The Allocation of Some Pelagic Larvae of Bivalve Mollusks in the Western Part of Chukchi Sea

Collected in September-October 2016 in the 48th cruise of SRS “Academician Oparin” the plankton samples with the assistance of Norpac net with the cell of 150 μm in the horizon 15-0 m have shown the plenty of pelagic larvae of bivalve mollusk in Chukchi Sea. Its biggest quantity was found in the period from the 22nd of September until the 1st of October. The most yield area was situated on the opposite side of the Bering Strait and the second maximum of larvae quantity was found on the Herald’s bank. Most valuable factors influencing the territorial allocation of the researched larvae are the water surface temperature and the water depth.

Ecological Groups and Fauna of the Two Sub Species Mollusks in the Bank of Amu Darya

A brief information about two subspecies mollusks in the bank of Amu Darya river is collected according to the experience. As a result, we identified 9 types and 2 small types of two sub species mollusks live in Amu Darya river. Sinanodonta gibba, Sinanodonta orbicularis and Sinanodonta puerorum types for fauna were shown for the first time from the river.

Method of Biogeochemical Diagnostics of Heavy Metals Accumulation in Mollusks （Unionidae） and Estimation of Their Ecological Condition （The Case of the Amur River, Russia）

The present study gives a detailed analysis of HM （heavy metals） accumulation in mollusks Nodularia （Bivalvia, Unionidae） from the transboundary part of the Amur River （Russia-China）. This river basin experiences different levels of toxic pollution. Differences in the rate of HM bioaccumulation in mollusks are identified depending on their size, sex （male and female）, content of HM in environment, and ratio of accumulating macro- and micro-components in tissue. Mollusks＇ response to the change of HM content in the environment is expressed in the different intensities of their accumulation in tissue. The possibility of estimating toxic danger for mollusk according to the index of HM bioaccumulation with consideration of frequency of pathologies is shown. These indexes permitted estimation of the ecotoxicological condition of the mollusks population in the parts of the Amur, upstream and downstream of the inflow of the Sungari River and before and after the accidental pollution, respectively. It is found out that mollusks are able for bioremediation when pollution of the aquatic environment decreases. Quantitative correlation of HM bioaccumulation index in mollusks to HM content in the environment makes it possible to forecast the population condition, and to substantiate the necessity of ecological control of anthropogenic load on the ecosystem.

Detection of Relation between V and Zn in Two Species of Mollusks and the Surrounding Water in the Marshes of Southern Iraq

Elements （vanadium and zinc） were determined in the two most abundant species of shell mollusks （Unio tigridis and Fiviparous bengalensis） and the water where they live in five stations in the Iraqi marshes. The study of concentrations elements was a target organ for aquatic environmental. Comparison between the mean concentrations of the elements in the water concentration levels of all studied elements was the highest with the mollusks. The results show that the station 5 is where the highest concentrations are found in water and in the two species. There is a significant correlation （P = 0.224） for concentrations of vanadium and P = 0.735 for zinc in two species of mollusks relative to their concentrations in surface water. All significant differences were accepted at a level of P 〈 0.05. The potential uptake of elements including V and Zn, as Viviparous bengalensi 〉 Unio tigridis, The mechanism for elements uptake determined by water for organisms confined to the contaminated areas seemed to be largely independent of species, mollusks demonstrated a significant positive relationship with water. These results have important implications for the utility of marshes biota as subjects for elements monitoring program.

