Global population genetic structure of the starlet anemone <Emphasis Type="Italic">Nematostella vectensis</Emphasis>: multiple introductions and implications for conservation policy

Distinguishing natural versus anthropogenic dispersal of organisms is essential for determining the native range of a species and implementing an effective conservation strategy. For cryptogenic species with limited historical records, molecular data can help to identify introductions. Nematostella vectensis is a small, burrowing estuarine sea anemone found in tidally restricted salt marsh pools. This species’ current distribution extends over three coast lines: (i) the Atlantic coast of North America from Nova Scotia to Georgia, (ii) the Pacific coast of North America from Washington to central California, and (iii) the southeast coast of England. The 1996 IUCN Red List designates N. vectensis as “vulnerable” in England. Amplified fragment length polymorphism (AFLP) fingerprinting of 516 individuals from 24 N. vectensis populations throughout its range and mtDNA sequencing of a subsample of these individuals strongly suggest that anthropogenic dispersal has played a significant role in its current distribution. Certain western Atlantic populations of N. vectensis exhibit greater genetic similarity to Pacific populations or English populations than to other western Atlantic populations. At the same time, F-statistics showing high degrees of genetic differentiation between geographically proximate populations support a low likelihood for natural dispersal between salt marshes. Furthermore, the western Atlantic harbors greater genetic diversity than either England or the eastern Pacific. Collectively, these data clearly imply that N. vectensis is native to the Atlantic coast of North America and that populations along the Pacific coast and in England are cases of successful introduction.     

A review of the gobioid fish genusgobioides

The gobioid genusGobioides Lacepède, 1800 shares with the amblyopine gobies (Gobiidae: Amblyopinae) an eel-like, elongate body with a continuous dorsal fin and an affinity for shallow water, muddy bottom habitats. Due to similarities in external morphology and habitat requirements, some workers consideredGobioides allied with amblyopine gobies. Others, however, dispute a close relationship betweenGobioides and the Amblyopinae; morphological and ecological similarities are considered to be homoplasious. Results of this study concur with placingGobioides separate from amblyopine gobies and within the gobiid subfamily Gobionellinae.Gobioides is easily distinguished from the Amblyopinae by its larger eyes (small inGobioides vs. inconspicuous in the Amblyopinae), fewer dorsal and anal-fin rays (14–20 vs. 27–48), and different fin element to vertebra ratios (1∶1 vs. 2∶1).Gobioides reaches lengths of 500 mm SL or greater whereas amblyopines rarely exceed 300 mm SL.Gobioides comprises five species (G. africanus, G. broussoneti, G. grahamae, G. peruanus, andG. sagitta). Although these gobies occupy habitats with similar conditions,Gobioides and amblyopines are nowhere sympatric.Gobioides occurs in tropical and subtropical coastal waters of the eastern and western Atlantic as well as the tropical eastern Pacific Ocean. In the eastern Atlantic.Gobioides is known from Senegal to Zaire. In the western Atlantic.Gobioides is reported from South Carolina to southern Brazil. In the eastern Pacific,Gobioides is known from Mexico to Peru.     

Genetic diversity and phylogenetic position of the subclass Astomatia (Ciliophora) based on a sampling of six genera from West African oligochaetes (Glossoscolecidae, Megascolecidae), including description of the new genus Paraclausilocola n. gen

To more confidently assess phylogenetic relationships among astome ciliates, we obtained small subunit (SSU) rRNA sequences from nine species distributed in six genera and three families: Almophrya bivacuolata, Eudrilophrya complanata, Metaracoelophrya sp. 1, Metaracoelophrya sp. 2, Metaracoelophrya intermedia, Metaradiophrya sp., Njinella prolifera, Paraclausilocola constricta n. gen., n. sp., and Paraclausilocola elongata n. sp. The two new species in the proposed new clausilocolid genus Paraclausilocola n. gen. are astomes with no attachment apparatus, two files of contractile vacuoles, and an arc-like anterior suture that has differentiations of thigmotactic ciliature on the anterior ends of the left kineties of the upper surface. Phylogenetic analyses were undertaken using neighbor-joining, Bayesian inference, maximum likelihood, and maximum parsimony. The nine species of astomes formed a strongly supported clade, showing the subclass Astomatia to be monophyletic and a weakly supported sister clade to the scuticociliates. There were two strongly supported clades within the astomes. However, genera assigned to the same family were found in different clades, and genera assigned to the same order were found in both clades. Thus, astome taxa appear to be paraphyletic when morphology is used to assign species to genera.     

