Corbicula an annotated bibliography 1774 2005

The ornithine content of an extract of the brackishwater bivalve, Corbicula japonica, increased when the bivalve was frozen. It was not influenced by the period of freezing. This phenomenon was not apparent in the scallop, little-neck clam, or hard clam. Various low-temperature conditions for processing the bivalve were applied from 4^oC to -10^oC and measured the ornithine content of each extract. The ornithine content was maximized by processing at -4^oC. The increase in this ornithine content was reduced when the bivalve was stored at 5^oC or 15^oC after processing at -4^oC, this decrease being reversed when the bivalve was again processed at -4^oC after warming. Low-temperature processing of the brackish-water bivalve therefore increased the ornithine content of the extract.

Changes of the general integral characteristics (density, biomass, diversity) of micro-, meio- and macrobenthos along a salinity gradient (from 0 to 20 ppt) in the Chernaya River estuary (Russia, Kandalaksha Bay, White Sea) are considered. Species diversity of these three size blocks in estuarine and marine communities is similar and maintains on the constant level by complementary of taxonomic groups, which have different resistance to salinity. Trophic structure of micro- and meiobenthos is not related with salinity changes and depends on sediment type. Trophic structure of macrobenthos depends on hydrodynamic conditions of estuary and organic matter content. The biomass changes of the neighbouring size blocks of zoobenthos along a salinity gradient occur in contrary directions (the biomass of microzoobenthos and macrobenthos decrease, the biomass of meiobenthos increase with decreasing salinity). Moreover, an opposite character of distribution was demonstrated for the neighbouring size groups within microbenthos, meiobentos and macrobenthos. It allows considering this tendency as the general rule on all levels of benthic community organization.

Ueji, T. 1934. Fresh water mollusks from Kitamatsuura Coalfield, northern Kyushu, Japan. Venus, Japanese Journal of Malacology 4(6):341 350. [English with Japanese summary]

Corbicula hizensis sp. nov. is described (p. 344) and figured (Pl. 5, fig. 3, Pl. 6, figs. 9 11) from the Oligocene of Utagaura, Shishimachi mura, Kitamatsuura gun, Nagasaki Prefecture, Japan.

Uno, S., H. Shiraishi, S. Hatakeyama and A. Otsuki. 1997. Uptake and depuration kinetics and BCFs of several pesticides in three species of shellfish (Corbicula leana, Corbicula japonica, and Cipangopludina chinensis): Comparison between field and laboratory experiment. Aquatic Toxicology 39(1):23-43.

Uptake and depuration rate constants, and bioconcentration factors (BCFs) of pesticides in shellfish (Corbicula leana, Corbicula japonica and Cipangopludina chinensis) were estimated from both field and laboratory experiments. The simulation of pesticide concentrations in shellfish in the field using the rate constants obtained from the laboratory experiments and the actual concentrations of pesticides in the river water, roughly predicted the concentration of pesticides in shellfish in the field. The interspecies difference found in the BCF values in the field experiment could possibly be explained by the faster uptake rate and slower depuration rate of Corbicula leana than those of Cipangopludina chinensis.

Uno, S., H. Shiraishi, S. Hatakeyama, A. Otsuki and J. Koyama. 2001. Accumulative Characteristics of pesticide residues in organs of bivalves (Anodonta woodiana and Corbicula leana) under natural conditions. Archives of Environmental Contamination and Toxicology 40(1):35-47.

Accumulative characteristics of pesticide residues in the gill, midgut gland, gonad, and the remaining tissues of the bivalve mollusks Anodonta woodiana and Corbicula leana were examined during the rice planting seasons of 1992 and 1994. Although seven pesticides, except thiobencarb, were accumulated all at ppb levels in the midgut gland (liver) and gonad of both bivalves during their application period, thiobencarb was accumulated in C. leana at extremely high levels of 15.70 μg g^-1 in 1992 and 12.45 μg g^-1 in 1994 in the midgut gland and 15.80 μg g^-1 in 1992 and 16.40 μg g^-1 in 1994 in the gonad, respectively. These levels were about 100 times higher than those in A. woodiana. Thiobencarb and molinate in A. woodiana and chlornitrofen (CNP) and molinate in C. leana remained in the gonad and midgut gland longer than in the gill and remaining tissues, while thiobencarb in organs of C. leana remained at ppm levels until the end of the experiments. The present study suggests that these interspecies differences can be attributed to differences between the two species in their ability to eliminate pesticides.

Urban, R. D. and J. L. Miller. 1974. Evaluation of Nonfisheries Biological Data of the Aquatic Ecosystem in the Vicinity of Kingston Steam Plant   Watts Bar Reservoir   1973. Tennessee Valley Authority, Limnology Section (Muscle Shoals, Alabama) I EB 74 11. 60 pp.