Differences in Trace Element Content between Non-Indigenous Farmed and Invasive Bivalve Mollusks of the South African Coast

contents of 23 trace elements (Sc, V, Cr, Mn, Fe, Co, Zn, As, Se, Br, Rb, Sr, Mo, Ag, Sb, I, Ba, La, Ce, Sm, Eu, Hf, Ta) were quantitatively determined in soft tissues and shells of mass non-indigenous bivalve mussels—farmed Pacific oysters (Crassostrea gigas) and farmed and wild invasive Mediterranean mussels (Mytilus galloprovincialis) at the Atlantic coast of South Africa. The study revealed that the contents of the majority of elements in the soft tissues of both species were higher than those in the shells. The tissues of wild invasive Mediterranean mussels contain higher levels of a range of trace elements comparing to farmed mussels. The tissues of Pacific oysters contain much higher levels of almost all elements studied compared to the tissues of Mediterranean mussels. Higher content of zinc in the mussels and oysters from Saldanha Bay may evidence anthropogenic pollution of the bay’s ecosystem by this metal, which necessitates continued monitoring of levels of potentially toxic metals. Both alien species, and especially Pacific oysters, may serve as reliable biomonitors for trace elements in marine ecosystems. Both species are rich in essential elements and provide nutritionally-valuable seafoods.

Combined Action of Lysozymes of Fresh-Water Bivalve Mollusks and Antibacterial Preparations against Some Clinical Strains of Microorganisms

The aim of the present study was to determine the MICs using broth microdilution method and their combination effect by （minimum inhibitory concentrations） of selected antibiotic agents determination of FICindex （fractional inhibitory concentrations）. Lysozyme Anodonta cygnea was more active than Lysozyme Uniopictorum, especially against Gram-negative bacterias. Combination of Macropen and Lysozyme Unio pictorum has a synergistic effect, while a separation of these antibacterial agents was not active against some of the strains of microorganisms.

Commercially Important Marine Mollusks for Human Consumption in Acapulco,Mexico

Acapulco, offers for international tourism a variety of mollusks that are delightful to the palate and a source of economic revenue for its residents;however there are no studies on the species consumed. Furthermore, data from the State agencies responsible for registration of these products are unclear. This work is aimed to develop an inventory of Gastropoda, Bivalvia and Polyplacophora marketed as food, to gain knowledge on the species native to Acapulco and the introduced ones. The places that sell shellfish were interviewed from 2008 to 2011 in order to determine the geographical origin of their products being offered. We identified 42 species: 15 species of gastropods are captured locally and three are introduced. On Bivalvia, seven species are caught locally and 16 are introduced. There are Bivalvia species caught locally;however, their capture is now unaffordable. It is likely that this situation is due to overfishing and/or the transmission of diseases or parasites caused by the introduction of foreign living organisms to Acapulco. Within the list of species caught locally, there are some listed as of subject protection;all of these organisms are exploited in Acapulco without control. The wealth of marine mollusks for human consumption in Acapulco is very high. The capture does not satisfy local market demand and the amount of introduced species is very high. It is necessary to make a diagnostic analysis of mollusk fishing industry in the state of Guerrero, also implement a management program, including the sanitary measures and control of introduced species, as they arrive alive and stay alive in the waters of Acapulco. A significant number of native species that have aquaculture potential should be studied for commercial culture practice as well as to conduct studies on their biology on those species that are considered over-exploited and allow recovery of the species in its habitat.

Mollusks of the Rocky Intertidal Zone at Three Sites in Oaxaca,Mexico

The community of mollusks at three rocky intertidal zone in Oaxaca, Mexico was analyzed. Two samplings per site were conducted. At each sampling the inspected area was 10 m2. The sampling unit was 1 m2. 5862 specimens were examined. 68 mollusks species were identified. The families better represented in species richness were: FISSURELLIDAE, MURICIDAE, LOTIIDAE, MYTILIDAE, CHAMIDAE, ISCHNOCHITONIDAE y CHITONIDAE. The species that had the greatest density were Lottia discors, Siphonaria palmata, Lottia acutapex, Chormoytilus palliopunctatus, Brachidontes adamsianus, Chton articulatus e Ischnochiton muscarius. The species with the widest distribution represent 11.76%. With irregular distribution was found in 58.82% of the species. The gastropod Crucibulummonticulus, the bivalve C. palliopunctatus and the polyplacophoran C. articulatus had the greatest size. The value of diversity index was H’ = 4.29 bits/ind. and J’ = 0.72. The mollusks community in the rocky intertidal zone study sites is characterized by small size, because they rarely exceed seventy millimeters. The values of H’ and J’ indicate that the mollusk community in the study area has a high diversity and high uniformity, corresponding to mature and stable communities in a tropical region.

