Microsoft Academic Search

The symbiosis between giant sea anemones and anemonefish on coral reefs is well known, but little information exists on impacts of this interaction on the sea anemone host. On a coral reef at Eilat, northern Red Sea, individuals of the sea anemone Entacmaea quadricolor that possessed endemic anemonefish Amphiprion bicinctus expanded their tentacles significantly more frequently than did those lacking

D. Porat; N. E. Chadwick-Furman

2004-01-01

36

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

37

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

38

Biochemical and Electrophysiological Characterization of Two Sea Anemone Type 1 Potassium Toxins from a Geographically Distant Population of Bunodosoma caissarum  

PubMed Central

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.

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

2013-01-01

39

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, José E P W; Freitas, José C; Zaharenko, André J; Tytgat, Jan

2013-03-06

40

Analysis of soluble protein contents from the nematocysts of a model sea anemone sheds light on venom evolution.  

PubMed

The nematocyst is one of the most complex intracellular structures found in nature and is the defining feature of the phylum Cnidaria (sea anemones, corals, jellyfish, and hydroids). This miniature stinging organelle contains and delivers venom into prey and foe yet little is known about its toxic components. In the present study, we identified by tandem mass spectrometry 20 proteins released upon discharge from the nematocyst of the model sea anemone Nematostella vectensis. The availability of genomic and transcriptomic data for this species enabled accurate identification and phylogenetic study of these components. Fourteen of these proteins could not be identified in other animals suggesting that they might be the products of taxonomically restricted genes, a finding which fits well their origin from a taxon-specific organelle. Further, we studied by in situ hybridization the localization of two of the transcripts encoding the putative nematocyst venom proteins: a metallopeptidase related to the Tolloid family and a cysteine-rich protein. Both transcripts were detected in nematocytes, which are the cells containing nematocysts, and the metallopeptidase was found also in pharyngeal gland cells. Our findings reveal for the first time the possible venom components of a sea anemone nematocyst and suggest their evolutionary origins. PMID:23151943

Moran, Yehu; Praher, Daniela; Schlesinger, Ami; Ayalon, Ari; Tal, Yossi; Technau, Ulrich

2012-11-15

41

Benefits to host sea anemones from ammonia contributions of resident anemonefish  

Microsoft Academic Search

Large ectosymbionts (especially fishes and crustaceans) may have major impacts on the physiology of host cnidarians (sea anemones and corals), but these effects have not been well quantified. Here we describe impacts on giant sea anemone hosts (Entacmaea quadricolor) and their endosymbiotic zooxanthellae (Symbiodinium spp.) from the excretion products of anemonefish guests (Amphiprion bicinctus) under laboratory conditions. Starved host anemones

Modi Roopin; Nanette E. Chadwick

2009-01-01

42

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

PubMed

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 PLA(2) isolated from the sea anemone B. caissarum on the isolated perfused kidney, the arteriolar mesenteric bed and on insulin secretion. Specimens of B. caissarum were collected from the São Vicente Channel on the southern coast of the State of São Paulo, Brazil. Reverse phase HPLC analysis of the crude extract of B. caissarum detected three PLA(2) proteins (named BcPLA(2)1, BcPLA(2)2 and BcPLA(2)3) found to be active in B. caissarum extracts. MALDI-TOF mass spectrometry of BcPLA(2)1 showed one main peak at 14.7 kDa. The N-terminal amino acid sequence of BcPLA(2)1 showed high amino acid sequence identity with PLA(2) group III protein isolated from the Mexican lizard (PA23 HELSU, HELSU, PA22 HELSU) and with the honey bee Apis mellifera (PLA(2) and 1POC_A). In addition, BcPLA(2)1 also showed significant overall homology to bee PLA(2). The enzymatic activity induced by native BcPLA(2)1 (20 microg/well) was reduced by chemical treatment with p-bromophenacyl bromide (p-BPB) and with morin. BcPLA(2)1 strongly induced insulin secretion in presence of high glucose concentration. In isolated kidney, the PLA(2) from B. caissarum increased the perfusion pressure, renal vascular resistance, urinary flow, glomerular filtration rate, and sodium, potassium and chloride levels of excretion. BcPLA(2)1, however, did not increase the perfusion pressure on the mesenteric vascular bed. In conclusion, PLA(2), a group III phospholipase isolated from the sea anemone B. caissarum, exerted effects on renal function and induced insulin secretion in conditions of high glucose concentration. PMID:19463845

Martins, René D; Alves, Renata S; Martins, Alice M C; Barbosa, Paulo Sergio F; Evangelista, Janaina S A M; Evangelista, João José F; Ximenes, Rafael M; Toyama, Marcos H; Toyama, Daniela O; Souza, Alex Jardelino F; Orts, Diego J B; Marangoni, Sérgio; de Menezes, Dalgimar B; Fonteles, Manassés C; Monteiro, Helena S A

2009-05-20

43

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

44

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

45

Growth, reproduction and survival of a tropical sea anemone (Actiniaria): benefits of hosting anemonefish  

Microsoft Academic Search

The ecological performance of the sea anemone Heteractis magnifica was examined during a 36-month experiment with respect to season and the presence and numbers of a mutualist (orange-fin anemonefish Amphiprion chrysopterus). Anemones primarily grew during the autumn, with most asexual reproduction occurring in winter; mortality was not strongly seasonal. Individual growth rates did not differ between anemones harboring one or

S. J. Holbrook; R. J. Schmitt

2005-01-01

46

Temperature adaptation in sea anemones: Physiological and biochemical variability in geographically separate populations of Metridium senile  

Microsoft Academic Search

Latitudinally separate populations of the sea anemone Metridium senile (L.) are very similar genetically by electrophoretic criteria, yet respond differently to temperature. Anemones from southern and northern California (USA) have different oxygen consumption patterns in response to acclimatory and acute changes in temperature. Northern anemones show a pronounced increase in Q10 at temperatures just above the normal environmental range, but

P. J. Walsh; G. N. Somero

1981-01-01

47

Time-course of photoadaptation in the symbiotic sea anemone Anemonia viridis  

Microsoft Academic Search

The time-course of photoadaptation in the symbiotic sea anemone Anemonia viridis (Forskäl) was determined on freshly collected anemones which were maintained under low light (LL: 10 µE m-2s-1) or high light (HL: 300 µE m-2s-1) over a period of 35 d. Photosynthesis versus irradiance curves (P vs I) normalised to anemone dry weight were determined for anemones at the start

A. D. Harland; P. S. Davies

1994-01-01

48

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

49

Acute renal failure after a sea anemone sting.  

PubMed

A 27-year-old man suffering from severe swelling and pain in his right arm was referred to our hospital. He showed signs of acute renal failure (ARF) with severe dermatitis of his right arm. Three days before being admitted, he accidentally touched some kind of marine organism with his right hand while snorkeling in the Sulu Sea around Cebu Island. Within a few minutes, he was experiencing severe pain in his right hand. Then his right hand gradually became swollen. The marine creature responsible for this injury was thought to have been a sea anemone, which is a type of coelenterate. Histologic findings of a renal biopsy indicated that acute tubular necrosis (ATN) had caused ARF in this patient's case. Supportive therapies improved renal function of this patient, and steroid pulse therapy attenuated the severe skin discoloration. The ATN was thought to have been caused by the poison from a sea anemone because there were no other conceivable reasons for the patient's condition. This is the first time that a marine envenomation case has been reported in which the sting of a sea anemone has caused ATN without the failure of any other organs. PMID:10922331

Mizuno, M; Nishikawa, K; Yuzawa, Y; Kanie, T; Mori, H; Araki, Y; Hotta, N; Matsuo, S

2000-08-01

50

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.

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

2010-01-01

51

Peptide Toxins in Sea Anemones: Structural and Functional Aspects  

Microsoft Academic Search

Sea anemones are a rich source of two classes of peptide toxins, sodium channel toxins and potassium channel toxins, which\\u000a have been or will be useful tools for studying the structure and function of specific ion channels. Most of the known sodium\\u000a channel toxins delay channel inactivation by binding to the receptor site 3 and most of the known potassium

Tomohiro Honma; Kazuo Shiomi

2006-01-01

52

Novel peptide toxins recently isolated from sea anemones.  

PubMed

Sea anemones are a rich source of peptide toxins acting on ion channels. Two classes of peptide toxins, site-3 sodium channel toxins and Kv1 potassium channel toxins, have been well characterized and some of them used as valuable pharmacological reagents. Recently, the following six peptides toxins, which structurally constitute a new family but target different ion channels, have been isolated: BDS-I and -II (Kv3 potassium channel toxins) from Anemonia sulcata, APETx1 (human ether-a-go-go-related gene potassium channel toxin) and APETx2 (acid-sensing sodium channel toxin) from Anthopleura elegantissima, BcIV (sodium channel toxin) from Bunodosoma caissarum and Am II (whose target is unknown) from Antheopsis maculata. In addition, the following structurally novel peptide toxins have also emerged in sea anemones: gigantoxin I (epidermal growth factor-like toxin) from Stichodactyla gigantea and acrorhagins I and II from acrorhagi (specialized aggressive organs) of Actinia equina. This review deals with the structural and functional features of these recently isolated sea anemone peptide toxins that are promising tools in studying the physiology of diverse ion channels. PMID:19269303

Shiomi, Kazuo

2009-03-06

53

Nanotoxicology using the sea anemone Nematostella vectensis: from developmental toxicity to genotoxicology.  

PubMed

Abstract Concomitant with the fast-growing advances in the synthesis and engineering of colloidal nanocrystals, an urgent evaluation of their toxicity on human beings and environment is strongly encouraged by public health organisations. Despite the in vitro approaches employed for toxicological screening of hazardous compounds, the use of simple and cost-effective living organisms may enormously contribute to solve unanswered questions related to embryotoxic and teratogenic effects of nanomaterials. Here, the sea anemone Nematostella vectensis (Cnidaria, Anthozoa) is presented as a novel model organism to profile bio/non-bio interactions and to show a comprehensive toxicological analysis performed on embryos, larvae and adults treated with fluorescent cadmium-based nanocrystals. Spanning from in vivo biodistribution to molecular investigations, different behaviours and effects depending on the composition and surface coatings are showed. Rod-shaped cadmium selenide/cadmium sulfide (CdSe/CdS) nanocrystals resulted in excellent imaging probes to track N. vectensis development with negligible adverse effects, while spherical CdTe nanocrystals severely impaired embryogenesis, resulting in aberrant phenotypes and deregulation of developmental genes, which raise severe worries for a safe use of this type of nanoparticles for human purposes and environmental contamination. PMID:23641943

Ambrosone, Alfredo; Marchesano, Valentina; Mazzarella, Veronica; Tortiglione, Claudia

2013-06-01

54

Mutualism with sea anemones triggered the adaptive radiation of clownfishes  

PubMed Central

Background Adaptive radiation is the process by which a single ancestral species diversifies into many descendants adapted to exploit a wide range of habitats. The appearance of ecological opportunities, or the colonisation or adaptation to novel ecological resources, has been documented to promote adaptive radiation in many classic examples. Mutualistic interactions allow species to access resources untapped by competitors, but evidence shows that the effect of mutualism on species diversification can greatly vary among mutualistic systems. Here, we test whether the development of obligate mutualism with sea anemones allowed the clownfishes to radiate adaptively across the Indian and western Pacific oceans reef habitats. Results We show that clownfishes morphological characters are linked with ecological niches associated with the sea anemones. This pattern is consistent with the ecological speciation hypothesis. Furthermore, the clownfishes show an increase in the rate of species diversification as well as rate of morphological evolution compared to their closest relatives without anemone mutualistic associations. Conclusions The effect of mutualism on species diversification has only been studied in a limited number of groups. We present a case of adaptive radiation where mutualistic interaction is the likely key innovation, providing new insights into the mechanisms involved in the buildup of biodiversity. Due to a lack of barriers to dispersal, ecological speciation is rare in marine environments. Particular life-history characteristics of clownfishes likely reinforced reproductive isolation between populations, allowing rapid species diversification.

2012-01-01

55

Genomic Organization of a Receptor from Sea Anemones, Structurally and Evolutionarily Related to Glycoprotein Hormone Receptors from Mammals  

Microsoft Academic Search

Cnidarians (e.g., sea anemones and corals) are the lowest animal group having a nervous system. Previously, we cloned a receptor from sea anemones that showed a strong structural similarity to the glycoprotein hormone (TSH, FSH, LH\\/CG) receptors from mammals. Here, we determine the genomic organization of this sea anemone receptor. The receptor gene contains eight introns that are all localized

Nikolaj Vibede; Frank Hauser; Michael Williamson; Cornelis J. P. Grimmelikhuijzen

1998-01-01

56

Development and Characterization of Sea Anemones as Bioindicators of Offshore Resource Exploitation and Environmental Impact.  

National Technical Information Service (NTIS)

Five species of sea anemones were characterized as potential sentinels of marine pollution. Proteins of 50-60 KDa were recognized by antibodies (Ab) raised to fish or mammalian cytochromnes P450 (CYP) in microsomes of all sea anemones. Microsomal ethoxyre...

G. W. Winston L. M. Heffernan

1999-01-01

57

Host selection by shrimps symbiotic with sea anemones: A field survey and experimental laboratory analysis  

Microsoft Academic Search

In three coastal areas of the Republic of China, we found six species of anemoneshrimps and five of host sea anemones in 13 symbiotic combinations; four of the 13 combinations were previously documented. In the laboratory, we tested host preference of the three common shrimps, Periclimenes ornatus Bruce, P. brevicarpalis (Schenkel), and Thor amboinensis (De Man), for anemones of three

Chau-Chih Guo; Jiang-Shiou Hwang; Daphne Gail Fautin

1996-01-01

58

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

59

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 (0.45â€\\

KENNETH P. SEBENS

1981-01-01

60

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

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

Detachment of Sea Anemones by Commensal Hermit Crabs and by Mechanical and Electrical Stimuli  

Microsoft Academic Search

THE ability of some hermit crabs to detach commensal sea anemones and place them on their shells has interested ecologists and ethologists for many years1. Anemones belonging to the genus Calliactis are perhaps best known in this respect. Excellent accounts of the behaviour of the Mediterranean hermit crab Dardanus (= Pagurus) arrosor Herbst, towards C. parasitica (Couch) have long been

D. M. Ross; L. Sutton

1968-01-01

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.

2009-01-01

64

Redescription and biological aspects of Hormathia alba (Andres, 1881), a luminescent sea anemone (Anthozoa, Actiniaria)  

NASA Astrophysics Data System (ADS)

The sea anemone Hormathia alba (Andres, 1881) is redescribed and definitely established as distinct from H. coronata. Synonymy, external morphology, anatomy and cnidom are treated in detail. Aspects of its reproduction, ecology, distribution and distinctive characteristics are also reported. The species, largely mistaken throughout literature, is rather common on Mediterranean infralittoral soft bottoms. It has also been found in the SW of Ireland. This is the only known sea anemone with luminescence, a feature that has never been reported before.

Tur, J. M.

1993-06-01

65

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

66

Factors affecting zooplankton feeding by the sea anemone Aiptasia pallida  

NASA Astrophysics Data System (ADS)

Effects of various treatments on prey capture, prey ingestion and ingestion time of individual Artemia salina nauplii by the sea anemone Aiptasia pallida Verrill were studied in the laboratory. Exposure to crude Artemia homogenate, 5 × 10-4 M reduced glutathione or 5 × 10-4 M proline significantly decreased the number of Artemia that were captured and ingested but had no significant effect on the ingestion time of individual Artemia. Multiple captures increased the total ingestion time but decreased ingestion time per prey item. Results suggest that, under these conditions, the prey capture phase of zooplankton feeding was somewhat distinct from the ingestion phase since chemical stimuli that significantly reduced prey capture had no significant effect on ingestion time.

Clayton, William S.

1986-03-01

67

Development of a rational nomenclature for naming peptide and protein toxins from sea anemones.  

PubMed

Sea anemone toxins are predominantly peptide and proteins that act mainly on sodium and potassium channels, as well as in a variety of target cells causing lysis. Over recent years, the number of sea anemone peptide toxins as well as cytolytic pore-forming proteins and phospholipase A(2) sequences submitted to databases has been rapidly increasing due to the developments in DNA sequencing technology and proteomic approaches. However, the lack of a systematic nomenclature has resulted in multiple names being assigned to the same toxins, toxins from unrelated species being designated by the same name, and ambiguous name designations. Therefore, in this work we propose a systematic nomenclature in which we adopted specific criteria, based on order of discovery and phylogenetic analysis, in order to avoid redundant sea anemone toxin names. Implementation of the nomenclature proposed here not only allowed us to rename the already published 191 anemone toxins without ambiguities, but it can be used to unambiguously name newly discovered toxins whether or not they are related to previously published sea anemone sequences. In the new nomenclature each toxin name contains information about the toxin's biological activity, origin and relationship to known isoforms. Ongoing increases in the speed of DNA sequencing will raise significantly the number of sea anemone toxin sequences in the literature. This will represent a constant challenge in their clear identification and logical classification, which could be solved using the proposed nomenclature. PMID:22683676

Oliveira, Joacir Stolarz; Fuentes-Silva, Deyanira; King, Glenn F

2012-06-05

68

Sedimentary nitrogen uptake and assimilation in the temperate zooxanthellate sea anemone Anthopleura aureoradiata  

Microsoft Academic Search

The sea anemone Anthopleura aureoradiata (Carlgren), which harbours symbiotic dinoflagellates (zooxanthellae), is abundant on mudflats and rocky shores around New Zealand. We measured the potential for particulate nitrogen uptake from sediment by A. aureoradiata and the subsequent consequences of this uptake on the nitrogen status of its zooxanthellae. Sediment was rinsed, labelled with (15NH4)2SO4, and provided to anemones at low

Shyam R. Morar; Sarah J. Bury; Shaun P. Wilkinson; Simon K. Davy

2011-01-01

69

Population characteristics of the intertidal green sea anemone, Anthopleura xanthogrammica, on the Oregon coast  

NASA Astrophysics Data System (ADS)

Field population censuses using a photographic quadrat method were used to describe the density and size structure of intertidal populations of the green sea anemone, Anthopleura xanthogrammica, on different types of rocky intertidal habitats on the Oregon coast. Anemone populations in marked plots were monitored for individual motility, growth, mortality and recruitment. Experiments were performed to evaluate anemone population responses to simulated harvesting. Rocky intertidal locations with dense populations of the green anemone are not abundant along the Oregon coast. No detectable fluctuations in anemone population density or size-frequency distribution were found during the 2-year study. Adult anemones showed little movement in either disturbed or undisturbed populations. No natural mortality or recruitment was found in study plots at any Oregon coastal location between July 1977 and May 1979. Removal of adult anemones from rock surfaces did not promote recruitment from the plankton onto the newly available surface, nor did individuals adjacent to depopulated plots rapidly immigrate into the cleared areas. Individual growth is inferred to be very slow in intertidal populations. Field studies indicate that A. xanthogrammica is a long-lived, slow growing species with limited, low or erratic recruitment and highly stable intertidal adult populations. This study indicates that harvest of A. xanthogrammica will probably not be possible on a continuing basis.

Batchelder, H. P.; Gonor, J. J.

1981-09-01

70

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.

Rodríguez, E.; López-González, P. J.; Gili, J. M.

2007-08-01

71

Anemonefish symbiosis: vulnerability and resistance of fish to the toxin of the sea anemone.  

PubMed

Protein toxins (20 kD molecular mass) causing lysis of human erythrocytes were isolated from sea anemones (Heteractis magnifica, Madang, Papua New Guinea, and Entacmaea quadricolor, Red Sea), which host anemonefish (Amphiprion sp.). These toxins are also ichthyotoxic. Freshwater and marine fish exposed to toxin concentrations of 0.5 micrograms/ml water were killed within 2 hr and exhibited extensive pathological alterations of the gill filaments. Amphiprion species, e.g. clarkii and percula, which live in the sea anemones Heteractis crispa and Stichodactyla mertensii, were highly vulnerable to the Heteractis magnifica toxin, whereas A. percula from the sea anemone H. magnifica proved to be toxin resistant. However, another species, A. perideraion also living in H. magnifica, was highly sensitive to the toxin. The two toxins exhibited cross-reactivity: Amphiprion, resistant to H. magnifica toxin, was also resistant to Entacmaea quadricolor toxin; but all fish were killed by other membrane-active substances such as gramicidin, saponin and latrunculin. The results of the study indicate that resistance to toxins secreted by the sea anemone has evolved in some Amphiprion species, but it is not an essential or a major factor in the anemonefish symbiosis. The skin's mucus layer seems to provide protection from nematocyst discharge. PMID:7801342

Mebs, D

1994-09-01

72

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

Microsoft Academic Search

The accumulation of metals by the North American Pacific Coast temperate sea anemone Anthopleura elegantissima, and its dinoflagellate-algal symbiont Symbiodinium muscatinei was examined following laboratory metal exposures. Both, naturally occurring symbiotic and symbiont-free (aposymbiotic) anemones were used in this study to investigate differences in metal uptake due to the symbiotic state of the animal. The effects of metal exposures on

Carys L. Mitchelmore; E. Alan Verde; Amy H. Ringwood; Virginia M. Weis

2003-01-01

73

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

74

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

75

Scanning electron microscopy of the sensory surface of the tentacles of sea anemones and corals  

Microsoft Academic Search

Examination of the sensory surface of the tentacles of sea anemones and corals prepared by the Freon critical-point method has revealed three primary structures: ciliary cones consisting of a cilium surrounded by a cluster of shorter stereocilia, single long cilia, and microvilli. The ciliary cones occur on, and the single cilia and microvilli occur both on and between, the nematocyst-

Richard N. Mariscal

1974-01-01

76

The annual gametogenic cycle of the sea anemone Metridium senile from the Gulf of Maine  

Microsoft Academic Search

A year-long study was conducted to quantify the reproductive cycle of the clonal sea anemone, Metridium senile, an important member of the benthic community in the Gulf of Maine (GOM). M.senile is an abundant sessile invertebrate that forms identifiable clonal aggregations that are maintained by pedal laceration but individuals can also reproduce sexually. Specimens were collected monthly from a shallow

Michael R. Lombardi; Michael P. Lesser

2010-01-01

77

Accumulation of Glutamate in Sea Anemones Exposed to Heavy Metals and Organic Amines.  

National Technical Information Service (NTIS)

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. While free glycine in B. cavernata generally shows a reduction in ...

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

1980-01-01

78

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

79

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 Castañeda; Vivian Sotolongo; Ana Maria Amor; Reto Stöcklin; Amanda J. Anderson; Alan L. Harvey; Åke Engström; Christer Wernstedt; Evert Karlsson

1995-01-01

80

Conformational Stability and Hemolytic Activity of Actinoporin RTX-SII from the Sea Anemone Radianthus macrodactylus  

Microsoft Academic Search

The spatial organization of actinoporin RTX-SII from the sea anemone Radianthus macrodactylus on the level of tertiary and secondary structures was studied by UV and CD spectroscopy and intrinsic protein fluorescence. The specific and molar extinction coefficients of RTX-SII were determined. The percentages of canonical secondary structures of actinoporin were calculated. The tertiary structure of the polypeptide is well developed

T. I. Vakorina; E. V. Klyshko; M. M. Monastyrnaya; E. P. Kozlovskaya

2005-01-01

81

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

82

Sea anemone toxins affecting voltage-gated sodium channels--molecular and evolutionary features.  

PubMed

The venom of sea anemones is rich in low molecular weight proteinaceous neurotoxins that vary greatly in structure, site of action, and phyletic (insect, crustacean or vertebrate) preference. This toxic versatility likely contributes to the ability of these sessile animals to inhabit marine environments co-habited by a variety of mobile predators. Among these toxins, those that show prominent activity at voltage-gated sodium channels and are critical in predation and defense, have been extensively studied for more than three decades. These studies initially focused on the discovery of new toxins, determination of their covalent and folded structures, understanding of their mechanisms of action on different sodium channels, and identification of the primary sites of interaction of the toxins with their channel receptors. The channel binding site for Type I and the structurally unrelated Type III sea anemone toxins was identified as neurotoxin receptor site 3, a site previously shown to be targeted by scorpion alpha-toxins. The bioactive surfaces of toxin representatives from these two sea anemone types have been characterized by mutagenesis. These analyses pointed to heterogeneity of receptor site 3 at various sodium channels. A turning point in evolutionary studies of sea anemone toxins was the recent release of the genome sequence of Nematostella vectensis, which enabled analysis of the genomic organization of the corresponding genes. This analysis demonstrated that Type I toxins in Nematostella and other species are encoded by gene families and suggested that these genes developed by concerted evolution. The current review provides a brief historical description of the discovery and characterization of sea anemone toxins that affect voltage-gated sodium channels and delineates recent advances in the study of their structure-activity relationship and evolution. PMID:19268682

Moran, Yehu; Gordon, Dalia; Gurevitz, Michael

2009-03-05

83

Collecting, rearing, spawning and inducing regeneration of the starlet sea anemone, Nematostella vectensis.  

PubMed

Over the past 20 years, the starlet sea anemone, Nematostella vectensis, a small estuarine animal, has emerged as a powerful model system for field and laboratory studies of development, evolution, genomics, molecular biology and toxicology. Here we describe how to collect Nematostella, culture it through its entire sexual life cycle and induce regeneration for the production of clonal stocks. In less than 1 h at a suitable field site, a researcher on foot can collect hundreds of individual anemones. In a few months, it is possible to establish a laboratory colony that will be reliable in generating hundreds or thousands of fertilized eggs on a roughly weekly schedule. By inducing regeneration roughly every 2 weeks, in less than 6 months, one can establish a clonal stock consisting of hundreds of genetically identical anemones. These results can be achieved very inexpensively and without specialized equipment. PMID:23579780

Stefanik, Derek J; Friedman, Lauren E; Finnerty, John R

2013-04-11

84

Short Toxin-like Proteins Abound in Cnidaria Genomes  

PubMed Central

Cnidaria is a rich phylum that includes thousands of marine species. In this study, we focused on Anthozoa and Hydrozoa that are represented by the Nematostella vectensis (Sea anemone) and Hydra magnipapillata genomes. We present a method for ranking the toxin-like candidates from complete proteomes of Cnidaria. Toxin-like functions were revealed using ClanTox, a statistical machine-learning predictor trained on ion channel inhibitors from venomous animals. Fundamental features that were emphasized in training ClanTox include cysteines and their spacing along the sequences. Among the 83,000 proteins derived from Cnidaria representatives, we found 170 candidates that fulfill the properties of toxin-like-proteins, the vast majority of which were previously unrecognized as toxins. An additional 394 short proteins exhibit characteristics of toxin-like proteins at a moderate degree of confidence. Remarkably, only 11% of the predicted toxin-like proteins were previously classified as toxins. Based on our prediction methodology and manual annotation, we inferred functions for over 400 of these proteins. Such functions include protease inhibitors, membrane pore formation, ion channel blockers and metal binding proteins. Many of the proteins belong to small families of paralogs. We conclude that the evolutionary expansion of toxin-like proteins in Cnidaria contributes to their fitness in the complex environment of the aquatic ecosystem.

Tirosh, Yitshak; Linial, Itai; Askenazi, Manor; Linial, Michal

2012-01-01

85

Short toxin-like proteins abound in Cnidaria genomes.  

PubMed

Cnidaria is a rich phylum that includes thousands of marine species. In this study, we focused on Anthozoa and Hydrozoa that are represented by the Nematostella vectensis (Sea anemone) and Hydra magnipapillata genomes. We present a method for ranking the toxin-like candidates from complete proteomes of Cnidaria. Toxin-like functions were revealed using ClanTox, a statistical machine-learning predictor trained on ion channel inhibitors from venomous animals. Fundamental features that were emphasized in training ClanTox include cysteines and their spacing along the sequences. Among the 83,000 proteins derived from Cnidaria representatives, we found 170 candidates that fulfill the properties of toxin-like-proteins, the vast majority of which were previously unrecognized as toxins. An additional 394 short proteins exhibit characteristics of toxin-like proteins at a moderate degree of confidence. Remarkably, only 11% of the predicted toxin-like proteins were previously classified as toxins. Based on our prediction methodology and manual annotation, we inferred functions for over 400 of these proteins. Such functions include protease inhibitors, membrane pore formation, ion channel blockers and metal binding proteins. Many of the proteins belong to small families of paralogs. We conclude that the evolutionary expansion of toxin-like proteins in Cnidaria contributes to their fitness in the complex environment of the aquatic ecosystem. PMID:23202321

Tirosh, Yitshak; Linial, Itai; Askenazi, Manor; Linial, Michal

2012-11-16

86

Biological activity of sea anemone proteins: II. Cytolysis and cell line toxicity.  

PubMed

Potent cytolytic activity was exhibited by proteins extracted from three sea anemones viz. Heteractis magnifica, Stichodactyla haddoni and Paracodylactis sinensis by affecting the red blood corpuscles (RBC) and the mouse fibroblast cell line (L929) and leukemia cell line (P388). Crude toxin of all the three anemone species induced spontaneous hemolysis of chicken, goat and human erythrocytes. The crude toxin of H. magnifica (0.98 mg/ml) elicited hemolysis at levels of 4096, 512 and 4096 HU (hemolytic unit) in chicken, goat and human erythrocytes respectively. Subsequently, the crude toxin of S. haddoni (0.82 mg/ml) exhibited a hemolytic activity of 256, 128 and 512 HU and that of P. sinensis (0.60 mg/ml) had a hemolytic activity of 128, 4096 and 512 HU. Most of the partially purified proteins of these anemones also exhibited the activity against the three different erythrocytes. The viability of L929 and P388 was adversely affected on adding the crude toxins. The symptoms of toxicity shown by the cells were rounding, lysis and detachment from the substratum. These effects were the least in S. haddoni, as compared to those the crude toxins of the other two species. Inhibition of growth of L929 exhibited by the toxin of the three species ranged between 61.08 and 93.38%. Similarly, inhibition of the growth of P388 ranged between 51.32 and 86.16%. The present investigation reveal the cytotoxic nature of anemone toxins. PMID:21250606

Ravindran, Vinoth S; Kannan, L; Venkateshvaran, K

2010-12-01

87

Another bipolar deep-sea anemone: new species of Iosactis (Actiniaria, Endomyaria) from Antarctica  

NASA Astrophysics Data System (ADS)

A new species of deep-sea burrowing sea anemone is described and illustrated from Antarctica. Iosactis antarctica sp. nov. is characterised by easily deciduous tentacles with sphincters in the base, smooth column, endodermal marginal sphincter, same mesenteries proximally and distally, 24 perfect mesenteries regularly arranged, diffuse retractor musculature and basilar muscles well developed. Iosactis antarctica sp. nov. is the second species of the deep-sea abyssal genus Iosactis; it differs from I. vagabunda in internal anatomy, cnidae and geographic distribution. The description of I. antarctica sp. nov. provides the opportunity to revaluate the morphology of the proximal end of this genus.

Rodríguez, Estefanía

2012-06-01

88

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

89

Functional expression and characterization of an acidic actinoporin from sea anemone Sagartia rosea  

Microsoft Academic Search

Src I is the first reported acidic actinoporin from sea anemone Sagartia rosea with a pI value of 4.8 and comprises 13.9% ?-helix, 65.1% ?-sheet, and 18.2% random coil. For structure–function studies, Src I was expressed in Escherichia coli as a cleavable fusion protein. Recombinant Src I exhibited obviously hemolytic activity, but the fusion protein Trx-Src I almost lost its

Xiaoyu Jiang; Huiping Chen; Wenli Yang; Yun Liu; Wei Liu; Jianwen Wei; Hongbin Tu; Xiaojin Xie; Lei Wang; Anlong Xu

2003-01-01

90

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 (Forskål) was examined by following the pathway of assimilation using

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

1999-01-01

91

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 44–50% ?-sheet, 18–20% ?-turn, 12–15% ?-helix, and 19–22% random coil. Upon

Gianfranco Menestrina; Veronique Cabiaux; Mayra Tejuca

1999-01-01

92

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 µE 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

93

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.

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

2010-01-01

94

Rates of overgrowth by macroalgae and attack by sea anemones are greater for live coral than dead coral under conditions of nutrient enrichment  

Microsoft Academic Search

A mesocosm experiment was conducted to determine the effects of nutrient enrichment on competitive interactions between a hard coral, a green alga, and a sea anemone. In the low-nutrient controls, abundances of the green alga, Codium edule, and a sea anemone, Mesactinia genesis, remained low, and they coexisted with the live or dead scleractinian coral, Acropora muricata. Combined nitrogen and

Pi-Jen Liu; Shiue-Ming Lin; Tung-Yung Fan; Pei-Jie Meng; Kwang-Tsao Shao; Hsing-Juh Lina

2009-01-01

95

SENSITIVITY TO LIGHT IN THE SEA ANEMONE METRIDIUM SENILE (L.)  