Ussing, N. V. 1910. Handbuch der Regionalen Geologie. (Heidelberg).

Corbicula fluminalis is discussed on pages 18 and 20.

Usuki, I. 1962. Distribution of glycogen, fat and phospholipid in the gill tissues of certain marine bivalves. Scientific Reports of Tohoku University (4) Biology 28:53 57.

The distribution of glycogen, fat, and other biochemical constituents of Corbicula japonica tissues is examined.

Utoh, H. 1981. Growth of the brackish water bivalve Corbicula japonica in Lake Abashiri, Japan. Scientific Reports of Hokkaido Fisheries Experimental Station 23:65 82. [Japanese with English summary]

Growth of Corbicula japonica in Lake Abashiri was studied using the shell reading method. Concentric circular growth pauses were seen on the surface of the shell. These pauses appear to occur once a year from November through May, irrespective of shell size. The alternate formation of the translucent and opaque layers in the prismatic layer of the shell was found on the transverse section of the shell. The growth pauses were situated on each corresponding translucent layer or it's outer edge. The aletration of each layer is annually cyclic and the opaque layer appears to correspond to the growth of the shell. The frequency distribution of the length of the first growth pause zone was little different from that of first year clams. The growth of the shell in different year classes was different. This difference appears to be caused by accelerating growth rates during the third or fourth year. The growth of shell is similar for both sexes. The growth of shell commenced in May, and was rapid in the summer. This gradual growth continued until October, but in the winter the measurement of growth was negligible.
-- V --
Vaas, K. F. and M. Sachlan. 1952. Notes on fisheries exploitation of artificial Lake Tijburu in West Java. Pemberitaan Balai Fesar Penjelidikan Pertamian. General Research Station, Bopor 128:1 22.

Valenciennes, A. 1833. Coquilles marines bivalves de l'Amerique equinoxiale recueilli'es pendant le voayage de MM. de Humboldt et Bonpland. Recueil d'Observations.

Van Alstine, J. B. 1975. Paleontology of brackish water faunas in two tongues of the Cannonball formation (Paleocene, Danian), Slope and Golden Valley counties, southwestern North Dakota. Proceedings of the North Dakota Academy of Science 29(1):30. [Abstract]

In June and July, 1972, four stratigraphic sections containing the Cannonball and Ludlow formations were measured and described in Slope and Golden Valley counties, North Dakota. The Cannonball consists of two tongues, in the upper part of the Ludlow (perhaps the Lebo member), separated stratigraphically by about 30 m of Ludlow. The biota of the upper tongue of the Cannonball consists of three bivalves (Corbicula? berthoudi, Corbicula (Bicorbicula) subtrigonalis, and Crassostrea glabra) and the trace fossil Ophiomorpha. The biota of the lower tongue consists of two foraminiferids (Trochammina sp. and ?Haplophragmoides sp.) and three bivalves (Corbicula? berthoudi, Corbicula (Bicorbula) subtrigonalis and ?Ostrea sp.). The Ludlow biota consists of three gastropods (Viviparus sp., Goniobasis cf. tenuicarinata, and ?Goniobasis sp.), two ostracods (Candona sp. and Ilyocypris sp.), and l charophyte (Sphaerochara sp.). No species are in common with the two formations, and only two species are in common with the two Cannonball tongues. The ostracods and the charophyte in the Ludlow, and the foraminiferids, ?Ostrea sp., and Ophiomorpha in the Cannonball tongues are here newly reported. ?Ostrea sp. is newly reported for the entire Cannonball formation.

van der Schalie, H. 1973. The mollusks of the Duck River drainage in central Tennessee. Sterkiana 52:45 55.

van der Schalie, H. and G. L. Pace. 1967. The freshwater Mollusca of Taiwan (Formosa). Annual Reports, American Malacological Union, 1967:26 27.

van der Sleen, W. G. N. 1912. Bydrage tot de Kennis der chemische zamenstelling van het dünwater. Akademische Proefschrift (Amsterdam). 133 pp.

Van Heurn, F. C. and E. M. M. Paravicini. 1922. Conchylienfauna der Gajo Landen. Natuurkundig Tijdschrift voor Nederlandsch Indies 82:20 33. [Dutch]

Corbicula moltkiana Prime is reported from the Peusang River and Lake Tawar, Sumatra.

Vanamuro, M. and I. Koike. 1994. Diel changes of nitrogen species in surface and overlying water of an estuarine lake in summer: Evidence for benthic-pelagic coupling. Limnology and Oceanography 39(7):1726-1733.