A megapterygium larva of <Emphasis Type="Italic">Discoverichthys praecox</Emphasis> (Aulopiformes: Ipnopidae) from the tropical western Pacific

The larva of Discoverichthys (Aulopiformes: Ipnopidae) is described for the first time based on a specimen 39.5 mm in standard length collected in surface waters near the Marianas in the western North Pacific. Despite its remote location from the previous record in eastern North Atlantic (type locality), this larva was identified as Discoverichthys praecox by general agreements of meristic counts and other morphological features. It is characterized by the following possible autapomorphic features: body moderately elongate, with uniformly distended abdomen, terminating in long, stout trailing gut; all fins, particularly the pectoral and pelvic, are extensively produced; body pigmentation is scanty, but all fins except the caudal are polka-dotted distally and covered by unusually thick skin; the skeleton is largely cartilaginous, with poorly differentiated axial components and uniquely expanded dorsal- and anal-fin pterygiophores. Its peculiar morphology is discussed with special reference to transformation events.     

Paramoeba: A Common Marine Genus

Amoebae of the genus Paramoeba Schaudinn, 1896, have been found in British waters, further attesting to the wide distribution and common occurrence of these unusually interesting marine protozoa. The British strains belong to the species P. pemaquidensis Page, 1970, first described from the Atlantic coast of North America. The Nebenkörper appears to be characteristic of a morphologically and systematically homogeneous group of amoebae.     

Peltidiphonte gen. n., a New Taxon of Laophontidae (Copepoda: Harpacticoida) from Coral Substrates of the Indo-West Pacific Ocean

A new genus of the harpacticoid family Laophontidae is described and named Peltidiphonte gen. n. Eight new species are assigned to this genus; they were collected from different locations in the Indo-West Pacific Ocean, including the Comoros, the Kenyan coast, the Red Sea, the Andaman Islands, the northern coast of Papua New Guinea, the Solomon Islands and the northeastern coast of Australia. Most of the specimens were collected from dead coral substrates, suggesting a close affinity between the members of the new genus and this substrate. Peltidiphonte gen. n. can easily be discriminated from other genera of the family by the extremely depressed body and by the shape of the antennule, bearing two (or three) processes on the first segment and a hook-like process along the outer margin of the second segment. An identification key for the new genus is provided.     

Gorgonians (Anthozoa: Octocorallia) of the northwestern Sea of Japan

Three species of gorgonians (Primnoa pacifica, Calcigorgia japonica, and Thouarella superba) are reported as new records for the northwestern Sea of Japan; one of them (Calcigorgia japonica sp. n.) has been described as a new species. Variations of colony morphology in some species are described; the taxonomical value of specific characters is discussed. The geographical range of Primnoa pacifica in the northwestern Pacific is shown to be wider than was considered earlier. Variations of sclerite morphology (number of marginal plates, presence of additional basal plates, and number of marginal spines on the basal plate) are regarded as intracolonial or intraspecific variability. The distribution range of Thouarella superba described earlier from the Aleutian Islands (Nutting, 1912) was shown to extend into the low-boreal part of the boreal Pacific. An examined specimen of Paragorgia sp. differed from all known species and appeared similar only to P. regalis Nutting, 1912 reported from the eastern coast of Japan. The most distinctive characters of Calcigorgia japonica sp. n. were the shape of polyp, with a thin lower part looking like folded podia (in fixed specimens) and the presence of two types of clubs scattered among the sclerites of the polyp.     