PubMed Central

1. The reaction time of the photosensitive response of Metridium was found to be composed almost entirely of a sensitization period. If a latent period exists, it is too short to be detected by the methods used and is probably less than a second in duration. The length of the reaction time, therefore, was used as a measure of the radiant energy necessary at any intensity to elicit a response. 2. The length of the reaction time was found to vary randomly by a factor of seven under constant environmental and stimulating conditions. Determination of large numbers of reaction times on several anemones, grouped according to length, gave closely similar distributions resembling Poisson distributions. It was suggested that the variability may be caused by the same factor or mechanism in each individual. An experimental scheme was presented for determining the expected error and variation in statistical quantities when groups of ten observations are used. 3. The means of groups of reaction times determined at different intensities formed a hyperbolic relationship when plotted against intensity, suggesting that the animal obeys the Bunsen-Roscoe law of reciprocity. No marked changes were noted of per cent deviation from the mean or of randomness at different intensities. Stimulation of Metridium requires roughly 5 x 109 incident quanta/cm.2 of blue-green light. 4. No temperature effect could be found on either the means, the per cent deviation from the mean, or the degree of randomness of series of about ten observations, studied over a 17°C. range. It was concluded that the variability in reaction time was not due to changes in any complex physiological state such as muscular tone. 5. A possible use of the photosensitive response is suggested and the potentialities of "integrative" photosensitivity are discussed. 6. Possible mechanisms to explain the variability in reaction time are discussed. In the light of evidence presented, the most likely hypothesis appears to be the uncertainty of quantum capture caused by low concentrations of photosensitive pigment. Assuming the validity of this hypothesis, evidence suggests that the anemones responded to less than 10 quanta of absorbed light. Caution, however, is recommended in accepting the hypothesis because of the indirect nature of the supporting evidence.

North, Wheeler J.

1957-01-01

96

Introduction to Cnidaria  

NSDL National Science Digital Library

In depth site covers Cnidarian life history, ecology, morphology, systematics, and fossil record. Organisms described include corals, anemones, sea pens, box jellies, siphonophores, hydroids, fire corals, medusae, and true jellyfish. Nice explanations, diagrams, and photos.

97

Bunodosine 391: an analgesic acylamino acid from the venom of the sea anemone Bunodosoma cangicum.  

PubMed

A new acylamino acid, bunodosine 391 (BDS 391), was isolated from the venom of the sea anemone Bunodosoma cangicum. The structure was elucidated by spectroscopic analyses (2D NMR, ESIMS/MS) and verified by its synthesis. Intraplantar injection of BDS 391 into the hind paw of a rat induced a potent analgesic effect. This effect was not altered by naloxone (an opioid receptor antagonist), but was completely reversed by methysergide (a serotonin receptor antagonist), indicating that the effect is mediated by activation of serotonin receptors. PMID:21309590

Zaharenko, André J; Picolo, Gisele; Ferreira, Wilson A; Murakami, Takanori; Kazuma, Kohei; Hashimoto, Masaru; Cury, Yara; de Freitas, José C; Satake, Motoyoshi; Konno, Katsuhiro

2011-02-10

98

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

99

Differential accumulation of cadmium and changes in glutathione levels as a function of symbiotic state in the sea anemone Anthopleura elegantissima  

Microsoft Academic Search

Coastal ecosystems are increasingly impacted by anthropogenic activities and contaminant inputs, including heavy metals. This paper investigates the responses to laboratory cadmium exposures in the North American Pacific coast temperate sea anemone Anthopleura elegantissima. Anemones were exposed to cadmium chloride (control, 20 and 100 ?g l?1 Cd) for 14 days (sampled at days 0, 2, 7 and 14) and analyzed

Carys L. Mitchelmore; Amy H. Ringwood; Virginia M. Weis

2003-01-01

100

Atypical reactive center Kunitz-type inhibitor from the sea anemone Heteractis crispa.  

PubMed

The primary structure of a new Kunitz-type protease inhibitor InhVJ from the sea anemone Heteractis crispa (Radianthus macrodactylus) was determined by protein sequencing and cDNA cloning. InhVJ amino acid sequence was shown to share high sequence identity (up to 98%) with the other known Kunitz-type sea anemones sequences. It was determined that the P1 Thr at the reactive site resulted in a decrease of the K(i) of InhVJ to trypsin and ?-chymotrypsin (7.38 × 10(-8) M and 9.93 × 10(-7) M, respectively). By structure modeling the functional importance of amino acids at the reactive site as well as at the weak contact site were determined. The significant role of Glu45 for the orientation and stabilization of the InhVJ-trypsin complex was elucidated. We can suggest that there has been an adaptive evolution of the P1 residue at the inhibitor reactive site providing specialization or functional diversification of the paralogs. The appearance of a key so-called P1 Thr residue instead of Lys might lead to refinement of inhibitor specificity in the direction of subfamilies of serine proteases. The absence of Kv channel and TRPV1-receptor modulation activity was confirmed by electrophysiological screening tests. PMID:22851925

Gladkikh, Irina; Monastyrnaya, Margarita; Leychenko, Elena; Zelepuga, Elena; Chausova, Victoria; Isaeva, Marina; Anastyuk, Stanislav; Andreev, Yaroslav; Peigneur, Steve; Tytgat, Jan; Kozlovkaya, Emma

2012-07-19

101

[Actinoporins from the Sea of Japan anemone Oulactis orientalis: isolation and partial characterization].  

PubMed

Two cytolytic toxins (cytolysins Or-A and Or-G) were isolated from the Sea of Japan anemone Oulactis orientalis and characterized. Their purification scheme involved a hydrophobic chromatography on Polychrom 1, a gel filtration on Akrilex P-4, a cation-exchange chromatography on CM-32 cellulose, and a reversed-phase HPLC on a Nucleosil C18 column. The molecular masses of Or-A and Or-G were determined by SDS-PAGE in 14% PAG to be ca. 18 kDa. The absence of Cys residues and a high content of basic amino acid residues are characteristic of their amino acid compositions. The hemolytic activities of Or-A and Or-G were found to be 295.86 and 322.58 HU/mg, respectively; these are by three orders of magnitude lower than those of sphingomyelin-inhibitable cytolysins from the tropic sea anemones. The amino acid sequences of the N-terminal fragments of Or-A and Or-G were determined to be ATFRVLAK and GAIIAGAA, respectively. Action of the cytolysins on the erythrocyte membrane is inhibited by exogenous sphingomyelin. They form ion channels in bilayer lipid membranes with the conductivity of 16, 32, and 40 pSm in 0.1 M NaCl and 168, 240, and 320 pSm in 1 M NaCl at pH 7.2. Therefore, they were attributed to the group of actinoporins. PMID:15787212

Il'ina, A P; Monastyrsnaia, M M; Sokotun, I N; Egorov, Ts A; Nazarenko, Iu A; Likhatskaia, G N; Kozlovskaia, E P

102

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

103

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

104

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

105

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 (33°C and 1900 µmol 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, Stéphane; Herman, Anne-Catherine; Tonk, Linda; Hoegh-Guldberg, Ove; Plumier, Jean-Christophe

2013-05-28

106

Force-dependent discharge of nematocysts in the sea anemone Haliplanella luciae (Verrill)  

PubMed Central

Summary Sea anemones discharge cnidae (‘stinging capsules’ including nematocysts) to capture prey and to defend themselves. In the present study, we tested the relationship between the force of test probes striking feeding tentacles and discharge of microbasic p-mastigophore nematocysts into the test probes. In seawater alone, the response curve is bimodal with maximal discharge observed at 0.33 and 1.10 millinewtons (mN) and with minimal discharge at 1.50?mN. Upon activating chemoreceptors for N-acetylated sugars, maximal discharge is observed across a broad range of smaller forces from 0.16 to 0.9?mN before decreasing to a minimum at 1.50?mN. Likewise, in the presence of nearby vibrations at key frequencies, maximal discharge is observed over a broad range of smaller forces before decreasing to a minimum at 1.50?mN. It appears that sensory input indicating proximity of potential prey expands the range of small forces of impact that stimulate maximal discharge (i.e. to less than 1.10?mN) but not at larger forces of impact (i.e. at approximately 1.50?mN). Thus, contact by small prey would stimulate maximal discharge, and all the more so if such contact is accompanied by specific odorants or by vibrations at specific frequencies. Nevertheless, anemones would not maximally discharge nematocysts into large animals that blunder into contact with their tentacles.

Todaro, Dustin; Watson, Glen M.

2012-01-01

107

A bifunctional sea anemone peptide with Kunitz type protease and potassium channel inhibiting properties.  

PubMed

Sea anemone venom is a known source of interesting bioactive compounds, including peptide toxins which are invaluable tools for studying structure and function of voltage-gated potassium channels. APEKTx1 is a novel peptide isolated from the sea anemone Anthopleura elegantissima, containing 63 amino acids cross-linked by 3 disulfide bridges. Sequence alignment reveals that APEKTx1 is a new member of the type 2 sea anemone peptides targeting voltage-gated potassium channels (K(V)s), which also include the kalicludines from Anemonia sulcata. Similar to the kalicludines, APEKTx1 shares structural homology with both the basic pancreatic trypsin inhibitor (BPTI), a very potent Kunitz-type protease inhibitor, and dendrotoxins which are powerful blockers of voltage-gated potassium channels. In this study, APEKTx1 has been subjected to a screening on a wide range of 23 ion channels expressed in Xenopus laevis oocytes: 13 cloned voltage-gated potassium channels (K(V)1.1-K(V)1.6, K(V)1.1 triple mutant, K(V)2.1, K(V)3.1, K(V)4.2, K(V)4.3, hERG, the insect channel Shaker IR), 2 cloned hyperpolarization-activated cyclic nucleotide-sensitive cation non-selective channels (HCN1 and HCN2) and 8 cloned voltage-gated sodium channels (Na(V)1.2-Na(V)1.8 and the insect channel DmNa(V)1). Our data show that APEKTx1 selectively blocks K(V)1.1 channels in a very potent manner with an IC(50) value of 0.9nM. Furthermore, we compared the trypsin inhibitory activity of this toxin with BPTI. APEKTx1 inhibits trypsin with a dissociation constant of 124nM. In conclusion, this study demonstrates that APEKTx1 has the unique feature to combine the dual functionality of a potent and selective blocker of K(V)1.1 channels with that of a competitive inhibitor of trypsin. PMID:21477583

Peigneur, Steve; Billen, Bert; Derua, Rita; Waelkens, Etienne; Debaveye, Sarah; Béress, László; Tytgat, Jan

2011-04-06

108

A natural point mutation changes both target selectivity and mechanism of action of sea anemone toxins.  

PubMed

APETx3, a novel peptide isolated from the sea anemone Anthopleura elegantissima, is a naturally occurring mutant from APETx1, only differing by a Thr to Pro substitution at position 3. APETx1 is believed to be a selective modulator of human ether-á-go-go related gene (hERG) potassium channels with a K(d) of 34 nM. In this study, APETx1, 2, and 3 have been subjected to an electrophysiological screening on a wide range of 24 ion channels expressed in Xenopus laevis oocytes: 10 cloned voltage-gated sodium channels (Na(V) 1.2-Na(V)1.8, the insect channels DmNa(V)1, BgNa(V)1-1a, and the arachnid channel VdNa(V)1) and 14 cloned 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, K(V)7.2, K(V)7.4, hERG, and the insect channel Shaker IR). Surprisingly, the Thr3Pro substitution results in a complete abolishment of APETx3 modulation on hERG channels and provides this toxin the ability to become a potent (EC(50) 276 nM) modulator of voltage-gated sodium channels (Na(V)s) because it slows down the inactivation of mammalian and insect Na(V) channels. Our study also shows that the homologous toxins APETx1 and APETx2 display promiscuous properties since they are also capable of recognizing Na(V) channels with IC(50) values of 31 nM and 114 nM, respectively, causing an inhibition of the sodium conductance without affecting the inactivation. Our results provide new insights in key residues that allow these sea anemone toxins to recognize distinct ion channels with similar potency but with different modulatory effects. Furthermore, we describe for the first time the target promiscuity of a family of sea anemone toxins thus far believed to be highly selective. PMID:22972919

Peigneur, Steve; Béress, László; Möller, Carolina; Marí, Frank; Forssmann, Wolf-Georg; Tytgat, Jan

2012-09-12

109

New Actinoporins from sea anemone Heteractis crispa: cloning and functional expression.  

PubMed

A new actinoporin Hct-S4 (molecular mass 19,414 ± 10 Da) belonging to the sphingomyelin-inhibited ?-pore forming toxin (?-PFT) family was isolated from the tropical sea anemone Heteractis crispa (also called Radianthus macrodactylus) and purified by methods of protein chemistry. The N-terminal nucleotide sequence (encoding 20 amino acid residues) of actinoporin Hct-S4 was determined. Genes encoding 18 new isoforms of H. crispa actinoporins were cloned and sequenced. These genes form a multigene Hct-S family characterized by presence of N-terminal serine in the mature proteins. Highly conserved residues comprising the aromatic phosphorylcholine-binding site and significant structure-function changes in the N-terminal segment (10-27 amino acid residues) of actinoporins were established. Two expressed recombinant actinoporins (rHct-S5 and rHct-S6) were one order less hemolytically active than native actinoporins. PMID:22098238

Tkacheva, E S; Leychenko, E V; Monastyrnaya, M M; Issaeva, M P; Zelepuga, E A; Anastuk, S D; Dmitrenok, P S; Kozlovskaya, E P

2011-10-01

110

Population impacts of collecting sea anemones and anemonefish for the marine aquarium trade in the Philippines  

NASA Astrophysics Data System (ADS)

Tropical marine ornamentals comprise an increasingly important fishery worldwide. Although the potential for overexploitation of marine ornamentals is great, few studies have addressed the population-level impacts of ornamental exploitation and few ornamental fisheries are managed. Analysis of catch records obtained from collectors over a four-month period in the vicinity of Cebu, Philippines, showed that anemonefish and anemones comprised close to 60% of the total catch. Underwater visual census surveys revealed that both anemone and anemonefish densities were significantly lower in exploited areas than in protected areas. The low density of anemones on exploited reefs accounted for over 80% of the reduced density of anemonefish at those sites. There were similar numbers of anemonefish per unit area of anemone in protected and exploited sites; however, biomass of anemonefish per unit area of anemone was lower in exploited areas. Reduction of anemone removals is recommended to support the sustainable harvest of anemonefish from this region.

Shuman, Craig S.; Hodgson, Gregor; Ambrose, Richard F.

2005-12-01

111

Modulation of neuronal sodium channels by the sea anemone peptide BDS-I.  

PubMed

Blood-depressing substance I (BDS-I), a 43 amino-acid peptide from sea anemone venom, is used as a specific inhibitor of Kv3-family potassium channels. We found that BDS-I acts with even higher potency to modulate specific types of voltage-dependent sodium channels. In rat dorsal root ganglion (DRG) neurons, 3 ?M BDS-I strongly enhanced tetrodotoxin (TTX)-sensitive sodium current but weakly inhibited TTX-resistant sodium current. In rat superior cervical ganglion (SCG) neurons, which express only TTX-sensitive sodium current, BDS-I enhanced current elicited by small depolarizations and slowed decay of currents at all voltages (EC(50) ? 300 nM). BDS-I acted with exceptionally high potency and efficacy on cloned human Nav1.7 channels, slowing inactivation by 6-fold, with an EC(50) of approximately 3 nM. BDS-I also slowed inactivation of sodium currents in N1E-115 neuroblastoma cells (mainly from Nav1.3 channels), with an EC(50) ? 600 nM. In hippocampal CA3 pyramidal neurons (mouse) and cerebellar Purkinje neurons (mouse and rat), BDS-I had only small effects on current decay (slowing inactivation by 20-50%), suggesting relatively weak sensitivity of Nav1.1 and Nav1.6 channels. The biggest effect of BDS-I in central neurons was to enhance resurgent current in Purkinje neurons, an effect reflected in enhancement of sodium current during the repolarization phase of Purkinje neuron action potentials. Overall, these results show that BDS-I acts to modulate sodium channel gating in a manner similar to previously known neurotoxin receptor site 3 anemone toxins but with different isoform sensitivity. Most notably, BDS-I acts with very high potency on human Nav1.7 channels. PMID:22442564

Liu, Pin; Jo, Sooyeon; Bean, Bruce P

2012-03-21

112

EXCITATORY ACTIONS OF Antho-RFamide, AN ANTHOZOAN NEUROPEPTIDE, ON MUSCLES AND CONDUCTING SYSTEMS IN THE SEA ANEMONE CALLIACTIS PARASITICA  

Microsoft Academic Search

SUMMARY In the sea anemone Calliactis parasitica endodermal application of the anthozoan neuropeptide Antho-RFamide (

I. D. McFARLANE

113

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

114

Analgesic Compound from Sea Anemone Heteractis crispa Is the First Polypeptide Inhibitor of Vanilloid Receptor 1 (TRPV1)*  

PubMed Central

Venomous animals from distinct phyla such as spiders, scorpions, snakes, cone snails, or sea anemones produce small toxic proteins interacting with a variety of cell targets. Their bites often cause pain. One of the ways of pain generation is the activation of TRPV1 channels. Screening of 30 different venoms from spiders and sea anemones for modulation of TRPV1 activity revealed inhibitors in tropical sea anemone Heteractis crispa venom. Several separation steps resulted in isolation of an inhibiting compound. This is a 56-residue-long polypeptide named APHC1 that has a Bos taurus trypsin inhibitor (BPTI)/Kunitz-type fold, mostly represented by serine protease inhibitors and ion channel blockers. APHC1 acted as a partial antagonist of capsaicin-induced currents (32 ± 9% inhibition) with half-maximal effective concentration (EC50) 54 ± 4 nm. In vivo, a 0.1 mg/kg dose of APHC1 significantly prolonged tail-flick latency and reduced capsaicin-induced acute pain. Therefore, our results can make an important contribution to the research into molecular mechanisms of TRPV1 modulation and help to solve the problem of overactivity of this receptor during a number of pathological processes in the organism.

Andreev, Yaroslav A.; Kozlov, Sergey A.; Koshelev, Sergey G.; Ivanova, Ekaterina A.; Monastyrnaya, Margarita M.; Kozlovskaya, Emma P.; Grishin, Eugene V.

2008-01-01

115

Caissarolysin I (Bcs I), a new hemolytic toxin from the Brazilian sea anemone Bunodosoma caissarum: purification and biological characterization.  

PubMed

Two cationic proteins, C1 and C3, were purified to homogeneity from the hemolytic fraction of the venom of Bunodosoma caissarum sea anemone. The purification processes employed gel filtration followed by ion exchange chromatography, being the purity and molecular mass confirmed by SDS-PAGE and mass spectrometry. Protein C1 represented the second major peak of the hemolytic fraction and was previously believed to be a cytolysin belonging to a new class of hemolysins. The C1 protein has a molecular mass of 15495 Da and was assayed for hemolysis, PLA2 activity and acute toxicity in crabs and mice, showing no activity in these assays. It has an amino terminal with no similarity to all known hemolysins and, therefore, should not be considered a toxin, being its function completely unknown. The protein C3 (19757 Da), that also lacks PLA2 activity, was recognized by antiserum against Eqt II and presented high hemolytic activity to human erythrocytes (ED50 of 0.270 microg/ml), being named Caissarolysin I (Bcs I). Its activity was inhibited by pre-incubation with sphingomyelin (SM) and also when in presence of erythrocytes pre-treated with the SMase P2, a phospholipase D from the brown spider Loxosceles intermedia, indicating that SM is the main target of Bcs I. Caissarolysin I is the first hemolysin purified from a sea anemone belonging to the genus Bunodosoma and belongs to the Actinoporin family of sea anemone hemolysins. PMID:16458433

de Oliveira, Joacir Stolarz; Zaharenko, André Junqueira; de Freitas, José Carlos; Konno, Katsuhiro; de Andrade, Sonia A; Portaro, Fernanda C V; Richardson, Michael; Sant'anna, Osvaldo Augusto; Tambourgi, Denise V

2006-01-17

116

Development of a sea anemone toxin as an immunomodulator for therapy of autoimmune diseases.  

PubMed

Electrophysiological and pharmacological studies coupled with molecular identification have revealed a unique network of ion channels--Kv1.3, KCa3.1, CRAC (Orai1 + Stim1), TRPM7, Cl(swell)--in lymphocytes that initiates and maintains the calcium signaling cascade required for activation. The expression pattern of these channels changes during lymphocyte activation and differentiation, allowing the functional network to adapt during an immune response. The Kv1.3 channel is of interest because it plays a critical role in subsets of T and B lymphocytes implicated in autoimmune disorders. The ShK toxin from the sea anemone Stichodactyla helianthus is a potent blocker of Kv1.3. ShK-186, a synthetic analog of ShK, is being developed as a therapeutic for autoimmune diseases, and is scheduled to begin first-in-man phase-1 trials in 2011. This review describes the journey that has led to the development of ShK-186. PMID:21867724

Chi, Victor; Pennington, Michael W; Norton, Raymond S; Tarcha, Eric J; Londono, Luz M; Sims-Fahey, Brian; Upadhyay, Sanjeev K; Lakey, Jonathan T; Iadonato, Shawn; Wulff, Heike; Beeton, Christine; Chandy, K George

2011-08-12

117

[Conformational stability of serine proteinase inhibitor from the sea anemone Heteractis crispa].  

PubMed

The influence of different environmental values of the pH and temperature on the spatial organization of serine proteinase inhibitor from the sea anemone Heteractis crispa (=Radianthus macrodactylus) on the level of tertiary and secondary structure was studied by CD spectroscopy. The molecule InhVJ was shown to possess a high conformational thermo- and pH-stability. We determined the point of conformational thermotransition of polypeptide (70 degrees C) after which the molecule gets denaturational stable state with conservation of 80% proteinase inhibitory activity. The significant partial reversible changes of molecule spatial organization were established to occur at the level of tertiary structure in the process of acid-base titration in the range of pH 11.0-13.0. This can be explained by of ionization of tyrosine residues. The molecule InhVJ is conformationally stable at the low pH values (2.0). The quenching of tyrosine residues by acrylamide showed that two of these residues are accessible to the quencher in full, while the third part is available. PMID:21899045

Vakorina, T I; Gladkikh, I N; Monastyrnaia, M M; Kozlovskaia, E P

118

Purification and Characterization of Gigantoxin-4, a New Actinoporin from the Sea Anemone Stichodactyla Gigantea  

PubMed Central

A new Cytolysin, termed as Gigantoxin-4, was isolated from the sea anemone Stichodactyla gigantea and found to be highly homologous with Cytolysin-3 (HMg III) from Heteractis magnifica, RTX-A from Radianthus macrodactylus, and Sticholysin-1 (St I) and Sticholysin-2 (St II) from Stichodactyla helianthus (homology 82%, 86%, 82% and 86% respectively). Its 20 N-terminal residues were identified and the full-length cDNA sequence was obtained by reverse transcription-polymerase chain reaction (RT-PCR). Multiple sequence alignments with other Cytolysins of the actinoporin family clearly indicated that Gigantoxin-4 belongs to this protein family. SDS-PAGE electrophoresis showed that this new actinoporin had a molecular mass of about 19 kDa, and possessed a high hemolytic activity to human erythrocytes (HA50= 40 ng/ml), which was inhibited by pre-incubation with sphingomyelin (SM) or SM-cholesterol mixtures. Our in vivo experiments showed that Gigantoxin-4 had wide toxicity to the rat cardiovascular system and the respiratory system. A concentration of 30?g/kg Gigantoxin-4, i.v. produced a positive inotropic effect on the rat heart although final cardiovascular failure was inevitable, and 60?g/kg Gigantoxin-4 caused respiratory arrest rapidly resulting in rat death. HE staining indicated pathological changes in various organs and tissues after i.v. administration of Gigantoxin-4.

Hu, Bo; Guo, Wei; Wang, Liang-hua; Wang, Jian-guang; Liu, Xiao-yu; Jiao, Bing-hua

2011-01-01

119

[New polypeptide components from the Heteractis crispa sea anemone with analgesic activity].  

PubMed

Two new polypeptide components which exhibited an analgesic effect in experiments on mice were isolated from the Heteractis crispa sea tropical anemone by the combination of chromatographic methods. The APHC2 and APHC3 new polypeptides consisted of 56 amino acid residues and contained six cysteine residues. Their complete amino acid sequence was determined by the methods of Edman sequencing, mass spectrometry, and peptide mapping. An analysis of the primary structure of the new peptides allowed for their attribution to a large group of trypsin inhibitors of the Kunitz type. An interesting biological function of the new polypeptides was their analgesic effect on mammals, which is possibly realized via the modulation of the activity of the TRPV1 receptor and was not associated with the residual inhibiting activity towards trypsin and chymotrypsin. The analgesic activity of the APHC3 polypeptide was measured on the hot plate model of acute pain and was significantly higher than that, of APHC2. Methods of preparation of the recombinant analogues were created for both polypeptides. PMID:20208578

Kozlov, S A; Andreev, Ia A; Murashev, A N; Skobtsov, D I; D'iachenko, I A; Grishin, E V

120

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.

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

2010-01-01

121

Development of a sea anemone toxin as an immunomodulator for therapy of autoimmune diseases  

PubMed Central

Electrophysiological and pharmacological studies coupled with molecular identification have revealed a unique network of ion channels—Kv1.3, KCa3.1, CRAC (Orai1 + Stim1), TRPM7, Clswell—in lymphocytes that initiates and maintains the calcium signaling cascade required for activation. The expression pattern of these channels changes during lymphocyte activation and differentiation, allowing the functional network to adapt during an immune response. The Kv1.3 channel is of interest because it plays a critical role in subsets of T and B lymphocytes implicated in autoimmune disorders. The ShK toxin from the sea anemone Stichodactyla helianthus is a potent blocker of Kv1.3. ShK-186, a synthetic analog of ShK, is being developed as a therapeutic for autoimmune diseases, and is scheduled to begin first-in-man phase-1 trials in 2011. This review describes the journey that has led to the development of ShK-186.

Chi, Victor; Pennington, Michael W.; Norton, Raymond S.; Tarcha, Eric; Londono, Luz; Sims-Fahey, Brian; Upadhyay, Sanjeev K.; Lakey, Jonathan T.; Iadonato, Shawn; Wulff, Heike; Beeton, Christine; Chandy, K. George

2012-01-01

122

Enzymatic characterization of the major phospholipase A2 component of sea anemone (Aiptasia pallida) nematocyst venom.  

PubMed

The purified beta phospholipase A2 (PLA2; EC 3.1.1.4) (PLA2) from sea anemone (Aiptasia pallida) nematocysts is larger and more labile than other known venom PLA2s. In common with all other known venoms and most secretory PLA2s, the beta PLA2 requires mM Ca2+ for optimal activity and is surface-activated by aggregated lipids such as mixed micelles of detergent and phospholipid. The beta PLA2 exhibits an unusually steep and narrow pH optimum of activity at pH 7.7. The effects of changes in pH on the activity of the enzyme suggest that the active site contains functional groups having a pKs of about 7.0 and 8.0. The effects of temperature on beta PLA2 activity show a marked decrease in the energy of activation above the pre-transition temperature, suggesting that the enzyme "melts" both fatty chains in order for catalysis to occur. PMID:10728831

Grotendorst, G R; Hessinger, D A

2000-07-01

123

Membrane insertion of the N-terminal ?-helix of equinatoxin II, a sea anemone cytolytic toxin  

PubMed Central

Equinatoxin II (Eqt-II) is a member of the actinoporins, a unique family of cytotoxins comprising 20 kDa pore-forming proteins isolated from sea anemones. Actinoporins bind preferentially to lipid membranes containing sphingomyelin, and create cation-selective pores by oligomerization of three to four monomers. Previous studies have shown that regions of Eqt-II crucial for its cytolytic mechanism are an exposed aromatic cluster and the N-terminal region containing an amphipathic ?-helix. In the present study, we have investigated the transfer of the N-terminal ?-helix into the lipid membrane by the use of three mutants containing an additional tryptophan residue in different positions within the amphipathic ?-helix (Ile18?Trp, Val22?Trp and Ala25?Trp). The interaction of the mutants with different model systems, such as lipid monolayers, erythrocytes and ghost membranes, was extensively characterized. Intrinsic fluorescence measurements and the use of vesicles containing brominated phospholipids indicated a deep localization of the N-terminal amphipathic helix in the lipid bilayer, except for the case of Val22?Trp. This mutant is stabilized in a state immediately prior to final pore formation. The introduction of additional tryptophan residues in the sequence of Eqt-II has proved to be a suitable approach to monitor the new environments that surround defined regions of the molecule upon membrane interaction.

2004-01-01

124

Multiple conformations of the sea anemone polypeptide anthopleurin-A in solution.  

PubMed Central

Anthopleurin-A (AP-A) is a member of a family of sea anemone-derived polypeptides that interact with sodium channels in a voltage-dependent manner, producing a positive inotropic effect on the mammalian heart. There has been considerable interest in this molecule as a lead compound for the development of novel therapeutic agents. Earlier attempts to define the 3-dimensional structure of AP-A were complicated by the fact that it was found to exist in 2 conformations in solution. Using 1H- and 13C-NMR spectroscopy, we have now shown that this conformational heterogeneity arises from cis-trans isomerization about the Gly 40-Pro 41 peptide bond and that in the major form of the protein this peptide bond adopts a cis conformation. Furthermore, the increased sensitivity afforded by higher-field NMR has allowed identification of additional minor conformations of AP-A, the origin of which is presently unknown. We believe there will be many more examples of the detection by high-field NMR of previously unobserved minor conformations of proteins in solution.

Scanlon, M. J.; Norton, R. S.

1994-01-01

125

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. Solé-Cava; J. P. Thorpe

1997-01-01

126

Bacillus neizhouensis sp. nov., a halophilic marine bacterium isolated from a sea anemone.  

PubMed

A novel Gram-stain-positive, slightly halophilic, facultatively alkaliphilic, non-motile, catalase- and oxidase-positive, endospore-forming, rod-shaped, aerobic bacterium, strain JSM 071004(T), was isolated from a sea anemone collected from Neizhou Bay in the South China Sea. Growth occurred with 0.5-10 % (w/v) total salts (optimum 2-4 %) and at pH 6.5-10.0 (optimum pH 8.5) and 4-30 degrees C (optimum 25 degrees C). meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The predominant respiratory quinone was menaquinone 7 (MK-7) and the polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major cellular fatty acids were anteiso-C(15 : 0) and iso-C(15 : 0). The genomic DNA G+C content was 39.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JSM 071004(T) belongs to the genus Bacillus, being related most closely to the type strain of Bacillus agaradhaerens (sequence similarity 97.3 %), followed by the type strains of Bacillus cellulosilyticus (96.2 %), Bacillus clarkii (96.1 %) and Bacillus polygoni (96.0 %). The combination of phylogenetic analysis, DNA-DNA hybridization, phenotypic characteristics and chemotaxonomic data support the proposal that strain JSM 071004(T) represents a novel species of the genus Bacillus, for which the name Bacillus neizhouensis sp. nov. is proposed, with JSM 071004(T) (=CCTCC AB 207161(T) =DSM 19794(T) =KCTC 13187(T)) as the type strain. PMID:19643899

Chen, Yi-Guang; Zhang, Yu-Qin; Wang, Yong-Xia; Liu, Zhi-Xiong; Klenk, Hans-Peter; Xiao, Huai-Dong; Tang, Shu-Kun; Cui, Xiao-Long; Li, Wen-Jun

2009-07-30

127

Viable algae released by the seastar Dermasterias imbricata feeding on the symbiotic sea anemone Anthopleura elegantissima  

Microsoft Academic Search

Echinoderms are major predators of anemones in temperate ecosystems. The fate of two algae, zooxanthellae and zoochlorellae,\\u000a after their host anemone (Anthopleura elegantissima Brandt) was consumed by the leather star Dermasterias imbricata Grube was determined in experiments conducted in July and August 2004. Productivity, photosynthetic pigments, and mitotic\\u000a index (percent of cells dividing) were used as indicators of algal health;

Sarah Bachman; Gisèle Muller-Parker

2007-01-01

128

Toxins from the Caribbean sea anemone Bunodeopsis globulifera increase cisplatin-induced cytotoxicity of lung adenocarcinoma cells  

PubMed Central

Background Lung cancer causes 1.4 million deaths worldwide while non-small-cell lung cancer (NSCLC) represents 80-85% of the cases. Cisplatin is a standard chemotherapy against this type of cancer; however, tumor cell resistance to this drug limits its efficacy. Sea anemones produce compounds with pharmacological activities that may be useful for augmenting cisplatin efficacy. This study aimed to evaluate the pharmacological activities of crude venom (CV) from the sea anemone Bunodeopsis globulifera and four derived fractions (F1, F2, F3 and F4) to test their increase efficiency cisplatin cytotoxicity in human lung adenocarcinoma cells. Results Pre-exposure to CV, F1 and F2 fractions increases cisplatin cytotoxicity in human lung adenocarcinoma cells under specific conditions. Exposure to CV at 50 ?gmL-1 induced a reduction of approximately 50% in cell viability, while a similar cytotoxic effect was observed when cell culture was exposed to F1 at 25 ?gmL -1 or F2 at 50 ?gmL-1. The cell culture exposure to F1 (10 ?gmL-1) fraction combined with cisplatine (25 ?M) provoked a decrease in MTT reduction until 65.57% while F2 (25 ?gmL-1) fraction combined with cisplatin (10 ?M) provoked a decrease in MTT reduction of 72.55%. Conclusions The F1 fraction had the greatest effect on the lung adenocarcinoma cell line compared with CV and F2. The combination of antineoplastic drugs and sea anemone toxins might allow a reduction of chemotherapeutic doses and thus mitigate side effects.

