Fauna of anemonefishes (Pomacentridae,Amphiprioninae) and their host sea anemones (Cnidaria,Actiniaria) on reefs of Phu Quy,Con Son,and An Thoi Islands (South China Sea,South Vietnam,and Gulf of Thailand) and a review of these groups from the coastal waters of Vietnam

A full species composition of anemonefishes (Pomacentridae, Amphiprioninae) and their host sea anemones (Cnidaria, Actiniaria) from reefs of Phu Quy and Con Son Islands (off South Vietnam) and An Thoi Islands (northeastern Gulf of Thailand) is presented for the first time. A comparison of the faunas of anemonefishes and their host sea anemones is conducted in the coastal waters of Vietnam and adjacent waters. The presence of intermittent ranges of the anemonefishes in the coastal waters of Vietnam is demonstrated. For example, the ranges of two species, Amphiprion clarkii and A. frenatus, include the coastal waters of Vietnam, excluding the Gulf of Thailand, where they are not found even at the eastern border of the gulf. A. perideraion is absent in the Gulf of Tonkin, but it is distributed to the south along the entire coastal zone of Vietnam, including the Gulf of Thailand. In the coastal waters of Vietnam, A. sandaracinos is distributed only between the Gulf of Tonkin and Gulf of Thailand. A. polymnus is reliably indicated in the coastal waters of Vietnam between 12°50′ and 9°54′ N, but, most likely, its range is continuous along the entire Vietnamese coast. The richness of species composition of host sea anemones decreases (from nine to three species) in the southern direction, from Central Vietnam to the eastern border of the Gulf of Thailand.     

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.     

Symbiotic assemblage associated with the tropical sea urchin, Salmacis bicolor (Echinoidea:Temnopleuridae) in the An Thoi archipelago, Vietnam

The symbiotic assemblage associated with the tropical sea urchin, Salmacis bicolor was studied in the An Thoi archipelago, Vietnam. Five species of macrosymbionts were found on the surface of this echinoid host, including the polychaete, Ophiodromus sp. 3 (Hesionidae), gastropod, Vitreobalcis sp. (Eulimidae), shrimp, Allopontonia iaini (Palaemonidae), crab, Zebrida adamsii (Pilumnidae), and Ophiuroidea sp. This is the first record of A. iaini in association with S. bicolor in the coastal waters of Vietnam. The polychaete, Ophiodromus sp. 3 was located on the oral side of echinoids circled around the oral opening, while Vitreobalcis sp. was attached to the peristomial membrane. The shrimp, A. iaini and the crab, Z. adamsii were found among the spines; the latter was attached to the spines by chaelipeds. Of the 60 S. bicolor examined, 28 (46.6 %) were infested, with an average number of symbionts per host of 0.52. The prevalence increased with increasing sea urchin test size. We did not find symbionts on urchins whose test diameter was less than 35 mm. Almost all S. bicolor were inhabited by one symbiont, and in only three cases did we find two symbionts belonging to two different species on one host. Polychaete, Ophiodromus sp. 3 occurred most often, and only 1–6 specimens of the other species were found. The composition of the assemblage associated with S. bicolor was compared with that known for other assemblages associated with tropical sea urchins. The ecological characteristics of the association and the possible host-symbiont relationships are discussed.     

Observations of novel locomotion in the sea star Luidia senegalensis (Lamark, 1816) (Asteroidea: Paxillosida)

During abundance surveys of the nine-armed sea star Luidia senegalensis (Lamark, 1816) in shallow waters north of Cubagua Island, Venezuela, novel locomotive behaviour was recorded in one sea star. The animal was observed to ‘walk’ with four arms in contact with the benthos whilst the remaining five were held erect. This previously unreported means of locomotion may be: for chemosensory detection of the surroundings; to alter the characteristic track pattern left in sediments as a means to avoid detection by predators; or, to lift the arms to attract commensal cleaners, thus eliminating epibiont commensals that may occupy the ambulacral groove. Whilst the predators of L. senegalensis remain unknown, earlier observations of serranid fish biting this species may support the notion of this behaviour as a predator avoidance strategy.     

