Corbicula an annotated bibliography 1774 2005

Gabriel, C. J. 1939. The freshwater Mollusca of Victoria. Memoirs of the National Museum of Victoria 11:100 139.

Gabriels, W., P Goethals and N.Pauw. 2005. Implications of taxonomic modifications and alien species on biological waterquality assessment as exemplified by the Belgian Biotic Index method. Hydrobiologia 542(1):137-150.

Gaillard, C. 1934. Contribution à l'étude de la faune prehistorique de l'Egyte. Archives Muséum Histoire Naturelle Lyon 14(Memoir 3):1 126.

Fossils from the Paleolithic (Quaternary) of Sebril Kon Ombo and described and discussed. Groups include mammals, fishes, and molluscs (including Corbicula consobrina).

Gainey, L. F. 1978. The response of the Corbiculidae (Mollusca: Bivalvia) to osmotic stress: the organismal response. Physiological Zoology 51(1):68 78.

There was no difference in the pattern of valve movements when Polymesoda was transferred from 10 ppt to freshwater and vice versa. Transfer from 5 ppt to freshwater had no effect on valve movements of Corbicula manilensis (Philippi), but a transfer from fresh water to 5 ppt S depressed activity. When Polymesoda was transferred from fresh water to 10 ppt S, the osmotic pressure of the blood increased exponentially toward an asymptote with a half time of 2.61 hrs.; upon transfer from 10 ppt S to fresh water, the osmotic pressure decreased exponentially toward an asymptote with a half time of 4.25 hrs. In C. manilensis, the half time for hyperosmotic stress (fresh water to 5 ppt S) was 2.30 hrs. In Polymesoda, volume regulation response to hypoosmotic stress (10 ppt S to fresh water) was complete in 6 hrs.; volume regulation in response to hyperosmotic stress (fresh water to 10 ppt S) was complete in 36 hrs. In C. manilensis, volume regulation in response to hypoosmotic stress (5 ppt S to fresh water) was, as in Polymesoda, complete in 6 hrs.; volume regulation in response to hyperosmotic stress (fresh water to 5 ppt S) was incomplete.

Gainey, L. F. 1978. The response of the Corbiculidae (Mollusca: Bivalvia) to osmotic stress: the cellular response. Physiological Zoology 51(1):79 91.

When Polymesoda was transferred from 10 ppt S to fresh water, the free amino acid (FAA) pool decreased by 70% in 24 hrs.; alanine accounted for 85% of the decrease. In Polymesoda blood, FAA doubled within 10 hrs. after hypoosmotic stress; between 10 and 24 hrs. the FAA pool decreased by 24%. Most of the increase and subsequent decrease were accounted for by alanine. In Corbicula manilensis (Philippi), transferred from 5 ppt S to fresh water, the FAA pool decreased by 87% in 48 hrs.; alanine accounted for 73% of the decrease. Upon transfer from fresh water to 10 ppt S, the FAA of Polymesoda foot muscle increased from 27 to 176 ìmol/g dry wt during the first 36 hrs.; between 36 and 73 hrs. the FAA pool increased only to 187 ìmol/g dry wt. Alanine accounted for 56% of the increase before 36 hrs. and 77% after 36 hrs. When C. manilensis was transferred from fresh water to 5 ppt S the FAA pool increased from 20 to 115 ìmol/g dry wt.; between 70 hrs and 30 days the pool increased to 197 ìmol/g dry wt. Alanine accounted for 78% of the initial increase in the FAA pool.

Gainey, L. F. and M. J. Greenberg. 1977. Physiological basis of the species abundance salinity relationship in molluscs: a speculation. Marine Biology 40(1):41 49.

The relationships between the osmotic pressures of the blood and the ambient medium was determined for 4 species of bivalve molluscs whose habitats represent distinct salinity regimes within the range from fresh to full seawater. These organisms included 3 corbiculids: Corbicula manilensis (Philippi) (freshwater); Polymesoda caroliniana (brackish water); Pseudocyrena floridana (marine), and 1 unionid, Elliptio lanceolata. On the basis of the data and similar measurements from the literature, the molluscs were placed into 5 categories: marine stenohaline, marine euryhaline, oligohaline, freshwater euryhaline, and freshwater stenohaline. Marine stenohaline and euryhaline species are osmoconformers. They differ only in the size of the free amino acid pool available for intracellular volume regulation, and thus in the range of salinities that they tolerate. Oligohaline species tolerate salinities from seawater down to freshwater; they not only possess a large capacity for volume regulation, but can also osmoregulate below 3 ppt S. Freshwater species also osmoregulate below 3 ppt S, but they are usually limited to salinities below 2 ppt S. Presumably, in evolving from the marine to the freshwater habitat, they have lost the ability to volume regulate in response to hyperosmotic stress. It is proposed that the varying physiological characteristics underlie the well known relationship that species abundance decline from both freshwater and full seawater to a minimum between 3 and 5 ppt S. This species minimum was related to a physical chemical discontinuities in the ionic composition of seawater which are, again, reflected in the physiological mechanisms of the molluscs.

Gale, H. S. 1906. Coal fields of the Danforth Hills and Grand Hogback in northwestern Colorado. Bulletin of the U.S. Geological Survey 316:264 301.

Gale, H. S. 1908. Geology of the Rangeley Oil District, Rio Blanco County, Colorado. Bulletin of the U.S. Geological Survey 350:1 61.

Gale, H. S. 1910. Coal fields of northwestern Colorado and northwestern Utah. Bulletin of the U.S. Geological Survey 415:1 265.

Gambetta, L. 1932. Sopra alcuni molluschi raccolti del Dott. H. Scaetta nel Lago Kivu, in rapporto alla fauna malacologia de Lago Edouardo (Africa Equatoriale Orientale). Bollettino Musei di Zoologia di Anatomia Comp. della R. Universitta di Torino 42 (No. 21):1 26.

García, M. L. and L. C. Protogino, L. C. 2005. Invasive freshwater molluscs are consumed by native fishes in South America. Journal of Applied Ichthyology 21(1):34-38.

Gardner, E. W. 1932. Some lacustrine Mollusca from the Faiyum Depression. Memoirs Institute Egypte 18: xvi + 123.

A monograph dealing with the molluscan fauna of the prehistoric and modern lakes of Faiyum Depression, Egypt. Corbicula vara sp. nov. is described from the Pleistocene of the lake. Outstanding features of the Pleistocene lake are 1) the admixture of palearctic and west African freshwater shells, many new to Egypt, 2) the development of peculiar and characteristic species not yet found in either living or fossil assemblages outside the Faiyum Depression, and 3) the marked difference between assemblages on the north and south sides of the lake, traced to ecological causes. Fossil Corbicula artini and recent Corbicula consobrina, Corbicula innesi, and Corbicula africana are discussed.

Gardner, J. 1933. The Midway group of Texas. Bulletin of the University of Texas 3301:1 343.

Gardner, J. A., R. A. Woodall, A. A. Staats, Jr. and J. F. Napoli. 1976. The invasion of the Asiatic clam (Corbicula manilensis) in the Altamaha River, Georgia. The Nautilus 90(3):117 125.

