Evidence for several types of biologically active substances in north pacific sea anemones

1. Twenty-two sea anemone samples from seven species were collected in Aleutian and Comandorskiye Islands from sub-littoral region (> 50 m depth).2. Water-ethanol extracts of sea anemones were tested using various test-systems after ethanol evaporation.3. All sea anemones extracts inhibited DNA and most of them inhibited RNA synthesis in Ehrlich carcinoma tumor cells.4. Extracts of most sea anemones species showed high hemolytic activity.5. The extracts proved to be nontoxic or display low toxicity being i.p. injected into mice.6. Some extracts precipitated virus of aleutian disease of mink.7. None of the extracts showed activity toward Gram + ve, Gram −ve bacteria or yeast.     

Active Nematocyst Isolation Via Nudibranchs

Cnidarian venoms are potentially valuable tools for biomedical research and drug development. They are contained within nematocysts, the stinging organelles of cnidarians. Several methods exist for the isolation of nematocysts from cnidarian tissues; most are tedious and target nematocysts from specific tissues. We have discovered that the isolated active nematocyst complement (cnidome) of several sea anemone (Cnidaria: Anthozoa) species is readily accessible. These nematocysts are isolated, concentrated, and released to the aqueous environment as a by-product of aeolid nudibranch Spurilla neapolitana cultures. S. neapolitana feed on venomous sea anemones laden with stinging nematocysts. The ingested stinging organelles of several sea anemone species are effectively excreted in the nudibranch feces. We succeeded in purifying the active organelles and inducing their discharge. Thus, our current study presents the attractive possibility of using nudibranchs to produce nematocysts for the investigation of novel marine compounds.     

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

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 anemonefish. When anemonefish were experimentally removed, sea anemone hosts contracted partially. Within 1–4 h in most cases, individuals of the butterflyfish Chaetodon fasciatus arrived and attacked the sea anemones, causing them to contract completely into reef holes. Upon the experimental return of anemonefish, the anemone hosts re-expanded. The long-term growth rate and survival of the sea anemones depended on the size and number of their anemonefish. Over several years, sea anemones possessing small or no fish exhibited negative growth (shrinkage) and eventually disappeared, while those with at least one large fish survived and grew. We conclude that host sea anemones sense the presence of symbiotic anemonefish via chemical and/or mechanical cues, and react by altering their expansion behavior. Host sea anemones that lack anemonefish large enough to defend them against predation may remain contracted in reef holes, unable to feed or expose their tentacles for photosynthesis, resulting in their shrinkage and eventual death.     

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

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 Received in revised form: 27 December 2000 Electronic Publication     

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

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 μg/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.     

Distribution of the under-ice mesozooplankton in the Kara Sea in February 2002

Mesozooplankton distribution was investigated under the sea ice in the Kara Sea at five stations in February of 2002 by Juday net hauls. Copepods dominated the mesozooplankton community, accounting for 46–88% of the total abundance and 68–99% of the biomass. Oithona similis was the most abundant species in Yenisei Bay, being present with all age stages (including egg-carrying females). For the first time, Oithona atlantica (CIII–CV copepodites, females and males) were found in the southeastern Kara Sea. In the southern part, Copepoda nauplii prevailed in terms of total abundance while the mesozooplankton in the northwestern part was entirely dominated by older stages of Pseudocalanus minutus. The mesozooplankton structure appears to be determined by available food resources and increased water temperature due to a strong influence of warm Atlantic waters.     

Ichtyotoxic activity of extracts from Mexican marine macroalgae

Seventy-three species of macroalgae from the Mexican Pacific, Atlantic and Caribbean coast were screened for ichtyotoxic activity. Ethanolic, acetonic and aqueous extracts were prepared and tested against the fish Carassius auratus. The extracts were classified on the basis of their effects as: toxic if the fish died in two hours or less; moderately toxic, if the organism behaved abnormally but death did notoccur, and non-toxic if the fish did not display any change. 79% species were ichtyotoxic to some degree. Extracts of 39 species were toxic, with at least one extract with lethal effects, 19 were moderately toxic and 15 species were non-toxic. Only the extracts ofDictyota bartayresiana, Dictyota cervicornis,Lobophora variegata, Bryothamnion triquetrum and Laurencia obtusa were toxic in all three solvents. The acetone and ethanol extracts were more active, and therefore are more suitable for extraction of toxic substances. This revised version was published online in August 2006 with corrections to the Cover Date.     

