Part II. Regne Organise (Paris). 60 vols

Blanc, T. J. and F. J. Margraf. 2002. Effects of nutrient enrichment on channel catfish growth and consumption in Mount Storm Lake, West Virginia. Lakes and Reservoirs: Research and Management 7(2):109-123.

With the objective of augmenting fish production in Mount Storm Lake, Virginia Electric and Power Company initiated a program of phosphorus addition to increase primary production, and ultimately, channel catfish (Ictaturus punctatus ) growth in the 486 ha cooling reservoir. Channel catfish growth dynamics were simulated using two bioenergetics modeling scenarios: (i) effects of average reservoir temperature on growth, conversion efficiency and consumption; and (ii) effects of reservoir enrichment on growth, which is simulated by increasing feeding rates. During 1991-1993, fish were sampled monthly, but sampling was increased to every 2 weeks during the peak growing season (June-September). Most of the channel catfish collected were aged 0 year and aged 1 year with rapid annual growth rates ranging from 9.0 to 13.7 J/g. Many age 1 250-300 mm catfish were found, but few beyond this size. Conversion efficiency (joules gained/joules consumed) was low at approximately 18-19%. High algae consumption (40%) was evident, but consumption of zooplankton and Asiatic clam (Corbicula sp.) increased over the study. Simulated increased feeding rates showed that channel catfish were food limited in summer and fall (July-December). Weight gains with 5 and 10% feeding increases were 6-13% and 18-38%, respectively, from the baseline. Catfish of all sizes should benefit from phosphorus additions.

Blanford, W. T. 1880. Contributions to Indian Malacology. No. 12. Descriptions of new land and freshwater shells from southern and western India, Burmah, the Andaman Islands, etc. Journal of the Asiatic Society of Bengal, 49(2):181 222.

"Specific differences are not well marked in the genus Corbicula and the genus appears to have been designed by a beneficient Providence for the amusement of species makers." Corbicula iravadica is discussed from Mandalay.

Blankenhorn, M. 1901. Neues zur Geologie und Palaeontologie Aegyptens. IV. Das Pliozän  und Quartärzeitalter in Aegypten, ausschliesslich des Roten Meer Gebietes. Zeitschrift der Duetschen Geologischen Gesellschraft 53. 431 pp.

Blankenship, S. and D. R. Crockett. 1972. Changes in the freshwater mussel fauna of the Rockcastle River at Livingston, Kentucky. Transactions of the Kentucky Academy of Science 33:37 39.

The collection of Corbicula manilensis (Philippi, 1844) at Livingston, Kentucky, in 1968 is reported.

Blondeau, A. C. Cavelier, C. Megnein and C. Pomerol. 1968. Interpretation generale et conclusions relatives aux sondages executes dans le bassin de Paris a Chaignes (Eure), Monjavoult, Ludes (Marne). Colloque sur l'Eocene 2:175 187.

Blye, R. W., W. S. Ettinger, and W. N. Nebane. 1985. Status of Asiatic clam Corbicula fluminea in southeastern Pennsylvania 1984. Proceedings of the Pennsylvania Academy of Science 59(1):74.

Bochenek, E. A. 1994. Assessing regional risk of invasion by zebra mussels. Zebra Mussel Conference, Atlantic City, New Jersey, 1-3 June.

Many aquatic non-indigenous species have entered waterways throughout North America as a result of intentional and accidental introductions. Some of these organisms have had a beneficial effect, such as many sport fishes and aquaculture species, while others have had a detrimental effect, such as the Asiatic clam (Corbicula fluminea) and zebra mussel (Dreissena polymorpha), and caused significant economic and environmental damage. Many more potentially harmful species will be intentionally or accidentally released into North American waterways. Scientists believe that nearly every waterway in North America could be infested by the zebra mussel (D. polymorpha) within the next 20 years. The zebra mussel has rapidly expanded it's range in North America, but has not yet been discovered in the coastal states of New Jersey, Delaware, Maryland, Virginia and North Carolina. Many of the waterbodies in these coastal states could be at risk of invasion by the zebra mussel.

Bodenheimer, F. S. 1935. Animal Life in Palestine. (Jerusalem). pp. 416, 419, 449.

Corbicula crassula and Corbicula fluminalis are figured.

Boettger, O. 1881. Sechstes Verzeichniss transkausischer, armenischer und nordperischen Mollusken aus Sendungen der Herren Hans Leder, r. z. in Kutais und Dr. G. Sievers in Saint Petersburg. Jahrbuchen der Deutschen Malakologishe Gesellschaft 8:167 261.

Boettger, O. 1888. Fauna und Flora des Caspi Gebietes.

Boettger, O. 1890. A. Strubell's Kanchylien aus Java, 1. Berichte der Senckenberg Naturforschenden Gesellschaft 1890:137 173.

Boettger, O. 1907. Neue Stenogyriden (aus v. Erlangers Reiseausbeute). Frankfurt a. M. Nachr. Blätter Deutsch Malakozoologishce Gesellschrift 39:137 140.

Boettger, O. 1910. Die Binnenkonchylien von Deutsch Sudwestafrika ind ihre Beziehungen zur Molluskenfauna des Kaplandes. Abhandlungen der Senckenbergischen Gesellschaft 32:429 456.

Boettger, O. and F. Haas. 1915. Beitrage zur Molluskenfauna des Sudans. Zoologischen Jahrbuchern 38(6):371 384.

Specimens of Corbicula fluminalis (Müller, 1774) were collected at Djebel Auel, El Duem, Khor Athar, and Aradeba. Specimens of Corbicula consorbrina Cailliaud are reported taken from El Duem and as subfossil from Asswan.

Bollinger, 1914. Süsswasser Mollusken von Celebes, ausbente der zweiten Celebes Reise der Herren Dr. P. un Dr. F. Sarasin. Revue Suisse Zoologie 22:557 579.

Corbicula linduensis sp. nov. is described (p. 575) and figured (pl. 18, fig. 12) from Lake Lindu, central Celebes.

Boltovskoy, D., M. Borges, D. Cataldo, C. Damborenea, G. Darrigran, S. Obenat, G. Pastorino, E. Schwindt, E. Spivakand F. Sylvester. 2005. Invasores Invertebrados Exoticos en el Rio de La Plata y Region Marina Aledana [Exotic Invertebrate Invasions in the Rio de la Plata and Nearby Marine Water Region], P. E. Penchaszadeh, Editor. Eudeba (Buenos Aires, Argentina). 384 pp. [Spanish with English summary].