The population of Corbicula manilensis (Philippi) in the Altamaha River, Georgia, increased considerably from October 1971 to November 1975. Density of C. manilensis generally reached a maximum in late summer or fall and was at a minimum during winter and spring, a relation which was inversely related to river discharge. Generally, densities of older age classes were greater in areas of low current velocity, whereas densities of younger age classes were greater in areas of high velocity. Average densities increased from a minimum of 0/m² to a maximum of 10,000/m² in 1974. The invasion of C. manilensis has been accompanied by a drastic decline in the populations of other bivalves. Several species of Unionidae endemic to the Altamaha River may be affected by C. manilensis and are considered endangered.

Gardner, J. H. 1910. The Carthage Coal Field, New Mexico. Bulletin of the U.S. Geological Survey 381:452 460.

Gardner, S. E. 1983. Diel and seasonal influences in the metabolic rate of the Asiatic clam, Corbicula fluminea (Müller), Bivalvia, Corbiculidae. Master of Science These, University of Virginia (Charlottesville). vi+91 pp.

Gardner, S. E. and D. J. Hornbach. 1983. Diurnal and seasonal influences on the metabolic rate of the Asiatic freshwater clam Corbicula fluminea. Virginia Journal of Science 34(3):122.

Garkalina, N. N. and I. M. Moskvicheva. 1979. Composition and distribution patterns of the molluscs in the estuary of the Amur. IN: Sixth Meeting on the Investigation of Molluscs. Molluscs. Main Results of Their Study. Abstracts of Communications, I. M. Likharev, Ed. Nauka (Leningrad). pp. 203 205. [Russian, Abstract]

Garrett, W. E., Jr. 1994. The effects of low level chlorination and chlorine dioxide on biofouling control in a once-through service water system. Master of Science Thesis, University of Alabama at Birmingham. vi+24 pp.

Geinitz, E. 1904. Das Quartär von Nordeuropa. Lethaea Geognostica III, 2. 1. (Stuttgart).

Geisy, J. P. and G. W. Dickson. 1981. The effect of season and location on phosphoadenylate concentrations and adenylate energy charge in two species of freshwater clams. Oecologia (Berlin) 49(1):1 7.

Concentrations of phosphoadenylate nucleotides and the adenylate energy charge ((ATP + 1/2ADP)/(ATP + ADP + AMP)) have been suggested as sensitive integrating measured of the energy state of organisms. This synoptic study investigated the seasonal and spatial variation of phosphoadenylate concentrations and AEC in two freshwater bivalves: the papaer shell, Anodonta imbecilis, and the Asian clam, Corbicula fluminea. Concentrations of all three adenylates, as well as the total concentration and the adenylate energy charge of both species varied seasonally. These fluctuations were closely related to reproductive periods in both species. Total adenylate concentrations and ATP concentrations were slightly negatively correlated with shell length in A. imbecilis but the ADP and AMP concentrations and AEC were not significantly correlated with shell length. In C. fluminea the AEC was negatively correlated with shell length, while all of the adenylate concentrations were positively correlated with shell length. Neither species exhibited significant differences in AEC between two collection locations. When C. fluminea collected from the Savannah River were acclimated and fed in the laboratory, their AEC increased significantly.

Geret, F., F. Rainglet and R. P. Cosson. 1998. Comparison between isolation protocols commonly used for the purification of mollusc metallothioneins. Marine Environmental Research 46(1-5):545-550. 1998.

Two centrifugation methods (at 30 000 and 100 000 g) combined with two isolation procedures (heat denaturation and solvent precipitation) were tested to check if their use introduced significant differences in the quantification of metals (Cd, Cu, Zn) and metallothioneins in blue mussel organs (gills and digestive gland). No contaminating compounds originating from the lowest centrifugation speed were likely to interfere with quantitative measurements of metal, protein and metallothionein. As isolation treatments act on specific properties of proteins in general and metallothionein isoforms in particular they cannot be used interchangeably. Therefore, any comparisons of MT amounts in bivalve tissues with data from the literature have to take into account the isolation procedure. Similar results were obtained with three other molluscs, Crassostrea gigas, Bathymodiolus thermophilus (hydrothermal mussel), and Corbicula fluminea (estuarine bivalve).

Geret, P. 1909. Liste des genres, sections et especes decrits par C. F. Ancey avec leurs references originales. Journal de Conchyliologie 51:1 37.

Corbicula bavayi Ancey, 1880 and Corbicula sikorae Ancey, 1891 are referenced.

Germain, L. 1905. Liste des mollusques recueillis par M. E. Foa dans le lac Tanganika et ses environs. Bulletin du Muséum d'Histoire Naturelle (Paris), Série I, 11:254 261.

Germain, L. 1905. Contributions à la faune malacologique de l'Afrique équatroriale. I. Note Préliminaire sur quelques Mollusques nouveaux du lac Tchad et du bassin du Chari. Bulletin du Muséum d'Histoire Naturelle (Paris), Série I, 11:483 489.

Germain, L. 1906. Contributions à la faune malacologique de l'Afrique équatoriale. VII. Sur le genre Spekia. Bulletin du Muséum d'Histoire Naturelle (Paris), Série I, 12:577 585.

Germain, L. 1907. Contributions à la faune malacologique de l'Afrique équatoriale. IX. Mollusques nouveaux de lac Tchad. (Mission R. Chudeau). Bulletin du Muséum d'Histoire Naturelle (Paris), Série I, 13:64 68.

Germain, L. 1908. Mollusques du lac Tanganyika et ses environs. IN: Resultants Scientifique des Voyages en Afrique d'Edouard Foa (Paris). pp. 16, 82.

Germain, L. 1909. Contributions à la faune malacologique de l'Afrique équatoriale. XXI. Mollusques nouveaux du Soudan Francais recueillis par M. G. Garde. Bulletin du Muséum d'Histoire Naturelle (Paris), Série I, 15:473 477.

Germain, L. 1910. Contributions à la faune malacologique de l'Afrique équatoriale. XII et XIII. Mollusques recueillis par M. le lieutenant Ferrandi dans l'Equer et le Bodele (nord est du Tchad). Bulletin du Muséum d'Histoire Naturelle (Paris) 16:204 213.

Germain, L. 1911. Notice malacologique. Documents Scientifique, Mission Tihlo, II. pp. 218, 236.

Germain, L. 1912. Contributions à la faune malacologique de l'Afrique équatoriale. XXX. Sur quelques mollusques recueillis par M. le Dr. Gromier dans le lac Albert, Edouard et ses environs. Bulletin du Muséum d'Histoire Naturelle (Paris) 18:77 83.

Germain, L. 1913. Contributions à la faune malacologique de l'Afrique Équatoriale. XXXVIII. Pélécypods du voyage en Afrique tropicale de M. le. Dr. Poutrin (1908). Bulletin du Muséum d'Histoire Naturelle (Paris) 19:290 296.

Germain, L. 1913. Mollusques terrestres et fluviatiles de l'Asie Antérieure: 6^e note.   Catalogue des Pélécypodes de la Syrie et de la Palestine. Bulletin du Muséum d'Histoire Naturelle (Paris) 19(7):469 473.

Germain, L. 1916. Seconde notice malacologique. Documents Scientifiques de la Mission Tilho. Vol. 3. pp. 285 322.