2013-01-01

129

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

130

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

PubMed

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 C(50) (INCC(50))=0.034 nM. Actinoporin RTX-A also was shown to inhibit the phenotype expression of HeLa human cancer cells with an INCC(50)=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 (IC(50)=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-kappaB, 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-kappaB 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

2009-11-26

131

Actinoporins from the sea anemones, tropical Radianthus macrodactylus and northern Oulactis orientalis: Comparative analysis of structure-function relationships.  

PubMed

Actinoporins Or-A and Or-G from the northern sea anemone Oulactis orientalis and actinoporins RTX-A and RTX-SII from the tropical sea anemone Radianthus macrodactylus (=Heteractis crispa) were compared with each other and with some known actinoporins. In this work the complete amino acid sequence of RTX-SII was determined by molecular biology methods. The following differences were revealed in functionally significant regions of Radianthus, Oulactis, and some other actinoporins: (i) tryptophan is substituted for leucine in the position equivalent to Trp112 in the POC binding site of EqtII; (ii) 13 and 5 residues are truncated in N-terminal regions of Or-A and Or-G, respectively. A possible role of these structural differences in specific regions of the actinoporin sequence was analyzed. Some differences in hydrophobicity parameters, distribution of charged residues, and length of actinoporins' N-terminus apparently cause considerable differences in their hemolytic activities. Homology models of Radianthus and Oulactis actinoporin monomers were generated using crystal structures of equinatoxin II from Actinia equina and sticholysin II from Stichodactyla helianthus as templates. The current data on actinoporin structures and activities, coupled with results of our earlier differential scanning calorimetric and electrophoretic experiments with RTX-A-modified erythrocyte ghosts (Shnyrov et al., 1992), suggests that the exposed RGD motif located near the POC binding site can interact with membrane integrin(s). PMID:20692277

Monastyrnaya, Margarita; Leychenko, Elena; Isaeva, Marina; Likhatskaya, Galina; Zelepuga, Elena; Kostina, Elena; Trifonov, Evgenie; Nurminski, Evgenie; Kozlovskaya, Emma

2010-08-06

132

Effects of satiation and starvation on nematocyst discharge, prey killing, and ingestion in two species of sea anemone.  

PubMed

Studies spanning 60 years with several cnidarian species show that satiation inhibits prey capture and ingestion and that starvation increases prey capture and ingestion. Most have attributed the effects of satiation to inhibition of nematocyst discharge. We hypothesized that satiation inhibits prey capture and ingestion in sea anemones (Haliplanella luciae and Aiptasia pallida) primarily by inhibiting the intrinsic adherence (i.e., holding power) of discharging nematocysts. Using a quantitative feeding assay for H. luciae, we found that satiation completely uncoupled prey killing from prey ingestion, while nematocyst-mediated prey killing was only partially inhibited. Using A. pallida to measure nematocyst discharge and nematocyst-mediated adhesive force, we showed that satiation completely inhibited the intrinsic adherence of discharging nematocysts from Type B and Type C cnidocyte/supporting cell complexes (CSCCs), while only partially inhibiting nematocyst discharge from Type Bs. These inhibitory effects of satiation were gradually restored by starvation, reaching a maximum at 72 h after feeding. Thus, the effects of satiation and starvation on prey killing and ingestion in two species of acontiate sea anemones are primarily due to changes in the intrinsic adherence of nematocysts from both Type B and Type C CSCCs. PMID:20972257

Thorington, Glyne U; McAuley, Virginia; Hessinger, David A

2010-10-01

133

A new sea anemone peptide, APETx2, inhibits ASIC3, a major acid-sensitive channel in sensory neurons  

PubMed Central

From a systematic screening of animal venoms, we isolated a new toxin (APETx2) from the sea anemone Anthopleura elegantissima, which inhibits ASIC3 homomeric channels and ASIC3-containing heteromeric channels both in heterologous expression systems and in primary cultures of rat sensory neurons. APETx2 is a 42 amino-acid peptide crosslinked by three disulfide bridges, with a structural organization similar to that of other sea anemone toxins that inhibit voltage-sensitive Na+ and K+ channels. APETx2 reversibly inhibits rat ASIC3 (IC50=63 nM), without any effect on ASIC1a, ASIC1b, and ASIC2a. APETx2 directly inhibits the ASIC3 channel by acting at its external side, and it does not modify the channel unitary conductance. APETx2 also inhibits heteromeric ASIC2b+3 current (IC50=117 nM), while it has less affinity for ASIC1b+3 (IC50=0.9 ?M), ASIC1a+3 (IC50=2 ?M), and no effect on the ASIC2a+3 current. The ASIC3-like current in primary cultured sensory neurons is partly and reversibly inhibited by APETx2 with an IC50 of 216 nM, probably due to the mixed inhibitions of various co-expressed ASIC3-containing channels.

Diochot, Sylvie; Baron, Anne; Rash, Lachlan D; Deval, Emmanuel; Escoubas, Pierre; Scarzello, Sabine; Salinas, Miguel; Lazdunski, Michel

2004-01-01

134

Arrhythmogenic effect of a crude extract from sea anemone Condylactis gigantea: possible involvement of rErg1 channels.  

PubMed

Sea anemones possess a number of peptide toxins that target ion channels which provide powerful tools to study the molecular basis of diverse signaling pathways. It is also acknowledged that currents through Erg1 K(+) channels in cardiac myocytes are important for electrical stability of the heart and alterations in its activity has been linked to the onset of a potentially life-threatening heart condition named long QT syndrome type 2. Here, we report that a crude extract from sea anemone Condylactis gigantea significantly increases the QT interval and has arrhythmogenic effects in the rat heart. Furthermore, a bioassay-guided purification procedure allowed the isolation of a chromatographic fraction containing a major component with a molecular mass of 4478 Da from the crude extract, which causes a significant inhibition of whole-cell patch-clamp currents through recombinant Erg1 channels, responsible of the rapid delayed rectifying current crucial for electrical activity in the heart. Further studies could provide relevant information on the molecular mechanism of C. gigantea peptide toxins which represent promising tools in studying the physiology of diverse ion channels. PMID:23499927

Santos, Yúlica; Martínez, Martín; Sandoval, Alejandro; Rodríguez, Armando A; Falcón, Andrés; Heimer de la Cotera, Edgar P; Aguilar, Manuel B; Flores, Pedro; Felix, Ricardo; Arreguín, Roberto

2013-03-13

135

Incorporating fine-scale seascape composition in an assessment of habitat quality for the giant sea anemone Stichodactyla gigantea in a coral reef shore zone  

Microsoft Academic Search

Habitat loss due to land reclamation often occurs in sandy coral reef shore zones. The giant sea anemone Stichodactyla gigantea, which harbors the false clown anemonefish Amphiprion ocellaris, both of which are potentially flagship species, inhabit these places. To assess habitat quality for S. gigantea, we examined correlative associations between the number and the body size of S. gigantea and

Akihisa Hattori; Miyako Kobayashi

2009-01-01

136

Antibacterial Properties of Isolated Amoebocytes From the Sea Anemone Actinia equina  

Microsoft Academic Search

The antimicrobial defenses of anthozoans were investigated in vitro by extracting amoebocytes from the mesenteric filaments of the beadlet anemone, Actinia equina, and testing for their ability to phagocy- tose and kill the gram-negative bacterium Psychrobacter immobilis. Only the hyaline amoebocytes exhibited phagocytosis in vitro, with about 40% seen to ingest one or more bacteria over 45 min. Mixed cultures

DANIELLE M. C. HUTTON; VALERIE J. SMITH

1996-01-01

137

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

ScienceCinema

The human genome contains three transcription factors termed p53, p63 and p73 which are related orthologues. The function of the p53 protein is to respond to a wide variety of stresses which can disrupt the fidelity of DNA replication and cell division in somatic cells of the body. These stress signals, such as DNA damage, increase the mutation rate during DNA duplication and so an active p53 protein responds by eliminating clones of cells with mutations employing apoptosis, senescence or cell cycle arrest. In this way the p53 protein acts as a tumor suppressor preventing the mutations that can lead to cancers. The p63 and p73 proteins act in a similar fashion to protect the germ line cells in females (eggs). In addition the p63 protein plays a central role in the formation of epithelial cell layers and p73 plays a critical role in the formation of several structures in the central nervous system. Based upon their amino acid sequences and structural considerations the oldest organisms that contain an ancestor of the p53/p63/p73 gene are the sea anemone or hydra. The present day representatives of these animals contain a p63/p73 like ancestor gene and the protein functions in germ cells of this animal to enforce the fidelity of DNA replication after exposure to ultraviolet light. Thus the structure and functions of this gene family have been preserved for over one billion years of evolution. Other invertebrates such as the worm, the fly and the clam contain a very similar ancestor gene with a similar set of functions. The withdrawal of a food source from a worm results in the p63/p73 mediated apoptosis of the eggs so that new organisms will not be hatched into a poor environment. A similar response is thought to occur in humans. Thus this ancestor gene ensures the fidelity of the next generation of organisms. The first time a clearly distinct new p53 gene arises is in the cartilaginous fish and in the bony fish a separation of the p

138

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 7days. Anemones were then transferred to metal-free seawater for an additional 7days 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 14days. 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 7days, 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

2013-07-09

139

Population impacts of collecting sea anemones and anemonefish for the marine aquarium trade in the Philippines  

Microsoft Academic Search

Tropical marine ornamentals comprise an increasingly important fishery worldwide. Although the potential for overexploitation\\u000a of marine ornamentals is great, few studies have addressed the population-level impacts of ornamental exploitation and few\\u000a ornamental fisheries are managed. Analysis of catch records obtained from collectors over a four-month period in the vicinity\\u000a of Cebu, Philippines, showed that anemonefish and anemones comprised close to

Craig S. Shuman; Gregor Hodgson; Richard F. Ambrose

2005-01-01

140

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, Bård Ove; Okkenhaug, Siri; Seternes, Ole Morten; Johansen, Steinar D; Emblem, Ase

2012-10-18

141

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.

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

2012-01-01

142

Inhibition of voltage-gated Na+ currents in sensory neurones by the sea anemone toxin APETx2  

PubMed Central

BACKGROUND AND PURPOSE APETx2, a toxin from the sea anemone Anthropleura elegantissima, inhibits acid-sensing ion channel 3 (ASIC3)-containing homo- and heterotrimeric channels with IC50 values < 100 nM and 0.1–2 µM respectively. ASIC3 channels mediate acute acid-induced and inflammatory pain response and APETx2 has been used as a selective pharmacological tool in animal studies. Toxins from sea anemones also modulate voltage-gated Na+ channel (Nav) function. Here we tested the effects of APETx2 on Nav function in sensory neurones. EXPERIMENTAL APPROACH Effects of APETx2 on Nav function were studied in rat dorsal root ganglion (DRG) neurones by whole-cell patch clamp. KEY RESULTS APETx2 inhibited the tetrodotoxin (TTX)-resistant Nav 1.8 currents of DRG neurones (IC50, 2.6 µM). TTX-sensitive currents were less inhibited. The inhibition of Nav 1.8 currents was due to a rightward shift in the voltage dependence of activation and a reduction of the maximal macroscopic conductance. The inhibition of Nav 1.8 currents by APETx2 was confirmed with cloned channels expressed in Xenopus oocytes. In current-clamp experiments in DRG neurones, the number of action potentials induced by injection of a current ramp was reduced by APETx2. CONCLUSIONS AND IMPLICATIONS APETx2 inhibited Nav 1.8 channels, in addition to ASIC3 channels, at concentrations used in in vivo studies. The limited specificity of this toxin should be taken into account when using APETx2 as a pharmacological tool. Its dual action will be an advantage for the use of APETx2 or its derivatives as analgesic drugs.

Blanchard, Maxime G; Rash, Lachlan D; Kellenberger, Stephan

2012-01-01

143

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

USGS Publications Warehouse

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 containing suitable habitat for them. Using occurrence data for anemonefishes or their host sea anemones, and data for environmental parameters, we generated maps of suitable habitat for the organisms. The fact that the fishes are obligate symbionts of the anemones allowed us to validate the KGSMapper output: we were able to compare the inferred occurrence of the organism to that of the actual occurrence of its symbiont. Characterizing suitable habitat for these organisms in the Indo-West Pacific, the region where they naturally occur, can be used to guide conservation efforts, field work, etc.; defining suitable habitat for them in the Atlantic and eastern Pacific is relevant to identifying areas vulnerable to biological invasions. We advocate distinguishing between these 2 sorts of model output, terming the former maps of realized habitat and the latter maps of potential habitat. Creation of a niche model requires adding biotic data to the environmental data used for habitat maps: we included data on fish occurrences to infer anemone distribution and vice versa. Altering the selection of environmental variables allowed us to investigate which variables may exert the most influence on organism distribution. Adding variables does not necessarily improve precision of the model output. KGSMapper output distinguishes areas that fall within 1 standard deviation (SD) of the mean environmental variable values for places where members of the taxon occur, within 2 SD, and within the entire range of values; eliminating outliers or data known to be imprecise or inaccurate improved output precision mainly in the 2 SD range and beyond. Thus, KGSMapper is robust in the face of questionable data, offering the user a way to recognize and clean such data. It also functions well with sparse datasets. These features make it useful for biogeographic meta-analyses with the diverse, distributed datasets that are typical for marine organisms lacking direct commercial value. ?? Inter-Research 2006.

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

2006-01-01

144

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

145

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

146

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

147

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.

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

2006-01-01

148

Exploiting the Nephrotoxic Effects of Venom from the Sea Anemone, Phyllodiscus semoni, to Create a Hemolytic Uremic Syndrome Model in the Rat  

PubMed Central

In the natural world, there are many creatures with venoms that have interesting and varied activities. Although the sea anemone, a member of the phylum Coelenterata, has venom that it uses to capture and immobilise small fishes and shrimp and for protection from predators, most sea anemones are harmless to man. However, a few species are highly toxic; some have venoms containing neurotoxins, recently suggested as potential immune-modulators for therapeutic application in immune diseases. Phyllodiscus semoni is a highly toxic sea anemone; the venom has multiple effects, including lethality, hemolysis and renal injuries. We previously reported that venom extracted from Phyllodiscus semoni induced acute glomerular endothelial injuries in rats resembling hemolytic uremic syndrome (HUS), accompanied with complement dysregulation in glomeruli and suggested that the model might be useful for analyses of pathology and development of therapeutic approaches in HUS. In this mini-review, we describe in detail the venom-induced acute renal injuries in rat and summarize how the venom of Phyllodiscus semoni could have potential as a tool for analyses of complement activation and therapeutic interventions in HUS.

Mizuno, Masashi; Ito, Yasuhiko; Morgan, B. Paul

2012-01-01

149

Exploiting the nephrotoxic effects of venom from the sea anemone, Phyllodiscus semoni, to create a hemolytic uremic syndrome model in the rat.  

PubMed

In the natural world, there are many creatures with venoms that have interesting and varied activities. Although the sea anemone, a member of the phylum Coelenterata, has venom that it uses to capture and immobilise small fishes and shrimp and for protection from predators, most sea anemones are harmless to man. However, a few species are highly toxic; some have venoms containing neurotoxins, recently suggested as potential immune-modulators for therapeutic application in immune diseases. Phyllodiscus semoni is a highly toxic sea anemone; the venom has multiple effects, including lethality, hemolysis and renal injuries. We previously reported that venom extracted from Phyllodiscus semoni induced acute glomerular endothelial injuries in rats resembling hemolytic uremic syndrome (HUS), accompanied with complement dysregulation in glomeruli and suggested that the model might be useful for analyses of pathology and development of therapeutic approaches in HUS. In this mini-review, we describe in detail the venom-induced acute renal injuries in rat and summarize how the venom of Phyllodiscus semoni could have potential as a tool for analyses of complement activation and therapeutic interventions in HUS. PMID:22851928

Mizuno, Masashi; Ito, Yasuhiko; Morgan, B Paul

2012-07-23

150

Isolation and biological characterization of neurotoxic compounds from the sea anemone Lebrunia danae (Duchassaing and Michelotti, 1860).  

PubMed

This paper describes two neurotoxic proteins obtained from the Caribbean sea anemone Lebrunia danae. To assess the neurotoxic activity of the venom of L. danae, several bioassays were carried out, and to evaluate the effect of the toxin, Median Lethal Doses (LD(50)) were determined in vivo using sea crabs (Ocypode quadrata) and Artemia salina nauplii with the crude extract of the proportion of 2.82 mg/m. The proteins with neurotoxic effects were isolated using low-pressure liquid chromatography. The fractions containing the neurotoxic activity were analyzed by SDS-PAGE and showed protein bands with an apparent molecular weight of 62.50 kDa (LdNt1) and 58 kDa (LdNt2). To demonstrate that these proteins were indeed responsible for the neurotoxic activity observed, we injected a small fraction of the purified protein into the third walking leg of a crab and observed the typical convulsions, paralysis and death provoked by neurotoxins. Hemolytic activity was also tested for 0.238 mg of crude extract; the hemolytic value was 39.5, 49.6 and 50.1% for cow, sheep and pig erythrocytes, respectively. PMID:16474963

Sánchez-Rodríguez, J; Cruz-Vazquez, Karina

2006-02-11

151

N-acetylneuraminic acid (NANA) stimulates in situ cyclic AMP production in tentacles of sea anemone (Aiptasia pallida): possible role in chemosensitization of nematocyst discharge.  

PubMed

Cnidocytes, the stinging cells of cnidarians, optimally discharge nematocysts in response to combined physical contact and stimulation of specific chemoreceptors. In the tentacles of certain sea anemones, the primary chemoreceptors bind N-acetylated sugars, such as N-acetylneuraminic acid (NANA). Sensitization with NANA predisposes contact-sensitive mechanoreceptors (CSMs) to trigger discharge in response to physical contact. In the ectoderm of sea anemone tentacles, cnidocyte/supporting cell complexes (CSCCs) control and trigger nematocyst discharge. Previous findings have implicated cyclic AMP (cAMP) as a second messenger in NANA-sensitized nematocyst discharge. However, no reports have directly demonstrated that the cAMP content of tentacles changes in response to NANA stimulation. We now show that NANA elevates in situ cAMP levels in a dose-dependent manner in the ectoderm of tentacles from the sea anemone Aiptasia pallida. However, the endoderm of tentacles shows no detectable cAMP response to NANA. The effect of NANA on the cAMP content of the ectoderm is biphasic. Micromolar NANA increases the in situ cAMP level, with a maximal response occurring at 1.8x10(-5)mol x l(-1) NANA. At higher NANA concentrations, the cAMP content decreases to that of controls. Because the cAMP dose/response curve to NANA coincides precisely with the dose/response curves of NANA-sensitized nematocyst discharge and nematocyst-mediated adhesive force, a second-messenger role for cAMP in NANA-sensitized nematocyst discharge is strongly suggested. The addition of isobutyl-1-methylxanthine (IBMX) to the medium with sea anemones increases tissue cAMP levels both in the absence and in the presence of NANA. However, anesthetizing anemones in sea water containing high levels of Mg(2+) blocks the NANA-stimulated cAMP response of the ectoderm. In addition, our results suggest that NANA-stimulated cAMP may activate endogenous cAMP-dependent protein kinase (PKA) in broken cell preparations of tentacles. Thus, NANA-stimulated cAMP may function as a second messenger in the NANA chemosensory signaling pathway controlling nematocyst discharge. PMID:11441042

Ozacmak, V H; Thorington, G U; Fletcher, W H; Hessinger, D A

2001-06-01

152

Sticholysins, two pore-forming toxins produced by the Caribbean Sea anemone Stichodactyla helianthus: their interaction with membranes.  

PubMed

Sticholysins (Sts) I and II (StI/II) are pore-forming toxins (PFTs) produced by the Caribbean Sea anemone Stichodactyla helianthus belonging to the actinoporin family, a unique class of eukaryotic PFTs exclusively found in sea anemones. As for the rest of the members of this family, Sts are cysteine-less proteins, with molecular weights around 20 kDa, high isoelectric points (>9.5), and a preference for sphingomyelin-containing membranes. A three-dimensional structure of StII, solved by X-ray crystallography, showed that it is composed of a hydrophobic beta-sandwich core flanked on the opposite sides by two alpha helices comprising residues 14-23 and 128-135. A variety of experimental results indicate that the first thirty N-terminal residues, which include one of the helices, are directly involved in pore formation. This region contains an amphipathic stretch, well conserved in all actinoporins, which is the only portion of the molecule that can change conformation without perturbing the general protein fold; in fact, binding to model membranes only produces a slight increase in the regular secondary structure content of Sts. Sts are produced in soluble form but they readily bind to different cell and model membrane systems such as lipidic monolayers, micelles, and lipid vesicles. Remarkably, both the binding and pore-formation steps are critically dependent on the physico-chemical nature of the membrane. In fact, a large population of toxin irreversibly binds with high affinity in membranes containing sphingomyelin whereas binding in membranes lacking this sphingolipid is relatively low and reversible. The joint presence of SM and cholesterol largely promotes binding and pore formation. Minor amounts of lipids favoring a non-lamellar organization also augment the efficiency of pore formation. The functional pore formed in cellular and model membranes has a diameter of approximately 2.0 nm and is presumably formed by the N-terminal alpha helices of four monomers tilted 31 degrees in relation to the bilayer normal. Experimental evidence supports the hypothesis that sticholysins, as well as equinatoxin II, another actinoporin, form a toroidal pore in membranes in which the polypeptide chains as well as the polar head groups of phospholipids are involved. PMID:19268489

Alvarez, Carlos; Mancheño, José M; Martínez, Diana; Tejuca, Mayra; Pazos, Fabiola; Lanio, María E

2009-03-04

153

Analogs of the Sea Anemone Potassium Channel Blocker ShK for the Treatment of Autoimmune Diseases  

PubMed Central

CCR7? effector memory T (TEM) lymphocytes are involved in autoimmune diseases such as multiple sclerosis, type 1 diabetes mellitus and rheumatoid arthritis. These cells express Kv1.3 potassium channels that play a major role in their activation. Blocking these channels preferentially inhibits the activation of CCR7? TEM cells, with little or no effects on CCR7+ naïve and central memory T cells. Blockers of lymphocyte Kv1.3 channels therefore show considerable potential as therapeutics for autoimmune diseases. ShK, a 35-residue polypeptide isolated from the Caribbean sea anemone Stichodactyla helianthus, blocks Kv1.3 channels at picomolar concentrations. Although ShK was effective in treating rats with delayed type hypersensitivity and a model of multiple sclerosis, it lacks selectivity for Kv1.3 channels over closely-related Kv1 channels. Extensive mutagenesis studies combined with elucidation of the structure of ShK led to models of ShK docked with the channel. This knowledge was valuable in the development of new ShK analogs with improved selectivity and increasing stability, which have proven efficacious in preventing and/or treating animal models of delayed type hypersensitivity, type 1 diabetes, rheumatoid arthritis, and multiple sclerosis without inducing generalized immunosuppression. They are currently undergoing further evaluation as potential immunomodulators for the treatment of autoimmune diseases.

Beeton, Christine; Pennington, Michael W.; Norton, Raymond S.

2012-01-01

154

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

155

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.

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

2011-01-01

156

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:FK719875–FK759813]. PMID:22288383

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

2012-01-31

157

Receptor-mediated endocytosis of a chemoreceptor involved in triggering the discharge of cnidae in a sea anemone tentacle.  

PubMed

Collodial gold coated with the glycoprotein, bovine submaxillary mucin (BSM-gold), was used to localize chemoreceptors known to be involved in triggering the discharge of cnidae in sea anemones. BSM-gold binds exclusively at the apical surface of the supporting cell, the cell adjacent to the cnidocyte (Watson and Hessinger, 1986). Subsequent to binding, BSM-gold is internalized into endosomes and then translocated to multivesicular bodies (MVBs) and lysosomes. At cold temperature (4 degrees C), BSM-gold appears in endosomes near the surface of the cell but not in endosomes located more medially in the cell, nor in MVBs or lysosomes. The kinetics and sequence of intracellular translocation of BSM-gold were studied by fixing animals at various intervals following incubation in BSM-gold. Unlike that for supporting cells adjacent to non-cnidocytes, the amount of gold at the surface of supporting cells adjacent to penetrant cnidocytes does not seem to change despite considerable internalization of the mucin-probe. Apparently, free receptors replace receptor-ligand complexes in a one-for-one fashion in these cells. PMID:18620220

Watson, G M; Hessinger, D A

1987-01-01

158

Embryonic and larval development of the host sea anemones Entacmaea quadricolor and Heteractis crispa.  

PubMed

Little information is available on the sexual reproductive biology of anemones that provide essential habitat for anemonefish. Here we provide the first information on the surface ultrastructural and morphological changes during development of the embryos and planula larvae of Entacmaea quadricolor and Heteractis crispa, using light and scanning electron microscopy. Newly spawned eggs of E. quadricolor and H. crispa averaged 794 microm and 589 microm diameter, respectively, and were covered by many spires of microvilli that were evenly distributed over the egg surface, except for a single bare patch. Eggs of both species contained abundant zooxanthellae when spawned, indicating vertical transmission of symbionts. Fertilization was external, and the resulting embryos displayed superficial cleavage. As development continued, individual blastomeres became readily distinguishable and a round-to-ovoid blastula was formed, which flattened with further divisions. The edges of the blastula thickened, creating a concave-convex dish-shaped gastrula. The outer margins of the gastrula appeared to roll inward, leading to the formation of an oral pore and a ciliated planula larva. Larval motility and directional movement were first observed 36 h after spawning. E. quadricolor larval survival remained high during the first 4 d after spawning, then decreased rapidly. PMID:17928518

Scott, Anna; Harrison, Peter L

2007-10-01

159

Enzymatic and structural characterization of a basic phospholipase A(2) from the sea anemone Condylactis gigantea.  

PubMed

This work aimed at the isolation and structural/functional characterization of a phospholipase A(2) (CgPLA(2)) from the extract of the anemone Condylactis gigantea. CgPLA(2) was isolated with a high purity level through three chromatographic steps, showing pI 8.6 and molecular weights of 14,500 and 29,000 for the monomer and dimer, respectively. CgPLA(2) showed a high catalytic activity upon fluorescent phospholipids inducing no direct hemolytic activity. This enzyme, which is Ca(2+)-dependent, showed a lower stability against temperature and pH variations when compared with snake venom enzymes. The enzymatic activity was significantly reduced or completely abolished after chemical modification of CgPLA(2) with BPB. Its cDNA was then obtained, with 357 base pairs which codified for a mature protein of 119 amino acid residues. A comparative analysis of the primary structure of CgPLA(2) revealed 84%, 61%, 43% and 42% similarity to the PLA(2)s from Adamsia carciniopados, Nematostella vectensis, Vipera russelli russelli and Bothrops jararacussu, respectively. PMID:20562011

Romero, Lazara; Marcussi, Silvana; Marchi-Salvador, Daniela P; Silva, Floriano P; Fuly, André L; Stábeli, Rodrigo G; da Silva, Saulo L; González, Jorge; Monte, Alberto Del; Soares, Andreimar M

2010-05-26

160

Evaluation of the sea anemone Anthothoe albocincta as an augmentative biocontrol agent for biofouling on artificial structures.  

PubMed

Augmentative biocontrol, defined as the use of indigenous natural enemies to control pest populations, has not been explored extensively in marine systems. This study tested the potential of the anemone Anthothoe albocincta as a biocontrol agent for biofouling on submerged artificial structures. Biofouling biomass was negatively related to anemone cover. Treatments with high anemone cover (>35%) led to significant changes in biofouling assemblages compared to controls. Taxa that contributed to these changes differed among sites, but included reductions in cover of problematic fouling organisms, such as solitary ascidians and bryozoans. In laboratory trials, A. albocincta substantially prevented the settlement of larvae of the bryozoan Bugula neritina when exposed to three levels of larval dose, suggesting predation as an important biocontrol mechanism, in addition to space pre-emption. This study demonstrated that augmentative biocontrol using anemones has the potential to reduce biofouling on marine artificial structures, although considerable further work is required to refine this tool before its application. PMID:23682610

Atalah, Javier; Bennett, Holly; Hopkins, Grant A; Forrest, Barrie M

2013-05-17

161

A new species of sea anemone ( Saccactis coliumensis n. sp.) living under hypoxic conditions on the central Chilean shelf  

Microsoft Academic Search

The new speciesSaccactis coliumensis is described with an emendation of genusSaccactis lager, 1911 (family Actiniidae). The taxonomic relations of the genus are discussed giving additional information onIsoulactis chilensis Carlgren, 1959 andIsocradactis magna sensu Carlgren, 1924. The terms “verrucae”, “vesicles” and “acrorhagi” are discussed and taxonomically valuated. The anemoneS. coliumensis lives in eutrophicated sediments on the central Chilean shelf that is

Karin Riemann-Zürneck; Victor A. Gallardo

1990-01-01

162

Autotrophy versus heterotrophy: The origin of carbon determines its fate in a symbiotic sea anemone  

Microsoft Academic Search

Cnidarians – corals and their relatives – dominate the shallow, illuminated sea-floor in tropical nutrient-poor seas, mainly because their food sources are both heterotrophic, by predation, and autotrophic, from their intracellular symbiotic microalgae, the zooxanthellae. This trophic flexibility is rare in the animal kingdom, and the cellular usage and biological lifetime of the organic food molecules derived from both sources

Ami Bachar; Yair Achituv; Zohar Pasternak; Zvy Dubinsky

2007-01-01

163

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, André Junqueira; Ferreira, Wilson Alves; Konno, Katsuhiro; Shida, Cláudio Saburo; Richardson, Michael; Lúcio, Aline Duarte; Beirão, Paulo Sérgio Lacerda; de Freitas, José Carlos

2006-08-26

164

Differential-scanning-calorimetric study of the irreversible thermal denaturation of 8 kDa cytotoxin from the sea anemone Radianthus macrodactylus.  

PubMed Central

A differential-scanning-calorimetric study of the thermal denaturation of a sea-anemone (Radianthus macrodactylus) 8 kDa cytolytic toxin was carried out. The calorimetric traces were found to be irreversible and scan-rate-dependent under the experimental conditions employed. Scan-rate-dependent thermograms were explained in terms of a two-state kinetic model N k -->D, where k is a first-order kinetic constant that changes with temperature as given by the Arrhenius equation, N is the native state of the toxin, and D the denatured one.

Zhadan, G G; Shnyrov, V L

1994-01-01

165

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

2013-08-16

166

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

167

Modulation of Kv3 Subfamily Potassium Currents by the Sea Anemone Toxin BDS: Significance for CNS and Biophysical Studies  

PubMed Central

Kv3 potassium channels, with their ultra-rapid gating and high activation threshold, are essential for high-frequency firing in many CNS neurons. Significantly, the Kv3.4 subunit has been implicated in the major CNS disorders Parkinson’s and Alzheimer’s diseases, and it is claimed that selectively targeting this subunit will have therapeutic utility. Previous work suggested that BDS toxins (“blood depressing substance,” from the sea anemone Anemonia sulcata) were specific blockers for rapidly inactivating Kv3.4 channels, and consequently these toxins are increasingly used as diagnostic agents for Kv3.4 subunits in central neurons. However, precisely how selective are these toxins for this important CNS protein? We show that BDS is not selective for Kv3.4 but markedly inhibits current through Kv3.1 and Kv3.2 channels. Inhibition comes about not by “pore block” but by striking modification of Kv3 gating kinetics and voltage dependence. Activation and inactivation kinetics are slowed by BDS-I and BDS-II, and V1/2 for activation is shifted to more positive voltages. Alanine substitution mutagenesis around the S3b and S4 segments of Kv3.2 reveals that BDS acts via voltage-sensing domains, and, consistent with this, ON gating currents from nonconducting Kv3.2 are markedly inhibited. The altered kinetics and gating properties, combined with lack of subunit selectivity with Kv3 subunits, seriously affects the usefulness of BDS toxins in CNS studies. Furthermore, our results do not easily fit with the voltage sensor “paddle” structure proposed recently for Kv channels. Our data will be informative for experiments designed to dissect out the roles of Kv3 subunits in CNS function and dysfunction.