The problem of invasive alien or non-indigenous species is not only occurring in the Rio de la Plata system (Argentina-Uruguay), several other aquatic American ecosystems experienced this phenomenon, whether from unvoluntary transportation or from intentional introduction, the effects of incorporating foreign species to natural coastal systems have been identified as threatening. Aquatic organisms are introduced in different ways, usually associated to human activities. Ships are the main transport vehicle of alien species, but intentional aquaculture translocations, human or animal feeds, and sport activities are also important. Among these alien species established in the SW Atlantic, only the Japanese oyster was intentionally introduced, and this same oyster and the halophylic plant Spartina angelicana were the only two artificially propagated after introduction. The species or group of species included in the book are those recognized as invaders in the La Plata system or those considered potentially invaders after introduction. For freshwater environments, the golden mussel Limnoperna fortunei and the clam Corbicula fluminea are mentioned, for brackishwater the reef building Polychaete Ficopomatus enigmaticus (introduced not long ago) and the whelk Rapana venosa (recently incorporated), and for marine waters the littoral barnacle Cirripedia, Balanomorpha and the Japanese oyster Crassostrea gigas. Each chapter contributes to give a broader knowledge of these aquatic organisms in the Rio de la Plata and coastal waters of the Buenos Aires Province (Anegada Bay and Mar Chiquita Lagoon, Argentine Sea).

Boltovskoy, D., N. Correa, D. Cataldo, J. Stripeikis and M. Tudino. 1997. Environmental stress on Corbicula fluminea (Bivalvia) in the Parana River delta (Argentina): Complex pollution-related disruption of population structures. Archiv für Hydrobiologie 138(4):483-507.

Boltovskoy, D., I. Izaguirre and N. Correa. 1995. Feeding selectivity of Corbicula fluminea (Bivalvia) on natural phytoplankton. Hydrobiologia 312(3):171-182.

Phytoplankton in water samples from the lower delta of the Parana River (Argentina) and in the gut contents of a local population of the Asiatic clam Corbicula fluminea was identified and counted monthly between April 1992 and March 1993. Relative abundances of algal species were generally similar in the medium and in the stomachs of clams, suggesting the absence of feeding selectivity on the basis of taxonomic group or size-class. Diatoms made up a slightly but consistently larger (yet not significantly different) proportion of the diet of C. fluminea than of the plankton; this pattern is attributed to enhanced preservation of algal siliceous frustules, rather than to feeding selectivity. t is suggested that non-selective feeding by the bivalve is a response to the overall scarcity of food and, probably, to food collection by a combination of deposit and filter feeding.

Bone, D. A. 1976. The Tertiary deposits at Newhaven, Sussex. Tertiary Research 1(2):47 49.

The succession of London Clay and Woolwich Beds exposed at Newhaven and the present condition of the section is described. Most of the shell beds are comprised of fragmented Corbicula cuneiformis (Sowerby, 1817), but occasional complete specimens can be found.

Bonne, C. 1941. Zoetwatermosselen en echinostomiasis. Natuurewetenschappelijk Tijdschrift voor Nederlandish Indie 101(6):176 179.

Parasitism of Corbicula rivalis ('Busch' Philippi, 1850) by echinostomes is reported.

Bonne, C. 1941. Echizestomiasis aan het Lindomeer in Centraxl Celebes (Echinostomiasis at Lake Lindo in central Celebes). Geneeskundig Tijdschrift voor Nederlandish Indie 81(21): 1139 1167. [Dutch with English summary]

Echinostome metacercariae are abundant in mussels, Corbicula lindoensis Bollinger, 1914, on Lake Lindoe, associated with infected snails Anisus sarasinorum. Mussel infections are rarely found on Celebes coast. Cercariae from A. sarasinorum show preference for C. lindoensis over Corbicula celebensis von Martens, 1897. Experimental feeding of C. lindoensis to animals leads to infection with two echinostomes: Echinostoma lindoensis (with 37 spines, developing in pigeons and ducks as well as mice); and a species resembling Echinostoma murinum, with 45 spines, infective for rats and mice. Man is more easily infected with E. lindoensis than any laboratory animal investigated and no reservoir host has been found. The 45   spined species must have some animal host as it does not occur in man.

Bonne, C., G. Bras and L. K. Joe. 1948. Five human echinostomes in the Malayan Archipelago. Medisch Maandblat (Batavia). 23:456 465.

Bonne, C. and J. H. Sandground. 1939. Echinosomiasis in Glebes veroorzaakt door het eten van Zoelwater mosselen. Geneeskundig Tijdschrift voor Nederlandisch Indie 34:3016 3034. [Dutch]

Inhabitants of the Lake Lindu area eat large numbers of Corbicula lindoensis Bollinger, 1914, which are not completely cooked. As a result, approximately 70% of the population is infected by Echinostoma lindoensis.

Booth, G. M., C. C. Yu and D. J. Hansen. 1973. Fate, metabolism, and toxicity of 3 isopropyl  1H 2,1,3   benzothiadiazin 4   (3H)   1,2,2   dioxide in a model ecosystem. Journal of Environmental Quality 2:408 411.

Boozer, A. C. 1978. Some observations on the fingernail clam, Musculium partumeium (Bivalvia: Sphaeriidae), and its association with the introduced Asiatic clam, Corbicula fluminea (Bivalvia: Corbiculidae). Master of Science in Public Health, University of South Carolina (Columbia). iv + 34 pp.

Boozer, A. C. and P. E. Mirkes. 1979. Observations on the fingernail clam, Musculum partumeium (Pisiidae), and its association with the introduced Asiatic clam, Corbicula fluminea. The Nautilus 93(2 3):73 83.

In the cooling water system at the U. S. Energy Research and Development Administration's Savannah River Plant, Corbicula fluminea (Müller, 1774), is inhabiting the floor of the sedimentation basin and is contributing to fouling problems. A second species of bivalve, the fingernail clam, Musculum partumeium, permanently inhabits the wall of the basin by means of a byssal  like attachment. The possibility of spatial competition between these two bivalves is discussed with emphasis on observations of reproduction. It is concluded that, because physiological adaptability, M. partumeium can coexist with C. fluminea.

Borcherding, J. 1992. Another early warning system for the detection of toxic discharges in the aquatic environment based on valve movements of the freshwater mussel Dreissena polymorpha. IN: Limnologie Aktuell. Vol. 4. The Zebra Mussel Dreissena polymorpha, D. Neumann and H.A. Jenner, Eds. Springer-Verlag, Gustav Fischer Verlag GmbH & Co. KG, (Stuttgart). pp. 127-146.