Germain, L. 1916. Contributions à la faune malacologique de l'Afrique Équatoriale. XLIII. Faunule malacologique du lac Albert  Éduoard (Afrique Orientale). Bulletin du Muséum d'Histoire Naturelle (Paris), Série I, 22:193 210.

Germain, L. 1918. Contributions à la faune malacologique de Madagascar. Bulletin du Muséum d'Histoire Naturelle (Paris) 24:13 21.

Germain, L. 1918. Contributions à la faune malacologique de Madagascar. Bulletin du Muséum d'Histoire Naturelle (Paris), Série I, 24:34 42, 43 54.

The genus Corbicula in Madagascar is discussed.

Germain, L. 1918. Contributions à la faune malacologique de Madagascar. Bulletin du Muséum d'Histoire Naturelle (Paris), Série I, 24:181 186, 516 524.

The genus Corbicula in Madagascar is discussed.

Germain, L. 1922. Mollusques Terrestres et Fluviatiles Recueillis en Syrie par M. H. Gadeau de Kerville, Vol. 2. Pelecypods. J. B. Bailliere et Fils (Paris). 242 pp.

Germain, L. 1931. Contributions à la faune malacologique de l'Afrique Équatoriale. Mollusques du Hodlé (Sahara Soudanais) recueillis par M. le Lieutenant Boëry. Bulletin du Muséum d'Histoire Naturelle (Paris), Second Series, 3:355 359.

Germain, L. 1931. Mollusques terrestres et fluviatiles recueillis par M. le Lieutenant Boery a Oualata (Sahara Soudanais). Bulletin du Comité d'Études Historiques et Scientifiques de l'Afrique Occidentale Francaise 14(3):205 217.

Germain, L. 1932. Contributions à la faune malacologique de l'Afrique Équatoriale. LXIV. Mollusques subfossiles recueillis dans le Sahara par M. le Colonel Roulet. Bulletin du Muséum d'Histoire Naturelle (Paris), Second Series, 4(7):890 894.

Germain, L. 1933. Mollusques terrestres et fluviatiles de l'Afrique Occidentale Francaise (Mission A. Chevalier, 1931 1932). Bulletin du Comité d'Études Historiques et Scientifiques de l'Afrique Occidentale Francaise 16(2):169 236.

Germain, L. 1933. Mollusques terrestres et fluviatiles du voyage de M. A. Chevalier au Sahara et en Afrique Occidentale Francaise 1931 1932. Bulletin du Muséum d'Histoire Naturelle (Paris), Second Series, 5(6):469 474.

Germain, L. 1934. Contributions à la faune du Mozambique. Voyage de M. P. Lesne (1928 1929). 17^e Note   Mollusques terrestres et fluviatiles de la Province de Mozambique (Afrique Orientale Portugaise). Memórias e Estudos do Museu Zoológico da Universidade de Coimbra, Série 1, 80:1 72.

Gifford, C. A. 1974. The Asiatic clam, Corbicula sinensis, in Lake Oklawaha, Florida. Association of Southeastern Biologists, Bulletin 21(2):56. [Abstract]

Girotti, O. 1969. Der "Lago Tiberino" und sine Mollusken. Eighth Congress, INQUA, Paris. Résumés des Communications pp. 439 440.

The distribution and paleoecology of Corbicula fluminalis (Müller, 1774) in the Quaternary of Italy at Lake Tiberino is presented.

Girotti, O. 1970. On the "Lago Tiberino" and his (sic) mollusks. Eighth Congress, INQUA, Paris. Résumés des Communications 1969:125. [Abstract]

The distribution and paleoecology of Corbicula fluminalis (Müller, 1774) in the Quaternary of Italy at Lake Tiberino is discussed.

Givens, C. R. 1974. Eocene molluscan bio stratigraphy of the Pine Mountain area Ventura County, California. University of California Publications Geological Sciences 109:1 107.

A possible new species of Corbicula aff. Corbicula williamsoni Anderson and Hanna, 1925, is described (p. 52) from three poorly preserved specimens collected southwest of Pine Mountain Lodge, 950 ft. south, 2,450 ft. west of the northwest corner of section 14, T 6 N, R 22 W, Lion Canyon Quadrangle (1943 Ed.). This is the type Tejon Formation, but the specimens are distinguished by higher beaks and a more prominent umbonal ridge.

Gilbert, M. and L. van de Poel. 1967. Les Bivalvia fossiles du Cenozoique etranger des collections de l'Institute Royale des Sciences Naturelles de Belgique 4. Heteroconcha. Part 2. Corbiculidae a Petricolidae. Memoirs de l'Institute Royal des Sciences Naturelles du Belgique, Series 2, 82:1 108.

Cenozoic species of Corbicula in the collections of the Royal Institute are listed.

Gmelin, J. F. 1788. Systema Naturae, 13th Edition.

Tellina fluminalis is discussed.

Golightly, C. G., Jr. 1982. Movement and Growth of Unionidae (Mollusca: Bivalvia) in the Little Brazos River, Texas. Ph.D. Dissertation, Texas A.&M. University (College Station). 109 pp.

The growth and movement of the Unionidae of the Little Brazos River, Texas, was investigated. Turnover rates of individuals (all species pooled) were similar at widely separated pool riffle sites and tended to vary jointly in time, suggesting that turnover is linked to large scale disturbance processes (such as flooding). Although maximum turnover after flood events was observed (approximately 1.0%/day), at least 30% of all individuals persisted in the study sites to the end of the sampling year. In contrast with turnover, movement patterns were site dependent. Direction and magnitude of movement was random in the pool site. At the riffle site, clams moved preferentially downstream and moved significantly (p = 0.05) greater distances downstream than in other directions. Comparison of new mark/recapture sampling technique (tagging clams with small metal tags and "recapturing" with a metal detector) was made with hand sampling and repetitive quadrat sampling. Hand sampling missed approximately half the individuals present. Repetitive quadrat sampling by excavating and sieving was laborious, but efficient in detecting all individuals within small areas. The metal detector technique offers promise of efficient, long distance movement detection, but problems with tag loss and detection efficiency remain to be solved. Measurement of growth rates was made for three common species (Amblema perplicata, Quadrula quadrula, and Quadrula pustulosa) over all times of the year. Growth did not correlate significantly with sample date, days between samples, initial temperature, average temperature, or season. Growth did correlate significantly (p = 0.05) with initial length. Negative growth of individuals of all three species was observed. This phenomenon has not been reported for unionids. The early stages of the colonization of the Little Brazos River by Corbicula fluminea (Müller, 1774) was documented. C. fluminea densities increased 2100% from August 1980 to August 1981.

Gonzales, C. N., S. V. Bersamin and J. I. Sulit. 1975. Tulya (Corbicula manilensis Philippi), Paros (Soletellina bioncata Lamarck) and oysters as good sources of available calcium. Japanese Journal of Ecology 15(6):228 238. (Bureau of Fisheries, Manila)

Gooch, C. 1978. Corbicula chlorine bioassay: Corbicula control project : Final Report. Tennessee Valley Authority, Division of Environmental Planning, Water Quality and Ecology Branch (Muscle Shoals, Alabama). 20 pp.