Mollusks Resources in Western Coast of the Tonkin Gulf

It has been classed 856 species of the mollusks which belong to 120 families and five classes living in western coast of the Tonkin Gulf. The class Gastropod was the most abundant, with 449 species, the Bivalve with 368 species, the Scaphopoda with 10 species, the Cephalopods with 19 species and the Amphineura with eight species. Standing stock was estimated about 366,749 tons, that annually caught 80,000 tons. The causes of the resource depletion were human and natural, but the human factors played a key role. The fundamental orientations for developing the resources include： exploiting during harvest seasons, planning suitable aquaculture, moderate exploitation so the resources can restore themselves, combining exploitation and conservation.

Findings on three endocommensal scuticociliates(Protista,Ciliophora)from freshwater mollusks,including their morphology and molecular phylogeny with descriptions of two new species

Species of the ciliate genera Myxophyllum and Conchophthirus are found as endocommensals of terrestrial and freshwater mollusks,respectively.So far,there have been few studies of these genera and morphological data for most members are often incomplete.In the present work,two new species,Myxophyllum weishanense sp.nov.and Conchophthirus paracurtus sp.nov.,and a known species,Conchophthirus lamellidens,were isolated from hosts in Lake Weishan Wetland,China.Taxonomic studies indicate that M.weishanense sp.nov.can be recognized mainly by the combination of about 60 somatic kineties on both ventral and dorsal sides and the presence of caudal cilia.Conchophthirus paracurtus sp.nov.differs from congeners in its body shape and size,having a glabrous area on the posterior right side,and having fewer somatic kineties.In addition,differences in their ITS2(Internally Transcribed Spacer 2)secondary structures support the discrimination of the two new species from their highly similar congeners.An improved diagnosis for the poorly known species,C.lamel-lidens is also provided.Phylogenetic analyses reveal that members of the genus Myxophyllum belong to a fully supported clade that is sister to a large,poorly supported clade consisting of Hemispeiridae,Ancistridae,and several lineages of the nonmonophyletic Cyclidiidae.The Myxophyllum clade also includes Protophyra ovicola JQ956552,a possible misidenti-fication.Sequences of the two new Conchophthirus species cluster with other congeners in a fully supported clade that is unrelated to either the‘typical’thigmotrichs or to pleuronematids,thus conflicting with the traditional classification,and may represent an orphan scuticociliate lineage.

Impacts of Early Pleistocene glacial vicariance among refugial lineages and Mid-Late Pleistocene interglacial dispersal and expansion on forging population genetic structure of the giant clam Tridacna squamosa(Bivalvia:Cardiidae:Tridacninae)across the Red Sea and Indo-West Pacific oceans

This study aims at identifying the microevolutionary processes responsible for the onset of the remarkable phylogeographic structure already recorded for the endangered giant clam Tridacna squamosa across its distribution range.For this purpose,the evolutionary,biogeographic and demographic histories of the species were comprehensively reconstructed in a mitochondrial dataset comprising nearly the whole available published cytochrome c oxidase 1 gene sequences of T.squamosa.Relatively higher level of genetic diversification was unveiled within T.squamosa,in comparison to earlier macro-geographic investigations,whereby five mitochondrial clusters were delineated.The resulting divergent gene pools in the Red Sea,western Indian Ocean,Indo-Malay Archipelago and western Pacific were found to be driven by Early Pleistocene glacial vicariance events among refugial lineages.Accentuated genetic diversification of the species across the Indo-Malay Archipelago was successively triggered by historical dispersal event during the Mid-Pleistocene MIS19c interglacial.This latter historical event might have also enabled genetically distinct giant clams from the Indo-Malay Archipelago to subsequently colonize the western Pacific,accounting for the genetic diversity hotspot detected within this region(comprising three divergent mitochondrial clusters).Late Pleistocene demographic expansion of T.squamosa,during the Last Interglacial period,could have contributed to forging spatial distribution of the so far delineated genetic entities across the Indo-Western Pacific.Overall,being resilient to major climate shifts during the Pleistocene through adaptation and consequent diversification,T.squamosa could be used as a model species to track the impact of climate change on genetic variability and structure of marine species.In particular,the new information,provided in this investigation,may help with understanding and/or predicting the consequences of ongoing global warming on genetic polymorphism of endangered coral reef species among which Tridacna sp.are listed as ecologically important.