Bose, K. C., M. C. Mahata and A. Dey. 1975. Freshwater molluscs of Chotanagpur: (Bihar). Indian Journal of Animal Research 9(2):107 109.

Boss, K. J. 1971. Critical estimate of the number of Recent Mollusca. Occasional Papers on Mollusks, Museum of Comparative Zoology, Harvard University (Cambridge, Massachusetts) 3(40):81 135.

It is estimated that there are 100 living species in the family Corbiculidae.

Boss, K. J. 1974. Oblomovism in the Mollusca. Transactions of the American Microscopical Society 93(4):460 481.

The ability of some species of Corbicula to burrow into the substratum to avoid extreme winter or summer temperatures is reported.

Boudou, A. 1998. Field and experimental studies of cadmium bioaccumulation by the Asiatic clam (Corbicula fluminea). 8th Annual Meeting of Society of Environmental Toxicology and Chemistry -Europe, Bordeaux (France), 14-18 April.

Bourguignat, J. R. 1853. Catalogue raisonné des mollusques terrestres et fluviatiles recueillis par F. Saulcy, pendant son voyage en Oritent. IN: Voyage Autour de la Mer Morte par Fr. de Saulcy. (Paris). 96 pp.

Bourguignat, J. R. 1856. Aménités malacologiques. Revue et Magasin de Zoologie, Série 2., 8:152.

Bourguignat, J. R. 1868. Mollusques nouveaux, litigieux ou peu connus. Revue et Magasin de Zoologie, Série 2, 20:269 384.

Bourguignat, J. R. 1883. Histoire malacologique Abyssinie. Annales des Sciences Naturelles, (Sixth Series) 18:47 162.

Bourguignat, J. R. 1885. Mollusques Terrestres et Fluviatiles Receuillis par M. Paul Soleillet dan son Voyage au Choa (Ethiope Meridionale). (Paris). 48 pp.

Bourguignat, J. R. 1885. Notice Prodromique sur les Mollusques Terrestres et Fluviatiles Recueillis par M. Victor Giraud dans la Region Meridionale du lac Tanganyika. (Paris). 110 pp.

Bourguignat, J. E. 1888. Melanidees du lac Nyassa suivies d'un apercu comparatif sur la fauna malacologique de la lac avec celle du grand lac Tanganyika. Bulletin de la Société Malacologique de la France 6:1 66.

Bourguignat, J. R. 1889. Mollusques de l'Afrique Equatoriale de Moguedouchu á Bagamoyo et de Bagamoyo au Tanganyika. Dumolin (Paris). 229 pp.

Bowen, C. F. 1915. The stratigraphy of the Montana group, with special reference to the position and age of the Judith River formation in north central Montana. U. S. Geological Survey, Professional Paper 90 I:95 153.

Bowers, R., J. Sudomir, M. Kershner and F. Szalay. 2005. The effects of predation and unionid burrowing on bivalve communities in a Laurentian Great Lake coastal wetland. Hydrobiologia 545(1):93-102.

Bowles, M. W. 2003. Biomonitoring of mercury in the South River using the Asiatic clam, Corbicula fluminea. Master of Science Thesis, James Madison University (Harrisonburg, Virginia). ix+54 pp.

Boyle, C. B. 1893. A catalogue and bibliography of North American Mesozoic Invertebrata. Bulletin of the U. S. Geological Survey 102. 1 315 pp.

Twenty three species of fossil bivalves in the genus Corbicula are reported. These are: Corbicula? nucalis (Meek, 1860), Cretaceous, southwest of Salina, Kansas; Corbicula? subtrigonalis (Meek, 1870), Dakota Cretaceous, 12 miles southwest of Salina, Kansas; Corbicula annosa (Conrad, 1868), Cretaceous of South River, New Jersey; Corbicula? emacerata Whitfield, 1885, Cretaceous of New Jersey; Cyrena (Corbicula) durkeei (Meek, 1869), Cretaceous of Wyoming, Bear River Valley; Corbicula augheyi White, 1882, and Corbicula berthoudi White, 1882, Cretaceous of South Platte Valley, Colorado; Corbicula cardiniaeformis White 1878, and Corbicula cleburni White, 1878, Cretaceous of Crow Creek, Colorado; Corbicula cytheriformis (Meek and Hayden, 1860) and Corbicula occidentalis (Meek and Hayden, 1856), Cretaceous of Colorado, Montana, Wyoming, and Canada; Corbicula (Leptesthes) fracta (Meek, 1870), Cretaceous of Colorado and Wyoming; Cyrena intermedia Meek and Hayden, 1856, Corbicula (Leptesthes) fracta (Meek, 1870), Cretaceous of Colorado and Wyoming; Cyrena intermedia Meek and Hayden, 1856, Corbicula (Leptesthes) subelliptica moreauensis (Meek, 1856), and Corbicula moreauensis (Meek and Hayden, 1856), Cretaceous of South Dakota; Corbicula obesa White, 1878 and Corbicula? (Leptesthes) planumbona Meek, 1875 and Corbicula umbonella `Meek' White, 1883, Cretaceous of Northeastern Colorado; Corbicula obliqua Whiteaves, 1885, Cretaceous of Canada; Corbicula (Valoritina) bannisteri Meek, 1872, Cretaceous of Black Buttes, Wyoming; Corbicula subelliptica (Meek and Hayden, 1856, Cretaceous, upper Missouri River region; Corbicula pugetensis White, 1889, Cretaceous, Carbonado, Washington; Corbicula willisi White, 1889, Cretaceous of Washington.

Brancotte, V. and T. Vincent. 2002. L'invasion du reseau hydrographique francais par les mollusques Corbicula spp. Modalites de colonisation et role preponderant des canaux de navigation [The invasion of French hydrographic system by the molluscs Corbicula spp. Details of settlement and main role of ship canals]. Bulletin Français de la Peche et de la Pisciculture 365-366:325-337. [French with English summary]

Coming from Asia and Africa, Corbicula colonized most of European hydrographic areas since 1980. Thanks to the discovery of new stations, authors bring out the main role of the ship canals in the mollusc spreading, making the connection between the sloping fields and the presence of an environment which is particularly favorable to the species biology. Corbicula entered France using at least seven different main ways among which the Rhine has a dominating role. [Originaire d'Asie et d'Afrique, Corbicula a colonise la plupart des bassins hydrographiques europeens depuis 1980. A la faveur de la decouverte de nouvelles stations, les auteurs mettent en evidence l'importance du role des canaux de navigation dans la propagation du mollusque, par la mise en connexion des bassins versants et l'existence d'un milieu particulierement favorable a la biologie de l'espece. Corbicula a penetre en France par au moins sept axes differents, parmi lesquels le Rhin joue un role preponderant].