Diel changes in the concentration of nitrogen species [ammonium, nitrite, nitrate, dissolved organic N, and particulate organic N (PON)] and some biological parameters were monitored in the water column of Lake Shinji, a shallow estuarine lake in Japan. The sediment of the lake was densely inhabited by the filter-feeding bivalve Corbicula japonica. An overlying water sampler showed that PON at the sediment-water interface (less than a few millimeters above the sediment) was not depleted; nevertheless, active uptake of PON by C. japonica (10.4 mg-atoms N/m²/d) is reported. Dissolved and particulate N species showed vertically uniform profiles at night, which we attributed to nocturnal water mixing associated with cooling surface water. These observations suggest benthic-pelagic coupling between filter-feeding bivalves and phytoplankton which enables the removal of nitrogen from the eutrophic lake through fisheries yield of bivalves.

Vasisht, H. S. and R. S. Bhandal. 1979. Seasonal variation of benthic fauna in some Indian lakes and ponds. Indian Journal of Ecology 6(2):33 37.

Studies were made on the quality and quantity of benthos and their seasonal variation with reference to temperature and nature of substratum. The oligochaetes Branchiodrilus sp., Dero sp., Nais sp., Branchiura sp. and Aulodrilus sp. were found in Sukhna Lake and Dhanas Pond throughout the year but were completely absent in Kanjli Lake, which may be due to the sandy substratum. Their advance was favored by high temperature. The molluscs were represented by few genera in Sukhna Lake and Dhanas Pond, the gastropod Lymnaea auricularia in the former and the pelecypod Lamellidens marginalis in the latter, as compared to Kanjli Lake containing the gastropods Viviparus bengalensis, Melania scarba, L. acuminata, Planorbis exustus and Gyraulus convexisculus and the pelecypods Parreysia favidens, L. marginalis, Villorita cyprinoides and Corbicula striatella. They may be due to the marked differences in the nature of substratum between the 2 water bodies.

Vasisht, H. S. and S. Gulati. 1972. The fresh water mollusks of north India. Research Bulletin, Punjab University of Science 22(3 4):465 467.

The occurrence and distribution of 14 species of freshwater molluscs, including Corbicula striatella, from northern India is reported.

Vaughn, C. C. and C. C. Hakenkamp. 2001. The functional role of burrowing bivalves in freshwater ecosystems. Freshwater Biology 46(11):1431-1446.

Freshwater systems are losing biodiversity at a rapid rate, yet we know little about the functional role of most of this biodiversity. The ecosystem roles of freshwater burrowing bivalves have been particularly understudied. A summary is presented of what is known about the functional role of burrowing bivalves in the orders Unionoida and Veneroida in lakes and streams globally. Bivalves filter phytoplankton, bacteria and particulate organic matter from the water column. Corbicula and sphaeriids also remove organic matter from the sediment by deposit feeding, as may some unionids. Filtration rate varies with bivalve species and size, temperature, particle size and concentration, and flow regime. Bivalves affect nutrient dynamics in freshwater systems, through excretion as well as biodeposition of faeces and pseudofaeces. Excretion rates are both size and species dependent, are influenced by reproductive stage, and vary greatly with temperature and food availability. Bioturbation of sediments through bivalve movements increases sediment water and oxygen content and releases nutrients from the sediment to the water column. The physical presence of bivalve shells creates habitat for epiphytic and epizoic organisms, and stabilizes sediment and provides refugia for benthic fauna. Biodeposition of faeces and pseudofaeces can alter the composition of benthic communities. There is conflicting evidence concerning the role of resource limitation in structuring bivalve communities. Control by bivalves of primary production is most likely when their biomass is large relative to the water volume and where hydrologic residence time is long. Future studies should consider exactly what bivalves feed upon, whether feeding varies seasonally and with habitat, and whether significant overlap in diet occurs. In particular, we need a clearer picture of the importance of suspension versus deposit feeding and the potential advantages and tradeoffs between these two feeding modes. In North America, native burrowing bivalves (Unionidae) are declining at a catastrophic rate. This significant loss of benthic biomass, coupled with the invasion of an exotic burrowing bivalve (Corbicula), may result in large alterations of ecosystem processes and functions.

Vaughn, C. C., C. M. Mather, M. Pyron, P. Mehlhop amnd nE. K. Miller. 1996. The current and historical mussel fauna of the Kiamichi River, Oklahoma. Southwestern Naturalist 41(3):325-328.