Microsatellite development for a tetrodotoxin-containing sea slug (Pleurobranchaea maculata)

Using 454 pyrosequencing data, 24 polymorphic microsatellite markers were identified for the grey side-gilled sea slug, Pleurobranchaea maculata. The grey side-gilled sea slug is found throughout the western and south Pacific and is known to contain high concentrations of tetrodotoxin. Polymorphism was assessed in 20 individuals obtained from geographically distinct locations within New Zealand. Between 2 and 15 alleles were identified at each locus. The observed heterozygosity (H_o) and expected heterozygosity (H_e) ranged from 0.10 to 1 and 0.10–0.94, respectively. No significant linkage disequilibrium between pairs of loci or deviations from the Hardy–Weinberg proportions were observed. The markers are central to understanding the population biology and genetic structure of P. maculata.     

External calcium concentration and fertilization in the sea urchin, Strongylocentrotusfranciscansus (A. Agassiz) (Echinodermata)

The role of external calcium ions in the fertilization of the sea urchin, Strongylocentrotusfranciscansus (A. Agassiz), was studied. When eggs were inseminated with jelly-treated sperm in artificial sea waters containing various concentrations of calcium, the percentage of fertilization decreased with decreasing concentrations of calcium. A small amount of external calcium ions was also found to be essential for fertilization by spermatozoa with reacted acrosomes. The binding capacity of jelly-treated spermatozoa to eggs was, however, not adversely affected by a calcium deficiency. These results suggest that calcium ions are required not only for the initiation of the acrosome reaction, but also for successful levels of fertilization following sperm-binding to eggs even after the acrosome reaction has occurred.     

Features of biology of the sea anemone Charisea saxicola Torrey, 1902 (Actiniaria: Condylanthidae) from the northwest Pacific

The first data on features of the biology of the sea anemone Charisea saxicola, which is widespread in the Northwest Pacific, were obtained. That species, inhabiting the littoral of Shikotan Isl. (the Minor Kurile Ridge), belongs by its trophological attributes to nonselective deposit feeders. Animals swallow soil together with the organisms in it, not separating mineral particles from organic ones. Populations of Ch. saxicola are presented by individuals of mail and female sex, however the females prevailed in number. Hermaphrodites and evidence of sex change were not revealed in that species. Females were in the postspawning condition in all settlements. Spermatogenic cells of the new generation at two stages of development were recorded in males.     

Distribution pattern, population structure, and growth of Septifer bilocularis (Bivalvia: Mytilidae) on reefs of Southern Vietnam

The features of the spatial distribution, size and age structure of populations, and growth of the bivalve mollusk Septifer bilocularis (Linnaeus, 1758) were investigated for the first time in the waters of Vietnam. It is shown that in the subtidal area, on reefs well protected from wave effects, S. bilocularis occupies a corallogenous substrate constructed of dead branchy colonies of Acropora and Porites and forms settlements there with a population density and biomass exceeding those in populations located along the open coast and developing on massive coral colonies of the genera Porites, Favia, and Favites. The extensive accumulation of sediments in the inner part of Vanphong Bay (Khanh Hoa Province) correlated with a decrease in the size and age ranges for populations of S. bilocularis. It is found that in places with regularly active hydrodynamics the mollusks grew somewhat more slowly and formed a more convex shell than on reefs protected from surf. The longevity of S. bilocularis estimated both from the greatest observed age and from the growth equation of Bertalanffy was somewhat greater in the former case compared with the latter one, but in general did not exceed 11 years for both cases. The results of the studies are discussed from the position of morphophysiological adaptations of sessile bivalve mollusks to life in contrasting environmental conditions of the upper subtidal zone.     

New records of a rare species of spariform fish Acanthopagrus schlegelii (Bleeker, 1854) (Osteichthyes: Sparidae) from Russian waters of the sea of Japan, with notes on the taxonomy of the genus Acanthopagrus Peters, 1855

A rare species of the spariform fish Acanthopagrus schlegelii from Russian waters is described. The synonymy of this species and the related literature data are analyzed. It is suggested that two species occur in Russian waters that differ in body coloration: A. schlegelii and A. czerskii.     

Copepods in spring annual sea ice at Terra Nova Bay (Ross Sea,Antarctica)

The aim of this study was to investigate patterns of abundance, distribution, temporal changes and species composition of the dominant ice-associated copepods in the spring annual pack ice, platelet ice and water column at Terra Nova Bay, Ross Sea, during late spring 1997. Ice cores were drilled for temporal and spatial scales. Stephos longipes and Harpacticus furcifer dominated the sea ice meiofauna in terms of numbers in the lower few centimeters of the bottom ice associated with high chlorophyll a and phaeopigment levels. Nauplii dominated the S. longipes population (91.6%) and occurred in extremely high concentrations. In contrast, copepodids were the dominant stages in H. furcifer. How H. furcifer carries out its entire life cycle and how it differs from ecologically similar species such as Drescheriella glacialis should be examined in more detail.     