Brandt, R. A. M. 1971. General Studies on Trematodes in Thailand: Classification of Cercariae in Thailand. Annual Report No. 2, February 1970   January 1971. NTIS AD 726035.

Brandt, R. A. M. 1974. The non marine aquatic Mollusca of Thailand. Archiv für Molluskenkunde 105:1 423.

Corbicula heardi sp. nov. (p. 328, pl. 29, fig. 104) and Corbicula vokesi sp. nov. (p. 327, pl. 29, fig. 103) are described and figured from specimens taken in the Mekong River at Nakon Panom, Thailand. Corbicula occidentiformis sp. nov. is described (p. 325) and figured (pl. 28), fig. 94) from specimens taken at Maenam Loei at Loei, Thailand. Corbicula pingensis sp. nov. is described (p. 344) and figured (pl. 28, fig. 93) from specimens taken at Maenam Ping at Chieng Mai, North Thailand. Corbicula virescens sp. nov. is described (p. 324) and figured (pl. 29, fig. 101) from specimens taken at Maenam Chao, Praya Ord Nakon Sowan, Thailand.

Branson, B. A. 1944. Corbicula notes. Minutes of the Conchological Club of Southern California 38:13.

Branson, B. A. 198l. The Sphaeriacean pelecypods of Oklahoma. Proceedings of the Oklahoma Academy of Science 61(1):1 6.

Keys, distributional data, and ecological information are presented for three genera and 11 species of sphaeriid and corbiculid clams (including Corbicula fluminea) known from Oklahoma.

Branson, B. A. and D. L. Batch. 1969. Notes on exotic molluscs in Kentucky. The Nautilus 82(3):102 106.

Ecological and zoogeographic distribution of Corbicula manilensis (Philippi, 1841) in the Kentucky, Red, and Ohio Rivers are presented.

Branson, B. A. and D. L. Batch. 1971. Annotated distribution records for Kentucky Mollusca. Sterkiana 43:1 9.

Zoogeographic records for Corbicula fluminea (Müller, 1774) are reported for the Cumberland and Tennessee Rivers.

Branson, B. A. and D. L. Batch. 1982. Molluscan distributional records from the Cumberland River, Kentucky. The Veliger 24(4):351 354.

Corbicula manilensis (Philippi, 1841) is reported from the Rockcastle River at Livingston.

Branson, B. A. and D. L. Batch. 1982. The Gastropoda and Sphaeriacean clams of Red River, Kentucky. The Veliger 24(3):200 204.

Britton, J. C. 1982. Biogeography and ecology of the Asiatic clam, Corbicula, in Texas. IN: Proceedings of the Symposium of Recent Benthological Investigations in Texas and Adjacent States, J. R. Davis, Ed. Aquatic Sciences Section, Texas Academy of Science. pp. 21 31.

The spread and distribution of Corbicula fluminea (Müller, 1774) in Texas is described and discussed. The clam appears to be primarily adapted for life in flowing water, but occurs in both lotic and lentic habitats. The possibility of a second Corbicula species in Texas is discussed.

Britton, J. C., W. J. Barcellona, J. Hagan and M. L. LaGrone. 1981. Ctenidial autotomy in Corbicula fluminea in response to massive granulomas. Science 212:551 553.

Large granulomas (>2 mm in diameter), stimulated by the presence of and formed around necrotic larval tissue of the inner demibranchs of Corbicula fluminea (Müller, 1774), are eliminated by autotomy. Granulocytes invade and destroy ctenidial epithelium adjacent to the granuloma, causing it and the granuloma to slough away into the mantle cavity, where they are removed as pseudofeces.

Britton, J. C., D. R. Coldiron, L. P. Evans, Jr., C. Golightly, K. D. O'Kane and J. R. TenEyck. 1979. Reevaluation of the growth pattern in Corbicula fluminea (Müller). IN: Proceedings of the First International Corbicula Symposium, J. C. Britton, Ed. Texas Christian University Research Foundation (Ft. Worth). pp. 177 192.

The growth potential of Corbicula fluminea (Müller, 1774) has been underestimated by many investigators for two reasons: 1. failing to recognize that the species usually produces two spatfalls per year (spring and fall), 2. assuming peaks of size frequency distributions to be "year classes". The growth of C. fluminea as expressed by increase in shell length can be predicted by an exponential function, which, when plotted, shows the shell length increasing rapidly at first, but the rate of increase in shell length diminishing as the size of the shell increases. This is in direct contrast to growth characteristics which may be inferred for C. fluminea from a large body of literature. Growth in this species is shown to be influenced by season (slower growth in winter) and by physical environment (a "container effect", described in the paper). The rapid growth of C. fluminea suggests that the organism is capable of completing a life cycle within two years or less.

Britton, J. C. and S. L. H. Fuller. 1979. The Freshwater Bivalve Mollusca (Unionidae, Sphaeriidae, Corbiculidae) of the Savannah River Plant. Savannah River Ecology Laboratory U. S. Department of Energy, SRO NERP 3. iii + 37 pp.

The systematics, distribution, ecology, and life history of Corbicula fluminea (Müller, 1774) is detailed for populations in the Savannah River and tributaries at the Savannah River Plant, South Carolina.

Britton, J. C. and B. Morton. 1979. Corbicula in North America: the evidence reviewed and evaluated. IN: Proceedings of the First International Corbicula Symposium, J. C. Britton, Ed. Texas Christian University Research Foundation (Ft. Worth). pp. 250 287.

Several species of Corbicula occur throughout Asia and the Pacific Islands, although there are probably fewer species than have been described taxonomically. One of these, a small, rounded, essentially freshwater (lotic), hermaphroditic, incubatory corbiculid, is widely distributed and can be assigned the name Corbicula fluminea (Müller, 1774). Sometime prior to 1938, a species of Corbicula was introduced into North America, though a confused taxonomy has subsequently indicated that more than one species has been introduced. A critical review of the evidence suggests that but one species has been introduced but which under different conditions assumes a variety of forms and exhibits a wide range of maximum size. Comparison of information on Corbicula in the United States with available data on the Asian corbiculids indicates that the introduced species is Corbicula fluminea. In its new range, growth and reproductive strategy are modified to suit changed conditions; these have been the principal causes of confusion.