Yeung, Shuk Yin M.; Thompson, Dawn; Wang, Zhuren; Fedida, David; Robertson, Brian

2005-01-01

168

Activities of Enzymes in beta -carboxylation Reactions and of Catalase in Cell-Free Preparations from the Symbiotic Dinoflagellates Symbiodinium Spp. from a Coral, a Clam, a Zoanthid and Two Sea Anemones  

Microsoft Academic Search

Cell-free extracts of cultured and freshly isolated symbiotic dinoflagellates, Symbiodinium spp, isolated from the stony coral Montipora verrucosa, the clam Tridacna maxima, the zoanthid Palythoa sp. and the sea anemone Aiptasia pulchella were assayed for the enzyme systems involved in beta -carboxylation and photorespiration. Markedly different levels of phosphoenolpyruvate carboxylase (EC 4. 1. 1. 31; PEP-case) activity were demonstrated in

E. M. Tytler; R. K. Trench

1986-01-01

169

Structure-function relationships of the major neurotoxin from the sea anemone Stichodactyla helianthus with a new sodium channel receptor site  

SciTech Connect

We have determined that ShN I, a 48-residue type 2 sea anemone toxin, delays the inactivation of the Na channel in lobster olfactory somas. The receptor for ShN I was identified in vesicle preparations of neuronal tissues from both crustaceans and mammals; however, the K{sub D} values for the former is more than 1,000 fold lower for the later. The binding of ({sup 125}I)-ShN I to this receptor was determined to be unaffected by Anemonia sulcata II, depolarization of the membrane, or veratridine. ShN I was unable to displace ({sup 125}I)-Androctonus austrialis Hector II, whereas unlabeled AaH II and As II displaced the labeled scorpion toxin from rat brain synaptosomes. This is the first characterization of a new Na channel receptor site which specifically binds type 2 anemone toxins. To study the interactions that specific amino acid residues of ShN I have with this receptor, we developed a strategy using solid phase peptide synthesis. Prior to the synthesis of analogs to ShN I, we assembled the native ShN I sequence and reoxidized the three intramolecular disulfide bonds. Chemical, physical, and pharmacological characterization of the purified synthetic ShN I showed it to be indistinguishable from the natural toxin.

Pennington, M.W.

1988-01-01

170

Insights into the Toxicological Properties of a Low Molecular Weight Fraction from Zoanthus sociatus (Cnidaria)  

PubMed Central

The phylum Cnidaria is an ancient group of venomous animals, specialized in the production and delivery of toxins. Many species belonging to the class Anthozoa have been studied and their venoms often contain a group of peptides, less than 10 kDa, that act upon ion channels. These peptides and their targets interact with high affinity producing neurotoxic and cardiotoxic effects, and even death, depending on the dose and the administration pathway. Zoanthiniaria is an order of the Subclass Hexacorallia, class Anthozoa, and unlike sea anemone (order Actiniaria), neither its diversity of toxins nor the in vivo effects of the venoms has been exhaustively explored. In this study we assessed some toxicological tests on mice with a low molecular weight fraction obtained by gel filtration in Sephadex G-50 from Zoanthus sociatus crude extract. The gel filtration chromatogram at 280 nm revealed two major peaks, the highest absorbance corresponding to the low molecular weight fraction. The toxicological effects seem to be mostly autonomic and cardiotoxic, causing death in a dose dependent manner with a LD50 of 792 ?g/kg. Moreover, at a dose of 600 ?g/kg the active fraction accelerated the KCl-induced lethality in mice.

Dominguez-Perez, Dany; Diaz-Garcia, Carlos Manlio; Garcia-Delgado, Neivys; Sierra-Gomez, Yusvel; Castaneda, Olga; Antunes, Agostinho

2013-01-01

171

1H-n.m.r. study of the solution properties and secondary structure of neurotoxin III from the sea anemone Anemonia sulcata.  

PubMed Central

The solution properties, secondary structure and global fold of the 27-residue polypeptide neurotoxin III (ATX III), from the sea anemone Anemonia sulcata, have been investigated using high-resolution 1H-n.m.r. spectroscopy. Studies of the concentration dependence of the n.m.r. spectrum indicate that the molecule self-associates in the millimolar concentration range useable for n.m.r. analysis, the association being less pronounced at acidic pH values. The dependence on pH of association implies that electrostatic interactions play a role in this process, while the significant concentration-dependent shifts of the aromatic resonances of Tyr-7 and Trp-13 indicate that hydrophobic interactions also contribute. Individual pKa values have been determined for most ionizable groups in the molecule. Sequence-specific resonance assignments were obtained for all protons using a range of two-dimensional homonuclear-correlated and nuclear-Overhauser-effect (nOe) spectra. The secondary structure of the polypeptide was identified from sequential (i, i+1) and medium-range (i, i+2/3/4) nOe connectivities, NH to C alpha H coupling constants, C alpha H chemical shifts, and the location of slowly exchanging backbone-amide protons. ATX III contains no regular alpha-helix or beta-sheet, consisting instead of a network of reverse turns. nOe connectivities between half-cystine residues are consistent with the disulphide pairings 3-17, 4-11 and 6-22. ATX III has a well-defined structure and appears to lack the disordered loop which, in the longer sea anemone toxins (46-49 residues), may be part of the receptor-binding surface.

Norton, R S; Cross, K; Braach-Maksvytis, V; Wachter, E

1993-01-01

172

Molecular analysis of the sea anemone toxin Av3 reveals selectivity to insects and demonstrates the heterogeneity of receptor site-3 on voltage-gated Na+ channels  

PubMed Central

Av3 is a short peptide toxin from the sea anemone Anemonia viridis shown to be active on crustaceans and inactive on mammals. It inhibits inactivation of Navs (voltage-gated Na+ channels) like the structurally dissimilar scorpion ?-toxins and type I sea anemone toxins that bind to receptor site-3. To examine the potency and mode of interaction of Av3 with insect Navs, we established a system for its expression, mutagenized it throughout, and analysed it in toxicity, binding and electrophysiological assays. The recombinant Av3 was found to be highly toxic to blowfly larvae (ED50=2.65±0.46 pmol/100 mg), to compete well with the site-3 toxin Lqh?IT (from the scorpion Leiurus quinquestriatus) on binding to cockroach neuronal membranes (Ki=21.4±7.1 nM), and to inhibit the inactivation of Drosophila melanogaster channel, DmNav1, but not that of mammalian Navs expressed in Xenopus oocytes. Moreover, like other site-3 toxins, the activity of Av3 was synergically enhanced by ligands of receptor site-4 (e.g. scorpion ?-toxins). The bioactive surface of Av3 was found to consist mainly of aromatic residues and did not resemble any of the bioactive surfaces of other site-3 toxins. These analyses have portrayed a toxin that might interact with receptor site-3 in a different fashion compared with other ligands of this site. This assumption was corroborated by a D1701R mutation in DmNav1, which has been shown to abolish the activity of all other site-3 ligands, except Av3. All in all, the present study provides further evidence for the heterogeneity of receptor site-3, and raises Av3 as a unique model for design of selective anti-insect compounds.

Moran, Yehu; Kahn, Roy; Cohen, Lior; Gur, Maya; Karbat, Izhar; Gordon, Dalia; Gurevitz, Michael

2007-01-01

173

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

174

Crustaceans associated with Cnidaria, Bivalvia, Echinoidea and Pisces at São Tomé and Príncipe islands  

Microsoft Academic Search

Symbiotic crustaceans were searched for at sea anemones (Actiniaria), encrusting anemones (Zoantharia), horny coral (Gorgonaria), black coral (Antipatharia), bivalves (Bivalvia), and sea urchins (Echinoidea) at São Tomé and Príncipe Islands (Gulf of Guinea, eastern central Atlantic). Sixteen species of crustaceans were found in association with these invertebrate hosts; eleven of them were new records for the area and two species,

PETER WIRTZ

175

A SIMPLE TEST: EVALUATING EXPLANATIONS FOR THE RELATIVE SIMPLICITY OF THE EDWARDSIIDAE (CNIDARIA: ANTHOZOA)  

Microsoft Academic Search

Many members of the cnidarian subclass Zoantharia (sea anemones, corals, and their allies) pass through a larval stage with eight complete mesenteries and without posterior musculature. This larva is usually transient, developing into an adult with 12 or more mesenteries. The adults of one family of sea anemones, the Edwardsiidae, bear the larval number and arrangement of mesenteries and lack

Marymegan Daly; Diana L. Lipscomb; Marc W. Allard

2002-01-01

176

Ecological and morphological characteristics of Ephelota gemmipara (Ciliophora, Suctoria), epibiontic on Eudendrium racemosum (Cnidaria, Hydrozoa) from the Adriatic Sea.  

PubMed

The relationship between the suctorian Ephelota gemmipara and the large hydroid Eudendrium racemosum from the North Adriatic Sea has been studied over its full annual cycle. Ephelota gemmipara settles on the perisarc of the hydroid, usually close to the hydranths in order to exploit the hydroid's food discharges. The life cycle of E. gemmipara is influenced by temperature variations and by its relationship with the host. The hydroid shows an active phase in the summer, and it gets through the adverse winter season forming resting stages. In April, when temperature increases, the hydroid starts its active phase and it is colonized by suctorians. From May to September the suctorians produce multiple buds (swarmers) that detach from the parental cells to settle on an Eudendrium colony. The abundance of the suctorian peaks in September, with more than 1.2 million ind. m(-2). Their proliferation coincides with the maximal abundance of their host and the highest water temperatures. On the contrary, sexual reproduction and the encystment occur when the temperature and the abundance of E. racemosum decrease. Lastly, we also report the presence of symbionts such as bacteria and the parasitic protozoans Tachyblaston ephelotensis and Enigmocoma acinetarum. PMID:23711377

Tazioli, Silvia; Di Camillo, Cristina Gioia

2013-05-25

177

Phylogenetic Relationships within the Class Anthozoa (Phylum Cnidaria) Based on Nuclear 18S rDNA Sequences  

Microsoft Academic Search

Taxonomic relationships within the corals and anemones (Phylum Cnidaria: Class Anthozoa) are based upon few morphological characters. The significance of any given character is debatable, and there is little fossil record available for deriving evolutionary relationships. We analyzed complete 18S ribosomal sequences to examine subclass-level and ordinal-level organization within the Anthozoa. We suggest that the Subclass Ceriantipatharia is not an

Ewann A. Berntson; Scott C. France; Lauren S. Mullineaux

1999-01-01

178

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?µmol O2 g?1 h?1) and 231?Pa (3.30?µmol O2 g?1 h?1) than at the initial 37?Pa (1.53?µmol 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.

Towanda, Trisha; Thuesen, Erik V.

2012-01-01

179

Probing dimerization and intraprotein fluorescence resonance energy transfer in a far-red fluorescent protein from the sea anemone Heteractis crispa.  

PubMed

Proteins from Anthozoa species are homologous to the green fluorescent protein (GFP) from Aequorea victoria but with absorption/emission properties extended to longer wavelengths. HcRed is a far-red fluorescent protein originating from the sea anemone Heteractis crispa with absorption and emission maxima at 590 and 650 nm, respectively. We use ultrasensitive fluorescence spectroscopic methods to demonstrate that HcRed occurs as a dimer in solution and to explore the interaction between chromophores within such a dimer. We show that red chromophores within a dimer interact through a Forster-type fluorescence resonance energy transfer (FRET) mechanism. We present spectroscopic evidence for the presence of a yellow chromophore, an immature form of HcRed. This yellow chromophore is involved in directional FRET with the red chromophore when both types of chromophores are part of one dimer. We show that by combining ensemble and single molecule methods in the investigation of HcRed, we are able to sort out subpopulations of chromophores with different photophysical properties and to understand the mechanism of interaction between such chromophores. This study will help in future quantitative microscopy investigations that use HcRed as a fluorescent marker. PMID:18601536

Lessard, Guillaume A; Habuchi, Satoshi; Werner, James H; Goodwin, Peter M; De Schryver, Frans; Hofkens, Johan; Cotlet, Mircea

180

The 2.0-A crystal structure of eqFP611, a far red fluorescent protein from the sea anemone Entacmaea quadricolor.  

PubMed

We have crystallized and subsequently determined to 2.0-A resolution the crystal structure of eqFP611, a far red fluorescent protein from the sea anemone Entacmaea quadricolor. The structure of the protomer, which adopts a beta-can topology, is similar to that of the related monomeric green fluorescent protein (GFP). The quaternary structure of eqFP611, a tetramer exhibiting 222 symmetry, is similar to that observed for the more closely related red fluorescent protein DsRed and the chromoprotein Rtms5. The unique chromophore sequence (Met63-Tyr64-Gly65) of eqFP611, adopts a coplanar and trans conformation within the interior of the beta-can fold. Accordingly, the eqFP611 chromophore adopts a significantly different conformation in comparison to the chromophore conformation observed in GFP, DsRed, and Rtms5. The coplanar chromophore conformation and its immediate environment provide a structural basis for the far red, highly fluorescent nature of eqFP611. The eqFP611 structure extends our knowledge on the range of conformations a chromophore can adopt within closely related members of the green fluorescent protein family. PMID:12909624

Petersen, Jan; Wilmann, Pascal G; Beddoe, Travis; Oakley, Aaron J; Devenish, Rodney J; Prescott, Mark; Rossjohn, Jamie

2003-08-08

181

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

PubMed Central

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 show that ultraviolet (UV) irradiation at low levels selectively induces programmed cell death in early gametes but not somatic cells of adult N. vectensis polyps. We demonstrate with RNA interference that nvp63 mediates this cell death in vivo. Nvp63 is the most archaic member of three p53-like proteins found in N. vectensis and in congruence with all known p53-like proteins, nvp63 binds to the vertebrate p53 DNA recognition sequence and activates target gene transcription in vitro. A transactivation inhibitory domain at its C-terminus with high homology to the vertebrate p63 may regulate nvp63 on a molecular level. The genotoxic stress induced and nvp63 mediated apoptosis in N. vectensis gametes reveals an evolutionary ancient germ cell protective pathway which relies on p63-like proteins and is conserved from cnidarians to vertebrates.

Pankow, Sandra; Bamberger, Casimir

2007-01-01

182

Functional expression in Escherichia coli of the disulfide-rich sea anemone peptide APETx2, a potent blocker of acid-sensing ion channel 3.  

PubMed

Acid-sensing ion channels (ASICs) are proton-gated sodium channels present in the central and peripheral nervous system of chordates. ASIC3 is highly expressed in sensory neurons and plays an important role in inflammatory and ischemic pain. Thus, specific inhibitors of ASIC3 have the potential to be developed as novel analgesics. APETx2, isolated from the sea anemone Anthopleura elegantissima, is the most potent and selective inhibitor of ASIC3-containing channels. However, the mechanism of action of APETx2 and the molecular basis for its interaction with ASIC3 is not known. In order to assist in characterizing the ASIC3-APETx2 interaction, we developed an efficient and cost-effective Escherichia coli periplasmic expression system for the production of APETx2. NMR studies on uniformly (13)C/(15)N-labelled APETx2 produced in E. coli showed that the recombinant peptide adopts the native conformation. Recombinant APETx2 is equipotent with synthetic APETx2 at inhibiting ASIC3 channels expressed in Xenopus oocytes. Using this system we mutated Phe15 to Ala, which caused a profound loss of APETx2's activity on ASIC3. These findings suggest that this expression system can be used to produce mutant versions of APETx2 in order to facilitate structure-activity relationship studies. PMID:22851929

Anangi, Raveendra; Rash, Lachlan D; Mobli, Mehdi; King, Glenn F

2012-07-23

183

Functional Expression in Escherichia coli of the Disulfide-Rich Sea Anemone Peptide APETx2, a Potent Blocker of Acid-Sensing Ion Channel 3  

PubMed Central

Acid-sensing ion channels (ASICs) are proton-gated sodium channels present in the central and peripheral nervous system of chordates. ASIC3 is highly expressed in sensory neurons and plays an important role in inflammatory and ischemic pain. Thus, specific inhibitors of ASIC3 have the potential to be developed as novel analgesics. APETx2, isolated from the sea anemone Anthopleura elegantissima, is the most potent and selective inhibitor of ASIC3-containing channels. However, the mechanism of action of APETx2 and the molecular basis for its interaction with ASIC3 is not known. In order to assist in characterizing the ASIC3-APETx2 interaction, we developed an efficient and cost-effective Escherichia coli periplasmic expression system for the production of APETx2. NMR studies on uniformly 13C/15N-labelled APETx2 produced in E. coli showed that the recombinant peptide adopts the native conformation. Recombinant APETx2 is equipotent with synthetic APETx2 at inhibiting ASIC3 channels expressed in Xenopus oocytes. Using this system we mutated Phe15 to Ala, which caused a profound loss of APETx2’s activity on ASIC3. These findings suggest that this expression system can be used to produce mutant versions of APETx2 in order to facilitate structure-activity relationship studies.

Anangi, Raveendra; Rash, Lachlan D.; Mobli, Mehdi; King, Glenn F.

2012-01-01

184

Generation and analysis of transcriptomic resources for a model system on the rise: the sea anemone Aiptasia pallida and its dinoflagellate endosymbiont  

PubMed Central

Background The most diverse marine ecosystems, coral reefs, depend upon a functional symbiosis between cnidarian hosts and unicellular dinoflagellate algae. The molecular mechanisms underlying the establishment, maintenance, and breakdown of the symbiotic partnership are, however, not well understood. Efforts to dissect these questions have been slow, as corals are notoriously difficult to work with. In order to expedite this field of research, we generated and analyzed a collection of expressed sequence tags (ESTs) from the sea anemone Aiptasia pallida and its dinoflagellate symbiont (Symbiodinium sp.), a system that is gaining popularity as a model to study cellular, molecular, and genomic questions related to cnidarian-dinoflagellate symbioses. Results A set of 4,925 unique sequences (UniSeqs) comprising 1,427 clusters of 2 or more ESTs (contigs) and 3,498 unclustered ESTs (singletons) was generated by analyzing 10,285 high-quality ESTs from a mixed host/symbiont cDNA library. Using a BLAST-based approach to predict which unique sequences derived from the host versus symbiont genomes, we found that the contribution of the symbiont genome to the transcriptome was surprisingly small (1.6–6.4%). This may reflect low levels of gene expression in the symbionts, low coverage of alveolate genes in the sequence databases, a small number of symbiont cells relative to the total cellular content of the anemones, or failure to adequately lyse symbiont cells. Furthermore, we were able to identify groups of genes that are known or likely to play a role in cnidarian-dinoflagellate symbioses, including oxidative stress pathways that emerged as a prominent biological feature of this transcriptome. All ESTs and UniSeqs along with annotation results and other tools have been made accessible through the implementation of a publicly accessible database named AiptasiaBase. Conclusion We have established the first large-scale transcriptomic resource for Aiptasia pallida and its dinoflagellate symbiont. These data provide researchers with tools to study questions related to cnidarian-dinoflagellate symbioses on a molecular, cellular, and genomic level. This groundwork represents a crucial step towards the establishment of a tractable model system that can be utilized to better understand cnidarian-dinoflagellate symbioses. With the advent of next-generation sequencing methods, the transcriptomic inventory of A. pallida and its symbiont, and thus the extent of AiptasiaBase, should expand dramatically in the near future.

Sunagawa, Shinichi; Wilson, Emily C; Thaler, Michael; Smith, Marc L; Caruso, Carlo; Pringle, John R; Weis, Virginia M; Medina, Monica; Schwarz, Jodi A

2009-01-01

185

Cooperativity in the two-domain arginine kinase from the sea anemone Anthopleura japonicus. II. Evidence from site-directed mutagenesis studies.  

PubMed

The arginine kinase (AK) from the sea anemone Anthopleura japonicus has an unusual two-domain structure (contiguous dimer; denoted by D1-D2). In a previous report, we suggested cooperativity in the contiguous dimer, which may be a result of domain-domain interactions, using MBP-fused enzymes. To further understand this observation, we inserted six-Lys residues into the linker region of the two-domain AK (D1-K6-D2 mutant) using His-tagged enzyme. The dissociation constants, K(a) and K(ia), of the mutant were similar to those of the wild-type enzyme but the catalytic constant, k(cat), was decreased to 28% that of the wild-type, indicating that some of the domain-domain interactions are lost due to the six-Lys insertion. Y68 plays a major role in arginine binding in the catalytic pocket in Limulus AK, and introduction of mutation at the Y68 position virtually abolishes catalytic activity. Thus, the constructed D1(Y68G)-D2 and D1-D2(Y68G) mutants mimic the D1(inactive)-D2(active) and D1(active)-D2(inactive) enzymes, respectively. The k(cat) values of both Y68 mutants were decreased to 13-18% that of the wild-type enzyme, which is much less than the 50% level of the two-domain enzyme. Thus, it is clear that substrate-binding to both domains is necessary for full expression of activity. In other words, substrate-binding appears to act as the trigger of the functional cooperativity in two-domain AK. PMID:20434482

Tada, Hiroshi; Suzuki, Tomohiko

2010-04-29

186

Purification and partial characterization of the phospholipase A2 and co-lytic factor from sea anemone (Aiptasia pallida) nematocyst venom.  

PubMed

Functional nematocysts of one specific morphological class, the penetrant microbasic mastigophores, were isolated from the sea anemone, Aiptasia pallida. These nematocysts contain a multicomponent venom composed of several proteins, including those with neurotoxic, hemolytic, and lethal activities. Hemolytic activity is produced by at least three synergistic venom proteins. One of these proteins is identified as a phospholipase A2 (EC 3.1.1.4) which exists in two isozymic forms, alpha and beta, with molecular weights of 45,000 and 43,000, respectively. The beta isozyme has been purified to homogeneity. It is a single-chained glycoprotein with an isoelectric point (pI) of 8.8 and represents 70% of the phospholipase activity of the venom. The activity of the beta isozyme is relatively labile and is inactivated by 3.5 M urea or by heating at 45 degrees C. It is most stable at pH 4.0 and loses 50% of its activity at pH values below 3.5 and above 8.0. A second venom protein has also been purified. It is essential for the hemolytic activity of the venom and is termed co-lytic factor (CLF). It is a monomeric glycoprotein having a pI of 4.5. CLF has a molecular weight of approximately 98,000, a sedimentation coefficient of 4.8 S, and is prolate in shape, having a frictional ratio of about 1.6. CLF constitutes about 1.25% of the total venom protein and is assayed by reversing fatty acid inhibition of the venom hemolysis activity. PMID:10519655

Grotendorst, G R; Hessinger, D A

1999-12-01

187

Primary structure of the precursor for the sea anemone neuropeptide Antho-RFamide (less than Glu-Gly-Arg-Phe-NH2).  

PubMed Central

Neuropeptides containing the carboxylterminal sequence Arg-Phe-NH2 are found throughout the animal kingdom and are important substances mediating neuronal communication. Here, we have cloned the cDNA coding for the precursor protein of the sea anemone neuropeptide (Antho-RFamide) less than Glu-Gly-Arg-Phe-NH2. This precursor is 334 amino acids in length and contains 19 copies of unprocessed Antho-RFamide (Gln-Gly-Arg-Phe-Gly), which are tandemly arranged in the C-terminal part of the protein. Paired basic residues (Lys-Arg) or single basic residues (Arg) occur at the C-terminal side of each Antho-RFamide sequence. These are likely signals for posttranslational cleavage. The processing signals at the N-terminal side of each Antho-RFamide sequence, however, include acidic residues. Processing at these amino acids must involve either an amino- or an endopeptidase that cleaves C-terminally of aspartic acid or glutamic acid residues. Such processing is, to our knowledge, hitherto unknown for peptidergic neurons. The Antho-RFamide precursor also contains two copies of the putative Antho-RFamide-related peptide Phe-Gln-Gly-Arg-Phe-NH2 and one copy of Tyr-Val-Pro-Gly-Arg-Tyr-NH2. In addition, the precursor protein harbors four other putative neuropeptides that are much less related to Antho-RFamide. This report shows that the biosynthetic machinery for neuropeptides in coelenterates, the lowest animal group having a nervous system, is already very efficient and similar to that of higher invertebrates, such as mollusks and insects, and vertebrates. Images

Darmer, D; Schmutzler, C; Diekhoff, D; Grimmelikhuijzen, C J

1991-01-01

188

Cytotoxic effects produced on a continuous cell line by the nematocyst venom of Anemonia sulcata (Cnidaria: Anthozoa). I  

Microsoft Academic Search

i. INTRODUCTION The nematocyst venom of Cnidaria produces dermonecrotic, cardiotoxic and neurotoxic effects and is a serious health problem for sea-workers and bathers, particularly in some areas where exist several dangerous species whose stings are lethal also for humans. In the Mediterranean Sea there are not lethal species, nevertheless serious effects were reported, probably owing to the particular sensitivity of

G. L. Mariottini; S. Bussotti; A. Carli

1993-01-01

189

Sympagohydra tuuli (Cnidaria, Hydrozoa): Wrst report from sea ice of the central Arctic Ocean and insights into histology, reproduction and locomotion  

Microsoft Academic Search

Various cnidarians have adapted their life style to interstitial habitats of marine sediments. Recently, for the Wrst time a hydroid was reported from the interstitial brine channel system of Arctic fast ice. Due to its derived fea- tures, the new genus and species Sympagohydra tuuli was introduced. Here we describe Wndings of S. tuuli in sea ice at several sites

Stefan Siebert; Friederike Anton-Erxleben; Rainer Kiko; Maike Kramer

2008-01-01

190

Sympagohydra tuuli (Cnidaria, Hydrozoa): first report from sea ice of the central Arctic Ocean and insights into histology, reproduction and locomotion  

Microsoft Academic Search

Various cnidarians have adapted their life style to interstitial habitats of marine sediments. Recently, for the first time\\u000a a hydroid was reported from the interstitial brine channel system of Arctic fast ice. Due to its derived features, the new\\u000a genus and species Sympagohydra tuuli was introduced. Here we describe findings of S. tuuli in sea ice at several sites within

Stefan Siebert; Friederike Anton-Erxleben; Rainer Kiko; Maike Kramer

2009-01-01

191

Assemblage and interaction structure of the anemonefish-anemone mutualism across the Manado region of Sulawesi, Indonesia  

Microsoft Academic Search

The Manado area (Indonesia–North Sulawesi), a marine high diversity hot-spot, hosts 7 species of anemonefish (family Pomacentridae,\\u000a subfamily Amphiprioniae) living in symbiosis with 9 species of sea anemones (family Stichodactylidae and Actiniidae). This\\u000a high biological diversity ?27% and 80%, respectively, of the total known diversity of anemonefish and sea anemones—allows\\u000a us to test different hypotheses focused on the obligate mutualism

Francesco Ricciardi; Massimo Boyer; Jeff Ollerton

2010-01-01

192

Stranding events provide indirect insights into the seasonality and persistence of jellyfish medusae (Cnidaria: Scyphozoa)  

Microsoft Academic Search

It is becoming increasingly evident that jellyfish (Cnidaria: Scyphozoa) play an important role within marine ecosystems,\\u000a yet our knowledge of their seasonality and reproductive strategies is far from complete. Here, we explore a number of life\\u000a history hypotheses for three common, yet poorly understood scyphozoan jellyfish (Rhizostoma octopus; Chrysaora hysoscella; Cyanea capillata) found throughout the Irish and Celtic Seas. Specifically,

Jonathan David Roy Houghton; Thomas K. Doyle; John Davenport; Martin K. S. Lilley; Rory P. Wilson; Graeme C. Hays

2007-01-01

193

Acrorhagi, catch tentacles and sweeper tentacles: a synopsis of ‘aggression’ of actiniarian and scleractinian Cnidaria  

Microsoft Academic Search

Three types of organ (acrorhagi and catch tentacles in sea anemones, and sweeper tentacles in corals) are described with regard to both morphology and ‘aggressive’ function. Species known to possess such organs are listed. Research on the functions of these particular organs is reviewed and some exceptions to their usual behaviour patterns are highlighted. Further research on allogeneic recognition might

R. B. Williams

1991-01-01

194

Ammonia flux, physiological parameters, and Symbiodinium diversity in the anemonefish symbiosis on Red Sea coral reefs  

Microsoft Academic Search

Despite the ecological importance of anemonefish symbioses, little is known about how nutritional contributions from anemonefish\\u000a interact with sea anemone physiology and Symbiodinium (endosymbiotic dinoflagellate) genetic identity under field conditions. On Red Sea coral reefs, we measured variation in\\u000a ammonia concentrations near anemones, excretion rates of anemonefish, physiological parameters of anemones and Symbiodinium, and genetic identity of Symbiodinium within anemones.

Modi Roopin; Daniel J. Thornhill; Scott R. Santos; Nanette E. Chadwick

2011-01-01

195

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

196

On Some Features of Early Embryonic Development Stages of Cnidaria  

Microsoft Academic Search

Division of the life cycle of Cnidaria (except for Anthozoa) into two independent generations, polypoid and medusoid, i.e., metagenesis, is considered to be unjustified. Like other Metazoa, their life cycle can be divided into three periods: embryonic, postembryonic, and definitive, i.e., according to the age [9, 10]. An important feature of Cnidaria is the transition of some postembryonic stages to

Z. S. Kaufman

2004-01-01

197

Analysis of complete mitochondrial DNA sequences of three members of the Montastraea annularis coral species complex (Cnidaria, Anthozoa, Scleractinia)  

Microsoft Academic Search

Complete mitochondrial nucleotide sequences of two individuals each of Montastraea annularis, Montastraea faveolata, and Montastraea franksi were determined. Gene composition and order differed substantially from the sea anemone Metridium senile, but were identical to that of the phylogenetically distant coral genus Acropora. However, characteristics of the non-coding regions differed between the two scleractinian genera. Among members of the M. annularis

Hironobu Fukami; Nancy Knowlton

2005-01-01

198

High In Situ Repeatability of Behaviour Indicates Animal Personality in the Beadlet Anemone Actinia equina (Cnidaria)  

Microsoft Academic Search

‘Animal personality’ means that individuals differ from one another in either single behaviours or suites of related behaviours in a way that is consistent over time. It is usually assumed that such consistent individual differences in behaviour are driven by variation in how individuals respond to information about their environment, rather than by differences in external factors such as variation

Mark Briffa; Julie Greenaway

2011-01-01

199

CgNa, a type I toxin from the giant Caribbean sea anemone Condylactis gigantea shows structural similarities to both type I and II toxins, as well as distinctive structural and functional properties1  

Microsoft Academic Search

analysis using rat DRG (dorsal root ganglion) neurons indi- cated that CgNa preferentially binds to TTX-S (tetrodotoxin- sensitive) voltage-gated sodium channels in the resting state. This association increased the inactivation time constant and the rate of recovery from inactivation, inducing a significant shift in the steadystateofinactivationcurvetotheleft.Thespecificstructural featuresofCgNamayexplainitsweakerinhibitorycapacitywhen compared with the other type I and II anemone toxins.

Emilio Salceda; Javier Pérez-Castells; Blanca López-Méndez; Anoland Garateix; Hector Salazar; Omar López; Abel Aneiros; Ludger Ständker; Lászlo Béress; Wolf-Georg Forssmann; Enrique Soto; Jesús Jiménez-Barbero; Guillermo Giménez-Gallego

2007-01-01

200

Lipid Composition of Marine and Estuarine Invertebrates: Porifera and Cnidaria.  

National Technical Information Service (NTIS)

It is evident, although based upon somewhat limited data, that the Porifera and the Cnidaria differ substantially in their lipid composition and metabolism. Only one class of sponges, the Demospongiae, has been studied, but the lipids of these sponges are...

J. D. Joseph

1979-01-01

201

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

202

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

203

Bioluminescence of deep-sea coronate medusae (Cnidaria: Scyphozoa)  

Microsoft Academic Search

Bioluminescence is the production of visible light by a living organism. The light commonly appears as flashes from point sources (involving one or more cells, usually described as photocytes) or as a glandular secretion. A visible flash usually involves synchronous light emission from a group of cells or, if from a single-celled organism such as a dinoflagellate, from a group

P. J. Herring; E. A. Widder

2004-01-01

204

Neuronal cell death during metamorphosis of Hydractina echinata (Cnidaria, Hydrozoa)  

Microsoft Academic Search

In planula larvae of the invertebrate Hydractinia echinata (Cnidaria, Hydrozoa), peptides of the GLWamide and the RFamide families are expressed in distinct subpopulations of neurons,\\u000a distributed in a typical spatial pattern through the larval body. However, in the adult polyp GLWamide or RFamide-expressing\\u000a cells are located at body parts that do not correspond to the prior larval regions. Since we

Stefanie Seipp; Jürgen Schmich; Britta Will; Eva Schetter; Günter Plickert; Thomas Leitz

2010-01-01

205

AdE-1, a new inotropic Na(+) channel toxin from Aiptasia diaphana, is similar to, yet distinct from, known anemone Na(+) channel toxins.  

PubMed

Heart failure is one of the most prevalent causes of death in the western world. Sea anemone contains a myriad of short peptide neurotoxins affecting many pharmacological targets, several of which possess cardiotonic activity. In the present study we describe the isolation and characterization of AdE-1 (ion channel modifier), a novel cardiotonic peptide from the sea anemone Aiptasia diaphana, which differs from other cnidarian toxins. Although AdE-1 has the same cysteine residue arrangement as sea anemone type 1 and 2 Na(+) channel toxins, its sequence contains many substitutions in conserved and essential sites and its overall homology to other toxins identified to date is low (<36%). Physiologically, AdE-1 increases the amplitude of cardiomyocyte contraction and slows the late phase of the twitch relaxation velocity with no induction of spontaneous twitching. It increases action potential duration of cardiomyocytes with no effect on its threshold and on the cell's resting potential. Similar to other sea anemone Na(+) channel toxins such as Av2 (Anemonia viridis toxin II), AdE-1 markedly inhibits Na(+) current inactivation with no significant effect on current activation, suggesting a similar mechanism of action. However, its effects on twitch relaxation velocity, action potential amplitude and on the time to peak suggest that this novel toxin affects cardiomyocyte function via a more complex mechanism. Additionally, Av2's characteristic delayed and early after-depolarizations were not observed. Despite its structural differences, AdE-1 physiologic effectiveness is comparable with Av2 with a similar ED(50) value to blowfly larvae. This finding raises questions regarding the extent of the universality of structure-function in sea anemone Na(+) channel toxins. PMID:23356888

Nesher, Nir; Shapira, Eli; Sher, Daniel; Moran, Yehu; Tsveyer, Liora; Turchetti-Maia, Ana Luiza; Horowitz, Michal; Hochner, Binyamin; Zlotkin, Eliahu

2013-04-01

206

The Mechanism of Plateau Formation by Anemone Toxin.  