A New Polypeptide Toxin from the Nematocyst Venom of an Okinawan Sea Anemone Phyllodiscus semoni (Japanese name “unbachi-isoginchaku”)

The venomous sea anemone Phyllodiscus semoni causes cases of severe stinging. We isolated Phyllodiscus semoni toxin 20A (PsTX-20A), a hemolytic and lethal polypeptide (20 kDa), from the nematocyst venom of this species for the first time. Furthermore, we sequenced the cDNA encoding PsTX-20A. The deduced amino acid sequence of PsTX-20A showed that this toxin was a new member of the actinoporin family, which consists of several cytolytic polypeptides originating from sea anemones. PsTX-20A showed lethal toxicity to the shrimp Palaemon paucidens when administered via intraperitoneal injection (LD₅₀, 50 μg/kg) and hemolytic activity toward 0.8% sheep red blood cells (ED₅₀, 80 ng/ml).     

Some biological features and productive characteristics of <Emphasis Type="Italic">Oithona similis</Emphasis> (Copepoda) in the Sea of Okhotsk and western Bering Sea

The biological peculiarities of Oithona similis were described based on the materials from 29 complex surveys that were conducted by the TINRO Center in the Sea of Okhotsk and the western Bering Sea from 1986 to 2005 and the production of the species was estimated. In this area, O. similis produces four generations a year, viz., one in the spring, one in the fall, and two in the summer. The peak of spawning in May and June coincides with the maximum development of phytoplankton. Somatic production of O. similis in both seas becomes higher during the summer season. In this species, the largest increment in body weight begins with the copepodite stage CIV, when basic nutrients are accumulated. The average specific daily production of O. similis in the epipelagic zone of the Sea of Okhotsk and Bering Sea was 0.0092 and 0.01 in the spring, 0.043 and 0.031 in the summer, and 0.023 and 0.014 in the fall, respectively. The total somatic production of this species reached 28.318 million tons in the Sea of Okhotsk and 4.811 million tons in the Bering Sea. The Sea of Okhotsk is more favorable for the development of O. similis.     

Effect of excretion-secretion products of some fouling species on the biochemical parameters of blue mussel <Emphasis Type="Italic">Mytilus edulis</Emphasis> L. (Mollusca: Bivalvia) in the White Sea

The effect of excretion-secretion products (ESP) of five abundant fouling invertebrate species (bivalve mollusks Hiatella arctica and Mytilus edulis, solitary ascidia Styela rustica, sponge Halichondria panacea, and sea star Asterias rubens, inhabiting the White Sea) on the biochemical status of blue mussel M. edulis was assessed by the dynamics of lysosomal enzymes activity (nucleases, glycoside hydrolases, and cathepsins). ESP of conspecific species had no effect on the metabolism of the mollusks of this species. ESP of A. rubens, S. rustica, and H. panicea activated the same enzymes. First, acid RNase and glycoside hydrolases activity increased, but in different ways. The metabolites of H. arctica affected the activity of proteometabolism enzymes.     

First record of a rare pelagic octopod,Ocythoe tuberculata (Cephalopoda: Ocythoidae), in Korea

The family Ocythoidae is found throughout the temperate and subtropical waters of the world’s ocean and contains a single species, Ocythoe tuberculata. Recently, a single female specimen of the rare pelagic species O. tuberculata was collected off Uljin in the East Sea/Sea of Japan of Korea by squid jigging for the first time. The appearance of this species could be considered as evidence of the changes in species distribution of sea surface. However, further studies are required to investigate whether this phenomenon is temporary or continuous.     