Britton, J. C. and B. Morton. 1982. A dissection guide, field and laboratory manual for the introduced bivalve Corbicula fluminea. Malacological Review, Supplement 3, vi + 82 pp.

This manual is written as a teaching aid for the malacology portion of courses on Invertebrate Zoology where Corbicula fluminea (Müller, 1774) may be substituted for other native freshwater bivalves. The world wide taxonomy of bivalves in the genus Corbicula is presented and discussed. The distribution of Corbicula in North America is presented with comments on its environmental impact, ecology, and population dynamics. Laboratory exercises that include observations on the living animal (burrowing mechanism, juvenile locomotion and byssal attachment, and siphons) are presented. Exercises on the functional morphology of C. fluminea are given for the shell, soft tissues, and ciliary currents. Experiments are provided for both field (population growth, population condition using biomass without recapture, growth or biomass using the same individuals, growth or biomass at different sites, and spatial distribution) and laboratory studies (reproductive cycle, potassium toxicity, biomass determination during potassium stress, amylase activity at varying pH, rate of particle filtration, respiration versus sediment particle size). A glossary of malacological terms and appendix of formulae for various stock solutions are also presented.

Britton, J. C. and B. Morton. 1986. Polymorphism in Corbicula fluminea (Bivalvia: Corbiculoidea) from North America. Malacological Review 19(1/2):1 44.

Evidence has recently appeared suggesting more than one species of Corbicula occurs in North America. In addition to the typical C. fluminea characterized herin (Form A), there is a second Corbicula morphotype (Form B) characterized by dark periostracum and a darkly pigmented shell interior, more closely speaced concentric sulcations in young specimens, and a narrower body. In North America, Form B is usually restricted to permanently flowing, oligotrophic, calcium and carbonate rich, often spring fed and travertine depositing streams in arid, warm temperature environments. A similar morphology also is known to occur in C. fluminea from flooded furrows of Hong Kong vegetable gardens. Comparative population, morphometrics and reproductive studies of Forms A and B were conducted. Sulcation spacing on the shell exterior serves to differentiate Form A and B morphotypes less than 15 mm in length, but becomes unreliable for morphotype discrimination on larger specimens. Arcsin transformed shell dimension ratios (calculated from length, height, and width measurements) demonstrate low intrapopulation variability, but moderate to considerable difference between populations, spearated by space or time. Differences are most apparent between Form A and B morphotypes, but are also commonly significant (p < 0.05) among Form A or B comparisons. Large samples of sympatrically distributed Form A and B considerable overlap with respect to these ratios. These data support the concept of self fertilization as an important reproductive mechanism (producing low variability within populations). Because of some outbreeding, however, differences between populations with low internal variability are more apparent that would be if each population displayed somewhat greater variability. It is concluded that shell dimension comparisons are unreliable for taxonomic discrimination in Corbicula. The restricted, habitat correlated distributions of Form B Corbicula, the presence of intermediate morphologies when some, but not all, environmental conditions normally associated with Form B are present, and the virtual absence of Form B in localities where conditions associated with this morphotype are absent are strong indications that the Form B morphology is a habitat specific response derived from the predominant (Form A) North American phenotype. In addition to differences in shell morphology, Forms A and B also display differences in sexual expression which may be an effect of habitat. The tendency for C. fluminea to develop different reproductive strategies in different environments may reinforce phenotypic differences between morphotypes. It is concluded that there is still insufficient evidence to justify a two species model for North American Corbicula. The preponderance of evidence supports the view that a single highly variable species, C. fluminea, is the only introduced corbiculid in North America.

Britton, J. C. and C. E. Murphy. 1977. New records and ecological notes for Corbicula manilensis in Texas. The Nautilus 91(1):20 22.

Britton, J. C., C. E. Murphy and L. W. Newland. 1978. Investigations on the Asiatic clam Corbicula a fouling pest in American waters. Office of Naval Research, Progress Report Abstracts, ONR Report ACR 228. pp. 41 42.

Field studies of Corbicula fluminea (Müller, 1774) in the Sacramento San Joaquin Estuary, California, reveals the species occur in low numbers (less than l/m²) in salinities as high as 17 ppt near Benicia, California; occurring in moderate numbers (300   400/m²) in salinities of about 10 ppt; and occurring in markedly increasing numbers (up to 1000/m²) as the waters become more saline. The study of a granuloma cyst formation on the inner demibranchs of specimens brooding larvae in gill marsupia reveals: 1) the frequency of cyst formation is positively correlated with age of the clam, 2) cysts occur primarily as a result of the inability of the clam to fully evacuate brood chambers of larvae, 3) cyst formation can be induced by other factors such as sand grains in the demibranch water tubes, and 4) large cysts cannot be assimilated by phagocytic amoebocytes but rather the amoebocytes will attack normal gill tissue causing excision of the cyst.

Brock, Robert J. 2000. Assessment of aquatic food web alterations in the presence of the exotic clam, Corbicula fluminea and the cichlid, Oreochromis aureus. Doctor of Philosophy Dissertation, University of Florida (Gainesville). xiv + 218 pp.

Broekman, J. A. 1978. Le Paleogene Inferieur de I'lle de France Septembrionale   essai de reconstruction paleographique et stratigraphique   I, II. Koninkijke Nederlandse Akademie van Wetenshappen, Series B, 81:389 415. [French with English summary]

The sequential analysis of Lower Paleogene successions in the northern part of the Ile de France and nearby Picardy shows the diachronic nature of lithological units and biostratigraphic zones. The regional distribution of sequences of deltaic, estuarine and littoral origin permits the distinction of six successive phases of deposition. The western and northern margins of the northern part of the Ile de France approximately coincide with paleographic boundaries of primary origin.

Bronn, H. G. 1825. System der Urweltlichen Pflanzen Thiere durch Diagnose, Analyse und Abbildung der Geschlachter Erlautert. (Heidelberg).

Corbicula euphratica sp. nov. is described and figured (pl. 4, fig. 10).

Brown, B. 1907. The Hell Creek beds of the upper Cretaceous of Montana. Bulletin of the American Museum of Natural History 23(1)823 845.

Brown, B. 1914. Cretaceous Eocene correlation in New Mexico, Wyoming, Montana and Alberta. Bulletin of the Geogological Society of America 25:355 380.

Brown, C. Ll. and S. N. Luoma. 1992. Metal contamination in the invading bivalve Potamocorbula amurensis in San Francisco Bay. Abstracts, 13th Annual Meeting Society of Environmental Toxicology and Chemistry.

