ECOLOGICAL DATA
Distribution: exotic species; common in protected
beaches in bays and estuaries in Georgia Strait and west coast of Vancouver Island; small
isolated populations in Queen Charlotte Strait and around Bella Bella.
Habitat: sand-gravel beaches; burrow just below surface, to maximum depth of
approximately 10 cm; planktonic larvae dispersed by currents; adults remain in same
location for life.
Tidal elevation: from 1 m intertidal zone to well above mid-intertidal level;
does not inhabit subtidal; limited spatial competition with native clams.
Food: suspension feeder; mainly phytoplankton, but also zooplankton and
detritus.
Predators: mainly water birds due to higher intertidal colonization.
GROWTH RATE
Slow; sexually mature at 20 mm (about 2 yr.); legal size of 38
mm is reached in 3.5 yr in Strait of Georgia and 5-6 yr in north coast.
FISHERY
Commercial, Native and sport fisheries; accounts for more than
65% (1894 t in 1986) of commercial intertidal clam harvest; sewage and paralytic shellfish
poisoning (PSP) have closed large areas of coast to harvesting.
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REFERENCES
Anon. (no date). Clams of British Columbia. Fish. Oceans Can.,
leaflet: 4 p.
Bernard, F.R. 1983. Catalogue of the living bivalvia of the eastern Pacific Ocean:
Bering Strait to Cape Horn. Can. Spec. Publ. Fish. Aquat. Sci. 61: 56.
Bourne, N. 1982. Distribution, reproduction and growth of Manila clam, Tapes
philippinarum (Adams and Reeves), in British Columbia. J. Shellfish Res. 2: 47-54.
Bourne, N. 1986. Intertidal clams, p. 22-31. In G.S. Jamieson and K. Francis
[ed.] Invertebrate and marine plant resources of British Columbia. Can. Spec. Publ. Fish.
Aquat. Sci. 91.
Holland, D.A., and K.K. Chew. 1974. Reproductive cycle of the Manaila clam (Venerupis
japonica), from Hood Canal, Washington. Proc. Natl. Shellfish. Assoc. 64: 53-58.
Jamieson, G.S. 1986. Paralytic shellfish poisoning, p. 44-46. In G.S. Jamieson
and K. Francis [ed.] Invertebrate and marine plant resources of British Columbia. Can.
Spec. Publ. Fish. Aquat. Sci. 91.
Quayle, D.B. 1978. The intertidal bivalves of British Columbia. B.C. Prov. Mus. Handb.
17: 63-64.
Quayle, D.B., and N. Bourne. 1972. The clam fisheries of British Columbia. Fish. Res.
Board Can. Bull. 179: 70 p.
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