Frederick Benjamin Isely collected mussels in 1911 from the Kiamichi River. Isely collected 27 species of mussels from three sites on the Kiamichi River. His site near Tuskahoma still exists, but his two sites in the lower Kiamichi River were destroyed by the construction of Hugo Reservoir. Valentine and Stansbery (1971) collected mussels from one site on the lower Kiamichi River in 1968. This site has since been inundated by Hugo Reservoir. A pre-impoundment study performed by the Oklahoma Biological Survey for Lake Hugo lists mussel collections from the early 1970's. Twenty-nine living species of mussels (not including the exotic non-unionid bivalve, Corbicula fluminea) have been found recently in the Kiamichi River. Most of these were found during surveys for the Ouachita rock-pocketbook mussel, Arkansia wheeleri.

Veatch, A. C. 1907. Geography and geology of a portion of southwestern Wyoming. U. S. Geological Survey Professional Paper 56. 1 178.

Veitenheimer Mendes, I. L. 198l. Corbicula manilensis (Philippi, 1844) molusco asiatico, na bacia do Jacui e do Guaiba, Rio Grande do Sul, Brasil (Bivalvia, Corbiculidae). Iheringia, Serie Zoologia 60:63 74. [Portugese with English summary]

The introduction of Corbicula manilensis (Philippi) into the hydrographic basins of Jacui and Guaiba, Rio Grande do Sul State, Brazil, is reported. Based on the most likely ages of the specimens collected, the species seems to have been introduced in the beginning of the 1970's.

Veitenheimer Medes, I. L. and J. Olazarri. 1983. Primeros registros de Corbicula Mergele, 1811. (Bivalvia, Corbiculidae), para el Rio Uruguay. Boletin de la Sociedad Zoologia del Uruguay 1:50 53. [Spanish with English summary]

The distribution of the genus Corbicula is extended to the rivers Uruguay and San Salvador, and also to the eastern coast of the Rio de la Plata, based on material of the Museu de Ciencias Naturais, Rio Grande do Sul, Museo de Historia Natural, Montevideo, and private collections.

Ventre, D. E. and A. W. McIntosh. 1990. Influence of suspended solids on short-term lead uptake in Corbicula fluminea. Society for Environmental Toxicology and Chemistry, SETAC '90 - Global Environmental Issues: Challenge for the 90s, Arlington, Virginia, 11-15 November.

Verdcourt, B. 1960. Some further records of Mollusca from N. Kenya, Ethiopia, Somaliland and Arabia, mostly from arid areas. Revue de Zoologie et de Botanique Africaines 61(3 4):220 265.

Corbicula africana is reported from Lake Rudolph, Fergusons Gulf, and 28 miles northeast of Lodwar in lacustrine deposits, Turkana, Kenya. Corbicula sp. is reported from Ramlat Sabatein and 50 miles southwest of Husn El Abr, East Aden Protectorate, Arabia. Corbicula sp. is also reported from 13 miles northwest of Sardo, Eritrea, Ethiopia.

Versteeg, D. J. and J. M. Rawlings. 2003. Bioconcentration and toxicity of dodecylbenzene sulfonate (C₁₂LAS) to aquatic organisms exposed in experimental streams. Archives of Environmental Contamination and Toxicology 44(2):237-246.

Fish, mollusks, and crustaceans were caged in the tail pool of streams during a C₁₂LAS (dodecyl benzene sulfonate) model ecosystem experimental program. Bioconcentration of total C₁₂LAS and individual isomers and acute and chronic toxicity were investigated during this study. Toxicity endpoints were based on water and tissue (i.e., body burden) concentrations at which adverse effects were observed. At 32 days, total C₁₂LAS bioconcentration factors (BCFs) for the fathead minnow and three invertebrate species ranged from 9 to 116. In general, bioconcentration was affected by isomer position, exposure concentration, and species. BCF values tended to decrease as isomer position moved from external (e.g., 2-phenyl) to internal (e.g., 5,6-phenyl). BCFs also decreased as exposure concentration increased. Mean acute 4-d LC₅₀ values ranged from 1.5 to >3.0 mg/L for the six species tested. Lethal body burdensassociated with 50% mortality (LBB₅₀) varied from 0.21 to 0.60 mmole/kg (wet weight). During the 32-day chronic exposures, the EC₂₀ values were 0.27 (0.204-0.352), 0.95 (0.597-1.29), and approximately 1.0 mg/L for Corbicula (length), Hyalella (survival), and fathead minnow (survival), respectively. At these EC₂₀ values, C₁₂LAS body burdens were 0.035, 0.23, and 0.19 mmoles/kg wet weight in Corbicula, Hyalella, and fathead minnow, respectively. Fish exposed to wastewater treatment plant effluent had total C₁₂LAS tissue concentrations ranging from 0.0005 to 0.0039 mmoles/kg wet weight. These concentrations are approximately 45-360 times below the tissue concentration associated with subtle effects in the model ecosystem stream exposures. Total C₁₂LAS body burdens in feral and caged Corbicula exposed to WWTP effluents were approximately 0013 mmoles/kg; approximately 25-fold below concentrations associated with effects in stream exposures.