The bivalve, Potamocorbula amurensis, was introduced into the San Francisco Bay in 1986. It is a native of China, Japan and Korea. It has become ubiquitous in the bay living in salinities ranging from 1 ppt -34 ppt. Its widespread distribution makes Potamocorbula amurensis ideal for studying the spatial and temporal distribution of metals throughout the bay. Metal signatures differ between the north and south bays. Concentrations of Cd, Cr and V are highest in the animals in the north bay. Concentrations of Ag are highest in the animals in the south bay. There is a distinct contamination gradient in the north bay with highest concentrations at sites near the mouth of the Sacramento River decreasing to lowest concentrations in San Pablo Bay. The inverse of the gradient is seen in the condition index of the animals. The more healthy animals are observed in San Pablo Bay and the poorest in condition are observed in sites of highest contamination. These gradients are consistent from month to month. Metal bioaccumulation of Potamocorbula amurensis was also compared with other resident bivalve species, Macoma balthica and Corbicula sp. M. balthica and Corbicula concentrate more Cu in their tissue than Potamocorbula amurensis in nature. However, in a bioaccumulation experiment in the lab using M. balthica and P. amurensis, Potamocorbula amurensis is more responsive to solute Cu than M. balthica. This contradiction suggests Potamocorbula amurensis may be exposed in some way to less Cu than M. balthica in nature. Potamocorbula amurensis concentrates more Cd in its tissue than M. balthica and Corbicula in nature, but in the lab experiment, Potamocorbula amurensis is less responsive to Cd. Potamocorbula amurensis was also more tolerant to metals.

Brown, D. C. 1967. A review of the freshwater Mollusca of Natal and their distribution. Annals of the Natal Museum 18(3):477 494.

The zoogeographic distribution of Corbicula africana is discussed. The species is found in the eastern region of Natal, particularly near the coast as far south as the Ifafa River. The furthest record inland is from the Umgeni River at Nagle Dam. Corbicula africana is distributed in the eastern and western portions of Cape Province northwards to the east African Great Lakes.

Brown, D. S. 1977. Freshwater molluscs. IN: Biogeography and Ecology of Southern Africa. 2. M. J. A. Werger, Ed. W. Junk (The Hague). pp. 1155 1180.

Bruggen, A. C. van. 1970. Non marine Mollusca. IN: South African Animal Life, Results of the Lund University Expedition in 1950 1951, 14:445 476.

Bruguière, J. G. 1798. Encyclopéde Méthodique.

Bryant, G. L. 1974. To catch a clam. Bureau of Reclamation Research News 4:2 3.

Description of techniques for collection of bivalves. Corbicula manilensis is included.

Bryant, G. L. 1974. A wheeled device for sampling biota of a concrete lined canal. California Fish and Game 60:97 99.

A device used to collect organisms (including Corbicula manilensis from the Delta Mendota Canal of California's Central Valley, is described.

Buchanan, A. C. 1987. Die off impacts on the mussel fauna of selected reaches of the Bourbeuse and Meramec rivers, Missouri. IN: Proceedings of the Workshop on Die Offs of Freshwater Mussels in the United States, R. J. Neves, Ed. U.S. Fish and Wildlife Servive, Upper Mississippi River Conservation Committee, and Virginia Polytechnic Institute and State University (Blacksburg). pp. 44 54.

Massive die offs of Corbicula sp. are reported in the Meramec and Bourbeuse rivers, Missouri.

Bullen, R. A. 1901. On two apparently new species of Corbicula. Proceedings of the Malacological Society of London 4:223 224.

Corbicula fulgida sp. nov. is described (p.224 and figured (pl. 22, fig 2) and Corbicula subtrianqularis sp. nov. is described (p. 223) and figured (pl. 23, fig. 1). No type locality cited for either species.

Bullen, R. A. 1904. Descriptions of new species of non marine shells from Java and a new species of Corbicula from New South Wales. Proceedings of the Malacological Society of London 6:109 111.

Bullen, R. A. 1906. On some land and freshwater Mollusca from Sumatra. Proceedings of the Malacological Society of London 7:12 16.

The presence of Corbicula moussoni Deshayes, 1854 in the River Kwantan, affluent of the Indragiri, and within the Souliki Range of Sumatra were collected in the spring and summer months of 1905.

Bullen, R. A. 1906. On some land and fresh water Mollusca from Sumatra. Part 2. Proceedings of the Malacological Society of London 7:126 130.

Burch, B. L. 1978. Asian clam, Corbicula threatens Hawaii. The Nautilus 92(1):54 55.

Burch, J. B. 1972. Freshwater Sphaeriacean Clams (Mollusca: Pelecypoda) of North America. Biota of Freshwater Ecosystems Identification Manual No. 11, U. S. Environmental Protection Agency (Washington, D. C.). 31 pp.

Burch, J. Q. 1944. Checklist of West American mollusks. Minutes of the Conchological Club of Southern California 38:18.

Burky, A. J. 1983. Physiological ecology of freshwater bivalves. IN: The Mollusca, Vol. 6, Ecology, W. D. Russell Hunter, Ed. Academic Press (New York). pp. 281 327.

A general discussion of the physiological ecology of Corbicula fluminea is presented. Temperature adaptation, oxygen consumption, dispersal, filtration rate, ionic and osmotic physiology, population dynamics, population energetics, and evolutionary strategies are discussed.

Burress, R. M. 1982. Effects of synergized rotenone on nontarget organisms in ponds. U. S. Department of the Interior, Fish and Wildlife Service, Investigations in Fish Control Report No. 91. 7 pp.

Applications of 2  or 5 ìL/L concentrations of synergized rotenone (2.5%) in the Pro Noxfish formulation to two shallow, 0.05 ha ponds caused a temporary reduction in both total numbers and diversity of benthic invertebrates and a total mortality of caged Asiatic clams (Corbicula manilensis) in both ponds, and a partial mortality of a resident population of larval leopard frogs (Rana pipieins) in the 5 ìL/L treatment. At day 7 after treatment, benthic organisms (number per square meter) were reduced 67% by the 2 ìL/L concentration and 96% by the 5 ìL/L application. The diversity index declined sharply in both ponds between days 3 and 7 after treatment, the lowest values being recorded on day 7 and day 37 in the 2  and 5 ìL/L treatments, respectively. The equitability index declined from day 3 to day 37 in both ponds. By day 69, however, total numbers of benthic organisms had more than doubled over those originally present in the 2 ìL/L treatment (121% increase), had more than tripled in the 5 ìL/L treatment (223% increase), and were virtually unchanged in the control pond (2% increase). Pretreatment zooplankton populations were low; no significant deleterious effects from the treatments were observed.