Gordon, M. E. 1983. A preliminary report on the Mollusca of the Buffalo National River. American Malacological Bulletin 1:97. [Abstract]

The Buffalo River is one of the few rivers in Arkansas for which any previous published survey of the molluscan fauna exists. Meek and Clark (1912) reported 22 species of mussels from a survey of about two thirds of the river's length. When the river was incorporated into the National Park Service in 1972, a series of studies were initiated to assess the flora, fauna, and general ecology of the Buffalo River valley. The Mollusca were noted only as an occasional component of the benthos; when in fact, they are often the dominant organisms in both terms of numbers and weight. This study was intended to correct this oversight and examine changes that may have occurred over the last 60 years. Thirty five molluscan species have been identified from recent intensive sampling. This represents seven gastropods and 28 bivalves. With the exception of Corbicula fluminea (Müller, 1774), this probably does not represent an actual increase in the faunal diversity since 1910.

Gordon, M. E. 1985. Mollusca of Frog Bayou, Arkansas. The Nautilus 99(1):6 8.

Gose, K. 1965. The shell zone of Lake Kitaura. Japanese Journal of Ecology 15(2):228 232.

The benthos of Lake Kitaura, Ibaragi Prefecture, Japan, was surveyed in August and November 1964. A shell zone was found in the lake situated at a depth not influenced by wave action. The the stations Futaesaku, Kajiyama, the shell zone is composed largely of the shells of Sinotaia histrica. At Uzaki and Tsumaki, where the water is more brackish, the shell zone is composed mainly of the shells of Corbicula japonica.

Goss, L. B. and C. Cain, Jr. 1975. Power plant condenser service water system fouling by Corbicula, the Asiatic clam. IN: Biofouling Control Procedure Workshop, L. Jensen, Ed. Johns Hopkins University, Electric Power Research Institute, Ecological Analyists, Inc. pp. 11 22.

The morphology, life history and distribution of Corbicula sp. is discussed in relation to the fouling of service water systems of power plants. Condenser fouling at plants of the Tennessee Valley Authority is discussed and engineering and chemical solutions to clam fouling are presented.

Goss, L. B. and C. Cain, Jr. 1977. Power plant condenser and service water system fouling by Corbicula, the Asiatic clam. IN: Biofouling Control Procedures, L. D. Jensen, Ed. Dekker (New York). pp. 11 17.

Goss, L. B., J. M. Jackson, H. B. Flora, B. G. Isom, C. Gooch, S. A. Murray, C. G. Burton and W. S. Bain. 1979. Control studies on Corbicula for steam electric plants. IN: Proceedings of the First International Corbicula Symposium, J. C. Britton, Ed. Texas Christian University Research Foundation (Ft. Worth). pp. 139 152.

Corbicula fouling problems were first noted at the Tennessee Valley Authority's (TVA) Shawnee Steam Plant in 1957 and have since spread to all of the TVA's power plants throughout the Tennessee Valley region. An assessment was made as to the nature and extent of Corbicula fouling problems, and studies were initiated to develop methodologies for adequate control of Corbicula in the various water systems associated with power plants.

Control methods currently under laboratory and field investigation include mechanical straining, controlled release surfaces, chemical biocides, and heat treatment. Controlled release surfaces being studied include tributyl tin oxide (TBTO), tributyl tin fluoride (TBTF), and triphenyl lean acetate (TPLA). Chemicals being tested include chlorine, chlorine dioxide, and bromine chloride. Detailed results of these studies along with an evaluation of potential application in the various power plant water systems are presented.

Gottfried, P. K. and J. A. Osborne. 1982. Distribution, abundance and size of Corbicula manilensis in a spring fed central Florida stream. Florida Scientist 45(3):178 188.

Asiatic clams (Corbicula manilensis Philippi) were sampled at 12 stations along a 16 km reach of the Wekiva River, Florida, at 3 month intervals between August 1976 and June 1977. The abundance of the clams ranged from 4 to 1210/m². The greatest number of clams were found where the bottom sediments were comprised of clean, fine sand; lowest numbers were found in silty, organic sediments near the headwaters. Seasonally, larger clams were collected in December 1976 (mean shell length = 13.7 mm); small clams were most evident in March 1977 (mean shell length = 13.1 mm).

Goudreau, S. E., R. J. Neves and R. J. Sheehan. 1993. Effects of wastewater treatment plant effluents on freshwater mollusks in the upper Clinch River, Virginia, USA. Hydrobiologia 252(3):211-230.

Field and laboratory studies were conducted to determine mollusk distributions in proximity to wastewater treatment plants (WTP's) in the upper Clinch River and to test the tolerance of two mollusk species to monochloramine and unionized ammonia, the major toxicants in domestic effluent. River reaches up to 3.7 km downstream of WTP's were devoid of freshwater mussels (Unionidae), and tolerance to effluents varied among snails, sphaeriid clams, and the Asian clam Corbicula fluminea . Residential communities with septic systems had no measurable impact on mollusk assemblages downstream. Laboratory bioassays with glochidia of Villosa iris yielded the following results: 24 h EC₅₀ and LC₅₀ values of 0.042 mg/l and 0.084 mg/l monochloramine, respectively; and 24 h EC₅₀ and LC₅₀ of 0.237 mg/l and 0.284 mg/l unionized ammonia, respectively. Glochidia rank among the most sensitive invertebrates in their tolerance to these toxicants. The snail Pleurocera unciale unciale was moderately sensitive, with 96 h LC sub(50) values of 0.252 mg/l monochloramine and 0.742 mg/l unionized ammonia. Monitoring of monochloramine and unionized ammonia concentrations 0.1 km below WTP outfalls indicated that monochloramine was the toxicant likely inhibiting mollusk recovery below these plants.

Gould, A. A. 1850. Shells from the United States Exploring Expedition. Proceedings of the Boston Society for Natural History 3:292 296.

Corbicula debilis sp. nov. is described (p. 293) and figured (Vol. 7, pl. 36, figs. 529a, b) from the Hunter River, New Holland, Australia.

Grabau, A. W. 1923. Cretaceous Mollusca from north China. Bulletin of the Geological Survey of China (Peking) 5:188 197.

Grabau, A. W. and H. W. Shimer. 1909. North American Index Fossils. (New York). Volume 1.

Graczyk, T. K. 2001. Asian freshwater clams (Corbicula fluminea) and zebra mussels (Dreissena polymorpha) as biological indicators of contamination with human waterborne pathogens. 11th International Conference on Aquatic Invasive Species, Alexandria,Virginia, 1-4 October.

Graczyk, T. K., D. B. Conn, D. J. Marcogliese, H. Graczyk and Y. De Lafontaine. 2002. Accumulation of human waterborne parasites by zebra mussels (Dreissena polymorpha) and Asian freshwater clams (Corbicula fluminea). Parasitology Research 89(2):107-112.

Zebra mussels (Dreissena polymorpha) and Asian freshwater clams (Corbicula fluminea) are nonindigenous invasive bivalves present in North American fresh waters that are frequently contaminated with human enteric parasites, Cryptosporidium parvum and Giardia lamblia. Six-week laboratory exposure of D. polymorpha and Corbicula fluminea to both parasites seeded daily at concentrations reported from surface waters demonstrated efficient removal of Cryptosporidium parvum oocysts and G. lamblia cysts by both bivalve species. The number of parasites in mollusk tissue progressively increased in relation to the concentration of waterborne contamination, and decreased after cessation of the contamination. Oocysts outnumbered cysts in the tissue of both bivalves, and more parasites were identified in D. polymorpha than in Corbicula fluminea; overall 35.0% and 16.3% of the parasites seeded, respectively. Because C. fluminea and D. polymorpha can accumulate human waterborne parasites in proportion to ambient concentrations, these species of bivalves can be effective bioindicators of contamination of freshwater habitats with Cryptosporidium and Giardia.