Materials on fauna of anemonefishes (Perciformes, Pomacentridae, Amphiprioninae) and host sea anemones (Cnidaria, Actiniaria) from Con Son Islands (South China Sea, Southern Vietnam)

The species composition of anemonefishes (Amphiprioninae) and host sea anemones (Actiniaria: Actiniidae, Stichodactylidae) from the Con Son Islands is given for the first time. The investigations carried out in archipelago waters revealed four species of the anemonefishes associated with four species of the host sea anemones: Amphiprion freanatus in the symbiosis with sea anemone Entacmaea quadricolor (Actiniidae), A. perideraion with sea anemone Heteractis magnifica (Stichodactylidae), A. sandaracinos with sea anemone Stichodactyla mertensii (Stichodactylidae), and A. polymnus with sea anemone S. haddoni. The possibility of larval carrying in one more species of anemonefishes, i.e., A. clarkii, into the water area of the Con Son Islands from the nearby regions of the South China Sea is discussed. The view on the probable revealing of this species in the investigated region in the future is expressed.     

Chemistry of Two Distinct Aeolid Spurilla Species: Ecological Implications

The lipophilic extracts of two marine aeolid nudibranch molluscs of the genus Spurilla collected in distinct geographical areas have been chemically analyzed. The Et₂O extracts of the nudibranchs were dominated by the presence of usual fatty acids and sterols and contained terpenoid compounds 1  –  3 as minor metabolites. Spurillin A ( 1 ) and spurillin B ( 3 ) were new molecules whereas cis‐γ‐monocyclofarnesol ( 2 ) was already reported in the literature as a synthesis product. Interestingly, bursatellin ( 4 ), previously isolated from anaspidean molluscs of the genus Bursatella, was found in the butanol extract of both Spurilla species. Compounds 1  –  4 were not detected in the extracts of the sea‐anemone preys collected together with the molluscs.     

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

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.     

<Emphasis Type="Italic">Bathyphellia margaritacea</Emphasis> (Cnidaria: Actiniaria): the most northern species of the world

The sea anemone Bathyphellia margaritacea (Danielssen in Actinida. The Norwegian North-Atlantic expedition 1876–1878, Groendahl, Oslo, 1890) was collected by the research submersible MIR at the North Pole at a depth of 4,262 m and by the North Pole Drifting Station NP-22 in the American sector of Arctic Ocean covered by permanent ice. These widely separated records significantly increase the known geographic range of the species. B. margaritacea is highly plastic and has an ability to occupy different types of substrates. It appears to be the only species of sea anemone that is able to range in the high Arctic up to the North Pole and the only reliably identified species known from this part of the world.     

Phospholipase A2 in cnidaria

Phospholipase A2 (PLA2) is an enzyme present in snake and other venoms and body fluids. We measured PLA2 catalytic activity in tissue homogenates of 22 species representing the classes Anthozoa, Hydrozoa, Scyphozoa and Cubozoa of the phylum Cnidaria. High PLA2 levels were found in the hydrozoan fire coral Millepora sp. (median 735 U/g protein) and the stony coral Pocillopora damicornis (693 U/g) that cause skin irritation upon contact. High levels of PLA2 activity were also found in the acontia of the sea anemone Adamsia carciniopados (293 U/g). Acontia are long threads containing nematocysts and are used in defense and aggression by the animal. Tentacles of scyphozoan and cubozoan species had high PLA2 activity levels: those of the multitentacled box jellyfish Chironex fleckeri contained 184 U/g PLA2 activity. The functions of cnidarian PLA2 may include roles in the capture and digestion of prey and defense of the animal. The current observations support the idea that cnidarian PLA2 may participate in the sting site irritation and systemic envenomation syndrome resulting from contact with cnidarians.     

A new polypeptide toxin from the nematocyst venom of an Okinawan sea anemone Phyllodiscus semoni (Japanese name "unbachi-isoginchaku")

The venomous sea anemone Phyllodiscus semoni causes cases of severe stinging. We isolated Phyllodiscus semoni toxin 20A (PsTX-20A), a hemolytic and lethal polypeptide (20 kDa), from the nematocyst venom of this species for the first time. Furthermore, we sequenced the cDNA encoding PsTX-20A. The deduced amino acid sequence of PsTX-20A showed that this toxin was a new member of the actinoporin family, which consists of several cytolytic polypeptides originating from sea anemones. PsTX-20A showed lethal toxicity to the shrimp Palaemon paucidens when administered via intraperitoneal injection (LD50, 50 microg/kg) and hemolytic activity toward 0.8% sheep red blood cells (ED50, 80 ng/ml).     

