The population dynamics of Corbicula fluminea (Bivalvia: Corbiculacea) in Plover Cove Reservoir, Hong Kong



Various aspects of the biology, population dynamics, growth, sexuality, reproduction, settlement and mortality of populations of Corbicula fluminea (Muller, 1774) inhabiting Plover Cove reservoir and the Shum Chuen river, Hong Kong are described. These data are correlated with the hydrological picture of the reservoir to obtain a better understanding of the conditions under which the processes of growth, reproduction and settlement occur. An analysis of the shell dimensions of the component age groups comprising the population is obtained and, using the growth formula of Bertalanffy (1938), the maximum theoretical length of C. fluminea for this locality is calculated, which when considered in conjunction with other data relevant to the biology provides a more meaningful definition of this species. Such information, if obtained for other species, would provide a better taxonomic picture of the Corbiculacea as a whole and permit a greater understanding of those corbiculids introduced into the U.S.A. which are a pest of water supply systems. A preliminary comparison with such information as is available from the North American populations of Corbicula, indicates that at least two species, namely C. fluminea (Muller 1774) and C. fluminalis (Muller 1774) have been possibly introduced.

Other species may have been introduced, but until a more thorough examination of the species both within their home and introduced ranges has been undertaken, the taxonomic picture will remain obscure.

This paper demonstrates that in Hong Kong C. fluminea is a protandric consecutive hermaphrodite, which incubates its young in a ctenidial marsupium. This refutes the conclusion reached by earlier researchers and emphasizes the need for more detailed studies.