Antibacterial substances from marine algae isolated from Jeddah coast of Red sea,Saudi Arabia

Marine algae are known to produce a wide variety of bioactive secondary metabolites and several compounds have been derived from them for prospective development of novel drugs by the pharmaceutical industries. However algae of the Red sea have not been adequately explored for their potential as a source of bioactive substances. In this context Ulva reticulata, Caulerpa occidentalis, Cladophora socialis, Dictyota ciliolata, and Gracilaria dendroides isolated from Red sea coastal waters of Jeddah, Saudi Arabia, were evaluated for their potential for bioactivity. Extracts of the algae selected for the study were prepared using ethanol, chloroform, petroleum ether and water, and assayed for antibacterial activity against Escherichia coli ATCC 25322, Pseudomonas aeruginosa ATCC 27853, Stapylococcus aureus ATCC 29213, and Enterococcus faecalis ATCC 29212. It was found that chloroform was most effective followed by ethanol, petroleum ether and water for the preparation of algal extract with significant antibacterial activities, respectively. Results also indicated that the extracts of red alga G. dendroides were more efficient against the tested bacterial strains followed by green alga U. reticulata, and brown algae D. ciliolata. Chemical analyses showed that G. dendroides recorded the highest percentages of the total fats and total proteins, followed by U. reticulata, and D. ciliolate. Among the bioflavonoids determined Rutin, Quercetin and Kaempherol were present in high percentages in G. dendroides, U. reticulata, and D. ciliolate. Estimation of saturated and unsaturated fatty acids revealed that palmitic acid was present in highest percentage in all the algal species analyzed. Amino acid analyses indicated the presence of free amino acids in moderate contents in all the species of algae. The results indicated scope for utilizing these algae as a source of antibacterial substances.     

A species of sea anemone Sagartia elegans (Dalyell, 1848) (Anthozoa, Actiniaria, Sagartiidae) that is new for the Black Sea and is capable of clonal reproduction

In the Black Sea, the sea anemone Sagartia elegans (Dalyell, 1848) has been found for the first time in the Gulf of Odessa (46°31′60 N, 30°48′ E) and karst caves and grottos of the Western Crimea (45°21′ N, 32°30′ E). Previously, S. elegans was known to inhabit coastal waters of Iceland, the British Isles, and continental Europe from Scandinavia to the Adriatic Sea. According to the available data, this gonochoristic species tends to asexual somatic reproduction through laceration: juvenile polyps develop from separated fragments of the pedal disc. A rich color polymorphism is observed. The numerous clonal populations that are found in caves consist of variously sized and similarly colored polyps. All of them descended from one parental individual.     

Deep‐sea bigscales,pricklefishes, gibberfishes and whalefishes (Teleostei: Stephanoberycoidei) off Brazil: new records,range extensions for the south‐western Atlantic Ocean and remarks on the taxonomy of Poromitra

The Stephanoberycoidei includes 23 genera and c. 94 species of deep‐sea teleosts commonly known as bigscales, pricklefishes, gibberfishes and whalefishes. Stephanoberycoidei is one of the least known groups of deep‐sea fishes, in spite of their apparent relative abundance in meso and bathypelagic depths. Nine species of the Stephanoberycoidei are reported here for the first time in Brazilian waters, and most of them represent new range extensions for the south‐western Atlantic Ocean. Those species are Melamphaes polylepis, Melamphaes typhlops, Poromitra sp. and Scopeloberyx robustus (Melamphaidae), Acanthochaenus luetkenii and Stephanoberyx monae (Stephanoberycidae), Rondeletia bicolor and Rondeletia loricata (Rondeletiidae) and Gyrinomimus sp. (Cetomimidae). Occurrences of the pricklefish Scopelogadus mizolepis (Melamphaidae), the gibberfish Gibberichthys pumilus (Gibberichthyidae) and the velvet whalefish Barbourisia rufa (Barbourisiidae) are confirmed in the Brazilian exclusive economic zone, but previously published records of Poromitra capito and Melamphaes simus (Melamphaidae) in the region most likely represent misidentifications. Validities of the recently described Poromitra kukuevi and Poromitra indooceanica are discussed in light of new specimens of the genus collected in the south‐western Atlantic Ocean. An identification key for the 13 species of Stephanoberycoidei reported off Brazil is also provided.