Vidal, M.-L., A. Basseres and J.-F. Narbonne. 2000. Interest of a multibiomarker approach in the assessment of freshwater ecosystem quality: laboratory and field studies. 1st World Water Congress: Operation and Management, Landfill and Sludge Management, Pareis, France, 3-7 July. Water Science and Technology 44(2-3):305-312.

The aims of this study were to validate several biochemical parameters as biomarkers of pollution in the freshwater bivalve Corbicula fluminea and to underline the interest of a multibiomarker approach in environmental biomonitoring. The study was divided into a laboratory exposure to 4 doses of trichloroethylene, toluene, cadmium chloride or a coal tar fraction for 5 days and a field exposure for one week in 5 sites surrounding an industrial effluent outlet. Whatever the product was, parameters that exhibited significant responses were mainly parameters related to oxidative stress and components of phase I metabolism. As a result of discriminant analysis, doses were clearly discriminated from the control and from each other. Likewise, products were discriminated from each other, based on results of the whole parameter responses obtained for the first dose. Concerning the field experiment, all biochemical parameters assayed exhibited significant responses for sites located downstream of the effluent outlet, compared to the upstream reference site. Through a discriminant analysis, sites could be distinguished from each other in terms of pollution intensity. In order to characterise pollution at a qualitative level, further laboratory and field studies are needed to obtain typical profiles for the main pollutants present in freshwater ecosystems.

Vidal, M.-L., A. Basseres and J.-F. Narbonne. 2001. Potential biomarkers of trichloroethylene and toluene exposure in Corbicula fluminea. Environmental Toxicology and Pharmacology 9(3):87-97.

Freshwater clams Corbicula fluminea were exposed in aquariums to four doses of trichloroethylene-TCE-(1.56 up to 100 mg/1) or toluene-TOL-(7.5 up to 60 mg/1) for 5 days. At the end of exposure, components of (de)toxification metabolism of phases I and II, parameters related to oxidative stress and propionylcholinesterase activity were assayed. Determination of TCE and TOL concentrations in water revealed an important evaporative loss during the experiment, characteristic of acute and occasional contaminations by such products occurring in the environment. Appropriate statistical methods such as ANOVA, Tukey test and discriminant analysis underlined the relevance of cytochromes P450 and P418, NADH-cytochrome c reductase, catalase, peroxided and peroxidizable lipids and net peroxidation as biomarkers of exposure to these solvents in C. fluminea. This experiment emphasised the importance of a multi-biomarker approach in environmental surveys and will be completed further by mesocosm studies.

Vidal, M.-L., A. Basseres and J.-F. Narbonne. 2002. Seasonal variations of pollution biomarkers in two populations of Corbicula fluminea (Müller). Comparative Biochemistry and Physiology, Part C 131(2):133-151.

Seasonal variations of pollution biomarkers have been studied in two populations of Corbicula fluminea (Müller) for 2 years. Clams were collected from the Sanguinet lake and the Dronne river (Southwest France), sites characterised by water of excellent and passable quality, respectively. Biological parameters studied were enzymatic activity (catalase, propionylcholinesterase, glutathione S-transferase, NADPH-cytochrome c reductase and NADH-cytochrome c reductase activities) and indicators of physiological (protein, carbohydrate, lipid and ash contents, fresh and dry tissue weights, condition factor) and reproductive (amount of oocytes present in gonads and clams incubating larvae in gills) status. Environmental parameters (e.g. water temperature, chlorophyll a concentration) were also monitored. Effects of site, sampling date and season (from spring to winter) were studied, as well as relationships between abiotic and biotic factors. Finally, an index of variability was calculated for each biomarker. Catalase, propionylcholinesterase, NADH-cytochrome c reductase and lipids experienced the most pronounced seasonal fluctuations, whereas glutathione S-transferase, NADPH-cytochrome c reductase and proteins suffered less pronounced ones. For some parameters, results differed depending on the site. Most seasonal changes were related to the reproductive cycle and/or water temperature. Implications of such variations in the use of pollution biomarkers in environmental surveys are discussed.

Vidal, M.-L., A. Basseres and J.-F. Narbonne. 2002. Influence of temperature, pH, oxygenation, water-type and substrate on biomarker responses in the freshwater clam Corbicula fluminea (Müller). Comparative Biochemistry and Physiology, Part C, 132(1):93-104.