Burress, R. M., J. H. Chandler, Jr. and L. L. Marking. 1976. Use of the Asiatic clam, Corbicula leana Prime, in toxicity tests. Progressive Fish Culturist 38(1):10.

Busch, R. L. 1974. Asiatic clams Corbicula manilensis Philippi as biological filters in channel catfish Ictalurus punctatus (Rafinesque). Master of science Thesis, Auburn University (Auburn, Georgia). xi + 84 pp.

Butenko, J. V. 1967. On the fauna of freshwater molluscs of the south and south east Kazakhastan. Trudy Zoologicheskogo Instituta Leningrad 4:205 212. [Russian]

The shell and hinge apparatus of Corbicula tibetensis is described.

Butler, P. A. 1973. Organochlorine residues in estuarine mollusks, 1965   1972   National Pesticide Monitoring Program. Pesticides Monitoring Journal 6(4):238 362.

Analysis of 8,095 samples for 15 persistent organochlorine compounds showed that DDT residues were ubiquitous; the maximum DDT residue detected was 5.39 ppm. Dieldrin was the second most commonly detected compound with a maximum residue of 0.23 ppm. Endrin, morex, toxaphene, and polychlorinated biphenyls were found only occasionally. Results indicate a clearly defined trend towards decreased levels of DDT residues, beginning in 1969 1970. At no time were residues observed of such magnitude as to imply damage to molluscs (including Corbicula fluminea); however, residues were large enough to pose a threat to other elements of the biota through the process of recycling and magnification.

Butot, L. J. M. 1952. How to collect shells of land and freshwater molluscs. Tropische Natuurwetschlappelijk 32(4):135 140.

Notes on the biology and collection of Corbicula javanica are given.

Buttner, J. K. 1981. Asiatic clam in channel catfish rearing ponds: Its biology and its effect on water quality. Ph.D. Dissertation, University of Southern Illinois (Carbondale). 253 pp.

Between 1 June and 20 September 1977, 1 June and 1 July 1978, and 1 July and 4 October, 1979, the Asiatic clam, Corbicula fluminea (Müller, 1774) was stocked in four 0.06 ha channel catfish rearing ponds. Its effect on pond biota and water quality were investigated. In 1977 and 1978, clams were stocked in cages suspended in the water column of mechanically circulated ponds at 828 to 1010 kg/ha and 785 to 837 kg/ha, respectively. In l979 clams were stocked upon the substratum of uncirculated ponds at 1222 to 1717 kg/ha. Survival of C. fluminea averaged 36%, 56%, and 79% in 1977. 1978, and 1979, respectively. Growth of C. fluminea averaged 0.012 mm/day and 0.003 mm/day; weight gain was negligible. C. fluminea reproduced in ponds during all three years, but recruitment was not sufficient to maintain the initial stocking density. Clams were able to survive Karmex, Batex, and rotenone additions at concentrations commonly used in fish rearing ponds.

Effects of Corbicula fluminea on pond biota were similar in both circulated and uncirculated ponds. C. fluminea had no significant (P>0.05) effect on channel catfish survival (averaged 95%) or growth (doubling time ranged from 56 to 72 days and feed conversion ranged from 1.11 to 2.11). At clam densities stocked it was not possible to document an effect on bacterial and plankton abundance. Presence of variable numbers of planktophagic contaminant fish (usually < 4 kg/pond) may have masked any effect of the clam.

Corbicula fluminea frequently, but not always, increased average dissolved oxygen at dawn, reduced incidence of critical dissolved oxygen (< 3 mg/L), increased rate of diurnal production and nocturnal respiration, and reduced turbidity during 1977 and 1979. These observed trends were significant (P<0.05) only in 1977. Nitrogeneous waste as total ammonia nitrogen, nitrate nitrogen, and total nitrogen were frequently, but not always, significantly (P<0.05) greater in ponds with C. fluminea. Effects of C. fluminea on water quality in 1977 and 1979, probably due to an abbreviated collection period.

Results of the study indicate Corbicula fluminea can survive without detrimental effect to catfish and may promote superior water quality in catfish rearing ponds.

Buttner, J. K. 1986. Corbicula as a biological filter and polyculture organism in catfish rearing ponds. Progressive Fish Culturist 48(2):136 139.

Corbicula fluminea, an introduced Asian clam, was stocked with channel catfish (Ictalurus punctatus) in Illinois culture ponds. Survival of the stocked clams was 36 79% over summer, but reproduction was poor and the populations declined. Nevertheless, ponds with C. fluminea had less dissolved oxygen depletion, lower turbidity, and greater primary production than ponds without the clam. Growth of channel catfish was unaffected by the presence or absence of clams. Corbicula fluminea has potential value as a polyculture organism and as a biological filter where water temperatures do not exceed 30^oC.

Buttner, J. K. 1986. Biology of Corbicula in catfish rearing ponds. IN: Proceedings of the Second International Corbicula Symposium, J. C. Britton, Ed. American Malacological Bulletin Special Edition No. 2. pp. 211 218.

Buttner, J. K. and R. C. Heidinger. 1980. Seasonal variations in growth of the Asiatic clam, Corbicula fluminea (Bivalvia: Corbiculidae) in a southern Illinois fish pond. The Nautilus 94(1):8 10.

Fifty specimens of Corbicula fluminea were stocked into a 0.06 ha fish pond for 62 days during the summer, and 40 days for both fall and winter. Clam recovery for summer, fall, and winter observations was 82%, 60%, and 98%, respectively. Clam growth rates for summer and fall averaged 0.012 mm/day and 0.054 g/day and 0.0003 g/day. Summer and fall growth rates were not significantly different (P = 0.29), while winter growth rates were significantly lower (P = 0.001). Relative weight gain per day for all observations was significantly greater (P = 0.0l) for small clams. Absolute weight gain per day was significantly greater (P = 0.006) for larger clams during the summer, while fall and winter absolute growth was similar for all clams. Summer, fall, and winter water temperatures were significantly different (P = 0.001), while phytoplankton density remained relatively constant for all observations.

Buttner, J. K. and R. C. Heidinger. 1981. Rate of filtration in the Asiatic clam, Corbicula fluminea. Transactions of the Illinois Academy of Science 74(3 4):13 18.