National Technical Information Service (NTIS)

The cause of plateau formation in neurons poisoned by anemone toxin was investigated. Membrane resistance measurements in crustacean neurons disclosed low resistance plateaus. Sufficient transmembrane current pulses in hyperpolarizing direction terminated...

G. Lilleheil B. I. Shapiro

1968-01-01

207

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

208

Evolutionary Patterns Within the Anthozoa (Phylum Cnidaria) Reflected in Ribosomal Gene Sequences.  

National Technical Information Service (NTIS)

This project assessed phylogenetic relationships within the Class Anthozon (Cnidaria) using 185 rDNA sequences from 71 taxa, including museum specimens, providing the most thorough taxonomic sampling to date. Morphological taxonomists disagree over the ev...

E. A. Berntson

1998-01-01

209

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

210

Analysis of complete mitochondrial DNA sequences of three members of the Montastraea annularis coral species complex (Cnidaria, Anthozoa, Scleractinia)  

NASA Astrophysics Data System (ADS)

Complete mitochondrial nucleotide sequences of two individuals each of Montastraea annularis, Montastraea faveolata, and Montastraea franksi were determined. Gene composition and order differed substantially from the sea anemone Metridium senile, but were identical to that of the phylogenetically distant coral genus Acropora. However, characteristics of the non-coding regions differed between the two scleractinian genera. Among members of the M. annularis complex, only 25 of 16,134 base pair positions were variable. Sixteen of these occurred in one colony of M. franksi, which (together with additional data) indicates the existence of multiple divergent mitochondrial lineages in this species. Overall, rates of evolution for these mitochondrial genomes were extremely slow (0.03 0.04% per million years based on the fossil record of the M. annularis complex). At higher taxonomic levels, patterns of genetic divergence and synonymous/nonsynonymous substitutions suggest non-neutral and unequal rates of evolution between the two lineages to which Montastraea and Acropora belong.

Fukami, Hironobu; Knowlton, Nancy

2005-11-01

211

Bioindication Potential of Carbonic Anhydrase Activity in Anemones and Corals  

Microsoft Academic Search

Activity levels of carbonic anhydrase (CA) were assessed in anemones Condylactis gigantea and Stichodactyla helianthus with laboratory exposures to copper, nickel, lead, and vanadium, and also in animals collected from polluted vs pristine field sites. CA activity was found to be decreased with increase in metal concentration and also in animals collected from the polluted field site. Preliminary assessments to

Aubrey L Gilbert; Héctor M Guzmán

2001-01-01

212

@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.

213

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

214

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 Alfvén 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

215

The form and function of Cnidarian spirocysts  

Microsoft Academic Search

The commonest intracellular organelle characteristic of the Phylum Cnidaria or Coelenterata (Subclass Zoantharia) is the spirocyst. Based on scanning and transmission electron microscopy of the tentacles of sea anemones and corals, it appears that the tip of the spirocyst is either exposed to the environment or covered by a thin plasma membrane and often has a pebbled or knobby appearance.

Richard N. Mariscal; Charles H. Bigger; Richard B. McLean

1976-01-01

216

Cnidarian internal stinging mechanism  

Microsoft Academic Search

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

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

2009-01-01

217

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

218

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

Microsoft Academic Search

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

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

2009-01-01

219

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

220

Identification of rDNA-specific non-LTR retrotransposons in Cnidaria.  

PubMed

Ribosomal RNA genes are abundant repetitive sequences in most eukaryotes. Ribosomal DNA (rDNA) contains many insertions derived from mobile elements including non-long terminal repeat (non-LTR) retrotransposons. R2 is the well-characterized 28S rDNA-specific non-LTR retrotransposon family that is distributed over at least 4 bilaterian phyla. R2 is a large family sharing the same insertion specificity and classified into 4 clades (R2-A, -B, -C, and -D) based on the N-terminal domain structure and the phylogeny. There is no observation of horizontal transfer of R2; therefore, the origin of R2 dates back to before the split between protostomes and deuterostomes. Here, we in silico identified 1 R2 element from the sea anemone Nematostella vectensis and 2 R2-like retrotransposons from the hydrozoan Hydra magnipapillata. R2 from N. vectensis was inserted into the 28S rDNA like other R2, but the R2-like elements from H. magnipapillata were inserted into the specific sequence in the highly conserved region of the 18S rDNA. We designated the Hydra R2-like elements R8. R8 is inserted at 37 bp upstream from R7, another 18S rDNA-specific retrotransposon family. There is no obvious sequence similarity between targets of R2 and R8, probably because they recognize long DNA sequences. Domain structure and phylogeny indicate that R2 from N. vectensis is the member of the R2-D clade, and R8 from H. magnipapillata belongs to the R2-A clade despite its different sequence specificity. These results suggest that R2 had been generated before the split between cnidarians and bilaterians and that R8 is a retrotransposon family that changed its target from the 28S rDNA to the 18S rDNA. PMID:16870681

Kojima, Kenji K; Kuma, Kei-ichi; Toh, Hiroyuki; Fujiwara, Haruhiko

2006-07-26

221

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

222

The role of Cnidaria in drug discovery. A review on CNS implications and new perspectives.  

PubMed

Many organisms produce bioactive substances used in the production of drugs. In this context, Cnidaria occupy a major position; for this reason, research on new bioactive substances has focused upon them as an interesting target. As a matter of fact, substances and extracts able to fight human diseases have been found in cnidarians, several of which have been studied in laboratories using animal models or cell cultures and, at present, some are in the pre-clinical phase. This review aims to highlight the research on existing drugs or new drug candidates extracted from Cnidaria and the recent patents published in this field; furthermore, as many cnidarian venoms are known to have an impact on the CNS and on neuromuscular transmission, this review particularly considers the research concerning CNS drug discovery and pending patents. PMID:23713989

Mariottini, Gian Luigi; Pane, Luigi

2013-08-01

223

Cnidaria from the Croker passage (Antarctic Peninsula) with a special focus on Siphonophorae  

Microsoft Academic Search

Studies of “gelatinous” zooplankton are rather rare, and little is known about the biology and ecology of Antarctic Cnidaria,\\u000a especially for siphonophores. More investigations are necessary for complementing the current information on the “gelatinous”\\u000a zooplankton inhabiting this important but little know biogeographical region, especially because siphonophores very likely\\u000a play a significant role in the Antarctic food chains. The species composition,

Anna A. Panasiuk-Chodnicka; Maria I. ?mijewska

2010-01-01

224

Agent of whirling disease meets orphan worm: phylogenomic analyses firmly place Myxozoa in Cnidaria.  

PubMed

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

2013-01-30

225

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

226

Triterpenoid saponins from the root of Anemone tomentosa.  

PubMed

Three new triterpenoid saponins, tomentoside A (1), B (2) and C (3), along with four known saponins (4-7) were isolated from the root of Anemone tomentosa. The structures of the new compounds were elucidated as 3-O-?-D-ribopyranosyl-(1?3)-?-L-rhamnopyranosyl-(1?2)-[?-D-glucopyranosyl-(1?4)]-?-L-arabinopyranosyl hederagenin 28-O-?-L-rhamnopyranosyl-(1?4)-?-D-glucopyranosyl-(1?6)-?-D-glucopyranoside (1), 3-O-?-D-ribopyranosyl-(1?3)-?-L-rhamnopyranosyl-(1?2)-[?-D-glucopyranosyl-(1?4)]-?-D-xylopyranosyl hederagenin 28-O-?-L-rhamnopyranosyl-(1?4)-?-D-glucopyranosyl-(1?6)-?-D-glucopyranoside (2) and 3-O-?-D-galactopyranosyl-(1?3)-?-L-rhamnopyranosyl-(1?2)-?-D-xylopyranosyl oleanolic acid 28-O-?-L-rhamnopyranosyl-(1?4)-?-D-glucopyranosyl-(1?6)-?-D-glucopyranoside (3) on the basis of chemical and spectral evidence. In the oligosaccharide chains of compound 3, the characteristic D-galactose residue is a rare structural feature and secondly encountered among triterpenoid saponins from Anemone. PMID:22391801

Wang, Yi; Kang, Wei; Hong, Liang-jian; Hai, Wen-li; Wang, Xiao-yang; Tang, Hai-feng; Tian, Xiang-rong

2012-03-06

227

CHARACTERIZATION OF MICROSATELLITE LOCI IN THE WIDELY INTRODUCED ESTUARINE ANEMONE NEMATOSTELLA VECTENSIS  

EPA Science Inventory

We characterized ten polymorphic microsatellite loci from Nematostella vectensis, a burrowing anemone recently introduced to estuaries along the Pacific coast of North America and the southeast coast of England. Preliminary results indicate high variability and significant depar...

228

Is dimethylsulfoniopropionate (DMSP) produced by the symbionts or the host in an anemone–zooxanthella 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

229

Ecological speciation in anemone-associated snapping shrimps (Alpheus armatus species complex).  

PubMed

Divergent natural selection driven by competition for limited resources can promote speciation, even in the presence of gene flow. Reproductive isolation is more likely to result from divergent selection when the partitioned resource is closely linked to mating. Obligate symbiosis and host fidelity (mating on or near the host) can provide this link, creating ideal conditions for speciation in the absence of physical barriers to dispersal. Symbiotic organisms often experience competition for hosts, and host fidelity ensures that divergent selection for a specific host or host habitat can lead to speciation and strengthen pre-existing reproductive barriers. Here, we present evidence that diversification of a sympatric species complex occurred despite the potential for gene flow and that partitioning of host resources (both by species and by host habitat) has contributed to this diversification. Four species of snapping shrimps (Alpheus armatus, A. immaculatus, A. polystictus and A. roquensis) are distributed mainly sympatrically in the Caribbean, while the fifth species (A. rudolphi) is restricted to Brazil. All five species are obligate commensals of sea anemones with a high degree of fidelity and ecological specificity for host species and habitat. We analysed sequence data from 10 nuclear genes and the mitochondrial COI gene in 11-16 individuals from each of the Caribbean taxa and from the only available specimen of the Brazilian taxon. Phylogenetic analyses support morphology-based species assignments and a well-supported Caribbean clade. The Brazilian A. rudolphi is recovered as an outgroup to the Caribbean taxa. Isolation-migration coalescent analysis provides evidence for historical gene flow among sympatric sister species. Our data suggest that both selection for a novel host and selection for host microhabitat may have promoted diversification of this complex despite gene flow. PMID:23859595

Hurt, C; Silliman, K; Anker, A; Knowlton, N

2013-07-16

230

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

231

Influence of host anemone (Stichodactyla haddoni, saville-kent, 1893) locomotion on its resident anemonefish reproduction.  

PubMed

Anemonefish are found commonly in reef habitats and they select only limited anemone species to exist their life. This study describes the movement of anemone, Stichodactyla haddoni and its impact on the reproduction of anemonefishes in captivity. The anemone movement was found to be creeping and in straight-line between successive positions (based on overlay mapping). The distance traveled by the host with (60%) and without substrate (20%) varied significantly (P<0.05) at a random direction. Spawning interval of the resident fish (3-4 days) increased significantly to 8-12 days (P<0.001) because of anemone mobility. Furthermore, host locomotion affected the embryonic development of harbored fish clutches. Percentage of egg maturity (3.5-35.3%) showed an exponential decrease with increase in the distance of substrate from the clutches, from 98 to 100% in the absence of host mobility to 3.5-35% with movement of >60cm. This study concludes that the sedentary habitat would enhance the reproduction value of the harbored fish. Further, in captivity providing with a substrate, supplying regular feed and good light intensity could prevent anemone migration and its implications on the reproductive success of the anemonefish. PMID:23701833

Balamurugan, R J; Kumar, T T Ajith; Balasubramanian, T

2013-04-20

232

Biological community and sediment fatty acids associated with the deep-sea whale skeleton at the Torishima Seamount  

Microsoft Academic Search

A whale skeleton was discovered on the flat-topped summit of the Torishima Seamount, 4037 m deep, northwest Pacific Ocean, during a dive by the submersibleShinkai 6500 in 1992. The skeleton was encrusted with mytilid mussels and harbored benthic animals such as galatheid crabs, echinoderms, sea anemones, and unidentifiable tube worms. The whale skeleton was revisited in 1993. Sediment samples were

Takeshi Naganuma; Hideki Wada; Kantaro Fujioka

1996-01-01

233

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 Alfvén 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

234

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

235

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, René; Galli, Roberta; Stelling, Allison L; Sivkov, Viktor N; Petrova, Olga V; Vyalikh, Denis; Kummer, Kurt; Molodtsov, Serguei L; Nowak, Dorota; Nowak, Jakub; Ehrlich, Hermann

2012-04-21

236

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.

2008-01-01

237

Endobiotic bacteria and their pathogenic potential in cnidarian tentacles  

Microsoft Academic Search

Endobiotic bacteria colonize the tentacles of cnidaria. This paper provides first insight into the bacterial spectrum and\\u000a its potential of pathogenic activities inside four cnidarian species. Sample material originating from Scottish waters comprises\\u000a the jellyfish species Cyanea capillata and C. lamarckii, hydrozoa Tubularia indivisa and sea anemone Sagartia elegans. Mixed cultures of endobiotic bacteria, pure cultures selected on basis of

Christian Schuett; Hilke Doepke

2010-01-01

238

Internal and external relationships of the Cnidaria: implications of primary and predicted secondary structure of the 5'-end of the 23S-like rDNA.  

PubMed Central

Since both internal (class-level) and external relationships of the Cnidaria remain unclear on the basis of analyses of 18S and (partial) 16S rDNA sequence data, we examined the informativeness of the 5'-end of the 23S-like rDNA. Here we describe analyses of both primary and predicted secondary structure data for this region from the ctenophore Bolinopsis sp., the placozoan Trichoplax adhaerens, the sponge Hymeniacidon heliophila, and representatives of all four cnidarian classes. Primary sequence analyses clearly resolved the Cnidaria from other lower Metazoa, supported sister group relationships between the Scyphozoa and Cubozoa and between the Ctenophora and the Placozoa, and confirmed the basal status of the Anthozoa within the Cnidaria. Additionally, in the ctenophore, placozoan and sponge, non-canonical base pairing is required to maintain the secondary structure of the B12 region, whereas amongst the Cnidaria this is not the case. Although the phylogenetic significance of this molecular character is unclear, our analyses do not support the close relationship between Cnidaria and Placozoa suggested by previous studies.

Odorico, D M; Miller, D J

1997-01-01

239

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

240

PHOTOSYNTHETIC PRODUCTION BY THE CORAL REEF ANEMONE, LEBRUNIA CORALLIGENS WILSON, AND BEHAVIORAL CORRELATES OF TWO NUTRITIONAL STRATEGIES  

Microsoft Academic Search

The coral reef anemone Lebrunia coraiigens Wilson bears, in addition to its lanceolate, feeding tentacles, lobate pseudotentacles which are shown to be photo synthetic organs. Anemones exposed to light demonstrate a net oxygen production and, when incubatedin NaH'4C03 in the light, incorporate‘¿?4C into the zooxanthellae and animal tissue. Diurnalrhythmsofpseudotentacleexpansionand contractionareunderthe control of ambient light but are modified by the animal's

JOHN B. LEWIS

1984-01-01

241

Gross and microscopic morphology of lesions in Cnidaria from Palmyra Atoll, Central Pacific  

USGS Publications Warehouse

We conducted gross and microscopic characterizations of lesions in Cnidaria from Palmyra Atoll, Central Pacific. We found growth anomalies (GA) to be the most commonly encountered lesion. Cases of discoloration and tissue loss were rare. GAs had a focal or multi-focal distribution and were predominantly nodular, exophytic, and umbonate. In scleractinians, the majority of GAs manifested as hyperplasia of the basal body wall (52% of cases), with an associated absence or reduction of polyp structure (mesenteries and filaments, actinopharynx and tentacles), and depletion of zooxanthellae in the gastrodermis of the upper body wall. In the soft corals Sinularia sp. and Lobophytum sp., GAs exclusively manifested as prominent hyperplasia of the coenenchyme with an increased density of solenia. In contrast to scleractinians, soft coral GAs displayed an inflammatory and necrotizing component with marked edema of the mesoglea, accompanied by infiltrates of variably-sized granular amoebocytes. Fungi, algae, sponges, and Crustacea were present in some scleractinian GAs, but absent in soft coral GAs. Fragmentation of tissues was a common finding in Acropora acuminata and Montipora cf. dilatata colonies with tissue loss, although no obvious causative agents were seen. Discoloration in the zoanthid, Palythoa tuberculosa, was found to be the result of necrosis, while in Lobophytum sp. discoloration was the result of zooxanthellar depletion (bleaching). Soft corals with discoloration or tissue loss showed a marked inflammatory response, however no obvious causative organisms were seen. Lesions that appeared similar at the gross level were revealed to be distinct by microscopy, emphasizing the importance of histopathology.

Williams, Gareth J.; Work, Thierry M.; Aeby, Greta S.; Knapp, Ingrid S.; Davy, Simon K.

2011-01-01

242

Pollination ecology of the red Anemone coronaria (Ranunculaceae): honeybees may select for early flowering  

Microsoft Academic Search

Large red bowl-shaped flowers characterize the Mediterranean “poppy guild” plants, and were suggested to reflect convergence for beetle pollination. However, the earliest-blooming species in this guild, Anemone coronaria (L.), starts flowering about a month before beetle emergence. Early flowering can be adaptive if the plant receives sufficient pollination by other means during this period. We investigated A. coronaria’s pollination prospects

Tamar Keasar; Avi Shmida; Asaph Zylbertal

2008-01-01

243

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

244

A new species of antipatharian coral (Cnidaria: Anthozoa: Antipatharia: Schizopathidae) from the Pacific coast of Costa Rica  

SciTech Connect

A new species of black coral, Aphanipathes colombiana (Cnidaria:Antipatharia) from the Caribbean coast of Colombia is described. The species forms small flabellate colonies with anisomorphic polypar spines. It is morphologically similar to the western Atlantic species A. thyoides (Pourtales) but its hypostomal polypar spines are not reduced in size. The new species also resembles the Indo-Pacific species A. reticulata van Pesch but it has smooth-surfaced polypar spines, whereas in A. reticulata these spines have small tubercles on their surface

Opresko, Dennis M [ORNL; Breedy, Odalisca [University of Costa Rica

2010-09-01

245

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

246

Effects of Trypsin and Thioglycollate upon the Nematocysts of the Sea Anemone  

Microsoft Academic Search

ALL the hypotheses relating to the discharging mechanism of the stinging capsules of Coelenterates hitherto seem to postulate that an enhanced intracapsular pressure forces out the stinging thread. However, the elongated (about 50 µ) ellipsoid type of nematocysts (`penicilli' of Stephenson1), which can be isolated in quantity from the acontial filaments of Diadumene luciae in the form of a dense

T. M. Yanagita; Tuneyo Wada

1954-01-01

247

Cytotoxicity of the nematocyst venom from the sea anemone Aiptasia mutabilis  

Microsoft Academic Search

Crude extracts of the coelenterate Aiptasia mutabilis (Anthozoa, Aiptasiidae) nematocysts have been tested for their cytotoxicity of Vero and HEp-2 cells monolayers. The results indicate that the nematocyte venom contains one or more toxins with an extremely powerful cytolytic activity. An extract containing the equivalent of as little as 0.6 nematocysts\\/?L is sufficient to induce significant cellular necrosis, and IC50

Angela Marino; Vincenza Valveri; Carmelo Muià; Rosalia Crupi; Gianluca Rizzo; Giovanni Musci; Giuseppa La Spada

2004-01-01

248

Diffusion Limitation and Hyperoxic Enhancement of Oxygen Consumption in Zooxanthellate Sea Anemones, Zoanthids, and Corals  

Microsoft Academic Search

Absfract. Depending on their size and morphology, anthozoan polyps and colonies may be diffusion-limited in their oxygen consumption, even under well-stirred, air-saturated conditions. This is indicated by an en hancement of oxygen consumption under steady-state hyperoxic conditions that simulate the levels of 02 pro duced photosynthetically by zooxanthellae in the hosts' tissues. Such hyperoxia in the tissues of zooxanthellate species

J. MALCOLM SHICK

1990-01-01

249

Toxicity of jellyfish and sea-anemone venoms on cultured V79 cells  

Microsoft Academic Search

Cnidarian toxins exert an influence on human activities and public health. The cytotoxicity of crude toxins (nematocyst and surrounding tissue venom) of Aequorea aequorea, Rhizostoma pulmo and Anemonia sulcata was assessed on V79 cells. Rhizostoma pulmo and Anemonia sulcata crude venoms showed remarkable cytotoxicity and killed all treated cells at highest tested concentration within 2 and 3 hr, respectively. Aequorea

A. Carli; S. Bussotti; G. L. Mariottini; L. Robbiano

1996-01-01

250

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

251

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

252

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

253

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

254

Protection of a hermit crab by its symbiotic sea anemone Calliactis tricolor  

Microsoft Academic Search

Zusammenfassung Experimenteller Nachweis, dass Einsiedlerkrebse,Pagurus pollicaris, mit symbiontischer Seeanemone,Calliactis tricolor, anf ihrer Schale vom natürlichen Feind der Krabbe,Calappa flammea, weitgehend gemieden werden.

R. B. McLean; R. N. Mariscal

1973-01-01

255

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

256

Biodiversity of the white coral bank off Cape Santa Maria di Leuca (Mediterranean Sea): An update  

NASA Astrophysics Data System (ADS)

The biodiversity of the Santa Maria di Leuca (SML) coral bank is summarized and its description is updated using data collected by means of underwater video systems, benthic samplers and fishing gears. A total of 222 living species have been recorded within the coral bank area in the depth range 280-1121 m. The most abundant benthic taxa recorded are Porifera (36 species) followed by Mollusca (35) and Cnidaria (31). The scleractinian corals Madrepora oculata and Lophelia pertusa are the main colonial species in the structure of the SML bank. Annelida, Crustacea and Bryozoa have been found with 24, 23 and 19 species, respectively. A total of 40 species of demersal fish have been recorded. Other faunal taxa were found with small numbers of species. One hundred and thirty-five species are new for the SML bank, 31 of which represent new records for the north-western Ionian Sea (2 Porifera, 17 Cnidaria, 1 Mollusca, 3 Annelida, 2 Crustacea, 4 Bryozoa and 4 Echinodermata). The finding of the annelid Harmothoë vesiculosa represents the first record for the Mediterranean Sea. The SML coral bank represents a biodiversity "hot-spot" on the bathyal bottoms of the Mediterranean Sea.

Mastrototaro, F.; D'Onghia, G.; Corriero, G.; Matarrese, A.; Maiorano, P.; Panetta, P.; Gherardi, M.; Longo, C.; Rosso, A.; Sciuto, F.; Sanfilippo, R.; Gravili, C.; Boero, F.; Taviani, M.; Tursi, A.

2010-03-01

257

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

258

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

259

A new species of Hormathia (Actiniaria, Hormathiidae) from the eastern Weddell Sea, Antarctica  

NASA Astrophysics Data System (ADS)

A new species of sea anemone in the genus Hormathia, is described and illustrated based on forty-two specimens collected during the Polarstern cruises ANT XV/3 and ANT XVII/3 in the Weddell Sea. The main features of the new taxon are the crown of flattened and hooked tubercles at the distal end of the scapus, the regular arrangement of pointed tubercles along the column and the cnidom. The new species shares the pointed tubercles, at least in the upper part of the scapus, with two other species of Hormathia in the southern hemisphere: Hormathia spinosa Hertwig 1882 and H. pectinata Hertwig 1882

Rodríguez, Estefanía; López-González, Pablo

2001-04-01

260

DNA sequences of the mitochondrial COI gene have low levels of divergence among deep-sea octocorals (Cnidaria: Anthozoa)  

Microsoft Academic Search

We are analyzing genetic diversity in deep-seamount octocorals with the ultimate goal of studying the effect of retention and dispersal of larvae on genetic population structure. Here we report on the sequence diversity of the mitochondrial cytochrome oxidase I (COI) gene among 11 species. Uncorrected pairwise sequence divergences ranged from 0.4–10.3% for comparisons among species spanning the intrageneric to interordinal

Scott C. France; Loretta L. Hoover

2002-01-01

261

Substrate choice and settlement preferences of planula larvae of five Scyphozoa (Cnidaria) from German Bight, North Sea  

Microsoft Academic Search

The settlement behaviour of planula larvae and their development to young polyps was investigated in laboratory experiments\\u000a in five scyphozoan species [Aurelia aurita (L.), Cyanea capillata (L.), Cyanea lamarckii Péron and Leseur, Chrysaora hysoscella (L.), and Rhizostoma octopus (L.)]. The undersides of settling plates were strongly preferred for settlement. Shells, the only natural substrate type\\u000a offered, were less attractive than

Sabine Holst; Gerhard Jarms

2007-01-01

262

Oleanane-type saponins from Anemone taipaiensis and their cytotoxic activities.  

PubMed

Phytochemical investigation of the n-BuOH extract of the rhizomes of Anemone taipaiensis led to the isolation of three new oleanane-type triterpenoid saponins (1-3), together with four known saponins (4-7). Their structures were elucidated on the basis of spectroscopic analysis and chemical derivatization. All the compounds were isolated for the first time from A. taipaiensis. The cytotoxicity of these compounds was evaluated in five human cancer cell lines including A549 (lung carcinoma), HeLa (cervical carcinoma), HepG2 (hepatocellular carcinoma), HL-60 (promyelocytic leukemia), and U87MG (glioblastoma). The monodesmosidic saponin 4 exhibited cytotoxic activity toward all cancer cell lines, with IC50 values ranging from 6.42 to 18.16 ?M. In addition, the bisdesmosidic saponins 1 and 7 showed selective cytotoxicity against the U87MG cells. PMID:23774664

Wang, Xiaoyang; Zhang, Wei; Gao, Kai; Lu, Yunyang; Tang, Haifeng; Sun, Xiaoli

2013-06-15

263

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

264

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-1±14.7 (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

265

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.

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

2008-01-01

266

Calcium and cytoskeleton signaling during cell volume regulation in isolated nematocytes of Aiptasia mutabilis (Cnidaria: Anthozoa)  

Microsoft Academic Search

Cell volume regulation has not been completely clarified in Coelenterates. The present investigation focuses on cell volume regulation under anisosmotic conditions, both hyposmotic and hypertonic, and on the underlying signals in nematocytes isolated from the Coelenterate Aiptasia mutabilis living in sea water. Nematocytes, once isolated from acontia, that were submitted to either hyposmotic (35%) and hypertonic shock (45%) show RVD

A. Marino; G. La Spada

2007-01-01

267

A new species of hydra (Cnidaria: Hydrozoa: Hydridae) and molecular phylogenetic analysis of six congeners from China.  

PubMed

A new species of genus Hydra (Cnidaria: Hydrozoa: Hydridae), Hydra shenzhensis sp. nov. from Guangdong Province, China, is described and illustrated. Most polyps have five tentacles. Column length reaches 11 mm when relaxed. Buds do not acquire tentacles synchronously. Stenotele is broad and pyriform in shape, 1.2 times as long as its width. Holotrichous isorhiza is asymmetrical and slender (more than 2.7 times as long as its width), with transverse and slanting coils. Atrichous isorhiza is long, resembling a melon-seed in shape. Desmoneme is asymmetrically pyriform in shape. The new species, belonging to the vulgaris group, is dioecious; sexual reproduction was found to occur mostly during November and December under conditions of dense culture or food shortage. Two to thirteen testes, cone-like shape with papilla, formed beneath the tentacles. One to three ovaries, with an egg cup, milky white in color, formed on body column. Ninety percent of individuals developed only one ovum. On a mother polyp, a fertilized ovum developed an embryonic theca covering its surface. The embryotheca is brown, with a spine-like structure, covering a layer of transparent, membrane-like material. For phylogenetic analysis, the mitochondrial cytochrome oxidase subunit I gene (COI) of six hydra species collected from China was amplified by polymerase chain reaction (PCR) and sequenced. Morphological characters in combination with molecular evidence support the hydra described here as a new species. PMID:23215978

Wang, An-Tai; Deng, Li; Liu, Hong-Tao

2012-12-01

268

Sea Education Association (SEA)  

NSDL National Science Digital Library

The Sea Education Association (SEA) in Woods Hole, MA provides undergraduates with an opportunity to participate in an academic study-abroad program called the SEA Semester. The program combines intensive research in the areas of oceanography, maritime studies, and nautical science with hands-on experience aboard a traditional sailing ship. Piloting, celestial navigation, and practical seamanship are learned together with oceanographic sampling techniques and marine laboratory procedures. Critical thinking, problem-solving, team-building and leadership skills are emphasized throughout the program. SEA Semester is appropriate for students in marine biology, geology and physical science, environmental studies, American studies, and most other areas within the liberal arts and sciences. Academic credit for SEA Semester is obtained through Boston University.

269

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

270

Deep-water Scleractinia (Cnidaria: Anthozoa): current knowledge of reproductive processes  

Microsoft Academic Search

Little is known of the basic biology and ecology of the numerous species of deep-water scleractinians found in all the world’s oceans. Of all the biological processes, reproduction is the most fundamental. Without knowledge of a species’ reproduction, we know little about how they survive both the environment that is the deep-sea, and the increasing anthropogenic effects of man’s exploration

Rhian G. Waller; Woods Hole

271

First record of sympagic hydroids (Hydrozoa, Cnidaria) in Arctic coastal fast ice  

Microsoft Academic Search

We report on the first record of interstitial cnidarians in sea ice. Ice core samples were collected during eight field periods\\u000a between February 2003 and June 2006 in the coastal fast ice off Barrow, Alaska (71°N, 156°W) at four locations. A total of\\u000a 194 solitary, small (0.2–1.1 mm) elongated specimens of a previously unknown interstitial hydroid taxon were found. By cnidome

Bodil A. Bluhm; Rolf Gradinger; Stefano Piraino

2007-01-01

272

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

2013-08-11

273

Structural and functional characterization of haemocyanin from the anemone hermit crab Dardanus calidus.  

PubMed

Oxygen-binding to haemocyanin (Hc) is generally an exothermic process, with overall enthalphy of oxygenation varying from species to species. A number of crustacean Hcs showed a null or reduced enthalphy of oxygenation, among others, the anomuran Pagurus bernhardus and Paralithodes camtscaticae possess a completely temperature-independent oxygen-binding in a wide range of temperature and pH. Functional analysis performed on purified native, hexameric and dodecameric Hc forms of the anemone hermit crab Dardanus calidus allowed to calculate the enthalphy of oxygenation values that resulted equal to -36.2, -33.8 and -26.8 kJ/mol, respectively. Thus, the temperature sensitivity of oxygen binding of D. calidus Hc is in contrast with the temperature independence reported for P. bernhardus and P. camtscaticae, suggesting a high Hc functional heterogeneity within Anomura. Functional characterization also evidenced a strong oxygen affinity modulation by protons (DeltalogP(50)/DeltapH = -0.97) and lactate [DeltalogP(50)/Deltalog(lactate) = -0.38], and a significant decrease in cooperativity by physiological concentration of lactate (n(50) from 2.8 to 1.7 at pH 7.5). PMID:17984120

Podda, Gabriella; Manconi, Barbara; Olianas, Alessandra; Pellegrini, Mariagiuseppina; Messana, Irene; Mura, Marco; Castagnola, Massimo; Giardina, Bruno; Sanna, Maria Teresa

2007-11-04

274

A latitudinal gradient in seed nutrients of the forest herb Anemone nemorosa.  

PubMed

The nutrient concentration in seeds determines many aspects of potential success of the sexual reproductive phase of plants, including the seed predation probability, efficiency of seed dispersal and seedling performance. Despite considerable research interest in latitudinal gradients of foliar nutrients, a similar gradient for seeds remains unexplored. We investigated a potential latitudinal gradient in seed nutrient concentrations within the widespread European understorey forest herb Anemone nemorosa L. We sampled seeds of A. nemorosa in 15 populations along a 1900-km long latitudinal gradient at three to seven seed collection dates post-anthesis and investigated the relative effects of growing degree-hours >5 °C, soil characteristics and latitude on seed nutrient concentrations. Seed nitrogen, nitrogen:phosphorus ratio and calcium concentration decreased towards northern latitudes, while carbon:nitrogen ratios increased. When taking differences in growing degree-hours and measured soil characteristics into account and only considering the most mature seeds, the latitudinal decline remained particularly significant for seed nitrogen concentration. We argue that the decline in seed nitrogen concentration can be attributed to northward decreasing seed provisioning due to lower soil nitrogen availability or greater investment in clonal reproduction. This pattern may have large implications for the reproductive performance of this forest herb as the degree of seed provisioning ultimately co-determines seedling survival and reproductive success. PMID:21489100

De Frenne, P; Kolb, A; Graae, B J; Decocq, G; Baltora, S; De Schrijver, A; Brunet, J; Chabrerie, O; Cousins, S A O; Dhondt, R; Diekmann, M; Gruwez, R; Heinken, T; Hermy, M; Liira, J; Saguez, R; Shevtsova, A; Baskin, C C; Verheyen, K

2010-11-15

275

Mitochondrial genome of the moon jelly Aurelia aurita (Cnidaria, Scyphozoa): A linear DNA molecule encoding a putative DNA-dependent DNA polymerase.  