The influence of abiotic factors on responses of components of detoxification metabolism of phases I and II, indicators related to oxidative stress and propionylcholinesterase, proposed as biomarkers of pollution in Corbicula fluminea. Combined effects of temperature (10 and 20^oC), water-type (water purified by reverse-osmosis, lake water from the collection site and tap water) and habitat substrate (presence and absence of sand) were assessed in a five-day experiment. Additionally, clams were exposed to hypoxia or submitted to acidic, neutral or alkaline conditions at 20^oC, in lake water, without sand, for five days. Responses of biomarkers were generally higher when clams were placed in tap water, except for level of peroxidised lipids (PL). Catalase (CAT) and NADH-cytochrome c reductase (NADH-red.) activities increased whereas propionylcholinesterase (PChE) activity decreased in absence of sand. Decreasing temperature resulted in depressing PChE and NADPH-cytochrome c reductase (NADPH-red.) activities. Hypoxia induced an increase of CAT activity and glutathione S-transferase activity towards ethacrynic acid and a decrease of PL level. CAT and NADH-red. activities as well as PL level were reduced when clams were exposed to acidic and/or alkaline conditions. These results indicate that effects of abiotic factors should be taken into account in environmental studies.

Vidal, M. L. and J. F. Narbonne. 2000. NCharacterization of glutathione S-transferase activity in the Asiatic clam Corbicula fluminea. Bulletin of Environmental Contamination and Toxicology 64(3):455-462.

Vidal, M.-L., P. Rouimi, L. Debrauwer and J.-F. Narbonne. 2002. Purification and characterisation of glutathione S-transferases from the freshwater clam Corbicula fluminea (Müller). Comparative Biochemistry and Physiology, Part C 131(4):477-489.

Glutathione S-transferases (GSTs) are involved in the phase II detoxification metabolism. To provide a molecular basis for their use as biomarkers of pollution, cytosolic GSTs from the freshwater clam Corbicula fluminea have been purified by glutathione-Sepharose affinity chromatography, anion-exchange chromatography (AEC) and reversed-phase (RP) HPLC. SDS-PAGE of visceral mass (VM) affinity-purified extracts revealed four subunits with apparent molecular masses (MW) of 30.2, 29.2, 28.5 and 27.2 kDa. Analysis by non-denaturing PAGE revealed three acidic dimeric proteins with apparent MW of 64, 55 and 45 kDa, named GSTc1, GSTc2 and GSTc3, respectively, based on their elution order by AEC. Only GSTc2 and GSTc3 exhibited GST activity towards 1-chloro-2,4-dinitrobenzene. A tissue-specific subunit pattern was obtained by RP-HPLC of affinity-purified extracts from VM and gills (GI): three major peaks were resolved, one of which was common to both tissues. MW of each VM subunit was determined by electrospray ionisation-mass spectrometry: 23602 plus or minus 1 Da for the major subunit and 23289 plus or minus 1 Da for the minor ones. Immunoblot analysis revealed all subunits from both tissues were related to the Pi-class GSTs. In addition, minor VM subunits were slightly related to the Mu-class ones. The interest of such molecular studies in biomonitoring programs is discussed.

Vidrine, M. F. and M. S. DeRouen. 1976. Note on the bivalves (Sphaeriacea: Corbiculidae and Sphaeriidae and Unionacea: Margaratiferidae) of the Bayou Teche system in Louisiana. Association of Southeastern Biologists, Bulletin 23(2):102. [Abstract]

Corbicula manilensis inhabits most of the drainages of the Bayou Teche system, including the mainstream of the bayou and the following tributaries: Bayou Cocodrie (below its impoundment), Bayou Waukusha (a dredged bayou) and Bayou Carron. Bayou Bouef, also a tributary, is currently free of C. manilensis. This clam is abundant locally in Bayou Cocodrie and Bayou Wauksha.

Villadolid, D. and F. G. Del Rosario. 1930. Some studies on the biology of Tulla (Corbicula manilensis Philippi), a common food clam of Laguna de Bay and its tributaries. Philippine Agriculturist 19:355 382.

The present study attempted to determine and compare the rate of growth of the clam in Laguna de Bay and in Molawin Creek, Los Banos, from the same time the larvae are expelled from the gills of the clams until they become sexually mature and a few years older; to determine the time and length of the spawning season; to determine the approximate population of the clam in Laguna de Bay at Mayondon; and to determine the altitudinal distribution of the clam in Molawin Creek.

In the course of seven months, from May to November, 1929, the young clams in Laguna de Bay were found to increase at a minimum group rate of 0.15 cm or at a minimum group rate of 0.33 cm, or at an average group rate of 0.18 cm; the clam in Molawin Creek made increments at a minimum group rate of 0.15 cm, or at a maximum group rate of 0.30 cm or at an average group rate of 0.14 cm during the same period.