Graczyk, T. K., M. R. Cranfield and D. B. Conn. 1997. In vitro phagocytosis of Giardia duodenalis cysts by hemocytes of the Asian freshwater clam Corbicula fluminea. Parasitology Research 83(8):743-745.

Hemocytes of the Asian freshwater clam Corbicula fluminea, phagocytosed in vitro infectious Giardia duodenalis cysts. After 15, 30, 60, 90, and 120 min of incubation an average of 22%, 32%, 43%, 54%, and 72% of the cysts were phagocytosed by 22%, 55%, 63%, 81%, and 86% of the hemocytes, respectively. The number of hemocytes showing phagocytosis and the mean number of cysts ingested per hemocyte increased significantly over time (P < 0.01); the numbers of nonphagocytosed cysts significantly decreased (P < 0.02). Extrapolation reveals that C. fluminea can retain by phagocytosis an average of 1.6 x 10⁶ G. duodenalis cysts/ml hemolymph. The phagocytic capacity of C. fluminea hemocytes indicates the applicability of this freshwater benthic bivalve for bioindication of contamination of waste waters and agricultural drainage with Giardia cysts.

Graczyk, T. K., R. Fayer, D. B. Conn and E. J. Lewis. 1999. Evaluation of the recovery of waterborne Giardia cysts by freshwater clams and cyst detection in clam tissue. Parasitology Research 85(1):30-34.

The Asian freshwater clam, Corbicula fluminea, inhabits environments recognized to be contaminated with waterborne Giardia cysts. Sixty-four tissue samples of Giardia-free clams were spiked with various numbers of Giardia duodenalis cysts within the range of 50-700 cysts. Regression analysis showed that paired numbers of spiked (x) versus recovered (y) cysts regressed significantly (P < 0.01) according to the equation y = 42.57 +/- 1.81x (± 64.3). The cyst detection threshold was 43 cysts/clam, the coefficient of determination was 77%, and the overall sensitivity of cyst detection was 42.9%. All 20 values of cyst numbers in clam tissue samples that were processed blind were located within the 95% prediction limits of the linear regression equation. The cyst retention rate of 160 clams kept in an aquarium with 38 l of water spiked with 1.00 x 10⁵ G. duodenalis cysts was approximately 1.3 x 10³ cysts/clam. No waterborne cysts were detected by the membrane filtration method 90 min after spiking the aquarium water. G. duodenalis cysts were detected in clam tissue up to 3 weeks post-exposure. Filtration of water by clams substantially depleted the aquarium water of its particulate matter. The sampling program demonstrated that the population of 160 clams examined during the study could be accurately assessed for exposure to waterborne Giardia cysts by random sampling of 86 (54%) clams. The results indicate that C. fluminea clams can be used for biological monitoring of contamination with Giardia.

Graczyk, T. K., R. Fayer, M. R. Cranfield and D. B. Conn. 1997. In vitro interactions of Asian freshwater clam (Corbicula fluminea) hemocytes and Cryptosporidium parvum oocysts. Applied and Environmental Microbiology 63(7):2910-2912.

Corbicula fluminea hemocytes phagocytosed infectious oocysts of Cryptostosporidium parvum in vitro. After 15, 30, 60, 90, and 120 min of incubation, averages of 35.8, 58.0, 69.7, 77.7, and 81.6% of the oocysts were phagocytosed by 24.3, 70.0, 78.5, 87.3, and 93.0% of the hemocytes, respectively. A single clam can retain by phagocytosis an average of 1.84 x 10⁶ oocysts per ml of hemolymph. C. fluminea bivalves can serve as biological indicators of contamination of wastewaters and agricultural drainages with Cryptosporidium.

Graczyk, T. K., R. Fayer, M. R. Cranfield and D. B. Conn. 1998. Recovery of waterborne Cryptosporidium parvum oocysts by freshwater benthic clams (Corbicula fluminea). Applied and Environmental Microbiology 64(2):427-430.

Asian freshwater clams, Corbicula fluminea, exposed for 24 h to 38 liters of water contaminated with infectious Cryptosporidium parvum oocysts (1.00 x 10⁶ oocysts/liter; approximately 1.9 x 10⁵ oocysts/clam) were examined (hemolymph, gills, gastrointestinal [GI] tract, and feces) on days 1, 2, 3, 7, and 14 postexposure (PE). No oocysts were detected in the water 24 h after the contamination event. The percentage of oocyst-containing clams varied from 20 to 100%, depending on the type of tissue examined and the technique used - acid-fast stain (AFS) or immunofluorescent antibody (IFA). The oocysts were found in clam tissues and feces on days 1 through 14 PE; the oocysts extracted from the tissues on day 7 PE were infectious for neonatal BALB/c mice. Overall, the highest number of positive samples was obtained when gills and GI tracts were processed with IFA (prevalence, 97.5%). A comparison of the relative oocyst numbers indicated that overall, 58.3% of the oocysts were found in clam tissues and 41.7% were found in feces when IFA was used; when AFS was used, the values were 51.9 and 48.1%, respectively. Clam-released oocysts were always surrounded by feces; no free oocysts or oocysts disassociated from fecal matter were observed. The results indicate that these benthic freshwater clams are capable of recovery and sedimentation of waterborne C. parvum oocysts. To optimize the detection of C. parvum oocysts in C. fluminea tissue, it is recommended that gill and GI tract samples be screened with IFA (such as that in the commercially available MERIFLUOR test kit).

Graczyk, T. K., Y. R. Ortega and D. B. Conn. 1998. Recovery of waterborne oocysts of Cyclospora cayetanensis by Asian freshwater clams (Corbicula fluminea). The American Journal of Tropical Medicine and Hygiene 59(6):928-932.

Asian freshwater clams (Corbicula fluminea) were exposed for 24 hr in 38 liters of water contaminated with 1.0 x 10⁵ Cyclospora cayetanensis oocysts (2.6 x 10³ oocysts/L). The hemolyph and gill smears of 30 clams were examined by acid-fast stain on days 1, 3, 5, 7, 10, 13, and 18 postexposure (PE). Since no oocysts were detected in the water 24 hr after contamination by the membrane filter-dissolution method, the oocyst retention rate was 4.6 X 10² oocysts/clam. The prevalence of oocyst-positive clams significantly decreased (P <] 0.01) from 93% to 47% during 13 days PE. None of the clams contained oocysts on day 18 PE; no oocysts were detected in the clam feces. The numbers of oocysts recovered from six clam size classes varied and significantly decreased with smaller clam size (P <] 0.01). The lowest prevalence values of oocyst-positive clams, 45% and 34%, were observed in the two lowest size classes: 12.1-14.0 mm and 14.1-16.0 mm, respectively. The prevalence values in the remaining four classes ranged from 84% to 100%. The sampling program demonstrated that the population of 180 clams examined during the study up to 13 day PE could be assessed for C. cayetanensis positivity by random testing of a minimum of 75 clams (42%). When the two lowest clam size classes are eliminated, the population of 114 clams could be assessed by sampling a minimum of 32 clams (28%). The results demonstrate that Corbicula fluminea can recover waterborne oocysts of C. cayetanensis, and could be used as biological indicators of contamination of water with C. cayetanensis oocysts.

