Gobies (Gobioidei) of soft bottoms from Nha Trang and Van Phong bays (South China Sea,Vietnam)

Gobioid fishes collected in Nha Trang and Van Phong bays (Vietnam) represented by 44 species, including 30 species continuously associated with soft bottoms in the open parts of the bays with normal marine conditions are reviewed. A new species, Navigobius khanhoa sp. n., is described. This species differs from other species of the genus in much higher number of rays in the second dorsal fin (26), smaller size of the mouth, teeth on the jaws arranged in a single row, and other characters. Four species from the genera Acentrogobius, Eviota, Favonigobius, and Gnatholepis have not been identified to the species, and, most likely, some of them are new for science. Nine species are recorded in the fauna of Vietnam for the first time: Aulopareia unicolor, Bathygobius hongkongensis, Egglestonichthys bombylios, Glossogobius circumspectus, Oplopomops diacanthus, Oxyurichthys auchenolepis, Tomiyamichthys ex gr. russus, Tryssogobius porosus, and Valenciennea immaculata. An occurrence of Glossogobius olivaceus in the fauna of Vietnam is confirmed. Three species, G. olivaceus, Oligolepis acutipennis, and Periophthalmus kalolo, are recorded in the Cai River delta for the first time. A new synonymy is established: Eviota gurjanovae (Prokofiev, 2007) = E. prasina (Klunzinger, 1871). The current state of knowledge of Gobiidae fauna of Vietnam is discussed, and the updating of the species composition of Gobiodontini of Nha Trang Bay is presented in addition to the species list published earlier (Prokofiev, 2007).     

Reproductive features of <Emphasis Type="Italic">Upeneus margarethae</Emphasis> (Mullidae), a species recorded in the coastal zone of Vietnam for the first time

The species Upeneus margarethae described recently from the western Indian Ocean is recorded in the coastal zone of Vietnam for the first time. The reproductive features of the representatives of the species from southern Central Vietnam (Nha Trang Bay), Central Vietnam (Da Nang), and North Vietnam (Ha Long Bay) are studied. Based on the analysis of maturity stages of female’s ovaries and gonadosomatic index, the fishes spawn over the entire year in Central Vietnam, but the spawning interruption is observed in North Vietnam during a winter season. In Nha Trang Bay, 50% of females reach sexual maturity at the body length (FL) 9.8 cm. Based on histological structure of ovaries and frequency distribution of oocyte diameter before the spawning, the oogenesis is continuous. Anomalous oocyte structure is registered in 20% of the females. Egg morphology is described for 3 h after activation of ovulated oocytes. A comparison of reproductive parameters in U. margarethae and U. tragula is conducted.     

Two new species of fishes from families Muraenidae (Anguilliformes) and Mugiloididae (Perciformes) from the Waters of Vietnam

New species of the genera Gymnothorax (fam. Muraenidae) and Parapercis (fam. Mugiloididae) are described from coastal waters of central Vietnam. G. emmae sp. n. is a common species all along the coast from the Van Phong Bay to the Phan Thiet Bay and differs from other species of this genus in characters of coloration, dentition, and the vertebral formula. P. bicoloripes sp. n. is common in the Phan Thiet Bay and is also know from one specimen from the Nha Trang Bay; from other species of the genus, it differs in coloration and meristic characters.     

Metal concentrations in Sargassum algae from coastal waters of Nha Trang Bay (South China Sea)

The concentrations of metals, viz., Fe, Mn, Cu, Zn, Cd, Pb, and Ni, were investigated in brown algae of the genus Sargassum collected in the coastal waters of Nha Trang Bay (South China Sea). Metal concentrations in algae growing in the zone of influence of the city of Nha Trang were higher than those in macrophytes collected to the south and north of the city. Similar levels of Cu and Fe concentrations were observed in macrophytes from the urbanized coastal areas of Nha Trang Bay and in algae from the Peter the Great Bay (Sea of Japan). This is suggestive of comparable metal inputs from the anthropogenic sources of the cities of Nha Trang and Vladivostok (Peter the Great Bay). However, the concentrations of Pb, Ni, and Cd in algae from the coastal waters of Nha Trang Bay were lower than in macrophytes from the inshore zone of Vladivostok. The high level of pollution of sea water with Zn compounds near Nha Trang was local. The metal levels in macrophytes from background areas reflect the geochemical features of the environment. Sargassum algae from Nha Trang Bay had lower concentrations of Zn, Cd, and Ni and higher concentrations of Mn than algae from Peter the Great Bay. The background concentrations of Cu, Pb, and Fe in macrophytes from both bays were virtually the same.     

Two new genera of Oligocene Stomiiformes

New species of the genera Gymnothorax (fam. Muraenidae) and Parapercis (fam. Mugiloididae) are described from coastal waters of central Vietnam. G. emmae sp. n. is a common species all along the coast from the Van Phong Bay to the Phan Thiet Bay and differs from other species of this genus in characters of coloration, dentition, and the vertebral formula. P. bicoloripes sp. n. is common in the Phan Thiet Bay and is also know from one specimen from the Nha Trang Bay; from other species of the genus, it differs in coloration and meristic characters.     