Distribution of methylsiloxanes in benthic mollusks from the Chinese Bohai Sea

Methylsiloxanes are a class of silicone compounds that have been widely used in various industrial processes and personal care products for several decades. This study investigated the spatial distribution of three cyclic methylsiloxanes(D4–D6) and twelve linear methylsiloxanes(L5–L16) in mollusks collected from seven cities along the Bohai Sea. D4–D6(df = 71%–81%) and L8–L16(df = 32%–40%) were frequently detectable in the mollusk samples, while L5–L7 were not found in any mollusk samples. Cyclic methylsiloxanes(D4–D6) were found in mollusks with the mean concentrations of 15.7 ± 12.3 ng/g ww for D4,24.6 ± 15.8 ng/g ww for D5 and 34.0 ± 23.0 ng/g ww for D6. Among the seven sampling cities, the cyclic methylsiloxanes were predominant in mollusks, with the total cyclic methylsiloxanes(sum of D4–D6, ∑ CMS) accounting for 74.2%–80.7% of the total methylsiloxanes. ∑ CMS along the coastline demonstrated a clear gradient, with the highest concentrations in mollusks at the sampling sites located in the western part of the Bohai Sea and the lowest concentrations in mollusks from cities located in the eastern part of the Bohai Sea. The biota-sediment accumulation factors for cyclic methylsiloxanes(D4–D6) and linear methylsiloxanes(L8–L16) were estimated as 0.42 ± 0.06–0.53 ± 0.06 and0.13 ± 0.03–0.19 ± 0.05, respectively.

Microstructural Dependence of Friction and Wear Behavior in Biological Shells

As an essential renewable mineral resource,mollusk shells can be used as handicrafts,building materials,adsor-bents,etc.However,there are few reports on the wear resistance of their structures.The Vicker’s hardness and friction,and wear resistance of different microstructures in mollusk shells were comparatively studied in the pre-sent work.The hardness of prismatic structures is lower than that of cross-lamellar and nacreous structures.How-ever,the experimental results of sliding tests indicate that the prismatic structure exhibits the best anti-wear ability compared with foliated,crossed-lamellar,and nacreous structures.The anti-wear and hardness do not present a positive correlation,as the wear resistance properties of different microstructures in mollusk shells are governed jointly by organic matrix,structural arrangement,and basic building block actions.The present researchfindings are expected to provide fundamental insight into the design of renewable bionic materials with high wear resistance.

Reclassification of Oligodon ningshaanensis Yuan, 1983(Ophidia:Colubridae) into a New Genus, Stichophanes gen. nov. with Description on Its Malacophagous Behavior

The complete mitochondrial cytb gene and the partial nuclear c-mos gene of Oligodon ningshaanensis Yuan, 1983 were sequenced and used for reconstructing the phylogenetic relationship of this taxon amongst alethinophidian snakes. Its strong affinity to the New World subfamily Dipsadinae and the Old World species Thermophis baileyi was inferred. Hemipenial morphology found by authors conflicts with the original description and its similarity with those of the dipsadid snakes is in accordance with our molecular results. Feeding tests show that O. ningshaanensis is a malacophagous predator, which is another matchless character for this species. This behavior is described and compared with other known slug- and snail-feeding snakes. The discovery of the particular position of our subject indicates that erecting a new genus is necessary accommodate this unique species.