PubMed

The 16,937-nuceotide sequence of the linear mitochondrial DNA (mt-DNA) molecule of the moon jelly Aurelia aurita (Cnidaria, Scyphozoa) - the first mtDNA sequence from the class Scypozoa and the first sequence of a linear mtDNA from Metazoa - has been determined. This sequence contains genes for 13 energy pathway proteins, small and large subunit rRNAs, and methionine and tryptophan tRNAs. In addition, two open reading frames of 324 and 969 base pairs in length have been found. The deduced amino-acid sequence of one of them, ORF969, displays extensive sequence similarity with the polymerase [but not the exonuclease] domain of family B DNA polymerases, and this ORF has been tentatively identified as dnab. This is the first report of dnab in animal mtDNA. The genes in A. aurita mtDNA are arranged in two clusters with opposite transcriptional polarities; transcription proceeding toward the ends of the molecule. The determined sequences at the ends of the molecule are nearly identical but inverted and lack any obvious potential secondary structures or telomere-like repeat elements. The acquisition of mitochondrial genomic data for the second class of Cnidaria allows us to reconstruct characteristic features of mitochondrial evolution in this animal phylum. PMID:16945488

Shao, Zhiyong; Graf, Shannon; Chaga, Oleg Y; Lavrov, Dennis V

2006-07-18

276

Differential Gene Expression in the Siphonophore Nanomia bijuga (Cnidaria) Assessed with Multiple Next-Generation Sequencing Workflows  

PubMed Central

We investigated differential gene expression between functionally specialized feeding polyps and swimming medusae in the siphonophore Nanomia bijuga (Cnidaria) with a hybrid long-read/short-read sequencing strategy. We assembled a set of partial gene reference sequences from long-read data (Roche 454), and generated short-read sequences from replicated tissue samples that were mapped to the references to quantify expression. We collected and compared expression data with three short-read expression workflows that differ in sample preparation, sequencing technology, and mapping tools. These workflows were Illumina mRNA-Seq, which generates sequence reads from random locations along each transcript, and two tag-based approaches, SOLiD SAGE and Helicos DGE, which generate reads from particular tag sites. Differences in expression results across workflows were mostly due to the differential impact of missing data in the partial reference sequences. When all 454-derived gene reference sequences were considered, Illumina mRNA-Seq detected more than twice as many differentially expressed (DE) reference sequences as the tag-based workflows. This discrepancy was largely due to missing tag sites in the partial reference that led to false negatives in the tag-based workflows. When only the subset of reference sequences that unambiguously have tag sites was considered, we found broad congruence across workflows, and they all identified a similar set of DE sequences. Our results are promising in several regards for gene expression studies in non-model organisms. First, we demonstrate that a hybrid long-read/short-read sequencing strategy is an effective way to collect gene expression data when an annotated genome sequence is not available. Second, our replicated sampling indicates that expression profiles are highly consistent across field-collected animals in this case. Third, the impacts of partial reference sequences on the ability to detect DE can be mitigated through workflow choice and deeper reference sequencing.

Siebert, Stefan; Robinson, Mark D.; Tintori, Sophia C.; Goetz, Freya; Helm, Rebecca R.; Smith, Stephen A.; Shaner, Nathan; Haddock, Steven H. D.; Dunn, Casey W.

2011-01-01

277

Comparison of morphological and genetic analyses reveals cryptic divergence and morphological plasticity in Stylophora (Cnidaria, Scleractinia)  

NASA Astrophysics Data System (ADS)

A combined morphological and genetic study of the coral genus Stylophora investigated species boundaries in the Gulf of Aden, Yemen. Two mitochondrial regions, including the hypervariable IGS9 spacer and the control region, and a fragment of rDNA were used for phylogenetic analysis. Results were compared by multivariate analysis on the basis of branch morphology and corallite morphometry. Two species were clearly discriminated by both approaches. The first species was characterised by small corallites and a low morphological variability and was ascribed to a new geographical record of Stylophora madagascarensis on the basis of its phylogenetic distinction and its morphological similarity to the type material. The second species was characterised by larger corallite size and greater morphological variability and was ascribed to Stylophora pistillata. The analysis was extended to the intrageneric level for other S. pistillata populations from the Red Sea and the Pacific Ocean. Strong internal divergence was evident in the genus Sty lophora. S. pistillata populations were split into two highly divergent Red Sea/Gulf of Aden and western Pacific lineages with significant morphological overlap, which suggests they represent two distinct cryptic species. The combined use of morphological and molecular approaches, so far proved to be a powerful tool for the re-delineation of species boundaries in corals, provided novel evidence of cryptic divergence in this group of marine metazoans.

Stefani, Fabrizio; Benzoni, F.; Yang, S.-Y.; Pichon, M.; Galli, P.; Chen, C. A.

2011-12-01

278

Stycholysin II, a cytolysin from the sea anemone Stichodactyla helianthus promotes higher hemolysis in aged red blood cells  

Microsoft Academic Search

We have investigated the relationship between the status of red blood cells (RBCs) and their susceptibility to toxin sticholysin II (StII) hemolytic activity; we have evaluated this effect in different RBC ensembles, comprising young and old cells, and in cells partially damaged by their pre-exposition to a free radical source. Upon action of StII, young cell populations are less prone

Gloria Celedón; Gustavo González; Daniela Barrientos; Jose Pino; Fabiola Venegas; Eduardo A. Lissi; Carmen Soto; Diana Martinez; Carlos Alvarez; María Eliana Lanio

2008-01-01

279

Nutrient transfer in a marine mutualism: patterns of ammonia excretion by anemonefish and uptake by giant sea anemones  

Microsoft Academic Search

Many symbioses involve multiple partners in complex, multi-level associations, yet little is known concerning patterns of\\u000a nutrient transfer in multi-level marine mutualisms. We used the anemonefish symbiosis as a model system to create a balance\\u000a sheet for nitrogen production and transfer within a three-way symbiotic system. We quantified diel patterns in excretion of\\u000a ammonia by anemonefish and subsequent absorption by

Modi Roopin; Raymond P. Henry; Nanette E. Chadwick

2008-01-01

280

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

281

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

Microsoft Academic Search

Background: Membrane pore–forming 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; Dušan Turk

2001-01-01

282

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

283

Imaging intracellular pH in a reef coral and symbiotic anemone  

PubMed Central

The challenges corals and symbiotic cnidarians face from global environmental change brings new urgency to understanding fundamental elements of their physiology. Intracellular pH (pHi) influences almost all aspects of cellular physiology but has never been described in anthozoans or symbiotic cnidarians, despite its pivotal role in carbon concentration for photosynthesis and calcification. Using confocal microscopy and the pH sensitive probe carboxy SNARF-1, we mapped pHi in short-term light and dark-incubated cells of the reef coral Stylophora pistillata and the symbiotic anemone Anemonia viridis. In all cells isolated from both species, pHi was markedly lower than the surrounding seawater pH of 8.1. In cells that contained symbiotic algae, mean values of pHi were significantly higher in light treated cells than dark treated cells (7.41 ± 0.22 versus 7.13 ± 0.24 for S. pistillata; and 7.29 ± 0.15 versus 7.01 ± 0.27 for A. viridis). In contrast, there was no significant difference in pHi in light and dark treated cells without algal symbionts. Close inspection of the interface between host cytoplasm and algal symbionts revealed a distinct area of lower pH adjacent to the symbionts in both light and dark treated cells, possibly associated with the symbiosome membrane complex. These findings are significant developments for the elucidation of models of inorganic carbon transport for photosynthesis and calcification and also provide a cell imaging procedure for future investigations into how pHi and other fundamental intracellular parameters in corals respond to changes in the external environment such as reductions in seawater pH.

Venn, A. A.; Tambutte, E.; Lotto, S.; Zoccola, D.; Allemand, D.; Tambutte, S.

2009-01-01

284

Small-scale distribution of deep-sea demersal nekton and other megafauna in the Charlie-Gibbs Fracture Zone of the Mid-Atlantic Ridge  

NASA Astrophysics Data System (ADS)

Videotapes from manned submersibles diving in the area of the Charlie-Gibbs Fracture Zone of the Mid-Atlantic Ridge were used to investigate the distribution of fishes, large crustaceans, epifaunal and sessile organisms, and environmental features along a series of transects. Submersibles MIR 1 and MIR 2 conducted paired dives in an area of mixed sediment and rock (beginning depth ca. 3000 m) and on a large pocket of abyssal-like sediments (depth ca. 4000 m). In the shallower area, the submersibles passed over extremely heterogeneous terrain with a diversity of nekton, epifaunal forms and sessile forms. In the first pair of dives, MIR 1 rose along the Mid-Atlantic Ridge from 3000 to 1700 m, while MIR 2 remained near the 3000 m isobath. Nekton seen in these relatively shallow dives included large and small macrourids (genus Coryphaenoides), shrimp (infraorder Penaeidea), Halosauropsis macrochir, Aldrovandia sp., Antimora rostrata, and alepocephalids. The last two were more characteristic of the upper areas of the slope reached by MIR 1, as it rose along the Mid-Atlantic Ridge to depths less than 3000 m. Distributions of some forms seemed associated with depth and/or the presence of hard substrate. Sessile organisms such as sponges and large cnidaria were more likely to be found in rocky areas. The second pair of dives occurred in an abyssal area and the submersibles passed over sediment-covered plains, with little relief and many fewer countable organisms and features. The most evident of these were holes, mounds, small cerianthid anemones, small macrourids and the holothurian Benthodytes sp. A few large macrourids and shrimp also were seen in these deeper dives, as well as squat lobsters ( Munidopsis sp.). Sponges and larger cnidaria were mostly associated with a few small areas of rocky substrate. Holes and mounds showed distributions suggesting large-scale patterning. Over all dives, most sessile and epifaunal forms showed clumped distributions. However, large holothurians and large nekton often had distributions not significantly different from random.

Felley, J. D.; Vecchione, M.; Wilson, R. R., Jr.

2008-01-01

285

The biology and ecology of black corals (Cnidaria: Anthozoa: Hexacorallia: Antipatharia).  

PubMed

Antipatharians, commonly known as black corals, are treasured by many cultures for medicinal purposes and to produce jewellery. Despite their economic and cultural importance, very little is known about the basic biology and ecology of black corals because most species inhabit deeper-water environments (>50m) which are logistically challenging to study. There has been a recent increase of studies focusing on antipatharians; however, these have not yet been comprehensively reviewed. This literature review seeks to summarize the available information on the biology and ecology of antipatharians. Although black corals occur throughout all oceans and from subtidal to abyssal depths, they are particularly common in tropical and subtropical regions at depths below 50m. Antipatharians are generally found in areas with hard substrates, low-light and strong currents. Under favourable conditions, some black coral species form dense aggregations to the point of becoming ecologically dominant. Zooplankton appears to be the major component of the diet of black corals, which feed as suspension feeders and use mucus and nematocysts to capture their prey. Previously categorized as azooxanthellate corals, recent research has revealed that many antipatharians appear capable of harbouring symbionts, but unlike other corals, dinoflagellates of the genus Symbiodinium are generally not important to the nutrition of black corals. Antipatharians reproduce through both sexual and asexual processes. In general, polyps and colonies are gonochoric, with fertilization and larval development likely occurring externally; however, to date antipatharian larvae have only been observed for a single species. Antipatharians are generally slow-growing and long-lived organisms with maximum longevities ranging from decades to millennia. Black corals are more abundant with depth, a pattern which has been hypothesized to avoid competition with obligate photosynthetic fauna. Additionally, antipatharians may compete for space by using sweeper tentacles and secondary metabolites. With the exception of a few predators such as gastropods and green sea turtles, antipatharians appear to be little impacted by predation. Like other corals, antipatharians can be habitat engineers of importance to a myriad of associated organisms including arthropods, annelids, echinoderms, mollusks, sponges and cnidarians, several of which are adapted to live exclusively on black corals. Given that most black coral species inhabit remote environments, our understanding of these organisms will depend on our ability to effectively sample and study them. Future collections, particularly in deeper waters (>50m), will be needed to determine whether antipatharian species have limited biogeographical distributions or whether this has simply been an artefact of low sampling efforts away from population centres and taxonomic uncertainties within this group. Additionally, biological and ecological studies require increased sample sizes because most information is currently derived from the examination of only a handful of specimens. PMID:22877611

Wagner, Daniel; Luck, Daniel G; Toonen, Robert J

2012-01-01

286

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

287

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.

2013-01-01

288

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.

289

Sea Stars  

NSDL National Science Digital Library

At first glance, starfish, more properly called sea stars, arenât doing much of anything. In this video, Jonathanâs 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

290

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

291

Sea turtles  

Microsoft Academic Search

odern sea turtles are an important component of a wide range of tropical, temperate, and cold water marine ecosystems . Their inclusion on various lists of endangered specie s reflects past over-exploitation and the current need for better management . Today, seven or eight species of sea turtles are recognised, in two families and six genera. Adults typically migrate between

Catherine M. F. Lohmann; Kenneth J. Lohmann

2006-01-01

292

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

293

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 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. 9×108 kg, with some years showing biomasses in excess of 5×109 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 1°CSea 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.

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

2012-01-01

294

The Mitochondrial Genome of a Deep-Sea Bamboo Coral (Cnidaria, Anthozoa, Octocorallia, Isididae): Genome Structure and Putative Origins of Replication Are Not Conserved Among Octocorals  

Microsoft Academic Search

Octocoral mitochondrial (mt) DNA is subject to an exceptionally low rate of substitution, and it has been suggested that mt\\u000a genome content and structure are conserved across the subclass, an observation that has been supported for most octocorallian\\u000a families by phylogenetic analyses using PCR products spanning gene boundaries. However, failure to recover amplification products\\u000a spanning the nad4L–msh1 gene junction in

Mercer R. Brugler; Scott C. France

2008-01-01

295

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 2–3 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

296

Reproduction of Cnidaria  

Microsoft Academic Search

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 border between sexual and asexual reproduction appears to be faint. This may be due to analytical tools being in- sufficiently powerful to

Daphne Gail Fautin

2002-01-01

297

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

298

Sea Legs  

NASA Astrophysics Data System (ADS)

Forty-foot, storm-swept seas, Spitzbergen polar bears roaming vast expanses of Arctic ice, furtive exchanges of forbidden manuscripts in Cold War Moscow, the New York city fashion scene, diving in mini-subs to the sea floor hot srings, life with the astronauts, romance and heartbreak, and invading the last bastions of male exclusivity: all are present in this fast-moving, non-fiction account of one woman' fascinating adventures in the world of marine geology and oceanography.

Macdonald, Kenneth C.

299

Differences in the protein profiles of cultured and endosymbiotic symbiodinium sp. (pyrrophyta) from the anemone aiptasia pallida (anthozoa)  

SciTech Connect

One- and two-dimensional sodium dodecylsulfate-polyacrylamide gel electrophoresis and immunological analyses were used to visualize differences in polypeptides synthesized by Symbiodinium sp. from the anemone Aiptasia pallida when grown in the cultured and endosymbiotic states (freshly isolated zooxanthellae). Surprisingly, a comparison of proteins in cultured and endosymbiotic Symbiodinium sp. revealed only four major polypeptides with similar isoelectric and molecular mass characteristics. Using monospecific antibodies, we demonstrated differences in specific proteins synthesized by the dinoflagellate in the two different growth states. The dimeric, 14 kDa form of the peripheral membrane peridinin-chlorophyll a binding protein predominates under endosymbiotic conditions, whereas the monomeric, 35 kDa form predominates under the culture conditions used in this study. Antibodies to form II ribulose-1,5-bisphosphate carboxylase revealed 62 and 60 kDa forms of this protein in the alga grown as an endosymbiont and in culture, respectively. Differences in the integral membrane peridinin-chlorophyll a-c-binding proteins were also observed. These results demonstrate that there are major changes in the populations of proteins synthesized by Symbiodinium sp. in response to the conditions in hospite. Such changes may reflect a developmental switch that tailors the physiology of the alga to the conditions encountered in the endosymbiotic state. 77 refs., 6 figs.

Stochaj, W.R.; Grossman, A.R. [Carnegie Institution of Washington, Stanford, CA (United States)

1997-02-01

300

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.

301

Rising seas  

SciTech Connect

Predicting exactly how - or whether - sea level will shift in response to global warming remains a significant challenge. Scientists trained in many separate disciplines are attempting to glean answers using a variety of experimental approaches, ranging from drilling into the Antarctic ice cap to bouncing radar off the ocean from space. With such efforts, investigators have learned a great deal about how sea level has varied in the past and how it is currently changing. For example, most of these scientists agree that the ocean has been creeping upward by two millimeters a year for at least the past several decades. But determining whether a warmer climate will lead to a sudden acceleration in the rate of sea level rise remains an outstanding question. This article discusses the uncertainties, historical data, and possibilities regarding this issue.

Schneider, D.

1997-03-01

302

New taxa and revisionary systematics of alcyonacean octocorals from the Pacific coast of North America (Cnidaria, Anthozoa).  

PubMed

A taxonomic assessment of four species of octocorals from the northeastern Pacific Ocean (British Columbia to California) is provided. Included here are a new species of clavulariid stolonifieran Cryptophyton, a new species of the nephtheid soft coral Gersemia, an undetermined species of soft coral in the genus Alcyonium that has been referred in the literature by several other names, and a new genus is named for a plexaurid sea fan originally described in the Indo-Pacific genus Euplexaura. Discussions are included that compare the species to related taxa, or provide revisionary assessments. PMID:23794840

Williams, Gary C

2013-04-03

303

New taxa and revisionary systematics of alcyonacean octocorals from the Pacific coast of North America (Cnidaria, Anthozoa)  

PubMed Central

Abstract A taxonomic assessment of four species of octocorals from the northeastern Pacific Ocean (British Columbia to California) is provided. Included here are a new species of clavulariid stolonifieran Cryptophyton, a new species of the nephtheid soft coral Gersemia, an undetermined species of soft coral in the genus Alcyonium that has been referred in the literature by several other names, and a new genus is named for a plexaurid sea fan originally described in the Indo-Pacific genus Euplexaura. Discussions are included that compare the species to related taxa, or provide revisionary assessments.

Williams, Gary C.

2013-01-01

304

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

305

Saponin B, 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

2013-09-18

306

Distribución de las anémonas (Anthozoa: Actiniaria y Corallimorpharia) en el área de Santa Marta, Caribe colombiano Distribution of anemones (Anthozoa: Actiniaria and Corallimorpharia) in the area of Santa Marta  

Microsoft Academic Search

This work characterizes and compares the community of anemones at two coralline areas in the Tayrona National Natural Park, in the Colombian Caribbean, and also relates the species that were found with some important characteristics of the reef community as well as with factors that can condition its structure. The statistical tests performed allowed to differentiate two kinds of landscapes:

L. M. Barrios-Suárez; J. O. Reyes; G. R. Navas; C. B. García

2002-01-01

307

From Sea to Shining Sea  

ERIC Educational Resources Information Center

|Deep down in the depths of the sea, beautiful fish, mysterious ocean life, and unusual plants glimmer and glow in the eerie atmosphere of an ever-changing ocean. This article describes how, with this vision and a purpose in mind, three teachers pulled open classroom walls and joined forces so their second graders could create a mammoth 30 x 75"…

Scott, Beverly

2005-01-01

308

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

309

Sea Ice  

NSDL National Science Digital Library

In this resource, students will discover that there are notable differences between sea ice and fresh-water ice, such as density. In on segment, students learn that the first sign of freezing on the sea is an oily appearance of the water caused by the formation of needle-like crystals. The site explains the relationship between growth and the rate at which heat flows from the water and that the ice pack can alter its shape and dimension due to the movement of winds, currents, thermal expansion, and contraction of the ice. Types of ice described here include new ice, nilas, young ice, first-year ice, and old ice while the forms of ice covered include pancake ice, brash ice, ice cake, floe, and fast ice. The site also explains the meteorological and oceanographic factors that control the amount and movement of ice.

310

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.

311

Surficial geology of the sea floor in Long Island Sound offshore of Orient Point, New York  

USGS Publications Warehouse

The U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), and the Connecticut Department of Environmental Protection (CT DEP) are working cooperatively to map and interpret features of the sea floor along the northeastern coast of the United States. This report presents multibeam bathymetry and sidescan-sonar data obtained during NOAA survey H11446, which was conducted in a 12-km2 area in Long Island Sound offshore of Orient Point, NY. In addition, sediment and photographic data from 26 stations obtained during a USGS verification cruise are presented. Overall, the sea floor slopes gently seaward, but topography is more complex in sand-wave and boulder areas, which are evident in the multibeam and sidescan-sonar data from the study area. Sand waves generally have north-south-oriented crests with 10- to 20-m wavelengths. Sand-wave asymmetry indicates eastward net sediment transport in the east and westward net sediment transport in the northern and western parts of the study area. Areas with boulders on the sea floor are typically hummocky and are part of a glacial moraine system. Boulders are typically encrusted with seaweed, sponges, and anemones as shown in the bottom photography.

McMullen, K.Y.; Poppe, L.J.; Danforth, W.W.; Blackwood, D.S.; Schaer, J.D.; Guberski, M.R.; Wood, D.A.; Doran, E.F.

2011-01-01

312

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? Itâs 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

313

Mammals of the Sea.  

ERIC Educational Resources Information Center

|Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)|

Naturescope, 1986

1986-01-01

314

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....

315

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

2013-01-12

316

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

317

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

318

Sea-anemone toxin ATX-II elicits A-fiber-dependent pain and enhances resurgent and persistent sodium currents in large sensory neurons  

PubMed Central

Background Gain-of-function mutations of the nociceptive voltage-gated sodium channel Nav1.7 lead to inherited pain syndromes, such as paroxysmal extreme pain disorder (PEPD). One characteristic of these mutations is slowed fast-inactivation kinetics, which may give rise to resurgent sodium currents. It is long known that toxins from Anemonia sulcata, such as ATX-II, slow fast inactivation and skin contact for example during diving leads to various symptoms such as pain and itch. Here, we investigated if ATX-II induces resurgent currents in sensory neurons of the dorsal root ganglion (DRGs) and how this may translate into human sensations. Results In large A-fiber related DRGs ATX-II (5 nM) enhances persistent and resurgent sodium currents, but failed to do so in small C-fiber linked DRGs when investigated using the whole-cell patch-clamp technique. Resurgent currents are thought to depend on the presence of the sodium channel ?4-subunit. Using RT-qPCR experiments, we show that small DRGs express significantly less ?4 mRNA than large sensory neurons. With the ?4-C-terminus peptide in the pipette solution, it was possible to evoke resurgent currents in small DRGs and in Nav1.7 or Nav1.6 expressing HEK293/N1E115 cells, which were enhanced by the presence of extracellular ATX-II. When injected into the skin of healthy volunteers, ATX-II induces painful and itch-like sensations which were abolished by mechanical nerve block. Increase in superficial blood flow of the skin, measured by Laser doppler imaging is limited to the injection site, so no axon reflex erythema as a correlate for C-fiber activation was detected. Conclusion ATX-II enhances persistent and resurgent sodium currents in large diameter DRGs, whereas small DRGs depend on the addition of ?4-peptide to the pipette recording solution for ATX-II to affect resurgent currents. Mechanical A-fiber blockade abolishes all ATX-II effects in human skin (e.g. painful and itch-like paraesthesias), suggesting that it mediates its effects mainly via activation of A-fibers.

2012-01-01

319

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

320

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

321

The macrofauna of a stony sand area in the German Bight (North Sea)  

NASA Astrophysics Data System (ADS)

The sublittoral macrofauna of the Steingrund, a stony area east-northeast of Helgoland, was investigated from May till October 1991 using a van Veen grab and a small dredge. The diverse endo- and epifauna of the sandy bottoms, pebbles and boulders of this Saalian end moraine comprised 289 taxa, whereby the polychaetes Magelona papillicornis, Lanice conchilega and Spiophanes bombyx dominated in terms of abundance. Species rare in the German Bight, such as the sponge Leucandra fistulosa, the sea urchin Echinus esculentus, and the sea anemone Haliplanella lineata, were also found. The two sample sets were processed separately with multivariate techniques, and differentiated on the basis of occurrence and numbers of the abundant species. The analysis of the grab samples revealed two types of the Tellina-fabula-community. These associations were differentiated by the presence of species of the coarse-sand-inhabiting Goniadella-Spisula-community and were related to the distribution of the grain size of the sediment. Likewise, two epifaunal assemblages were distinguished. Sandy bottoms were characterized by Ophiura albida, Liocarcinus holsatus and Pagurus bernhardus, while boulders and pebbles were covered by a varied sessile and mobile epifauna dominated by the sessile bryozoan Flustra foliacea and the mobile pantopode Aechelia echinata. Numerical density, biomass and annual production estimates are in the range of values determined for the macrobenthos of the German Bight, while annual P/B ratios mounted up to 5.

Kühne, S.; Rachor, E.

1996-12-01

322

Surficial geology of the sea floor in Central Rhode Island Sound Southeast of Point Judith, Rhode Island  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA) are working together to study sea-floor environments off the northeast coast of the United States. During 2008, NOAA survey H11996 collected multibeam echosounder data in a 65-square kilometer area in central Rhode Island Sound, southeast of Point Judith, Rhode Island. During 2010, the USGS collected bottom photographs and sediment samples from 25 stations in this study area. The bathymetry, photography, and sediment data are used to interpret sea-floor features including scour depressions, sand waves, trawl marks, and dredge spoils. Scour depressions cover the bathymetric highs in much of the study area. Sand waves are located mostly in the southwest, and trawl marks tend to be in the northern regions. Dredge spoils are located at a disposal site in a bathymetric low in the western end of the study area. Most stations have a sea-floor surface of sand or silty sand, but eight of the stations have boulders to pea-sized gravel or gravelly sediment on the surface. Photographs show sandy areas typically have scattered burrows, shells, amphipod communities, and worm tubes. Boulders and cobbles are commonly overgrown with hydrozoans and anemones.

McMullen, K.Y.; Poppe, L.J.; Ackerman, S.D; Blackwood, D.S.; Schaer, J.D.; Nadeau, M.A.; Wood, D.A.

2011-01-01

323

Sea urchin granuloma.  

PubMed

Injuries caused by venomous and poisonous aquatic animals may provoke important morbidity in humans. The phylum Echinoderma include more than 6000 species of starfish, sea urchins, sand dollars, and sea cucumbers some of which have been found responsible for injuries to humans. Initial injuries by sea urchins are associated with trauma and envenomation, but later effects can be observed. Sea urchin granuloma is a chronic granulomatous skin disease caused by frequent and successive penetration of sea urchin spines which have not been removed from wounds. The authors report a typical case of sea urchin granuloma in a fisherman and its therapeutic implications. PMID:17086323

Rossetto, André Luiz; de Macedo Mora, Jamesson; Haddad Junior, Vidal

324

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

325

7 CFR 1437.310 - Sea grass and sea oats.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 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...

2009-01-01

326

Aral Sea basin: a sea dies, a sea also rises.  

PubMed

The thesis of this article is quite different from many other theses of papers, books, and articles on the Aral Sea. It is meant to purposely highlight the reality of the situation in Central Asia: the Aral Sea that was once a thriving body of water is no more. That sea is dead. What does exist in its place are the Aral seas: there are in essence three bodies of water, one of which is being purposefully restored and its level is rising (the Little Aral), and two others which are still marginally connected, although they continue to decline in level (the Big Aral West and the Big Aral East). In 1960 the level of the sea was about 53 m above sea level. By 2006 the level had dropped by 23 m to 30 m above sea level. This was not a scenario generated by a computer model. It was a process of environmental degradation played out in real life in a matter of a few decades, primarily as a result of human activities. Despite wishes and words to the contrary, it will take a heroic global effort to save what remains of the Big Aral. It would also take a significant degree of sacrifice by people and governments in the region to restore the Big Aral to an acceptable level, given that the annual rate of flow reaching the Amudarya River delta is less than a 10th of what it was several decades ago. Conferring World Heritage status to the Aral Sea(s) could spark restoration efforts for the Big Aral. PMID:17626470

Glantz, Michael H

2007-06-01

327

Sea Base Utility Vessel.  

National Technical Information Service (NTIS)

In the Navy's current Sea Base concept, significant amounts of cargo and personnel require transport over short distances between ships and between ships and shore. This places a heavy transport burden on the Sea Base's helicopters and LCACs, even though ...

D. Rigerink M. Newborn

2008-01-01

328

Monitoring Sea Level Rise.  

National Technical Information Service (NTIS)

While introducing the GLOSS network and its various engineering applications, the report first briefly summarizes several causes of sea level rise. The authors then discuss several computing methods of monthly and annual mean sea level and their error sou...

X. Peiliang

1990-01-01

329

Sea Turtle Populations  

NSDL National Science Digital Library

In this activity, learners will model how a sea turtle population changes over time, from eggs to adults, using puffed rice. Learners create a chart, calculate population fluctuation for each transitional stage of sea turtles' lives, and graph the population at each stage. Learners investigate different factors including migration and human fishing that affect the size of the sea turtle population. Relates to the linked video, DragonflyTV GPS: Sea Turtles.

Twin Cities Public Television, Inc.

2007-01-01

330

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....

331

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

332

Sea level changes  

SciTech Connect

The paper develops an approach to the issues relating to sea level change that will assist the non-scientist and the applied scientist in making the most effective use of our existing and developing knowledge. The human perception of ''sea level'' and how that changes as societies change and develop are discussed. After some practical perspectives on the relationships between societies and sea levels are developed, an approach to developing the best available local prediction of sea level changes is outlined, and finally present knowledge and uncertainties about the future course of events that will influence ''sea level'' as defined in the practical sense is discussed.

Buddemeier, R.W.

1987-08-21

333

Structure revision of hupehensis saponin F and G and characterization of new trace triterpenoid saponins from Anemone hupehensis by tandem electrospray ionization mass spectrometry.  

PubMed

Electrospray ionization ion-trap tandem mass spectrometry (ESI-MS(n)) was first employed for reinvestigating the structures of hupehensis saponin F and G previously isolated from Anemone hupehensis in our lab. Hupehensis saponin G was determined to contain one more trisaccharide unit (Rha-(1?4)-Glc-(1?6)-Glc-), not a glucose residue, than saponin F based on their molecular weights deduced from their [M+Na](+) ions in ESI-MS spectra. The (2,4)A(4?)-ion at m/z 551.3 formed by retro-Diels-Alder (RDA) rearrangement in positive mode illustrated that the C-28 sugar chains of the two saponins were composed of trisaccharide repeating moieties with (1?4) linkages rather than (1?3) linkages. The interpretation of 2D-NMR spectra of the two compounds also confirmed the results obtained by ESI-MS(n). Moreover, from the water soluble part of A. hupehensis, two novel triterpene saponins were tentatively characterized to contain 4 and 5 (1?4)-linked above trisaccharide repeating moieties at C-28 position according to their ESI-MS(n) behaviors, respectively. PMID:22507832

Li, Fu; Liu, Xin; Tang, Minghai; Chen, Bin; Ding, Lisheng; Chen, Lijuan; Wang, Mingkui

2012-03-27

334

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.

Mlinarec, J.; Satovic, Z.; Malenica, N.; Ivancic-Bace, I.; Besendorfer, V.

2012-01-01

335

Isozoanthus antumbrosus, a new species of zoanthid (Cnidaria: Anthozoa: Zoanthidea) symbiotic with Hydrozoa from the Caribbean, with a key to hydroid and sponge-symbiotic zoanthid species  

Microsoft Academic Search

Isozoanthus antumbrosus, a new species of zooxanthellate zoanthid, is described. Colonies associate with the arborescent hydroid Dentitheca dendritica in the Caribbean Sea at 1-60 m. The coenenchyme, column, and oral disk are seal brown. The tentacles are golden brown and number 30-38. The coloration of the oral disk and tentacles recalls an annular solar eclipse. Polyps are 4.1-8.9 mm long

TIMOTHY D. SWAIN

336

Focus on Sea Otters  

NSDL National Science Digital Library

A Monterey Bay Aquarium website where you can learn about the biology and population recovery of sea otters. Features include the opportunity to "meet" the otters on exhibit at the aquarium and viewing them through the live otter cam. Many sea otter-related games, activities, and resources. Links to other fascinating exhibits at the Aquarium. Several downloadable videos available, each with their own enjoyable sea otter antics.