Dragonets (Callionymidae) of soft bottoms from the coastal zone of southern Central Vietnam

A review of dragonets (Gallionymidae) from the coastal waters of Khanh Hoa (Nha Trang and Van Phong bays) and Binh Thuan (Phu Quy Island) provinces, Vietnam, was conducted based on the samples of the author. In total, nine species were recorded, including three species indicated in the fauna of the country for the first time. In addition, geographic and bathymetric distribution of C. altipinnis, as well as morphological variation of several other species, was specified.     

Anatomical description of the genus Perryena, and proposal to erect a new family for it based on its phylogenetic relationships with related taxa (Scorpaeniformes)

Osteological and myological characters of the genus Perryena are described and the phylogenetic position of the genus is inferred cladistically on the basis of 89 character transformation series, with Perryena representing a branch off a clade comprising the Tetrarogidae, Synanceiidae, Aploactinidae, Congiopodidae, Gnathanacanthidae and Pataecidae, following an initial divergence of the family Apistidae. Perryena is not closely related to Congiopodidae, despite its historical referral to that family. In keeping with the familial rankings given to successive branches of the remaining ingroup, the new family name Perryenidae is proposed for Perryena, here designated as the type genus of the family.     

Annotated checklist of species of the family pomacanthidae (Actinopterygii,Perciformes) from the Nha Trang Bay (South China Sea,Central Vietnam)

Angelfishes (Fam. Pomacanthidae) of the Nha Trang Bay (Central Vietnam) are reviewed. Fourteen species of pomacanthids belonging to six genera (Apolemichthys, Centropyge, Chaetodontoplus, Genicanthus, Pomacanthus, and Pygoplites) are recorded in the bay. All species are identified on preserved material. Two new species for the bay are found: Centropyge bispinosa and C. heraldi. C. herald is new species for coastal waters of Continental Vietnam and of adjacent areas. For all pomacanthid species of the bay, areas are described, brief diagnostic characteristics are supplied, and distribution by biotopes and depths is indicated based on data of underwater observations.     

Gurnards of the Genus Pterygotrigla (Triglidae) of Nha Trang Bay and Adjacent Waters (Vietnam,South China Sea)

Journal of Ichthyology - An overview of the species of gurnards of the genus Pterygotrigla, found in Nha Trang Bay and the adjacent water area of the South China Sea (south of Central Vietnam) has...     

Algal fouling of underwater structures at lobster farms in Nha Trang Bay (Vietnam)

The species composition and structure of algal fouling communities on the underwater artificial substrates at lobster farms in Nha Trang Bay (Vietnam) were studied for the first time. In total, 126 taxa (species and forms) of macroalgae (24% green, 16% brown, and 60% red), as well as eight species of cyanobacteria, were found. Depending on the area and quality of the substrate, fouling algae form polydominant turf communities, mono- and bidominant communities of crustose algae, or no specific communities. The flora of macroalgal fouling at lobster farms in Nha Trang Bay was similar in terms of its diversity and species composition to that of coral reefs in areas of the Indo-Pacific with a low level of pollution. This similarity might be due to the diversity and cleanness of the substrates (the absence of sediment on the surface of the underwater structures).     

New Moray Eel Species of Strophidon genus (Muraenidae) from Vietnam

Journal of Ichthyology - A new species, Strophidon dawydoffi sp. n., from Nha Trang Bay (South China Sea, Vietnam) was described. The new species is well distinguished from the cooccurring S....     

Impact of recent coastal development and human activities on Nha Trang Bay, Vietnam: evidence from a Porites lutea geochemical record

Nha Trang Bay (NTB) is located on the Central Vietnam coast, western South China Sea. Recent coastal development of Nha Trang City has raised public concern over an increasing level of pollution within the bay and degradation of nearby coral reefs. In this study, multiple proxies (e.g., trace metals, rare earth elements (REEs), and Y/Ho) recorded in a massive Porites lutea coral colony were used to reconstruct changes in seawater conditions in the NTB from 1995 to 2009. A 14-year record of REEs and other trace metals revealed that the concentrations of terrestrial trace metals have increased dramatically in response to an increase in coastal development projects such as road, port, and resort constructions, port and river dredging, and dumping activities since 2000. The effects of such developmental processes are also evident in changes in REE patterns and Y/Ho ratios through time, suggesting that both parameters are critical proxies for marine pollution.     