Systematic review of the genus <Emphasis Type="Italic">Bothrocara</Emphasis> Bean 1890 (Teleostei: Zoarcidae)

The systematics of the eelpout genus Bothrocara Bean 1890 is reviewed on the basis of 941 specimens. Eight mostly eurybathic, demersal species are recognized, distributed mainly along the continental slopes of the North and South Pacific oceans, with one species entering the South Atlantic. Distributions are: B. brunneum ranges from the Sea of Okhotsk to the Gulf of Panama at depths of 199–1,829 m; B. elongatum ranges from the Gulf of Panama to Chile at depths of 720–1,866 m; B. hollandi ranges from the Sea of Japan to the southeastern Bering Sea at depths of 150–1,980 m; B. molle ranges from the western Bering Sea to the South Atlantic at depths of 106–2,688 m; B. nyx is known only from the eastern Bering Sea at depths of 790–1,508 m; B. pusillum ranges from the northern Bering Sea to British Columbia, Canada, at depths of 55–642 m; B. tanakae is found along the northern coasts of Honshu and Hokkaido islands, Japan, at depths of 274–892 m; B. zestum ranges from the Izu Islands, Japan, and central Honshu, Japan, to the Gulf of Alaska at depths of 199–1,620 m (an unidentifiable specimen from off Taiwan may be B. zestum). The species are distinguished from one another mainly on the basis of head pore patterns, gill raker morphology, coloration and various meristic and morphometric values. A determination key to the species is provided.     

Molecular phylogeny, biogeography and insights into the origin of parthenogenesis in the Neotropical genus Leposoma (Squamata: Gymnophthalmidae): Ancient links between the Atlantic Forest and Amazonia

Leposoma is a conspicuous component of leaf litter herpetofauna of South and Central American rainforests. The 15 bisexual and one parthenogenetic species are allocated to the parietale and scincoides groups based on morphology. Phylogenetic analyses of 1830 bp (mtDNA + nuclear) were performed on 63 specimens of four species from Amazonian and Panamanian rainforests, and six species and one undescribed form from the Atlantic Forest. Different methods of tree reconstruction were explored, with Anotosaura vanzolinia and Colobosauroides cearensis as outgroups. The monophyly of the parietale and scincoides groups is strongly supported. Contrary to previous hypotheses suggesting a recent contact between Atlantic and Amazon forests, our estimates point to an initial split in Miocene. The position of Leposoma baturitensis, endemic to relictual forests in the semiarid Caatingas northeastern Brazil, and its divergence from the remaining species of the Atlantic Forest, suggests an ancient isolation with no indication of a secondary contact with forests of the eastern coast. Our data do not permit unambiguous assignment of parental species of the unisexual Leposoma percarinatum or the mechanism involved in the origin of parthenogenesis, but revealed two highly divergent diploid and triploid lineages within L. percarinatum, indicating that the unisexuals represent a species complex.     

Reproductive Biology of Three Commercially Important Hemiramphid Species in South-eastern Australia

Synopsis The reproductive biology of eastern sea garfish Hyporhamphus australis, eastern river garfish H. regularis ardelio, and snub-nosed garfish Arrhamphus sclerolepis were described throughout their respective ranges in the coastal waters of New South Wales (NSW), Australia. Peaks in gonadosomatic indices indicated that spawning of eastern sea garfish occurred in late spring and early summer (November–December) on the south coast of NSW, and in winter and early spring (June–September) on the north coast. Eastern river garfish spawned between July and December in NSW estuaries and snub-nosed garfish spawned between October and January in the Clarence River. The sex ratios in commercial catches of eastern sea garfish from the north coast of NSW were biased toward male fish, but approached equality for fish caught from the south coast. Sex ratios were significantly biased toward female snub-nosed garfish, and female eastern river garfish from all estuaries sampled. Mean (±SE) batch fecundity was 1498 ± 110 (range: 98 – 3449) ripe oocytes per female for eastern sea garfish, 917 ± 36 (range: 102 – 2268) ripe oocytes per female for eastern river garfish, and 716 ± 104 (range: 20 – 2956) ripe oocytes per female for snub-nosed garfish across the range of mature sizes examined. There was a linear relationship between batch fecundity and fish size for all three species of garfish. Eastern sea garfish approached 50% maturity at a larger size than snub-nosed, or eastern river garfish. Size at 50% maturity was similar for male and female eastern river and snub-nosed garfish, but male eastern sea garfish matured at a significantly smaller size than females. All three species appear capable of spawning in the spawning season immediately following the one in which they were born. Mature female fish of all three species had distributions of oocyte diameters consisting of three or four modes, which strongly suggests asynchronous oocyte development and a multiple spawning strategy during the spawning season. Implications for the management of garfish fisheries in NSW are also discussed.