In the length frequency measurements of clams taken from piles of duck feed in Laguna de Bay at Mayondon, three distinct size groups were defined and in Molawin Creek, four.

The average length of clams in Laguna de Bay and in Molawin Creek belonging to the different size groups was calculated to be as follows:

Size  Average Length in Average Length in

Groups Laguna de Bay (cm) Molawin Creek (cm)

I 1.44 1.07

II 2.17 1.58

III 2.75 1.96

IV 3.05 2.30

The average rate of increment of clams belonging to the different groups was calculated as follows:

Length in Length in

Size  Laguna de Molawin

Groups Bay (cm) Creek (cm)

I 1.42 1.05

II 0.73 0.51

III 0.58 0.38

IV 0.30 0.34

The clams attain sexual maturity in Laguna de Bay at an average length of from 1.21 to 1.75 cm; in Molawin Creek at from 10.3 to 1.25 cm. Clams of this size belong to size group I.

The small, probably immature ova, are hexagonal when still in the follicles. They measure from 20 um to 60 um in diameter. The large, probably mature ova, appear to be pear shaped with a distinct nucleus and nucleolus. They measure from 70 um to 160 um at widest diameter.

The spawning season of Corbicula manilensis, as indicated by the presence of larvae in the gills, was found to cover a period of from the first week of February to the last week of July in Laguna de Bay, and from the first week of January to the last week of July in Molawin Creek. The peak of spawning activity was shown to take place during the last two weeks of March in Laguna de Bay and during the middle of April in Molawin Creek.

The average number of clams per square meter in Laguna de Bay varied from 62 (September 1928) to 204 (May 1929). The clam population in Molawin Creek was found to decrease with increase in elevation up to an altitude of l03.3 meters and above, when it ceased altogether.

From a careful examination of the facts obtained from the study of Corbicula manilensis, it appears that legislative measures which may be recommended for the proper conservation of this species of economic bivalve are quite simple. The dredge nets which are used by clam collectors should have mesh openings of at least 2.5 cm, stretched. This will allow the easy passage of small clams which are still immature or which are just spawning for the first time. The mesh openings of the bas now used are only about 2 mm stretch, hence, the dredge nets collect even the newly hatched clams. It is also recommended that a thorough survey of the spawning grounds of C. manilensis be effected with the end in view of closing such areas to clam or snail collectors at certain seasons. February, March, and April of each year should be declared a closed season as it is in this period that the clams are heavily spawning. Such a law would protect the broods and young from unnecessary disturbance and destruction.

Villalaz, Janzel R., Juan A. Gómez H., Clement L. Counts, III, Carlos Vega, y José Simmonds. 2005. Ampliación de ámbito de distribución de Corbicula fluminea (Bivalvia: Corbiculidae) en Panama. Brenesia 63-64:143-144. [Journal of the National Museum of Costa Rica]

Villar, C., J. Stripeikis, L. D'Huicque, M. Tudino, O. Troccoli and C. Bonetto. 1999. Cd, Cu and Zn concentrations in sediments and the invasive bivalves Limnoperna fortunei and Corbicula fluminea at the Rio de la Plata basin, Argentina. Hydrobiologia 416:41-49.

Cd, Cu and Zn content in sediments and bivalves (Limnoperna fortunei and Corbicula fluminea) were studied in the lower 500 km stretch of the Parana River and in the right margin of the Rio de la Plata Estuary. Both bivalve species showed higher metal contents at the Parana River, possibly related to water chemistry. The Parana water is circumneutral and soft, while the Rio de la Plata coastal water is alkaline, hard, with a higher organic content. Bivalves sampled at the thermal effluent of the Atucha Nuclear Power Plant, at the Parana River, showed the highest metal content, either from increased absorption at the higher water temperatures (12^oC higher than the river water) or from metal corrosion of the power plant cooling system. L. fortunei and C. fluminea appeared to be successful biomonitor organisms for Cd pollution in the basin, while Cu and Zn content in bivalve tissues was apparently not related to metal load.

Villar, C., J. Stripeikis, D. Colautti, L. D'Huicque, M. Tudino and C. Bonetto. 2001. Metals contents in two fishes of different feeding behaviour in the Lower Parana River and Rio de la Plata Estuary. Hydrobiologia 457(1-3):225-233.