337

SeaWIFS Project  

NSDL National Science Digital Library

SeaWIFS (Sea-viewing Wide Field-of-view Sensor), a NASA project using satellites to collect ocean color data to quantify phytoplankton abundance. Provides background information on SeaWIFS project, technology and data. Teacher Resource section has: online presentation on how and why scientists study ocean color; Living Ocean Teacher's Guide with brief information on ocean color, carbon cycle and greenhouse gas effect; and, links to other websites with ocean color activities.

338

[Marine life envenomations: example in New Caledonia].  

PubMed

Marine life in the waters of New Caledonia is extraordinarily rich. However some of the animals inhabiting this wonderland are dangerous including a number of venomous species. A retrospective study conducted at the Territorial Hospital in Noumea for the three-year period between 1995 and 1998 showed that nearly 200 people/year were victims of envenomation by marine animals. Findings also indicated that the incidence of envenomation was rising as the practice of marine activities by the local population and tourists increased. Venomous species can be classified into 4 categories according to the mechanism of envenomation, i.e., biting animals such as sea snakes, cephalopoda, and eels; stinging animals including not only fish such as scorpion fish (Pterois, stonefish), sting-rays, saltwater catfish, surgeon fish, and flatfish but also cones and crown of thorns (Acanthaster planci); animals with contact venoms such as cnidaria (jellyfish, corals, sea anemones, and men-of-war), glaucus, sea cucumbers (holothurioidae), and sponges; and animals with more than one envenomation apparatus such as sea urchins and sea worms which can bite and sting. Study focused on the characteristics of each species including biology, envenomation apparatus, and chemical composition and action of the venom; pharmacological and clinical aspects of envenomation; and management and prevention of accidents. PMID:10701210

Rual, F

1999-01-01

339

Sea-floor geology in central Rhode Island Sound south of Sakonnet Point, Rhode Island  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA) are working together to study the sea floor along the northeastern coast of the United States. NOAA collected multibeam-echosounder data during hydrographic survey H11995 in a 63-square-kilometer area in central Rhode Island Sound, south of Sakonnet Point, Rhode Island. The USGS collected sediment samples, bottom video, and still photographs from 27 stations in this study area to verify an interpretation of the bathymetric data. Collected data are used to map areas of scour depressions and erosional outliers, megaripples, boulders, and relatively undisturbed modern marine sediments. In general, much of the eastern part of the study area, a submerged segment of the Harbor Hill-Roanoke Point-Charlestown-Buzzards Bay moraine, is bouldery. Bottom photography shows boulders are generally encrusted with hydrozoans, algae, and anemone. Scour depressions, presumably formed by long-period storm waves, and erosional outliers of Holocene sediments dominate the western part of the study area and several large areas in the east. The scour depressions tend to have coarser grained sediment than intervening erosional outliers. The coarseness likely creates turbulence in the water over these areas, which prevents fine-grained sediment deposition. Several small areas of megaripples are visible in the bathymetry data in the west. Other sandy areas are typically rippled, with burrows, worm tubes, and starfish present.

McMullen, K. Y.; Poppe, L. J.; Ackerman, S. D.; Worley, C. R.; Nadeau, M. A.; Van Hoy, M. V.

2012-01-01

340

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

341

Tree litter and forest understorey vegetation: a conceptual framework to understand the effects of tree litter on a perennial geophyte, Anemone nemorosa  

PubMed Central

Background and Aims Litter is a key factor in structuring plant populations, through positive or negative interactions. The litter layer forms a mechanical barrier that is often strongly selective against individuals lacking hypocotyle plasticity. Litter composition also interacts with plant growth by providing beneficial nutrients or, inversely, by allowing harmful allelopathic leaching. As conspicuous litter fall accumulation is often observed under deciduous forests, interactions between tree litter and understorey plant populations are worthy of study. Methods In a 1-year ex-situ experiment, the effects of tree litter on the growth of Anemone nemorosa, a small perennial forest geophyte, were investigated. Three ‘litter quantity’ treatments were defined, representative of forest floor litter (199, 356·5 and 514 g m?2), which were crossed with five ‘litter composition’ treatments (Quercus petraea, Fagus sylvatica, Carpinus betulus, Q. petraea + F. sylvatica and Q. petraea + C. betulus), plus a no-litter control. Path analysis was then used to investigate the pathways linking litter characteristics and components of adult plant growth. Key Results As expected, the heavier the litter, the longer the petiole; rhizome growth, however, was not depreciated by the litter-induced petiole lengthening. Both rhizome mass increment and number of initiated buds marginally increased with the amount of litter. Rhizome mass increment was in fact determined primarily by leaf area and leaf life span, neither of which was unequivocally correlated with any litter characteristics. However, the presence of litter significantly increased leafing success: following a late frost event, control rhizomes growing in the absence of litter experienced higher leaf mortality before leaf unfolding. Conclusions The study questions the role of litter as a physical or chemical barrier to ground vegetation; to better understand this role, there is a need for ex-situ, longer-term experiments coupled with in-situ observations in the forest.

Baltzinger, Marie; Archaux, Frederic; Dumas, Yann

2012-01-01

342

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

343

MMAB Sea Ice Analysis Page  

NSDL National Science Digital Library

This is the sea ice analysis page of the Marine Modeling and Analysis Branch (MMAB) of the National Oceanic and Atmospheric Administration (NOAA). Users can access images of sea ice extent that can be animated to show the previous 30 days activity. Images are available for the entire globe, the Northern Hemisphere (Alsaka, Sea of Okhotsk, and Sea of Japan), and the Southern Hemisphere (Weddell Polynya Watch, Ross Sea and Amery Basin). Information on sea ice modelling and forecasts is also accessible.

344

Antarctica: Sea Ice  

NSDL National Science Digital Library

This video segment, adapted from a NOVA broadcast, shows how sea ice forms in the Southern Ocean around Antarctica and how its seasonal fluctuation dramatically changes the continent. The segment, two minutes thirty-five seconds in length, includes rare footage of the destruction of the British ship 'Endurance', trapped and crushed by sea ice in 1914.

2010-09-30

345

Sea Otter Unit  

NSDL National Science Digital Library

Teacher's manual on sea otters with lesson plans on: using the web as a research tool; reading and developing writing skills; social studies with role playing activity in community conflict resolution. Includes a glossary, links to additional resources, and background materials on sea otter history, distribution, vital statistics, behavior, role in food web, threats and conservation measures. Suggests conservation activities for classroom or school.

346

Antarctica: Sea Ice  

NSDL National Science Digital Library

This video segment, adapted from a NOVA broadcast, shows how sea ice forms in the Southern Ocean around Antarctica and how its seasonal fluctuation dramatically changes the continent. The segment, two minutes thirty-five seconds in length, includes rare footage of the destruction of the British ship 'Endurance', trapped and crushed by sea ice in 1914.

347

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.

348

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...

349

Spotting Sea Otters  

USGS Multimedia Gallery

USGS wildlife biologist Alisha Kage looks through a telescope to help her locate and identify tagged sea otters, then records the otter's location for a study aimed at learning more about the species. USGS scientists study sea otters in efforts to help the threatened species continue to recover from...

350

Melting Ice Rising Seas  

NSDL National Science Digital Library

This NASA video presents animations, photos and footage of melting polar ice as a result of climate change, the resulting sea-level rise, and selected consequences of that rise. Excellent animations, interviews with scientists, and clear step-by-step explanations provide a solid introduction to one facet of sea level rise and its consequences.

Noaa

351

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.

Stoffregen, Thomas A.; Chen, Fu-Chen; Varlet, Manuel; Alcantara, Cristina; Bardy, Benoit G.

2013-01-01

352

Red Sea Drillings  

Microsoft Academic Search

Recent drilling in the Red Sea has shown that much of the basin is underlain by evaporites of a similar age to that of evaporites found in the Mediterranean Sea. These evaporites and their structural positions indicate that other brine areas are present-and, indeed, several others have been discovered.

David A. Ross; Robert B. Whitmarsh; Syed A. Ali; Joseph E. Boudreaux; Robert Coleman; Robert L. Fleisher; Ronald Girdler; Frank Manheim; Albert Matter; Catherine Nigrini; Peter Stoffers; Peter R. Supko

1973-01-01

353

Clustering sea bottom texture  

Microsoft Academic Search

The sea bottom in a region of the Marmara Sea was measured by a multi beam echo sounder, DGPS and a side scan sonar system; a map was produced using the amplitude and coordinate information. This map was later transformed into ten dimensional texture space by texture analysis. The iso-data (iteratively self organizing data) clustering technique was then employed to

E. Alparslan; S. Ergintav; C. Aydoner; R. Saatcilar; S. Canon; E. Gezgin; A. Unlu

2004-01-01

354

The north Sulu Sea productivity  

NASA Astrophysics Data System (ADS)

The Sulu Sea is a part of the western North Pacific. It is a closed sea for its deep water and a semi-closed sea for its upper layer. The Sulu Sea exchanges mainly surface waters with the South China Sea and the Celebes Sea. The Sulu Sea is more productive than the adjacent South China Sea (Jones, 2002). On the basis of MERIS satellite observations from 2002 to 2008, we focus on the high-chlorophyll area as an indicator of the abundance of primary productivity in the Sulu Sea. Strong chlorophyll concentration in the north Sulu Sea close to the Mindoro Strait mainly occurs from December to March and low chlorophyll concentration happens in April to November. The adjacent South China Sea on the other side of Mindoro Strait has shown persistent signs of low chlorophyll concentration. Based on 1/8° Global Navy Coastal Ocean Model, the intrusion of the South China Sea waters through the Mindoro Strait to the Sulu Sea from April to November is the main reason for the low chlorophyll concentration observed in the north Sulu Sea. During April to November, the South China Sea waters flow through the Mindoro Strait and stay on the surface of the north Sulu Sea because of their low density. The north Sulu Sea waters mix with fresher waters coming from the South China Sea without new nutrients supply. When the inflow from South China Sea to Sulu Sea ceases in December to March, the upwelling due to the summer monsoon wind becomes an important mechanism supplying deep nutrients to the surface water which lead to high chlorophyll concentration. Jones, I.S.F., 2002. Primary production in the Sulu Sea. Proceedings of the Indian Academy of Sciences-Earth and Planetary Sciences 111, 209-213.

Xiao, Z.

2009-12-01

355

Drag of the sea surface  

Microsoft Academic Search

It is shown how the drag of the sea surface can be computed from the wind speed and the sea state. The approach, applicable both for fully developed and for developing seas, is based on conservation of momentum in the boundary layer above the sea, which allows one to relate the drag to the properties of the momentum exchange between

V. K. Makin; V. N. Kudryavtsev; C. Mastenbroek

1995-01-01

356

Dead Sea Scrolls.  

National Technical Information Service (NTIS)

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 pot...

1994-01-01

357

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

358

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.

359

Science at Sea.  

ERIC Educational Resources Information Center

Describes a three-week inservice teacher education program that involves two sessions of preparatory classes ashore in nautical science and oceanography, and concludes with a nine-day sea voyage. (ASK)

Phillips, Mary Nied

2001-01-01

360

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.

361

Sea water activated battery  

Microsoft Academic Search

This single cell, sea water activated battery has a plurality of alternately sequenced plates each positioned to extend radially outwardly of a central core. The plates are made of magnesium and of silver chloride.

R. H. Dreisbach; R. G. Bergstedt; D. W. Sieglin

1970-01-01

362

South China Sea.  

PubMed

The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the South China Sea. What data are available, however, and if Hong Kong is used, as it is herein, as an indicator of what the perturbations of other regional cities upon the South China Sea are like, then it is impacted grossly and an ecological disaster has probably already, but unknowingly, happened. PMID:11827109

Morton, B; Blackmore, G

2001-12-01

363

All About Sea Ice  

NSDL National Science Digital Library

This comprehensive site is an introduction to sea ice: what it is, how it forms, how it is studied, how it affected historical expedition in the polar regions, and what role it plays in the global climate. The site contains a glossary of sea ice terms and references to additional information, which all serve as an excellent introduction. Data are also available from various collection methods for student interpretation.

364

Salton sea research well  

Microsoft Academic Search

Two University of California, Riverside, scientists propose to extend a planned 3.7-km-deep steam-production well in the Salton Sea geothermal field to 5.5 km for scientific study prior to the well's commercial use. The Salton Sea, a hydrothermal-magma system in the delta of the Colorado River, is one of the hottest, most saline geothermal fields known, and the proposed extension would

Wilfred A. Elders

1983-01-01

365

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

366

Green Sea Turtles  

NSDL National Science Digital Library

Detailed information on the biology, natural history, factors influencing the population, and protection measures of green sea turtles (Chelonia mydas). Included are three in-class activities and one field activity all designed to raise awareness of the green sea turtle and what humans are doing to affect the population. The site is geared towards the Hawaiian sub-species, however, most of the facts and activities are applicable elsewhere.

367

North Sea estuaries  

Microsoft Academic Search

Studies of the North Sea in the past two decades have shown that its estuaries and associated areas, such as the Wadden Sea,\\u000a are important as nursery grounds for young fish and as feeding grounds for seabirds. These same areas are also those most\\u000a likely to be affected by the highest inputs and concentrations of contaminants. The development of agriculture,

Donald S. McLusky

2001-01-01

368

Lipids in sea water  

Microsoft Academic Search

Acidified and filtered sea water samples which were extracted with petroleum ether and ethyl acetate have been shown to contain\\u000a a variety of lipid compounds in trace amounts. Concentrations of these solvent-soluble substances ranged from 0.5 to 6.0 mg\\/liter,\\u000a the lower concentrations being found in offshore waters. The solvent extracts of the sea water were separated into eight lipid\\u000a classes

Lela M. Jeffrey

1966-01-01

369

All About Sea Ice  

NSDL National Science Digital Library

This comprehensive site is an introduction to sea ice: what it is, how it forms, how it is studied, how it affected historical expedition in the polar regions, and what role it plays in the global climate. The site contains a glossary of sea ice terms and references to additional information, which all serve as an excellent introduction. Data are also available from various collection methods for student interpretation.

2011-07-15

370

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, Jörg; Taylor, James; Dannheim, Jennifer; Gutt, Julian; Purser, Autun; Nattkemper, Tim W

2012-06-05

371

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

372

Simulation and observations of annual density banding in skeletons of Montastraea (Cnidaria: Scleractinia) growing under thermal stress associated with ocean warming  

USGS Publications Warehouse

We present a model of annual density banding in skeletons of Montastraea coral species growing under thermal stress associated with an ocean-warming scenario. The model predicts that at sea-surface temperatures (SSTs) <29??C, high-density bands (HDBs) are formed during the warmest months of the year. As temperature rises and oscillates around the optimal calcification temperature, an annual doublet in the HDB (dHDB) occurs that consists of two narrow HDBs. The presence of such dHDBs in skeletons of Montastraea species is a clear indication of thermal stress. When all monthly SSTs exceed the optimal calcification temperature, HDBs form during the coldest, not the warmest, months of the year. In addition, a decline in mean-annual calcification rate also occurs during this period of elevated SST. A comparison of our model results with annual density patterns observed in skeletons of M. faveolata and M. franksi, collected from several localities in the Mexican Caribbean, indicates that elevated SSTs are already resulting in the presence of dHDBs as a first sign of thermal stress, which occurs even without coral bleaching. ?? 2007, by the American Society of Limnology and Oceanography, Inc.

Worum, F. P.; Carricart-Ganivet, J. P.; Benson, L.; Golicher, D.

2007-01-01

373

Epibenthic assemblages in the Celtic Sea and associated with the Jones Bank  

NASA Astrophysics Data System (ADS)

The epibenthic assemblages in the Celtic Sea are described from the catches from 2 m beam trawl surveys undertaken from 2000 to 2009. During this period 154 samples were collected. The most ubiquitous species in the study area were the natantid shrimps Processa spp. and Crangon allmanni, the hermit crabs Pagurus prideaux and Anapagurus laevis, sand star Astropecten irregularis and spotted dragonet Callionymus maculatus. Multivariate community analyses indicated that catches (numbers per tow) were distributed across six assemblages, two of which were predominant in the study area. Most catches were attributed to either a 'shelf edge assemblage', which was widespread in deeper waters (114–423 m water depth) or an 'outer shelf assemblage' that occurred across much of the Celtic Sea north of 49°N in waters 49–175 m deep. The dominant species along the edge of the continental shelf were the hormathid anemome Actinauge richardi, sea spider Pycnogonum littorale (which associated with A. richardi), Devonshire cup coral Caryophyllia smithii and the swimming crab Macropipus tuberculatus. The dominant species in the outer shelf assemblage included P. prideaux, C. allmanni, A. laevis and common starfish Asterias rubens. Stations closer to shore were relatively distinct and catches in this 'inner shelf assemblage' were composed primarily of an inshore fauna (e.g. Ophiura ophiura, C. allmanni and Liocarcinus holsatus). Stations in the southern part of the survey grid were also relatively distinct ('southern Celtic Sea assemblage'), and several large echinoderms (Porania pulvillus, Stichastrella rosea and Anseropoda placenta) dominated at these sites. Three of the deepest stations were also relatively distinct, as were a group of stations in the muddy habitat of the Celtic Deep and comparable grounds elsewhere in the region, where Nucula sulcata and Alpheus glaber were characteristic. Catches on the shallower parts of the Jones Bank (and on another bank in the region) were dominated by the anemone Paraphellia expansa, with off-bank sites comprising a greater number of species. In contrast to beam trawl sampling, baited camera observations on the Jones Bank showed a greater richness of species on the shallower part of the bank, and provided information on the nocturnal feeding behaviour of scavenging isopods.

Ellis, J. R.; Martinez, I.; Burt, G. J.; Scott, B. E.

2013-10-01

374

[Interaction of sea amemone Heteractis crispa Kunitz type polypeptides with pain vanilloid receptor TRPV1: in silico investigation].  

PubMed

Using methods of molecular biology we defined the structures of the 31 sea anemone Heteractis crispa genes encoding polypeptides which are structurally homologous to the Kunitz proteinase inhibitor family. Identified amino acid sequences have point residue substitutions, high degree of homology with sequences of known H. crispa Kunitz family members, and represent a combinatorial library of polypeptides. We generated their three-dimensional structures by homologous modeling methods. Analysis of their molecular electrostatic potential enabled us to divide given polypeptides into three clusters. One of them includes polypeptides APHC1, APHC2 and APHC3, which were earlier shown to possess a unique property of inhibiting of the pain vanilloid receptor TRPV1 in vitro and providing the analgesic effects in vivo in addition to their trypsin inhibitory activity. Molecular docking made possible establishing the spatial structure of the complexes, the nature of the polypeptides binding with TRPV1, as well as functionally important structural elements involved in the complex formation. Structural models have enabled us to propose a hypothesis contributing to understanding the APHC1-3 impact mechanism for the pain signals transduction by TRPV1: apparently, there is an increase of the receptor relaxation time resulted in binding of its two chains with the polypeptide molecule, which disrupt the functioning of the TRPV1 and leads to partial inhibition of signal transduction in electrophysiological experiments. PMID:22792722

Zelepuga, E A; Tabakmakher, V M; Chausova, V E; monastyrnaia, M M; Isaeva, M P; Kozlovskaia, É P

375

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

376

Sea Ice Rheology  

NASA Astrophysics Data System (ADS)

The polar oceans of Earth are covered by sea ice. On timescales much greater than a day, the motion and deformation of the sea ice cover (i.e., its dynamics) are primarily determined by atmospheric and oceanic tractions on its upper and lower surfaces and by internal ice forces that arise within the ice cover owing to its deformation. This review discusses the relationship between the internal ice forces and the deformation of the ice cover, focusing on representations suitable for inclusion within global climate models. I first draw attention to theories that treat the sea ice cover as an isotropic continuum and then to the recent development of anisotropic models that deal with the presence of oriented weaknesses in the ice cover, known as leads.

Feltham, Daniel L.

2008-01-01

377

New York Sea Grant  

NSDL National Science Digital Library

The National Sea Grant program was established in 1966, and a few years later, the state of New York sponsored the program's first outpost. Currently, the New York Sea Grant (NYSG) is a cooperative program of the State University of New York (SUNY) and Cornell University. On the homepage, visitors can look over sections that include "Extension", "Research", "Education", "Publications", and "Theme Areas". The "Theme Areas" is a good place to start, as it features topical material on coastal processes and hazards, fisheries, and aquatic invasive species. Their helpful publication "Currents" is also worth a look, and it contains materials on grant opportunities, research materials, fact sheets, and public awareness programs. Moving on, the "Related Sites" area contains links to "Hot Topics" (topical news items related to the sea and such) and affiliated organizations.

378

SeaWeb  

NSDL National Science Digital Library

SeaWeb is a nonprofit organization aimed at raising awareness of the ocean and marine life that play "a critical role in our everyday life and in the future of our planet." SeaWeb employs a team of professionals from biology, exploration, and various communication disciplines. The current campaigns include an effort to protect the declining Caspian Sea Sturgeon ("the source of most of the world's caviar"), an attempt to reduce overfishing of swordfish, and a report about the changes occurring in the world's oceans. This Web site is a robust source of information about many threats that are facing marine ecosystems, and an attempt to reduce the dangers by educating the public about the impacts of their behavior.

1996-01-01

379

Melting Sea Ice  

NSDL National Science Digital Library

This activity uses a mix of multimedia resources and hands-on activities to support a storyline of investigation into melting sea ice. The lesson begins with a group viewing of a video designed to get students to consider both the local and global effects of climate change. The class then divides into small groups for inquiry activities on related topics followed by a presentation of the findings to the entire class. A final class discussion reveals a more complex understanding of both the local and global impacts of melting sea ice.

Domain, Wgbh E.

380

Sea Surface Temperature Variability  

Microsoft Academic Search

A weekly mean Multi-Channel Sea Surface Temperature (MCSST) data set was used to study\\u000a seasonal and interannual variability of SSTs averaged over four regions of the Caspian Sea individually\\u000a (Northern, Middle, and Southern Caspian, and Kara-Bogaz-Gol Bay) and SST trends during 1982--2000.\\u000a The SST fields averaged for individual months of four hydrological seasons (February, April, August,\\u000a and October) were calculated and

Anna I. Ginzburg; Andrey G. Kostianoy; Nickolay A. Sheremet

381

National Sea Grant Library  

NSDL National Science Digital Library

This is the website for the only facility housing a complete collection of Sea Grant funded work. An archive and lending library for reprints, books, reports, maps, newsletters, handbooks, videos, CD-roms and computer programs regarding: oceanography; marine education; aquaculture; fisheries; limnology; coastal zone management; marine recreation and law. Lends documents worldwide, aiding scientists, teachers, students, fishermen and others in research and study. Bibliographic database is searchable from the website, where users may obtain citations, abstracts and access to over 20,000 downloadable texts of Sea Grant publications.

2011-05-05

382

Arctic Sea Ice Maximum 2011  

NASA Video Gallery

AMSR-E Arctic Sea Ice: September 2010 to March 2011: Scientists tracking the annual maximum extent of Arctic sea ice said that 2011 was among the lowest ice extents measured since satellites began collecting the data in 1979.

Holly Zell

2011-03-29

383

Sea ice microbial communities (SIMCO)  

Microsoft Academic Search

Sea ice microbial communities (SIMCO) grow luxuriantly within several microhabitats of sea ice, indicating that the microorganisms comprising these communities are well adapted to the physicochemical gradients which characterize sea ice. We used SIMCO obtained from the bottom of congelation ice in McMurdo Sound, Antarctica, to test the hypothesis that low temperature limits microbial productivity in polar oceans and also

Steven T. Kottmeier; Cornelius W. Sullivan

1988-01-01

384

The National Sea Grant Program.  

ERIC Educational Resources Information Center

|Described is the National Sea Grant College Program which supports education and training, research, and advisory extension services through the National Office of Sea Grant and the Sea Grant Network of 30 programs in coastal and Great Lake states. Water-related topics include water's relationship to nature, society, and human expression.…

Spector, Barbara S.

1980-01-01

385

The Sea Level Rise Challenge  

Microsoft Academic Search

Recent research on sea level rise suggests that sea level rise by the end of this century may well be significantly larger than those identified in the IPCC AR4 (2007). Whereas in the past, sea level rise was ascribed equally to thermal expansion of a warming ocean and the melting of land-based ice sheets and glaciers, the recent acceleration in

W. Abdalati; S. C. Moser; R. W. Schmitt

2010-01-01

386

Space Invaders at Sea  

NSDL National Science Digital Library

This radio broadcast discusses the recent issue of the increase and spread of tunicates (or 'sea squirts'), who have suddenly proliferated off the Atlantic Coast of the United States and Canada. The creatures, an invasive species likely from Asia or Europe, have carpeted the ocean floor and are smothering valuable shellfish.

Hoops, Richard

2010-10-13

387

Ships to the Sea.  

ERIC Educational Resources Information Center

This lesson contains materials for the U.S. Navy Museum's "Ships to the Sea" program. The program is appropriate for students in grades 2-4 and was designed in accordance with local and national social studies standards. The materials introduce students to the world of ship technology and naval terminology. The lesson is presented in five…

Department of the Navy, Washington, DC.

388

The Sea Around Us  

Microsoft Academic Search

Published in 1951, The Sea Around Us is one of the most remarkably successful books ever written about the natural world. Rachel Carson's rare ability to combine scientific insight with moving, poetic prose catapulted her book to first place on The New York Times best-seller list, where it enjoyed wide attention for thirty-one consecutive weeks. It remained on the list

Rachel L. Carson

1991-01-01

389

Harvesting the Sea.  

ERIC Educational Resources Information Center

|Information on commercial fishing is provided, and a board game is described which requires students to watch for ocean signs of good fishing, choose equipment to catch specific types of fish, and consider effects of weather on working at sea. A reproducible copy of the game, with instructions, is included. (IAH)|

Markle, Sandra

1989-01-01

390

Redlands Institute: Salton Sea  

NSDL National Science Digital Library

The Salton Sea Database Program (SSDP) at the University of Redlands, Redlands Institute (RI) was a project administered by the U.S. Environmental Protection Agency (EPA), Center for Special Programs. The purpose behind the SSDP was to bring a wide range of data management and analysis tools and professionals "to support multi-disciplinary and coordinated decision-making across all the professional and scientific teams and stakeholders involved in the restoration of California's largest inland body of water, the Salton Sea." Part of their outreach work includes this fine website, which includes sections titled "Ecological Issues", "Data & Research", and "Exploring the Area". First-time visitors may want to start by clicking on the "Ecological Issues" area. Here they can learn about the science of the area, the contemporary issues facing the survival of the Salton Sea, and some of the proposed solutions to restore the Sea. Journalists and scientists will appreciate the "Data & Research" area, as it features digital maps of the area, GIS data, public policy documents, and an image database. The casual traveler will enjoy the "Exploring the Area" section, and here they will find information about current weather conditions, fishing reports, and California State park materials.

391

Classroom of the Sea  

NSDL National Science Digital Library

Although most students do not have the opportunity to conduct in situ research projects until college, the Classroom of the Sea program at the American School for the Deaf (ASD) provides an unusual opportunity for students to work directly with scientists

Monte, Denise; Hupper, Mary L.; Scheifele, Peter

2000-03-01

392

SeaDiscovery.com  

NSDL National Science Digital Library

SeaDiscovery.com is an online source for "underwater tech and ocean science news." The site presents not only news, but information about maritime technology employment which includes featured jobs and resumes. It also allows access to the Maritime Technology Reporter magazine and provides links to a number of important directories.

2013-07-05

393

Dead Sea Scrolls  

Microsoft Academic Search

In today's society, many people are critical about the validity of the Bible. Archaeological excavations have unearthed many artifacts of the biblical time period, such as pottery, archives, and settlement remains, but Palestine had not produced virtually anything of extremely significant biblical evidence until 1947. The discovery of the Dead Sea Scrolls has clearly been \\

Janet Bull

1991-01-01

394

Rising Sea Levels  

NSDL National Science Digital Library

In the past century, as the climate has warmed, sea level rise has accelerated. Scientists predict it will only increase, and they're studying changes in the ocean and land to better understand how and why the water is rising. "Changing Planet" is produced in partnership with the National Science Foundation.

Learn, Nbc

2010-10-07

395

Western Tasman Sea Floor  

Microsoft Academic Search

The western Tasman Sea floor is characterised by physiographic units that tend to parallel the coastline of south-eastern Australia. The margin has a narrow continental shelf and a steep continental slope. Sediment derived mainly from northern New South Wales and Queensland in the north, and from Tasmania and Victoria in the south, has built a system of fans forming the

John R. Conolly

1969-01-01

396

Sea Grant's Education Mission.  

ERIC Educational Resources Information Center

|Considers the status of the education agenda of the Sea Grant Program as it turns 30. Projects described include Operation Pathfinder, which aims to educate minority teachers and/or teachers of minority students. Also described are a program in which seafood processors and resellers are trained in safety and health areas, and programs to train…

Sherman, Douglas

1998-01-01

397

Solar Sea Power  

ERIC Educational Resources Information Center

|In their preoccupation with highly complex new energy systems, scientists and statesmen may be overlooking the possibilities of Ocean Thermal Energy Conversion (OTEC). That is the view of a Carnegie-Mellon University physicist who is in the forefront of solar sea power investigation. (Author/BT)|

Zener, Clarence

1976-01-01

398

The Provident Sea  

NASA Astrophysics Data System (ADS)

The Provident Sea describes the history of fish stock management (including whales and seals). The book traces, on the basis of the original scientific material, the history of the management of "the provident sea" up to recent times when problems of over-exploitation have had dramatic effects upon stocks. The need for management arose mainly from the increasing industrialization of capture. Hence the preindustrial fisheries are covered, in particular the old cod fishery on the Grand Bank and the herring fishery in the North Sea, as an essential background to current problems. The origins of fisheries and whaling science are described, as is the development up to 1965 of the science and institution in fisheries, whaling, and sealing. In the sixties and seventies, certain major fishing nations took a heavy harvest of fish stocks using sophisticated and efficient gathering methods. This in turn led to conflict and one consequence was the "Law of the Sea" conference set up to try and resolve these issues.

Cushing, David H.

1988-09-01

399

Modern sea power  

Microsoft Academic Search

This book provides discussions of political, technical and military aspects of nuclear power. The contents include naval warfare in the nuclear age; politics, money, law and technology; a technological change; implications of technology; sea control; strategic deterrents; amphibious operations, maritime interdiction; inshore operations, naval diplomacy and conclusion.

Till

1987-01-01

400

Fire in the Sea  

Microsoft Academic Search

The legend of the lost city of Atlantis has captivated the human imagination for centuries. Did this city actually exist, and, if so, what happened to it? Was it destroyed in the greatest cataclysmic event of the Bronze Age? While the truth behind the legend of Atlantis may never be known, Fire in the Sea tells the story of one

Walter L. Friedrich

2000-01-01

401

Egyptian Sea Cave  

ERIC Educational Resources Information Center

|This brief article describes an archaeological expedition to the Red Sea coast area of Egypt in 2004. Kathryn Bard, an associate professor of archaeology at Boston University, along with her team, discovered the well-preserved cedar timbers of an ancient Egyptian seafaring vessel near the entrance to a large man-made cave. Limestone tablets with…

Journal of College Science Teaching, 2005

2005-01-01

402

Farming the Sea  

ERIC Educational Resources Information Center

|Florida has initiated a training program in an entirely new dimension--Sea Farming. Presented is a description of the vocational agriculture program designed to teach propagation, cultivation, harvesting, marketing, and conservation practices related to production of oysters, shrimp, scallops, crabs, and fin fishes. (Editor/GB)|

Morgan, William

1971-01-01

403

Arctic Sea Ice  

Microsoft Academic Search

Of all the recent observed changes in the Arctic environment, the reduction of sea ice cover stands out most prominantly. Several independent analysis have established a trend in Arctic ice extent of -3% per decade from the late 1970s to the late 1990s, with a more pronounced trend in summer. The overall downward trend in ice cover is characterized by

J. C. Stroeve; F. Fetterer; K. Knowles; W. Meier; M. Serreze; T. Arbetter

2004-01-01

404

Sea water rope batteries  

Microsoft Academic Search

This research demonstrated the feasibility of supplying approximately 1 watt of electrical power for one year on the sea bed with a novel battery, the rope battery. The proposed battery would look very much like a small diameter wire rope, possibly hundreds of feet long. This unusual shape permits the rope battery to take full advantage of the vastness of

M. Walsh

1984-01-01

405

Endobiotic bacteria and their pathogenic potential in cnidarian tentacles  

NASA Astrophysics Data System (ADS)

Endobiotic bacteria colonize the tentacles of cnidaria. This paper provides first insight into the bacterial spectrum and its potential of pathogenic activities inside four cnidarian species. Sample material originating from Scottish waters comprises the jellyfish species Cyanea capillata and C. lamarckii, hydrozoa Tubularia indivisa and sea anemone Sagartia elegans. Mixed cultures of endobiotic bacteria, pure cultures selected on basis of haemolysis, but also lyophilized samples were prepared from tentacles and used for DGGE-profiling with subsequent phylogenetic analysis of 16S rDNA fragments. Bacteria were detected in each of the cnidarian species tested. Twenty-one bacterial species including four groups of closely related organisms were found in culture material. The species within these groups could not be differentiated from each other (one group of Pseudoalteromonas spp., two groups of Shewanella spp., one group of Vibrio spp.). Each of the hosts exhibits a specific endobacterial spectrum. Solely Cyanea lamarckii harboured Moritella viscosa. Only in Cyanea capillata, members of the Shewanella group #2 and the species Pseudoalteromonas arctica, Shewanella violacea, Sulfitobacter pontiacus and Arcobacter butzleri were detected. Hydrozoa Tubularia indivisa provided an amazingly wide spectrum of nine bacterial species. Exclusively, in the sea anemone Sagartia elegans, the bacterial species P. aliena was found. Overall eleven bacterial species detected were described recently as novel species. Four 16S rDNA fragments generated from lyophilized material displayed extremely low relationship to their next neighbours. These organisms are regarded as members of the endobiotic “terra incognita”. Since the origin of cnidarian toxins is unclear, the possible pathogenic activity of endobiotic bacteria has to be taken into account. Literature data show that their next neighbours display an interesting diversity of haemolytic, septicaemic and necrotic actions including the production of cytotoxins, tetrodotoxin and R-toxin. Findings of haemolysis tests support the literature data. The potential producers are Endozoicimonas elysicola, Moritella viscosa, Photobacterium profundum, P. aliena, P. tetraodonis, Shewanella waksmanii, Vibrio splendidus, V. aestuarius, Arcobacter butzleri.