Marine Species Introduced on the French Channel-Atlantic Coasts: A Review of Main Biological Invasions and Impacts

The impacts of anthropogenisation modify permanently the distribution patterns of brackish and marine species. Globalization leads to a rapid increase of the numbers of introduced species anywhere in the world. Biological invasions often result in significant losses in the economic value, biological diversity and function of invaded ecosystems. This review presents the main pathways of introduction of non-indigenous species and the main benthic taxonomic groups being established and/or invasive along the French Channel-Atlantic coasts. A focus is put on main invasive marine species in the intertidal and subtidal zones of Brittany (France), among macroalgae (Sargassum muticum, Grateloupia turuturu, Undaria pinnatifida, Codium fragile and Gracilaria vermiculophylla), halophytes (Spartina alterniflora) and benthic invertebrates (Mollusks: Crepidula fornicata, Crassostrea gigas and Venerupis philippinarum). The species biology, introduction vectors, reproductive and dispersal capacities are considered, together with proliferation patterns along the Channel-Atlantic coasts. The ecological impacts of these species on the environment are also described, as well as the European regulations existing to limit alien species introduction and some examples of struggle against the invaders including eradication trials and biomass valorization. Last, the on-going impacts of global changes on alien species invasiveness along the Channel-Atlantic coasts are discussed.

Occurrence and Distribution of Marsh Clam, <em>Polymesoda</em>spp. in Marudu Bay, Sabah, Malaysia

Marudu Bay is part of the Tun Mustapha Marine Park, the largest marine protected area within the Malaysian region of the Coral Triangle Initiative. The bay is known for its diversed fisheries resources including bivalves. Although some of these bivalve species are commercially important, their occurrence, distribution and stock status in the bay are not well documented. Hence, the current study was conducted to determine the occurrence, distribution and the stock status of marsh clam, Polymerasoda spp. in the mangrove swamp situated at the southernmost of the Marudu Bay. Samplings were carried out at the mangrove swamps which covered an area of 500 sequare meter per sampling site. Two marsh clams species, Polymesoda erosa and P. expansa were found to inhabit the sampling sites. In general, juvenile marsh clams were noticed to dominate the seaward mangrove swamp, whereas the high tidal regions were dominated by adults. The current study also suggested a link in the distribution and the morphometric measurements of the marsh clams with the sediment grain size.

Antagonistic Activity, Antimicrobial Susceptibility and Potential Virulence Factors of Enterococcus faecalis

Enterococcus faecalis isolates （87） were phenotypically and genotypically identified and subsequently subjected to the antagonism test and antimicrobial susceptibility. The lipolitic, hemolytic and DNAse activities were identified along with the genes gelE, cylL, cylS, ccf, cpd and cob that, encode virulence determinants. Thirty seven percent of isolates inhibited Listeria monocytogenes （CERELA）, Listeria innocuous （CERELA）, Staphylococcus aureus （ATCC25932）, Lactococcus lactis （IL1403）, Micrococcus luteus （ATCC 10240） and Enterococcusfaecalis （ATCC29212）. All strains were sensitive to the ampicillin antibiotic, but 47% were resistant to at least one antimicrobial agent and 6% of isolates presented multidrug resistance. Ninety seven percent of isolates contained the gelE gene, but 77% of these isolates showed gelatinase activity. Presence of cylL and cylS genes was observed in 25% of the isolates, but only 5% presented hemolytic activity. None isolates showed lipase and DNAse activities. Eight percent of isolates contained the ccf gene and 2% showed the presence of the cpd and cob genes. The ability to inhibit pathogenic bacteria, low resistance to antibiotics and absence of virulence factors make some of Enterococcusfaecalis strains characterized in the present study promising for exploitation in other applications such as probiotics in aquaculture.