First record of the sea anemone Diadumene lineata (Verrill 1871) associated to Spartina alterniflora roots and stems, in marshes at the Bahia Blanca estuary, Argentina

We report the occurrence of the orange-striped green anemone Diadumene lineata (Verrill 1871) (=Haliplanella lineata) in salt marshes at the Bahía Blanca Estuary for the first time in August 2005. We also found this species attached to roots and stems of Spartina alterniflora, an association that has never been registered before. After their determination, sampling was performed during a year to evaluate seasonal abundance of this sea anemone. Results showed that D. lineata was present through the whole year, indicating the existence of a stable population. All individuals sampled were found attached to roots or stems of S. alterniflora, with the higher abundances detected in summer. Further studies are necessary to precise the potential effects of this exotic sea anemone on salt marsh communities.     

Ecological analysis of benthic ostracods in the northern Japan Sea, based on water properties of modern habitats and late Cenozoic fossil records

The ecology of ostracods in the northern Japan Sea is well documented. These ostracods can be grouped in two assemblages: (1) the Tsushima Warm Current Surface Water Assemblage (TWSA, northern), which lives in an environment where summer temperatures reach up to about 20 °C, winter temperatures up to about 5 °C. Several species in this assemblage, e.g., Loxoconcha optima and Pontocythere subjaponica tolerate seasonally low temperatures, and lived in the region since the early Pleistocene; (2) the Japan Sea Intermediate Proper Water Assemblage (JSI-PA), which lives at greater depths (lower shelf to upper slope). This assemblage lives under stable conditions, with a small annual range in temperature (0–5 °C). The assemblage has a relatively low diversity, contains species such as Acanthocythereis dunelmensis and Robertsonites spp., and has been present in the area since the Pliocene. These data indicate that the presently living species either tolerate seasonally low temperatures (TWSA, northern) or tolerate stable, but very low temperatures (near 0 °C), and therefore, they could survive the Pleistocene environmental fluctuations in the Japan Sea caused by glacio-eustatic changes in sea level. Our data document the survival of ostracod species during past climate change, and thus can be used to speculate on the effect of possible future climate change on the faunas. We predict that some of the cryophilic species in the Japan Sea cannot be expected to survive global warming for more than 2 centuries.     

Do the Anemonefish Amphiprion ocellaris (Pisces: Pomacentridae) Imprint Themselves to Their Host Sea Anemone Heteractis magnifica (Anthozoa: Actinidae)?

Juvenile anemonefishes detect their host sea anemone by olfactory stimuli; in order to investigate whether this behaviour is innate or acquired, the anemonefish species Amphiprion ocellaris was bred in two different ways: 1. With no host sea anemone present at all (–A); and 2. With the specific host sea anemone Heteractis magnifica present in the hatching aquarium, so that these eggs were laid and hatched close to the sea anemone, as in nature (+A). The two different types of juvenile A. ocellaris were presented to the odours of the host sea anemone H. magnifica in two sets of short-term experiments with the host (a) visually hidden in a net cage, and (b) visible but physically separated from the anemonefishes. In both cases, a water flow was established between fishes and host. The +A-fishes found their host by olfactory and not by visual stimuli. In both series, the –A-fishes showed a significantly lower affinity behaviour towards the odour compounds from the host sea anemone than the +A-fishes did. A third type of experiment was a direct confrontation between fishes and host; here, the –A-fishes were indifferent towards the host sea anemone for almost 48 h, while the +A-fishes acclimated to the host sea anemone within the first 5 min of the direct confrontation. The results of this study suggest that Amphiprion ocellaris imprints itself olfactorily to its species-specific host sea anemone Heteractis magnifica, and, furthermore, may be genetically disposed towards olfactory recognition of the host sea anemone.