Cd, Cr, Cu and Pb concentrations were measured in the water and these plus Zn were measured in the diet, muscle and liver of the detritivorous fish Prochilodus lineatus and the omnivorous fish Pterodoras granulosus at two sites (Lower Parana River and Rio de La Plata, right margin ) located upstream and downstream, respectively, from Buenos Aires, an important source of xenobiotics. Cu and Cr concentrations in water were higher in the Rio de la Plata coastal waters, while Cd and Pb were below detection limits. The stomach contents of P. lineatus showed a higher metal content at the estuary, attaining concentrations within the range reported for contaminated sediments. However, metals in fish tissue were not higher at the estuary and, except for Cd in liver, were lower than in the organic fraction of the stomach content. Thus, only Cd was accumulated. The P. granulosus diet was composed mainly of river vegetation debris and clams, Corbicula fluminea, at the estuary. Cd, Cu and Pb in liver were higher at the estuary while only Cu was higher in the diet at this site. The different nature of the diet seems associated with a differential bioavailability of its metal content. P. granulosus accumulates Cu at both sites and Cd at the estuary. Both fishes showed higher metal content in liver than in muscle. Cr in liver was below detection limits. No relation was found between metal content and fish size. Overall, metal content in fish tissues were low, except for Cu in P. granulosus and Cd in P. lineatus, similar to those of uncontaminated sites, suggesting that homeostatic mechanisms prevent metal accumulation.

Vincent, E. 1930. Mollusques des couches a Cyrene (Paleocene du Limbourg). Memoirs du Muséum Royal d'Histoire Naturelle de Belgique No. 43:9 43.

Vincent, T. and V. Brancotte. 2000. Le bivalve invasif asiatique Corbicula fluminea (Heterodonta, Sphaeriacea, Corbiculidae) dans le bassin hydrographique de la Seine (France): premiere prospection systematique et hypothese sur la colonisation [The invasive Asian bivalve Corbicula fluminea (Heterodonta, Sphaeriacea, Corbiculidae) in the drainage basin of the Seine (France): first systematic prospecting and hypothesis on the colonization]. Hydroecologie Appliquee, Paris 12(1-2):147-158. [French with English summary]

During summer 2000, the freshwater clam Corbicula fluminea was found at several locks in the Seine river (France), in three of its tributaries and five of the connecting canals. In the Seine, the species is found from downstream of Bray-sur-Seine to upstream of Poses. Corbicula has not yet invaded the estuary. The data are documented, the colonisation is discussed and the distribution is analysed.

Vlerk, I. M. van der. 1931. Caenozoic Amphinuera, Gastropoda, Lamellibranchiata, Scaphopoda. Rijksmuseum Geologische Miscellein, Feestbundel Martin. Leidsche Geologische Mededelingen 5:206 296.

Voelz, N. J., J. V. McArthur and R. B. Radar. 1998. Upstream mobility of the Asiatic clam Corbicula fluminea: Identifying potential dispersal agents. Journal of Freshwater Ecology 13(1):39-46.

Based on studies conducted in 1987 and 1993, we have determined that the Asiatic clam, Corbicula fluminea, has moved upstream at least 1.2 km/year in a southeastern U.S. blackwater stream. Since these studies were done in a protected area (the Savannah River Site, South Carolina), the data suggest that this was a process unaided by humans. In addition, the upstream movement has been halted by a large, permanent wetland and two culverts. Because the Asiatic clam has not colonized headwater areas, where several wetlands exist, this precludes the aided movement of C. fluminea by waterfowl. It is possible that fish are partially responsible for dispersing C. fluminea, at least for longer distances. It is suggested that unassisted upstream movements may also be an important dispersal mechanism for this species.

Vokes, H. E. 1939. Molluscan faunas of the Domengine and Arroyo Hondo formations of the California Eocene. Annals of the New York Academy of Science 38:1 246.

Corbicula carlosensis sp. nov. is described and figured (Pl. 5, figs. 1 6) from the Eocene of California.

Volkova, V. S. 1962. Paleogeographic significance of a Corbicula fluminalis Müll. find in the lower reaches of the Irtysh River. Doklady Akademii Nauk SSSR 145:628 630. [See also Doklady Akademii Nauk SSSR (Translation) (Earth Science) 145:65 66.]

Voloshkevich, E. V. and V. O. Son. 2002. Corbicula fluminalis - novyj vid dvustvorchatogo mollyuska dlya fauny Ukrainy [Corbicula fluminalis - a new species of bivalve molluscs in the fauna of Ukraine]. Vestnik Zoologii 36(6):94. [Russian]

The bivalve mollusc Corbicula fluminalis was introduced in Danube River basin about two decennials ago. Several new findings of C. fluminalis in Ukrainian part of Danube delta during 2001-2002 support suggestions for the active invading of the species in region.

Vrabec, V., T. Cejka, F. Sporka, L. Hamerlik and D. Kral. 2003. First records of Corbicula fluminea (Mollusca, Bivalvia) from Slovakia with a note about its dispersion in Central Europe. Biológia 58(5):942-965.