Campanian Climatic Change:Isotopic Evidence from Far East,North America,North Atlantic and Western Europe

Paleoclimatic settings have been reconstructed for the Campanian using original oxygenisotopic analyses of well-preserved molluskan and foraminifera shells from Russian Far East, Hokkaido, USA, Belgium and some DSDP holes （95, 98, 102, 390A, and 392A） in North Atlantic. Early Early Campanian climatic optimum has been recognized from data on high bottom shelf water paleotemperatures in middle latitudes of both the western circum-Pacific （to 24.2℃） and the eastern circum-Pacific （to 26.4℃） areas and high bottom shallow water paleotemperatures in high latitudes of the Koryak Upland （22.4-25.5℃）, which agrees with the data on the Campanian Barykovskaya flora in high latitudes （Golovneva and Herman, 1998） and Jonker flora and its equivalents in middle latitudes. Judging from the data on comparatively high bottom shallow water paleotemperature values in high latitudes, South Alaska （19.4℃） and the Koryak Upland （22.4-25.5℃）, we also expect Latest Campauian temperature maximum, which has not been confirmed, however, for low and middle latitudes by neither of isotopic nor paleobotanic data now. Main dimatic tendency during the Campanian （with the exception of Latest Campanian） has been learned from isotopic composition of Campanian aragonitic ammonoid shells from the Hokkaido-South Sakhalin （Krilyon） marine basin. In contrary to Huber＇s et al. （2002） assumption, we expect warm greenhouse conditions during the most part of the Campanian.

New Early Cambrian Maikhanellids(Mollusca) from Zhangjiagou Section, South Shaanxi, China

A new maikhanellid genus, Totornatus gen. nov., from the Lower Cambrian(Fortunian Stage) of Zhangjiagou section at Xixiang County, southern Shaanxi Province, South China, is based on a new taxon T. strigatus gen. et sp. nov. Although showing similar morphology with a cap-shaped shell and an oval aperture to other members of the family, the new species differs from previous maikhanellids in its smooth apex. The apical field consists of dense, small, round or oval granules, which gradually merge to bigger, elongated, scale-like protrusions toward the apertural margin. On this basis, we establish Totornatus strigatus, which shows a transverse groove in two-ninths of its shell. This result enriches the diversity of the earliest mollusks and maikhanellids.

Rudists(Bivalvia) from a Cretaceous Platform in Northern Egypt: Taxonomy and Paleobiogeography

New well-preserved rudist materials come from the Barremian–Turonian marine formations in the Yelleg, Minsherah, Maaza, and Raghawi sections in North Sinai, northern Egypt. There, 17 discovered rudist species belonging to 13 genera and seven taxonomic families are described in detail as follows: Eoradiolites plicatus(Conrad), Eoradiolites liratus(Conrad), Praeradiolites ponsianus(d'Archiac), Archaeoradiolites sp., Bournonia africana Douvillé, Bournonia fourtaui Douville, Biradiolites lombricalis(d'Orbigny), Biradiolites zumoffeni Douville, Radiolites lewyi lewyi Parnes, Radiolites sauvagesi(d'Hombres-Firmas), Durania arnaudi(Choffat), Toucasia carinata(Matheron), Toucasia sp., Neocaprina raghawiensis Steuber and Bachmann, Sellaea sp., Ichthyosarcolites sp. and Horoiopleura sp.. The Cenomanian deposits in the northern Eastern desert of Egypt only contain E. liratus. The domination of the Cenomanian rudist species in North Sinai, however, is attributed to changes in the platform, which passes mainly from carbonate in the north to siliciclastics in the south. The presence of Horiopleura sp. in the late Barremian-early Aptian deposits is documented for the first time, which suggests the expansion of taxa of the genus Horiopleura Douville to North Sinai during this interval. The age of the rudist species is documented from the late Barremian-Turonian formations, with their geographic distribution in the Mediterranean region considered..