Schuett, Christian; Doepke, Hilke

2010-09-01

406

Genomic view of the evolution of the complement system  

PubMed Central

The recent accumulation of genomic information of many representative animals has made it possible to trace the evolution of the complement system based on the presence or absence of each complement gene in the analyzed genomes. Genome information from a few mammals, chicken, clawed frog, a few bony fish, sea squirt, fruit fly, nematoda and sea anemone indicate that bony fish and higher vertebrates share practically the same set of complement genes. This suggests that most of the gene duplications that played an essential role in establishing the mammalian complement system had occurred by the time of the teleost/mammalian divergence around 500 million years ago (MYA). Members of most complement gene families are also present in ascidians, although they do not show a one-to-one correspondence to their counterparts in higher vertebrates, indicating that the gene duplications of each gene family occurred independently in vertebrates and ascidians. The C3 and factor B genes, but probably not the other complement genes, are present in the genome of the cnidaria and some protostomes, indicating that the origin of the central part of the complement system was established more than 1,000 MYA.

Kimura, Ayuko

2006-01-01

407

Sea Ice 2000 - 2008  

NSDL National Science Digital Library

This site features a video that illustrates both seasonal patterns and long-term changes in sea ice distribution across the Arctic Ocean. It draws data from two satellite instruments that measure emitted microwave radiation, which helps distinguish open ocean from ice. It shows that during the winter months, a layer of ice forms across vast expanses of the Arctic Ocean and each summer, more than half of that ice vanishes. Students discover that this natural cycle of freezing and thawing is influenced both by seasonal temperature variations and long-term climate change and that scientists are using satellite images to measure the distribution of Arctic sea ice in order to gain a better understanding of how it is linked to Earth's climate system.

408

WINDandSEA  

NSDL National Science Digital Library

Site was built in response to the many reference questions that are posed to the library and is meant to make internet searching more efficient for those concerned with oceanic and atmospheric issues, and the general public. Presently WINDandSEA has over 1,000 links to science and policy sites organized by topic and alphabetically within topic. All sites have been reviewed and annotated by NOAA staff.

409

Dauphin Island Sea Lab  

NSDL National Science Digital Library

Dauphin Island Sea Lab is Alabama's marine education and research center. Lab also provides a public aquarium that focuses solely on the native eco-systems of the Mobile Bay estuary. Site provides information on graduate programs, undergraduate opportunities, faculty, facilities, and news and events. Explore the Education and Aquarium sections for teacher resources and information on workshops, student summer camps, and academic-year programs.

410

Deep Sea Diver  

Microsoft Academic Search

From 2005 to 2009, Danny Lyon made several visits to Shanxi Province in northeast China, making pictures of locals that reveal the daily lives of industrial China. The images that follow are excerpted from Deep Sea Diver, a facsimile travel journal and photo book that showcases the black-and-white silver gelatin images Lyon shot with his vintage Leica cameras.Lyon's photo exhibition,

Danny Lyon

2012-01-01

411

Salish Sea Expeditions  

NSDL National Science Digital Library

At-sea education program combines classroom study with shipboard science studies in Puget Sound, Washington. Offers spring programs for schools and home schoolers, summer programs for families and youngsters; expeditions of 1 to 5 days involve oceanographic sampling activities, navigation and sailing responsibilities aboard a 61-foot sailing vessel. Teachers can join a preview sail to evaluate; site provides details on water quality, plankton and other studies and equipment used.

412

Variability modes of sea level in the Sea of Japan  

NASA Astrophysics Data System (ADS)

Variability of sea level in the Sea of Japan is studied using multivariate analysis of weekly altimetry fields spanning from October 1992 through October 2009. Interacting (non-orthogonal) modes of variability are revealed on seasonal time scale, representing synchronous oscillations in the entire Sea and meridional sea level gradient, respectively. The highest sea level and sharpest gradient occur in October and the strongest opposite phase occurs in March. Intra-seasonal and quasi-biennial synchronous oscillations also occur. The fluctuations of the level gradients are not statistically significant on these time scales. The 180-degree-out-of-phase oscillations occur in the western and eastern parts of the Sea on semiannual, annual, quasi-biennial, and longer interannual time scales, manifesting substantial changes in the regional circulation patterns. No secular trends related to the revealed modes were detected.

Trusenkova, O. O.; Kaplunenko, D. D.

2013-05-01

413

Sea & Ships: Explore online  

NSDL National Science Digital Library

The National Maritime Museum (NMM) in England notes that its goal is "working to illustrate for everyone the importance of the sea, ships, time and the stars and their relationship with people." There is so much to explore in the "Sea and Ships" portion of the NMM website, but a great way to see everything it has to offer is by using the "Sea and Ships Directory" at the bottom of the homepage. It divides the material up by "Subjects", "People", "Collections", "Online Galleries", and "Games and Interactives". Visitors interested in lessons about the ocean that come in the form of games, quizzes and stories, should definitely check out the "Your Ocean" link from the "Games and Interactives". The "Your Waste" lesson gives visitors the opportunity to test their skills at "managing an oil spill clean-up operation", in the game "Oil Crisis!" Keeping waste to a minimum is what the quiz "Pollution Solutions" addresses, and is also on the "Your Waste" page. Other lessons include "Your Energy", "Your Stuff" and "Your Climate".

414

Arctic Sea Ice  

NASA Astrophysics Data System (ADS)

Of all the recent observed changes in the Arctic environment, the reduction of sea ice cover stands out most prominantly. Several independent analysis have established a trend in Arctic ice extent of -3% per decade from the late 1970s to the late 1990s, with a more pronounced trend in summer. The overall downward trend in ice cover is characterized by strong interannual variability, with a low September ice extent in one year typically followed by recovery the next September. Having two extreme minimum years, such as what was observed in 2002 and 2003 is unusual. 2004 marks the third year in a row of substantially below normal sea ice cover in the Arctic. Early summer 2004 appeared unusual in terms of ice extent, with May a record low for the satellite period (1979-present) and June also exhibiting below normal ice extent. August 2004 extent is below that of 2003 and large reductions in ice cover are observed once again off the coasts of Siberia and Alaska and the Greenland Sea. Neither the 2002 or 2003 anomaly appeared to be strongly linked to the positive phase of the Arctic Oscillation (AO) during the preceding winter. Similarly, the AO was negative during winter 2003/2004. In the previous AO framework of Rigor et al (2002), a positive winter AO implied preconditioning of the ice cover to extensive summer decay. In this hypothesis, the AO does not explain all aspects of the recent decline in Arctic ice cover, such as the extreme minima of 2002, 2003 and 2004. New analysis by Rigor and Wallace (2004) suggest that the very positive AO state from 1989-1995 can explain the recent sea ice minima in terms of changes in the Arctic surface wind field associated with the previous high AO state. However, it is also reasonable to expect that a general decrease in ice thickness accompanying warming would manifest itself as greater sensitivity of the ice pack to wind forcings and albedo feedbacks. The decrease in multiyear ice and attendant changes in ice thickness distribution could in turn precondition the Arctic ice cover to further reductions in the subsequent summer(s) regardless if the summer temperatures were anomalously warm. The NSIDC Sea Ice Index (http://nsidc.org/data/seaice_index/) can be used to view trends and anomalies from 1979 on.

Stroeve, J. C.; Fetterer, F.; Knowles, K.; Meier, W.; Serreze, M.; Arbetter, T.

2004-12-01

415

Seasonal sea level cycle in the Caribbean Sea  

NASA Astrophysics Data System (ADS)

The seasonal sea level cycle has been investigated in the Caribbean Sea using altimetry and tide gauge time series from 27 stations and is characterized by large spatial variability. The coastal annual harmonic has amplitudes that range from 2 cm to 9 cm, peaking between August and October and semi-annual harmonic with maximum amplitude of 6 cm, with most stations peaking in April and October. The coastal seasonal sea level cycle accounts for up to 76% of the monthly sea level variance. The barometric effect on the coastal sea level seasonal cycles is insignificant in the annual component but dominant at 9 stations in the semi-annual cycle. The seasonal sea level cycle from 18 years of altimetry confirm the results obtained from the tide-gauges. In addition it illustrates areas where particularities in the seasonal cycle exist. The seasonal sea level cycle in the Caribbean Sea is unsteady in time, with significant variations in amplitude and phase lag at most of the stations, where the 5-year amplitude in the coastal annual cycle can change over 6 cm in a 24 year period. The seasonal sea level cycle has a larger range than the range from the annual and semi-annual components, and peaks about October when the probability of coastal impacts increases, especially in the northern coast of South America where the range is larger. This analysis is supported by the Lloyd's Register Trust Fund project Marine Extremes.

Torres, R.; Tsimplis, M.

2012-04-01

416

Long Term Variability of Sea Surface Temperature in Mediterranean Sea  

NASA Astrophysics Data System (ADS)

The long term variability of the sea surface temperature (SST) of the Mediterranean basin and its sub-basins for the period 1869-2006 (138 years) is investigated using the International Comprehensive Ocean-Atmosphere Data Set (I-COADS). Analysis of the SST time-series revealed a positive trend in both basin and sub-basin scale. During the last century, the highest positive SST trend is found in the Adriatic Sea (0.0141° C/y) and the lowest one in the Aegean sea (0.0011° C/y). This difference in the SST evolution in the two sub-basins can be related to the shift of the Eastern Mediterranean deep water formation site during the 90s, known as Eastern Mediterranean Transient (EMT). The SST variations of the Eastern Mediterranean sub-basins (Adriatic Sea, Ionian Sea, Aegean Sea, Levantine Sea) are highly correlated to each other, in contrast to the poor correlation of the SST variations between the Eastern and Western Mediterranean Sea. Harmonic analysis has shown that a dominant period of the Mediterranean variability is similar to the deep water turnover time of the basin. Comparison with climatic indices points out a high correlation of the Western Mediterranean and Adriatic Sea SST with the NAO index, while the Eastern Mediterranean SST variations are highly correlated to the Indian Summer Monsoon Index.

Axaopoulos, P.; Sofianos, S.

2010-01-01

417

Two new UV-absorbing mycosporine-like amino acids from the sea anemone Anthopleura elegantissima and the effects of zooxanthellae and spectral irradiance on chemical composition and content  

Microsoft Academic Search

Many tropical cnidarians living in shallow water contain a class of ultraviolet-A (UV-A, 320 to 400 nm) and ultraviolet-B (UV-B, 280 to 320 nm) absorbing compounds known as mycosporine-like amino acids (MAAs). These compounds may provide protection from the deleterious effects of solar UV radiation. Using a novel application of reverse-phase high performance liquid chromatography, we find that the temperate

W. R. Stochaj; W. C. Dunlap; J. M. Shick

1994-01-01

418

Sea Otter, River Otter. The Wonder Series.  

ERIC Educational Resources Information Center

This curriculum guide is all about otters and provides information on both sea and river otters. Included are activities related to the diet of sea otters, the adaptations sea otters have made to live in the sea, their tool-using abilities, where they live and how to spot them, comparative anatomy of sea and river otters, and otter movement. The…

Robinson, Sandra Chisholm

419

Sea Otter, River Otter. The Wonder Series.  

ERIC Educational Resources Information Center

|This curriculum guide is all about otters and provides information on both sea and river otters. Included are activities related to the diet of sea otters, the adaptations sea otters have made to live in the sea, their tool-using abilities, where they live and how to spot them, comparative anatomy of sea and river otters, and otter movement. The…

Robinson, Sandra Chisholm

420

Isotope studies in the Caspian Sea  

Microsoft Academic Search

Oceanographic and isotopic investigations in the Caspian Sea and the analyses of the available data on the discharge to the sea and the observed sea level changes suggest that climatically caused changes of river inflow are the major cause of the sea level fluctuations over the last century. Hydrogen-3 and 3H–3He data indicate that the deep basins of the sea

K. Froehlich; K. Rozanski; P. Povinec; B. Oregioni; J. Gastaud

1999-01-01

421

Sea Scallop Shell Lab Handout  

NSDL National Science Digital Library

Used in combination with the Sea Scallop Shell Lab teacher's guide, students will examine sea scallop shells to figure out as much as possible about the scallops living on the sea floor in one three important fishery grounds, Hudson Canyon, off New Bedford, MA, and George's Bank. The activity emphasizes observation, measurements, and basic calculations. The teacher's guide is available from the COSEE-NE OSEI resource site.

422

Experiencing the Full Research Process at Sea Education Association (SEA)  

NASA Astrophysics Data System (ADS)

While some undergraduate research experiences include only a small piece of the research process, students attending Sea Education Association's SEA Semester complete all aspects of oceanographic research in an intensive 12 week program that earns a full semester's credit. In the first half of the program, students read and discuss background literature on a subject, ask questions, pose hypotheses, and develop a written research proposal, which they defend orally. The second half of the course takes place at sea on one of SEA's state-of-the-art oceanographic research vessels where students carry out their sampling plans, analyze samples and data, write a final paper and present their results before the vessel reaches port, completing the course. At sea, students participate in sample collection and analysis for all student projects in addition to learning the general oceanography along their cruise track. This structure exposes students to the realities of research from start to finish and allows them to take full ownership of their projects. In addition to honing writing, public speaking, and problem-solving skills, students learn that research requires dedication, flexibility, and creativity, particularly when their results are unexpected or negate their hypothesis. SEA's undergraduate research program has been developing since 1971. Over that time, SEA has collected an extensive historical oceanographic database in the western Atlantic and Caribbean, plus Pacific data since 2001. This database is available to both students and outside research scientists. Collaborations with scientists outside SEA enhance the student experience and help facilitate oceanographic research by providing "ship-of-opportunity" sampling in remote locations. SEA Semester provides an excellent model for undergraduate research experiences with over 5000 alumni, about 30% of whom enter graduate school. About half the students in SEA's undergraduate programs are non-science majors. Although their experience at SEA may be their only hands-on exposure to scientific research, they take away an understanding of the process and an ability to think critically about scientific problems.

Harris, S. E.; Joyce, P.; Jaroslow, G.; Graziano, L.; Lea, C.; Witting, J.; Bower, A.

2003-12-01

423

Arctic Sea Level Since 1950  

NASA Astrophysics Data System (ADS)

We investigate sea level change and variability in the Arctic region over the 1950-2009 time span. Analysis of >60 long tide gauge records available since 1950 along the Norwegian and Russian sectors shows that coastal mean sea level was almost stable until about 1980 but since then displayed a clear increasing trend. In fact until the mid-1990s, the mean sea level closely followed the Arctic Oscillation (AO) index variations. However, since about 1995, the mea sea level curve departs from the AO influence and presents a large increasing trend of ~ 4 mm/yr. Using in situ ocean temperature data down to 700 m (from the WOD09 and JAMSTEC data bases), we estimated the thermosteric sea level at the tide gauge sites of the Norwegian sector and found that the recent increase in sea level has a dominant thermal origin. This suggests that inflow of warm North Atlantic waters may be responsible for the recent sea level changes observed along the Norwegian and Russian coasts. Comparison, over the altimetry era (since 1993), of altimetry-based and steric spatial trend patterns in sea level in the North Atlantic (>50°N) and Nordic Seas shows on the other hand that observed (altimetry-based) patterns essentially result from a combination of temperature and salinity effects, themselves driven by natural climate modes (AO and NAO).

Cazenave, A. A.; Henry, O.; Prandi, P.; Llovel, W.; Jevrejeva, S.

2011-12-01

424

Creating the College of the Sea: The Origin of the Sea Grant Program.  

National Technical Information Service (NTIS)

Contents: Creating the college of the sea: the origin of the sea grant program; Rediscovering the ocean; Rhode Island nurtures the sea grant concept; Congress acts; Sea Grant: The first 10 years; National Sea Grant College and Program Act of 1966; Sea Gra...

J. Miloy B. Crowder

1983-01-01

425

Evolutionary conservation supports ancient origin for Nudt16, a nuclear-localized, RNA-binding, RNA-decapping enzyme  

Microsoft Academic Search

Nudt16p is a nuclear RNA decapping protein initially identified in Xenopus (X29) and known to exist in mammals. Here, we identified putative orthologs in 57 different organisms ranging from humans to Cnidaria (anemone\\/coral). In vitro analysis demon- strated the insect ortholog can bind RNA and hydrolyze the m7G cap from the 5'-end of RNAs indi- cating the Nudt16 gene product

Melissa J. Taylor; Brenda A. Peculis

2008-01-01

426

Sea MARC II Investigation of the Norwegian-Greenland Sea.  

National Technical Information Service (NTIS)

More than 80,000 sq km of SeaMARC II imagery was obtained in the northern Norwegian-Greenland Sea during October and November, 1989. Regions insonified included the Bjorneya Fan, a transect at 73 deg N from the continental margin to the Mohns Ridge, an al...

C. De Moustier

1991-01-01

427

Ambient noise measurements in the Sea of Japan (East Sea)  

Microsoft Academic Search

Ambient noise signals were extracted during a pilot experiment in the Sea of Japan (also called East Sea) from September 11 to October 23, 1999, to assess the possibility of using acoustic tomographic techniques for the monitoring of water mass structure and dynamics. The measurement system consisted of a vertical line array with 10 elements (spaced 10 m apart) distributed

Youngshin Kim; Hyoungsul La; Jungyul Na; Suntaek Oh

428

Macronutrients in the Summer Sea ice of the Ross Sea  

Microsoft Academic Search

The development and production of sea ice microbial communities is often linked to limitations imposed by light, temperature and salinity. Nutrients also impose a limitation upon biomass development and production. Nutrient constraints on biomass development was readily evident in surface habitats of the pack ice of the Ross Sea during the summer of 1999. The spatial extent of nutrient depletions,

C. H. Fritsen; D. L. Garrison; D. R. Neenan; S. L. Coale; A. H. Gibson

2004-01-01

429

Glacial sea surface temperature of the East Sea (Japan Sea) inferred from planktonic foraminiferal assemblage  

Microsoft Academic Search

In order to reconstruct the last glacial sea surface temperature (SST) of the East Sea, we investigated planktonic foraminiferal\\u000a assemblage in the marine sediments of a piston core recovered from the Ulleung Basin, East Sea. For core top, the most dominant\\u000a species is right coiling Neogloboquadrina incompta, while left coiling Neogloboquadrina pachyderma and Globigerina bulloides clearly dominate the glacial assemblages.

Kyung Eun Lee; Katsunori Kimoto; Dae Hyun Kim

2010-01-01

430

Science Nation: Sea Turtles  

NSDL National Science Digital Library

Researchers at the University of North Carolina are studying how loggerhead and other sea turtles use the Earth's magnetic field for a journey of thousands of miles around the Atlantic Ocean. The turtles react to the Earth's magnetic field as they navigate a five-to-10-year journey that takes them from the east coast of the United States to the coast of Portugal, south toward the west coast of Africa, then back toward the beach where they were born. A better understanding of this turtle ability could help in research of both animal and human navigation.

431

Sea Level Rise: A Literature Survey.  

National Technical Information Service (NTIS)

Contents: Introduction; Causes of climatic change; Causes of temperature change; Relation between temperature rise and sea level rise; Sea level changes in the past; Future sea level rise; and Conclusions and recommendations.

G. H. P. O. Essink

1992-01-01

432

Sea Grant Publications Index 1975. Volume 1.  

National Technical Information Service (NTIS)

The Sea Grant Publications Index lists all materials received by the National Sea Grant Depository (NSGD) in 1975, with the exception of newsletters which appear in the Sea Grant Newsletters Index. It supplements the earlier publications covering the peri...

P. K. Weedman

1976-01-01

433

Sea modeling and rendering  

NASA Astrophysics Data System (ADS)

More and more defence and civil applications require simulation of marine synthetic environment. Currently, the "Future Anti-Surface-Guided-Weapon" (FASGW) or "anti-navire léger" (ANL) missile needs this kind of modelling. This paper presents a set of technical enhancement of the SE-Workbench that aim at better representing the sea profile and the interaction with targets. The operational scenario variability is a key criterion: the generic geographical area (e.g. Persian Gulf, coast of Somalia,...), the type of situation (e.g. peace keeping, peace enforcement, anti-piracy, drug interdiction,...)., the objectives (political, strategic, or military objectives), the description of the mission(s) (e.g. antipiracy) and operation(s) (e.g. surveillance and reconnaissance, escort, convoying) to achieve the objectives, the type of environment (Weather, Time of day, Geography [coastlines, islands, hills/mountains]). The paper insists on several points such as the dual rendering using either ray tracing [and the GP GPU optimization] or rasterization [and GPU shaders optimization], the modelling of sea-surface based on hypertextures and shaders, the wakes modelling, the buoyancy models for targets, the interaction of coast and littoral, the dielectric infrared modelling of water material.

Cathala, Thierry; Latger, Jean

2010-10-01

434

Greenland Sea observations  

SciTech Connect

ERS-1 SAR data have been acquired over the Greenland Sea and Fram Strait during two periods, the Ice Phase of three-day repeat cycle from January to March 1992 and a one-month period in the 35-day repeat cycle from 16 July to 15 August 1992. Most data became available by way of the Broadband Data Dissemination System, i.e. with a spatial resolution of about 100 m. With these data various algorithms have been tested to derive sea ice parameters such as ice extent, ice concentration and ice displacement. In the latter period data were collected to support the activities of a research vessel in the area mainly related to the large polynyas that form east and north of Greenland. The formation of polynyas could clearly be outlined but also other phenomena were observed related to the influence of wind streets and gravity waves associated with the atmospheric boundary layer. The data will have to be studied further including full-resolution data to substantiate the conclusions arrived at.

Gudmandsen, P.; Mortensen, H.B.; Pedersen, L.T.; Skriver, H. [Technical Univ. of Denmark, Lyngby (Denmark). Inst. of Electromagnetics; Minnett, P. [Brookhaven National Lab., Upton, NY (United States)

1992-12-31

435

Remote Sensing of Sea Ice.  

National Technical Information Service (NTIS)

We are studying fully polarimetric scattering of electromagnetic waves from snow and sea ice with a three-layer random medium model which can account for snow covered sea ice. The snow layer is modeled as an isotropic random medium characterized by a scal...

J. A. Kong R. T. Shin M. Borgeaud S. V. Nghiem

1989-01-01

436

Gallery: Sound in the Sea  

NSDL National Science Digital Library

Sound in the Sea offers a selection of audio recordings captured beneath the ocean surface. This page contains a selection of audio files of whales, ships, seismic disturbances, and unknown noises. There are also related video and animation products, and several spectrograms and other images of ocean sound. Students can click any image to listen and learn more about sound in the sea.

437

Yeasts from the North Sea  

Microsoft Academic Search

Yeasts were isolated from twelve established sites in the North Sea from 1964 to 1966. A percentage frequency of 99% with populations varying from 3000 viable cells\\/L was observed. This mycota was characterized by considerable spatial and temporal fluctuation, with the dominant yeast present being the ascosporogenous species, Debaryomyces hansenii. This taxon, as well as other common North Sea yeasts,

S. P. Meyers; D. G. Ahearn; W. Gunkel; F. J. Roth

1967-01-01

438

Adriatic Sea Seasonal Circulation Variability  

Microsoft Academic Search

The general circulation of the Adriatic Sea is studied using the Regional Ocean Modeling System (ROMS) with climatological forcing. The seasonal variability in the Adriatic Sea is established and affected by atmospheric forcing, river runoff, and exchanges with the Eastern Mediterranean thermohaline circulation. In addition, the circulation is affected by the complex bathymetry in the basin. Several simulations are carried

H. G. Arango; J. Chiggiato

2003-01-01

439

How SeaBirds Dine  

Microsoft Academic Search

As I have ascertained that the following fact is not well known, I send you this account in the hope that it may be of interest to naturalists and to the general public. Anyone who lives in the Western Hebrides will have often watched on a calm day the sea-birds feeding with noisy clamour in the sea-lochs and about the

1888-01-01

440

Dead sea asphalts: historical aspects  

Microsoft Academic Search

Asphalts are present in the Dead Sea basin in three forms: (1) huge blocks, up to 100 tons in weight, composed of extremely pure (>99.99%) solid asphalt occasionally found floating on the lake, (2) veins, seepages, and cavity and fissure fillings in Lower Cretaceous to Holocene rocks, and (3) ozocerite veins on the eastern shore of the lake. Dead Sea

Nissenbaum

1978-01-01

441

Probability of sea level rise  

Microsoft Academic Search

The report develops probability-based projections that can be added to local tide-gage trends to estimate future sea level at particular locations. It uses the same models employed by previous assessments of sea level rise. The key coefficients in those models are based on subjective probability distributions supplied by a cross-section of climatologists, oceanographers, and glaciologists.

J. G. Titus; V. K. Narayanan

1995-01-01

442

GLOBAL SEA RISE: A REDETERMINATION  

Microsoft Academic Search

It is well established that sea level trends obtained from tide gauge records shorter than about 50-60 years are corrupted by interdecadal sea level variation. However, only a fraction (<25%) of even the long records exhibit globally consistent trends, because of vertical crustal movements. The coherent trends are from tide gauges not at collisional plate boundaries, and not located in

Bruce C. Douglas

1997-01-01

443

Glass Munchers Under the Sea  

NSDL National Science Digital Library

This NASA Astrobiology Institute article documents recent findings of bacterial life beneath the sea floor. These newly discovered bacteria are thought to live as far down as 500 meters beneath the sea floor and eat through volcanic rock, leaving behind burrows. The article contains hyperlinks to websites explaining some key vocabulary, related websites, and color photos and maps.

Mullen, Leslie; Institute, Nasa A.

444

Country Analysis Briefs: Caspian Sea.  

National Technical Information Service (NTIS)

The Caspian Sea region has become a central focal point for untapped oil and natural gas resources from the southern portion of the former Soviet Union. Beginning in May 2005, oil from the southern sections of the Caspian Sea began pumping through a new p...

2007-01-01

445

At Sea Personnel Transfer Concepts.  

National Technical Information Service (NTIS)

At sea personnel transfer on any level is an operation that poses a problem for the modern Navy. Current operations are high risk, slow, inefficient, costly, and can only be accomplished in low sea states. As a result of this apparent gap in capability, O...

D. Jurkiewicz J. Gardner S. Marikle

2006-01-01

446

The Cnidaria of the Nile Basin  

Microsoft Academic Search

At least half of the cnidarian fauna of the Nile basin (7+ species) is suspected of being of allochtonous origin. In addition,\\u000a species that are native (Limnocnida sp., Hydra spp.) have been poorly studied and seem to lack basin ende-mism. The introduced species (two of Pontocaspian and two of marine\\u000a origin) are either salt-loving or tolerant of broad fluctuations in

Henri J. Dumont

447

Deep Sea Duel  

NSDL National Science Digital Library

This Android app for the Illuminations online game Deep Sea Duel card game helps users develop mental computation skills by finding sums of 3 or 4 numbers. A student and the opponent, Okta the octopus take turns selecting cards. The first one to reach the target sum with 3 cards (in the 9-card game) or 4 cards (in the 16-card game) wins the game. You can choose how many cards are presented (9 or 16), what types of numbers they display (small integers through tricky decimals), and Okta's level of strategy. The game is not timed but depends on strategic planning in order to defend against Okta's moves while trying to collect a winning group of cards.

2012-08-29

448

Deep Sea Duel  

NSDL National Science Digital Library

This iOS app for the Illuminations online card game Deep Sea Duel (cataloged separately) helps users develop mental computation skills by finding sums of 3 or 4 numbers. A student and the opponent, Okta the octopus take turns selecting cards. The first one to reach the target sum with 3 cards (in the 9-card game) or 4 cards (in the 16-card game) wins the game. You can choose how many cards are presented (9 or 16), what types of numbers they display (small integers through tricky decimals), and Okta's level of strategy. The game is not timed but depends on strategic planning in order to defend against Okta's moves while trying to collect a winning group of cards.

2012-08-02

449

Contrasts in Arctic shelf sea-ice regimes and some implications: Beaufort Sea versus Laptev Sea  

USGS Publications Warehouse

The winter ice-regime of the 500 km) from the mainland than in the Beaufort Sea. As a result, the annual freeze-up does not incorporate old, deep-draft ice, and with a lack of compression, such deep-draft ice is not generated in situ, as on the Beaufort Sea shelf. The Laptev Sea has as much as 1000 km of fetch at the end of summer, when freezing storms move in and large (6 m) waves can form. Also, for the first three winter months, the polynya lies inshore at a water depth of only 10 m. Turbulence and freezing are excellent conditions for sediment entrainment by frazil and anchor ice, when compared to conditions in the short-fetched Beaufort Sea. We expect entrainment to occur yearly. Different from the intensely ice-gouged Beaufort Sea shelf, hydraulic bedforms probably dominate in the Laptev Sea. Corresponding with the large volume of ice produced, more dense water is generated in the Laptev Sea, possibly accompanied by downslope sediment transport. Thermohaline convection at the midshelf polynya, together with the reduced rate of bottom disruption by ice keels, may enhance benthic productivity and permit establishment of open-shelf benthic communities which in the Beaufort Sea can thrive only in the protection of barrier islands. Indirect evidence for high benthic productivity is found in the presence of walrus, who also require year-round open water. By contrast, lack of a suitable environment restricts walrus from the Beaufort Sea, although over 700 km farther to the south. We could speculate on other consequences of the different ice regimes in the Beaufort and Laptev Seas, but these few examples serve to point out the dangers of exptrapolating from knowledge gained in the North American Arctic to other shallow Arctic shelf settings. ?? 1994.

Reimnitz, E.; Dethleff, D.; Nurnberg, D.

1994-01-01

450

Bindin from a sea star.  

PubMed

The genetic basis for the evolution of development includes genes that encode proteins expressed on the surfaces of sperm and eggs. Previous studies of the sperm acrosomal protein bindin have helped to characterize the adaptive evolution of gamete compatibility and speciation in sea urchins. The absence of evidence for bindin expression in taxa other than the Echinoidea has limited such studies to sea urchins, and led to the suggestion that bindin might be a sea urchin-specific molecule. Here we characterize the gene that encodes bindin in a broadcast-spawning asterinid sea star (Patiria miniata). We describe the sequence and domain structure of a full-length bindin cDNA and its single intron. In comparison with sea urchins, P. miniata bindin is larger but the two molecules share several general features of their domain structure and some sequence features of two domains. Our results extend the known evolutionary history of bindin from the Mesozoic (among the crown group sea urchins) into the early Paleozoic (and the common ancestor of eleutherozoans), and present new opportunities for understanding the role of bindin molecular evolution in sexual selection, life history evolution, and speciation among sea stars. PMID:19601971

Patiño, Susana; Aagaard, Jan E; MacCoss, Michael J; Swanson, Willie J; Hart, Michael W

451

Light and vision in the deep-sea benthos: I. Bioluminescence at 500-1000 m depth in the Bahamian islands.  

PubMed

Bioluminescence is common and well studied in mesopelagic species. However, the extent of bioluminescence in benthic sites of similar depths is far less studied, although the relatively large eyes of benthic fish, crustaceans and cephalopods at bathyal depths suggest the presence of significant biogenic light. Using the Johnson-Sea-Link submersible, we collected numerous species of cnidarians, echinoderms, crustaceans, cephalopods and sponges, as well as one annelid from three sites in the northern Bahamas (500-1000 m depth). Using mechanical and chemical stimulation, we tested the collected species for light emission, and photographed and measured the spectra of the emitted light. In addition, in situ intensified video and still photos were taken of different benthic habitats. Surprisingly, bioluminescence in benthic animals at these sites was far less common than in mesopelagic animals from similar depths, with less than 20% of the collected species emitting light. Bioluminescent taxa comprised two species of anemone (Actinaria), a new genus and species of flabellate Parazoanthidae (formerly Gerardia sp.) (Zoanthidea), three sea pens (Pennatulacea), three bamboo corals (Alcyonacea), the chrysogorgiid coral Chrysogorgia desbonni (Alcyonacea), the caridean shrimp Parapandalus sp. and Heterocarpus