Graney, R. L. 1980. Heavy metal dynamics in the Asiatic clam Corbicula fluminea. Master of Science Thesis, Virginia Polytechnic Institute and State University (Blacksburg). viii+207 pp.

Graney, R. L. 1986. Toxicological and comparative study of the concentration of free amino acids in freshwater benthic invertebrates. Doctor of Philosophy Dissertation, Michigan State University. viii+159 pp.

Graney, R. L., Jr., D. S. Cherry and J. Cairns, Jr. 1983. Heavy metal indicator potential of the Asiatic clam (Corbicula fluminea) in artificial stream systems. Hydrobiologia 102(2):81 88.

The potential of Corbicula fluminea (Müller, 1774) as a bioindicator of Cd, Cu, and Zn was studied during 28 day exposures in field artificial streams receiving river water on a once through basis. Cu as aquatic concentrations of 0.016 and 0.057 mg/l, showed the greatest degree of tissue uptake and had bioconcentration factors (BCF) of 22,571 and 17,720, respectively. A significant correlation (coefficient = 0.639) was observed between water concentration and tissue accumulation. Cd was intermediate relative of BCF (3770 and 1752 at aquatic exposures of 0.023 and 0.055 mg/l, respectively), and had a correlation coefficient of 0.758. Zn had the lowest potential for concentration (631, 358 and 511 BCF at 0.218, 0.433 and 0.835 mg/l, respectively) with a correlation coefficient of 0.478. The rate of accumulation in C. fluminea reached a maximum after 11 days for Cd while a steady state condition for Cu was observed in 28 days. Zn accumulation, like Cu showed a relative increase throughout the 28 day exposure period. The Asiatic clam may be used as a reliable indicator of uptake for exposure to heavy metals.

Graney, R. L., Jr., D. S. Cherry and J. Cairns, Jr. 1984. The influence of substrate, pH, diet and temperature upon cadmium accumulation in the Asiatic clam (Corbicula fluminea) in laboratory artificial streams. Water Research 18(7):833 842.

The influence of substrata, pH, diet and temperature upon the accumulation of Cd (0.05 mg/l dose, < 0.001 mg/l control) in the visceral mass of Corbicula fluminea (Müller, 1774) was studied in laboratory artificial streams at intervals of 0, 3, 5, 7, 10, and 14 day exposures. Four substratum conditions were used: sand, silt and clay (SSC); sand, clay, and organic matter (SCO); and no substratum (noS). The greatest tissue accumulation of Cd in C. fluminea occurred at 0.05 mg/l Cd in NoS and the lowest in clams occupying SCO. Complexation of available metals, lower clam filtering rates and physical protection by the substratum were attributed to the depressed Cd accumulation of clams exposed in the SCO substratum. Lower pH exposures (5.0 vs. 7.8) significantly (P at 0.05 level) reduced Cd uptake at 21^oC but had little effect at 9^oC. Uptake was higher in clams fed with Cd exposed Chlamydomonas reinhardti at 21^oC but not at 9^oC. In temperature exposures alone at 0.05 mg/l Cd, accumulation was significantly higher in C. fluminea exposed at 21^oC that 9^oC. The results were discussed relative to the importance of standardized laboratory protocol and the use of C. fluminea as a bioindicator of heavy metal stress.

Graney, R. L., D. S. Cherry, J. H. Rodgers, Jr., and J. Cairns, Jr. 1980. The influence of thermal discharge and substrate composition on the population structure and distribution of the Asiatic clam, Corbicula fluminea, in the New River, Virginia. The Nautilus 94(4):130 135.

By the summer of 1977, Corbicula fluminea (Müller, 1774) was successfully established in the confines of the thermal effluent of the Glen Lyn Power Plant, located along the New River in southwestern Virginia. Numbers were either greatly reduced or eliminated outside the thermal influence during severe winter conditions (lowest water temperature was 0^oC for about a two week period) in 1976 but inhibited to a lesser extent in winters of 1977 1978 (minimum temperatures of about 3 4^oC). Clam density and sediment composition, sampled from six stations established above and below, and within the thermal discharge indicated that C. fluminea numbers within and outside the effluent are generally independent of sediment composition. In the sediment (clay, silt, sand, pebble, cobble) from heated versus unheated stations, pebble constituted the greatest amount (59.0 versus 71.8%, respectively) followed sand (32.7 and 23.7%). Heated water appeared to be most influential on clam survivorship and size distribution. Peak densities reached about 11,522/m² (station 4) in the thermal discharge in February 1978 while highest densities in unheated areas (station 1) reached about 2,286/m² in November 1978. The diversification of size classes (shell length <7.5, 7.5 13.5, 13.6 18.5, 18.6 28.0, >28.0 mm) was higher in heated stations with more uniform distribution occurring in summer to fall of 1978. Small clam sizes (<7.5, 7.5 13.5 mm) were consistently greater in February and November in the thermally influenced stations and only during September and November in unheated areas. The ecological impact of these density changes and subsequent migration tendencies are discussed.

Graney, R. L., Jr., J. H. Rodgers, Jr., D. S. Cherry, K. L. Dickson and J. Cairns, Jr. 1978. Heavy metal accumulation by the Asiatic clam Corbicula manilensis from field collections and laboratory bioassays. Virginia Journal of Science 29(2):61.

Grantham, B. J. 1967. The Asiatic clam in Mississippi. Mississippi Water Resources Conference, Proceedings. pp. 81 85.

The distribution of Corbicula sp. in the Pearl, Pascagoula, Yazoo, and Tennessee river systems of Mississippi is presented. The predation on Corbicula sp. by the channel catfish, Ictalurus furcatus is discussed.

Grantham, B. J. 1969. The Freshwater Pelecypod Fauna of Mississippi. Ph.D. Dissertation, University of Southern Mississippi (Hattiesburg). 243 pp.

Corbicula leana (Philippi) is reported to occur in every major river system of Mississippi. A description of the shell, photographic plate of representative specimens, and a distribution map for the species in the state are given.

Gray, J. E. 1825. A list and description of some species of shells not taken notice of by Lamarck. Annals of Philosophy 25:134 140.

Gray notes Lamarck's failure to include Cyrena limosa (Maton) in his Animaux sans Vertebres.

Gray, M. 2002. Importance of Corbicula fluminea in the trophic dynamics of the upper Savannah Basin. 63rd Annual Meeting of the Association of Southeastern Biologists, Boone, NC (USA), 10-13 April.

Gray, M. J. S. 2002. Importance of Corbicula fluminea in the Trophic Dynamics of the Upper Savannah Basin. Doctor of Philosopjy Dissertation, Clemson University (South Carolina). [see Dissertation Abstracts International Part B: Science and Engineering 62(10):4353.

