Pitar

Abstract: Benthic fauna were collected from 17 stations in mid-Narragansett Bay, Rhode Island, during September 1973 from the vicinity of the recently-closed Quonset Point electroplating facility. Despite repeated sampling, most of the 14 species of molluscs taken, including the widgeon clam Pitar morrhuana, were absent from stations in the immediate vicinity of plant outfalls. In general, P. morrhuana captured near outfall sites exhibited high moisture content and elevated body burdens of silver, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead, and zinc compared to clams of similar size from more distant stations. Observed changes in metal concentrations and moisture content of P. morrhuana were probably attributable to plant operations during the preceding 30 years.

Abstract: . The mollusc associations of 29 hard-substrate localities in the Northern Bay of Safaga Red Sea, Egypt were studied. The hard substrates were classified into 7 types: reef flats, intertidal rock bottom, very shallow subtidal conglomerate, Porites carpet, faviid carpet, platy scleractinian association, Sarcophyton carpet. Based on a cluster analysis the molluscs of these hard substrates can be classified into 5 groups: Group A is dominated by Dendropoma maxima, Chamoidea and Tridacna maxima, group B by Pedum spondyloideum, T. maxima and Coralliophila neritoidea, group C by Chamoidea and Cerithium ruppelli, group D by Modiolus auriculatus, Chamoidea, Morula granulata and Nerita albicilla and group E by Chamoidea and Pitar hebraea. The latter group contains only samples which are generally poor in molluscs. Group A molluscs are diagnostic for reef flats, group B for Porites and faviid carpets, group C for Sarcophyton carpets and group D for tidal/shallow subtidal rock substrates. The different hard substrates are therefore characterized by diagnostic mollusc associations and some of them could also be identified in the fossil record.

Abstract: Community structure of macrobenthos was studied at forty one stations of Hampyung Bay, southwest coast of Korea. Three replicate sediment samples were taken at each station in October 1997, using a van Veen grab (surface area ). The types of surface sediment in the sampling area were muddy sandy gravel between bay mouth and bay proper, and gravelly sandy mud between bay proper and inner bay stations. The particulate organic carbon content in the surface sediment was . A total of 168 species collected during the study period is composed of 58 of polychaetes, 54 of crustaceans, 34 of molluscs and 22 of miscellaneous. The former two taxa together were accounted for of the total number of species. The mean density was , comprising of molluscs (), of polychaetes (), and of crustaceans (). The mean biomass was , which is consisted of of molluscs (), of echinoderms (), and of crustaceans (). Major dominant species at the inner stations of the study area was Ruditapes philippinarum with a density of (), and Lumbrineris lontifolia with (), while that at bay mouth stations Pitar indecoroides with . Reticunassa festiva, Heteromastus sp., Praxillella affinis, Chone sp. and Tharyx sp. were at from all stations. Based on the cluster analysis, the macrobenthic community in the bay was classified into five station groups depending on sediment types: Group A, a high gravel content in the sediment; Group B, stations with high mud content from bay mouth to bay proper, Group C, stations with fine and poorly sorted sediment from bay proper to the inner bay. The distribution pattern of the number of species, abundance and biomass is discussed in relation to environmental variables.

Abstract: Ten new species of veneroid bivalves from Australia are described including four species of the Veneridae (Pitar (Pitarina) marrowae, P.(P.) potteri, Dosinia lochi, Dosinia queenslandica), three species of Cardiidae (Acrosterigma kerslakae. A. punctolineata, Fulvia voskuili), a crassatellid (Talabrica donharrisi), a tellinid (Tellina ( Abranda) jeanae) and a mactrid (Spisula (Notospisula) colganae). With the exception of Dosinia lochi which is known only from Boucaut Bay, Arnhem Land (type locality), all of the new species described occur in Queensland waters. Acrosterigma kerslakae, however, ranges south to Co!Jaroy Beach, Sydney, New South Wales.