Biodiversity and Enzyme Activity of Marine Fungi with 28 New Records from the Tropical Coastal Ecosystems in Vietnam

The coastal marine ecosystems of Vietnam are one of the global biodiversity hotspots, but the biodiversity of marine fungi is not well known. To fill this major gap of knowledge, we assessed the genetic diversity (ITS sequence) of 75 fungal strains isolated from 11 surface coastal marine and deeper waters in Nha Trang Bay and Van Phong Bay using a culture-dependent approach and 5 OTUs (Operational Taxonomic Units) of fungi in three representative sampling sites using next-generation sequencing. The results from both approaches shared similar fungal taxonomy to the most abundant phylum (Ascomycota), genera (Candida and Aspergillus) and species (Candida blankii) but were different at less common taxa. Culturable fungal strains in this study belong to 3 phyla, 5 subdivisions, 7 classes, 12 orders, 17 families, 22 genera and at least 40 species, of which 29 species have been identified and several species are likely novel. Among identified species, 12 and 28 are new records in global and Vietnamese marine areas, respectively. The analysis of enzyme activity and the checklist of trophic mode and guild assignment provided valuable additional biological information and suggested the ecological function of planktonic fungi in the marine food web. This is the largest dataset of marine fungal biodiversity on morphology, phylogeny and enzyme activity in the tropical coastal ecosystems of Vietnam and Southeast Asia. Biogeographic aspects, ecological factors and human impact may structure mycoplankton communities in such aquatic habitats.     

Characterisation of 12 microsatellite loci in the Vietnamese commercial clam <Emphasis Type="Italic">Lutraria rhynchaena</Emphasis> Jonas 1844 (Heterodonta: Bivalvia: Mactridae) through next-generation sequencing

The marine clam Lutraria rhynchaena is gaining popularity as an aquaculture species in Asia. Lutraria populations are present in the wild throughout Vietnam and several stocks have been established and translocated for breeding and aquaculture grow-out purposes. In this study, we demonstrate the feasibility of utilising Illumina next-generation sequencing technology to streamline the identification and genotyping of microsatellite loci from this clam species. Based on an initial partial genome scan, 48 microsatellite markers with similar melting temperatures were identified and characterised. The 12 most suitable polymorphic loci were then genotyped using 51 individuals from a population in Quang Ninh Province, North Vietnam. Genetic variation was low (mean number of alleles per locus = 2.6; mean expected heterozygosity = 0.41). Two loci showed significant deviation from Hardy–Weinberg equilibrium (HWE) and the presence of null alleles, but there was no evidence of linkage disequilibrium among loci. Three additional populations were screened (n = 7–36) to test the geographic utility of the 12 loci, which revealed 100 % successful genotyping in two populations from central Vietnam (Nha Trang). However, a second population from north Vietnam (Co To) could not be successfully genotyped and morphological evidence and mitochondrial variation suggests that this population represents a cryptic species of Lutraria. Comparisons of the Qang Ninh and Nha Trang populations, excluding the 2 loci out of HWE, revealed statistically significant allelic variation at 4 loci. We reported the first microsatellite loci set for the marine clam Lutraria rhynchaena and demonstrated its potential in differentiating clam populations. Additionally, a cryptic species population of Lutraria rhynchaena was identified during initial loci development, underscoring the overlooked diversity of marine clam species in Vietnam and the need to genetically characterise population representatives prior to microsatellite development. The rapid identification and validation of microsatellite loci using next-generation sequencing technology warrant its integration into future microsatellite loci development for key aquaculture species in Vietnam and more generally, aquaculture countries in the South East Asia region.     

The fauna of the South China Sea include unknown phoronid species: new records of larvae and adults

The Phoronida is a phylum of marine invertebrates that have a worldwide distribution and that form huge benthic aggregations in many aquatic areas. Although there are only 11 recognized species of phoronids, many species clearly remain to be described. The matching of larval and adult stages of the same species will help indicate which larvae belong to described species and which represent undescribed species whose adults have yet to be found. Larvae of four phoronid species were collected in Nha Trang Bay and investigated by light microscopy and molecular methods. Three of the described larvae belong to new phoronid species that have yet to be named. These larvae have unique morphological features and occupy separate positions on the phylogenetic tree of phoronids. One of the described larvae belongs to Phoronis hippocrepia or to a closely related species. Observations made with a new macrophotographic method indicated that Phoronopsis californica also occurs in Nha Trang Bay. Thus, according to records of larvae and adults, Nha Trang Bay contains at least nine phoronid species: Phoronopsis californica, Phoronopsis malakhovi, Phoronis australis, Phoronis hippocrepia (or a closely related species), three unknown phoronid species whose larvae have unique morphological features and that apparently belong to the genus Phoronis, and two species, whose adults have unique set of morphological features. The richness of phoronids in this area suggests that the Indo-Pacific is a centre of phoronid biodiversity.     

Asexual reproduction, evisceration, and regeneration in holothurians (Holothuroidea) from Nha Trang Bay of the South China Sea

Peculiarities of asexual reproduction, evisceration, and regeneration were studied in 13 holothurian species of the orders Dendrochirotida and Aspidochirotida from Nha Trang Bay of the South China Sea. Asexual reproduction by fission has been described for the first time for Cladolabes schmeltzii. It has been shown for the first time that transected C. schmeltzii and Colochirus robustus successfully regenerate not only their anterior, but also their posterior structures. It was found that Pseudocolochirus violaceus was able to regenerate the anterior part of the body and to eject viscera through the anus. The modes of evisceration and regeneration of the gut have been elucidated for ten species of aspidochirotids. It has been shown that the intestine of Holothuria scabra forms from two anlagen rather than from a single one, as previously believed.