A coral reef is a rich resource patch in an otherwise nutrient poor ocean. In an analogous manner patches of clams may serve a similar function in oligotrophic fresh waters. By filtering the water column, clams are able to remove and concentrate nutrients from the water. The mucoid nature of feces and pseudofeces keeps substantial quantities of this nutritional material from washing away. Corbicula fluminea increase nutrient quality of water by the production of feces and pseudofeces. The shells of living and dead bivalves furnish substrate for attachment of sessile organisms and increase calcium concentration. A potential synergistic relationship exists between phytoplankton and clams in nutrient-poor waters. Corbicula supply areas of concentrated nutrients, rich in phosphate, which allows algal cells to grow. The increased concentrations of algal cells provide food to Corbicula. In a divided tank, containers with Corbicula were placed on one side and containers without clams were placed on the other side. Lake water was pumped through the tank for one month, then clams were removed and AGPT (Algal Growth Potential Test) phosphorus and calcium assays were performed on water samples from the containers. There was no difference in phosphorus and calcium results of water from containers with and without clams. AGPT results from containers with and without clams were notably higher than lake water. Containers with clams had statistically higher AGPT than containers without clams. Increased potential nutrients were attributed to feces and pseudofeces production. Leaching of calcium from clamshells incubated at 15^o, 25^o and 35^oC in various ionic concentrations was also determined. These shells can serve as an additional source of calcium in oligotrophic waters.

Greenwood, P. H. 1954. Mollusc eating Cichilidae from Lake Victoria. Publications Conseil Scientifique de l'Afrique Sud Sahara No. 6:125 127.

Corbicula africana is reported to be a food of the Chichilid fish Haplochromis sp.

Greer, D. E. 1971. Biological Removal of Phosphates from Aquatic Media. Master of Science These, University of Arizona (Tucson). 23 pp.

The precipitation of excess phosphates in the form of hydroxyl-apatite has been accomplished without the addition of chemical reagents. The process requires elevation of the OH(-) ion concentration through the removal of CO₂ from the water by algae, resulting in a hydroxyl-apatite algal suspension. This suspension is removed from the water by being filtered through beds of clams, Corbicula fluminea. These clams are able to survive in eutrophic water provided the water is continuously recirculated, and the temperature is kept below 30^oC. Estuarine phosphates may be even more susceptible to 'automatic' removal since sea water contains an average of 410 mg/L Ca²⁺, which should result in more complete precipitation. Overall quality of water receiving clam-algae phosphate-removal treatment is enhanced, since ph elevation without lime addition results in Ca²⁺ and Mg²⁺ precipitation. Tertiary treated wastewater, subjected to nutrient removal and containing less than 0.30 mg/l total phosphates, will allow high levels of primary productivity without the danger of anoxia from excessive buildups of the algal standing crop.

Greer, D. E. and C. D. Zeibell. 1972. Biological removal of phosphates from water. Journal of the Water Pollution Control Federation 44(12):2342 2348.

Various organisms were tested for their ability to remove orthophosphate ion solution. A system incorporating natural algal successions and beds of Corbicula fluminea (Müller, 1774) was the most effective of the systems tested. Experiments were conducted under controlled conditions at concentrations of 5.0, 10.0, and 15.0 mg/l PO₄³ . This system can remove orthophosphate ion to be low 0.30 mg/l in 16 days or less and yield a clear effluent.

Gregg, W. O. 1947. The fresh water Mollusca of California. Minutes, Conchological Club of Southern California 69:3 18.

The distribution of Corbicula fluminea (Müller, 1774) in the Sacramento and Mokelumne rivers of California are discussed.

Gregory, J. R. 1869. Corbicula (Cyrena) fluminalis in Cape Colony. Biological Magazine 6:91 92.

Griffith, E., and E. Pidgeon. 1834. The Mollusca and Radiata Arranged by the Baron Cuvier, with Supplementary Additions. Text by J. E. Gray. IN: Cuvier's Animal Kingdom. 434 pp.

Griffiths, R. W., S. Thornley and T. A. Edsall. 1991. Limnological aspects of the St. Clair River. Hydrobiologia 219:97-123.

The St. Clair River is a major navigable waterway transporting water southward for 63 km from Lake Huron to Lake St. Clair at an average flow of 5,100 m³/sec. Water entering the river is low in suspended solids, organic carbon, phosphorus and nitrates , typical of clear, oligotrophic waters. In contrast to many large rivers, dissolved and colloidal solids account for 90 to 95% of the total solids load transported by the river, giving the river a turquoise color common in glacial meltwater streams. The river supports a diverse floral and faunal community that includes 20 taxa of submergent macroflora, at least 300 benthic macroinvertebrates and 83 fishes. A number of exotic (European) species, including 3 plants, 4 mollusks, and 11 fishes, occur in the river with the macroalga, Nitellopsis obtusa, zebra mussel (Dreissena polymorpha), Asian clam (Corbicula fluminea), and white perch (Morone americana) being the most recent invaders. Production is estimated to be 200 gm/m²/a ash-free dry mass for submergent macrophytes and periphyton, 7 gm for macroinvertebrates and 5 gm for fishes. The river also supports a variety of water-oriented recreational activities, is a source of municipal and industrial water, a receiver of municipal and industrial wastes, and a shipping corridor. Industrial discharges have adversely affected aquatic life, particularly in the nearshore areas along the Canadian shoreline south of Sarnia , Ontario. In addition, channel dredging and shoreline modifications (bulkheading and backfilling) have destroyed large areas of valuable habitat in the main channel and along the shoreline. Improvements in the nearshore benthic macroinvertebrate community of the river over the past 20 years show that the river will respond to reductions in contaminant loading.

Grist, J. D. 2002. Analysis of a blue catfish population in a Southeastern reservoir, Lake Norman, North Carolina. Master of Science Thesis, Virginia Polytechnic Institute and State University (Blacksburg).

This investigation examined the diet, growth, movement, population genetics, and possible consumption demands of an introduced blue catfish Ictalurus furcatus population in Lake Norman, North Carolina. Clupeids, Corbicula fluminea, and Chara were the predominant food items (percent stomach contents by weight) found in blue catfish, and varied by season, lake-region, and fish size-class. Lake Norman blue catfish grow at a slower rate than has been reported for other reservoir populations, with fair to poor body conditions (Wr95). Movements and home ranges of blue catfish in Lake Norman were extremely varied, but individual blue catfish did establish specific seasonal home ranges and exhibited site fidelity. A spawning area in the upper region of the lake was identified and data suggested that blue catfish may have segregated populations within Lake Norman. The Lake Norman blue catfish population exhibited relatively little genetic variability, and was genetically differentiated from populations from Santee-Cooper, SC, and Arkansas. Genetic diversity could have been limited by a population bottleneck at the founding of the population or in subsequent generations. (see: http://scholar.lib.vt.edu/theses/available/etd-09132002-090010)

Gruber, D., M. Collins, D. G. Mackler and J. M. Diamond. 1990. Derivation of a freshwater silver criteria for the New River, Virginia, using representative species. Environmental Toxicology and Chemistry 9(11):1425-1434.