Filtration rate of Corbicula fluminea (Müller, 1774) (0.83   7.40 g) at 21 to 24^oC in a suspension of 3,314 to 17,742 plants/ml of Scenedesmus sp. averaged 347 ml/hr/clam, 177 ml/hr/g total weight, 1,561 ml/hr/g soft tissue weight, and 20,499 ml/hr/g dried soft tissue weight. Rate of filtration was not strongly correlated with clam weight (r > 0.10). Filtration rates determined in this and other studies were compared. It was concluded that the most acceptable filtration rate of C. fluminea ranges from 300 to in excess of 800 ml/hr/clam.

Buyle, B. 1989. Ecotoxicological tests on benthic organisms. Advances in Llimnology. 1989. International Conference on Reservoir Limnology and Water Quality, Ceske Budejovice, Czechoslovakia, 15 June 1987.

This paper describes the development of an ecotoxicological evaluation of effects of contaminants on the benthic ecosystem. It also proposes some methods to determine actual concentrations and bioavailability of contaminants to the benthos.

Byrne, M., H. Phelps, T. Church, V. Adair, P. Selvakumaraswamy, and J. Potts. 2000. Reproduction and development of the freshwater clam Corbicula australis in southeast Australia. Hydrobiologia 418(1): 185-897.

The freshwater clam Corbicula australis is an important component of the macrobiota of the river systems of southeast Australia. Reproduction of two populations of this clam in the Nepean River at Douglas Park and Menangle was investigated to document the gametogenic cycle, larval morphology and to determine when they incubate embryos. C. australis is a simultaneous hermaphrodite and broods its young in the inner demibranchs. The gonads are ovotestes with oogenic and spermatogenic regions in each ascinus. The sperm are biflagellate, a condition unique in the Bivalvia to clonal corbiculids. Gametogenesis was continuous and did not exhibit a seasonal pattern. In contrast, spawning and incubation of embryos was limited to the warmer months of the year. Embryos were present in the gills from October to May. C. australis develops through a modified veliger larva with a vestigially ciliated velum which is not used for swimming or particle capture. The velum is covered by microvilli and it is suggested that the velar epithelium may be specialized for nutrient uptake in the marsupial environment. C. australis produces several clutches each year and the young are released as advanced juveniles with a well-developed foot. Reproductive output differed between the two populations. This was in part due to the larger size of the clams from Menangle and may also reflect the enhanced productivity at this site. The suite of life history traits exhibited by C. australis: hermaphroditism, potential for self-fertilization/androgenesis, brooding progeny to the crawl-away juvenile stage and a high reproductive output, provide for rapid colonization and population growth in this clam which typically inhabits disturbance prone sandy lotic habitats.

Byrne, R. A. 1988. Physiological and behavioral responses to aerial exposure in the Asian clam, Corbicula fluminea (Müller). Doctor of Philosophy Dissertation, Louisiana State University (Baton Rouge). vii + 144 pp.

Byrne, R.A ., E. Gnaiger, R. F. McMahon and T. H. Dietz. 1990. Behavioral and metabolic responses to emersion and subsequent reimmersion in the freshwater bivalve, Corbicula fluminea. Biological Bulletin 178(3):251-259.

When exposed to air, the freshwater bivalve, Corbicula fluminea, displayed valve movement behaviors, such as mantle edge exposure, wider gaping "ventilatory" response, and an escape or "burrowing" response. The proportion of the emersion period spent in these behaviors, relative to valve closure, increased with decreasing temperature. Emersion at 35^oC inhibited valve movement behaviors, whereas emersion in a nitrogen atmosphere stimulated ventilatory activity. High rates of aerial oxygen uptake (M_O2) were associated with initial valve opening and ventilatory behaviors, and lower Mu _O2) occurred during bouts of mantle edge exposure. Heart rate was affected by temperature, but not by mantle edge exposure. Heart rate increased during burrowing and ventilatory behaviors suggesting a hydraulic function for hemolymph.

Byrne, R. A., R. F. McMahon and T. H. Dietz. 1987. O₂ uptake and NH₃ excretion following prolonged aerial exposure in Corbicula fluminea. American Zoologist 27(4).

Byrne, R. A., R. F. McMahon and T. H. Dietz. 1988. Temperature and relative humidity effects on aerial exposure tolerance in the freshwater bivalve Corbicula fluminea. Biological Bulletin 175:253-260.

The exposure tolerance, aerial respiratory behaviors, and the rates of water loss of the Asian freshwater clam, Corbicula fluminea , were assessed under three temperature conditions (15^o , 25^o and 35^oC) and five relative humidity (RH) treatments (5%, 33%, 53%, 75% and 95%). C. fluminea displayed low tolerance to aerial exposure (range of median tolerance times: 23.8-24.9 h at 35 ^oC, 71.4-78.2 h at 25 ^oC, and 248.5-341.6 at 15^oC). Relative humidity had no effect on median tolerance time except at 15 ^oC. The results suggest that C. fluminea can detect rates of desiccation and make behavioral adjustments.

Byrne, R. A., B. N. Shipman, N. J. Smatresk, T. H. Dietz and R. F. McMahon. 1991. Acid-base balance during emergence in the freshwater bivalve Corbicula fluminea. Physiological Zoölogy 64(3):748-766.

The Asian freshwater clam, Corbicula fluminea, was emersed at 23^oC under three conditions: humid air, N₂ hypoxia, or air with valves clamped or bound shut. Under all conditions, clams became acidotic during emersion. In air, hemolymph pH declined from 7.90 to 7.14 in 72 h. Hypoxic clams displayed a similar decline in pH, but clams with valves clamped became acidotic more rapidly. Hemolymph CO₂ content (CCO₂) and PCO₂ rose with duration of aerial exposure in all treatment groups. However, hemolymph of bound clams had significantly higher CCO₂ and PCO₂ than that of either air- or N₂-exposed bivalves after 48 h emersion. Although hemolymph PO₂ declined with emersion time in all groups, there was no effect of exposure condition, suggesting that ventilatory behaviors did not affect hemolymph PO₂ or that the effects were masked by rapid utilization of inspired O₂. Hemolymph calcium and osmolality increased with emersion time and were greatest in clams with clamped valves. Presumably, shell calcium carbonate was mobilized to provide bicarbonate to buffer the acidosis, while valve gaping, mantle edge exposure, and other ventilatory behaviors served to retard the progress of the acidosis by ventilatory loss of CO₂. However, these behaviors were not sufficient to maintain acid-base balance in C. fluminea. The inability of C. fluminea to maintain or restore acid-base balance during short emersion periods may account for this species' low tolerance of aerial exposure and is further evidence of its recent invasion of freshwater habitats.