The Environmental Protection Agency (EPA) has not published a 30 day average or continuous criterion for silver due to the apparent toxicity of this element and the lack of available chronic exposure data. Acute effects on nine species representative or indigenous to the New River, Virginia, and sublethal effects on three of those species using the Resident Species Approach were examined. The results showed that invertebrates were much more sensitive to silver than fish, including juvenile rainbow trout (Oncorhynchus mykiss). Hyalella azteca (amphipod) were the most sensitive species followed by the mayflies Stenonema sp. and Isonychia bicolor and the stonefly Leuctra sp. The Final Acute Value in this study was 1.32 μg/L total recoverable silver. In sublethal tests, Isonychia growth, as measured by the number of molts over time, was the most sensitive effect observed. Estimated acute:'chronic' ratios ranged from 2 to 34 with Corbicula fluminea having the largest ratio. Study results, along with available published data, suggest a Final Chronic Value of 0.13 μg/L total silver which is approximately one-half the level obtained using the EPA acute formula and ambient water hardness. These results suggest that a continuous criterion for silver may be predictable using the hardness-dependent formula and a safety factor of 0.5.

Gruvel, A. 1933. Sur la distribution de quelques especes de mollusques dans le lagunes de lac Timash (Canal de Suez). Compte Rendus de l'Academie des Sciences (Paris) 197:349 350.

Guardado Puentes, J. 1976. Concentracion de DDT y sus metabolitos en especies filtroalimentadores y sedimentos en el Valle de Mexicali y alto Golfo de California [Concentrations of DDT and its metabolites in filter and sediment feeders in the Mexicali Valley and the upper Gulf of California]. California Cooperative Oceanic Fisheries Investigations Reports 18:73-80.

High concentrations of DDT and its natural breakdown derivatives were found in clams, Veneridae; Corbicula sp., in irrigation channels of the Mexicali Valley. These concentrations increase as the sampling area approaches the mouth of the Colorado River. This observation suggests that the agricultural area of the Mexicali Valley is an important source of organochloride pollution for the Northern Gulf of California. This is an area in which many commercially and ecologically important species are found, such as shrimp, Panaeus sp., and, at least until very recently, the Totoaba, Cynoscion macdonaldi. The concentration of organochlorides in the Northern Gulf of California were also obtained for the clam Chione sp. and these were found to be somewhat lower. Lower concentrations of DDT and its natural breakdown derivatives were also found in the region of the mouth of the Colorado River. This is probably caused by the particular oceanographic conditions which include currents, turbidity, and sedimentation rates; these might combine to reduce the organochloride levels in the area, but may also carry some pollutants into the Gulf, south of the study area.

Guerrero, N. R. V. and E. A. Wider. 1999. Metal contaminants in the La Plata River, Buenos Aires, Argentina. Toxicology Letters, Supplement 1: 63.

The aquatic system of the La Plata Basin is one of the most important in South America. The La Plata River is the last river of the basin draining into the Argentine Sea as a big estuary. Along its coasts a lot of industrial, urban, and domestic discharges are continuously released, most of them without any previous treatment. At the same time, the river provides the principal tap water supply for Buenos Aires, capital city of Argentina, and its surroundings. For these reasons the water quality of the river is an issue of public health and environmental concern. Field bioaccumulation studies provide a useful tool to assess the level of contamination and the impact of chemical contaminants upon aquatic systems. Therefore, the purpose of the present work was to investigate the levels of six metal contaminants (cadmium, copper, chromium, nickel, lead, zinc) in a freshwater bivalve mollusc Corbicula fluminea. Sediment samples were also analysed to assess the extent of contamination of the area. The samples were collected from the Ecological Park, nearby Buenos Aires Port, during January 1998. Levels of metal were determined in the whole body soft tissue of bivalves, and in superficial sediments, employing wet digestion techniques. The analyses were performed by atomic absorption spectrophotometry (AAS). The following concentrations were obtained in bivalve samples: 0.35 ± 0.12 μg Cd/g; 17.35 ± 2.46 μg Cu/g; 3.79 ± 0.46 μg Pb/g; 22.95 ± 0.93 μg Zn/g. Cr and Ni were not detected. In the sediment samples, the concentrations were 0.21 ± 0.04 μg Cd/g; 36.94 ± 26.20 μg Cu/g; 4.50 ± 1.65 μg Cr/g; 5.79 ± 2.77 μg Ni/g; 44.38 ± 21.01 μg Pb/g; 36.42 ± 7.38 μg Zn/g. According to the data, C. fluminea showed a great ability to accumulated Cd, followed by Zn, Cu, and Pb. These results constitute a first step in assessing metal concentrations in bivalve and sediment samples from coastal zones of the La Plata River.

Gunning, G. E. and R. D. Suttkus. 1966. Occurrence and distribution of the Asiatic clam, Corbicula leana, in the Pearl River, Louisiana. The Nautilus 79(4):113 117.

Gunther, A. J., J. A. Davis, D. D. Hardin, J. Gold, D. Bell, J. R. Crick, G. M. Scelfo, J. Sericano and M. Stephenson. 1999. Long-term bioaccumulation monitoring with transplanted bivalves in the San Francisco Estuary. Marine Pollution Bulletin 38(3):170-181.

The California State Mussel Watch and the Regional Monitoring Program for Trace Substances have conducted biomonitoring for trace elements and organic contaminants in the San Francisco Estuary using transplanted bivalves (Mytilus californianus, Crassostrea gigas, and Corbicula fluminea). Significant declines (p < 0.01) in contaminant concentrations in M. californianus for the period 1980-1996 were observed for PCBs, p,p'-DDE, cis-chlordane, dieldrin, and Ag, while a significant increase was observed for Cr (p < 0.05). Certain limitations of the “mussel watch” approach are illustrated by examining data on survival, body condition, and contaminant uptake, including the inability of the technique to predict accumulation of mercury and selenium at higher trophic levels in the ecosystem. These results indicate that biomonitoring using transplanted bivalves, when part of a consistently supported long-term program, can produce valuable data on the spatially and temporally averaged abundance and distribution of certain contaminants in coastal ecosystems.

Gupta, P. D. 1973. Fauna of Rajasthan, India. Part 3. Mollusca. No. 2. Distribution of some Pelecypoda. Records of the Zoological Survey of India 67(1 4):159 163.

Gutierrez-Galindo, E. A., G. Flores Munoz and A.Aguilar Flores. 1988. Mercury in freshwater fish and clams from the Cerro Prieto geothermal field of Baja California, Mexico. Bulletin of Environmental Contamination and Toxicology 41(2):201-207.

The Cerro Prieto field is located in the agricultural Mexicali Valley, approximately 40 km south of the USA-Mexican border. A study was conducted to assess the geothermal mercury pollution arising from Cerro Prieto; for this purpose the fish Tilapia mossambica and the clam Corbicula fluminea were collected from watercourses of the Mexicali Valley. Mercury was determined by cold-vapor atomic-absorption spectrometry. Mercury concentrations were higher in clams than in fish; the differences are probably associated with differences in feeding habits and with habitat differences in the bioavailability of mercury. The results indicated much higher concentrations of mercury in fishes living in water receiving considerable geothermal discharges (Rio Hardy) than in fishes living in similar waters receiving no geothermal discharges. However, clam samples collected far away from Cerro Prieto (Canal Coahuila and Canal Zacatecas) were found to contain higher levels of mercury (0.17 to 0.32 μg/gram) than samples collected within the geothermal field itself; the mercury anomalies reflected in these bivalves may yield information on the presence of shallow geothermal circulation patterns. None of the fish or clam samples yielded mean mercury levels exceeding the widely-accepted tolerance limit of 1.0 mg/kg.