The distribution,size, and age composition,and growth of Saxidomus purpurata (Sowerby, 1852) (Bivalvia: Veneridae) in Vostok Bay,the Sea of Japan

Patterns of the distribution, the size and age composition of local populations, as well as the growth of the large bivalve Saxidomus purpurata, which is intensely farmed and reared in a number of East Asian countries, were studied for the first time in Russian Far East waters. It was determined that in the Vostok Bay, which is a bay of the second order within the limits of the Peter the Great Bay, S. purpurata forms local populations with densities of up to 7.5 ± 2.7 ind./m² and a biomass up to 1070.0 ± 384.0 g/m² at a depth of 1–9 m on mixed bottom substrates of boulders, pebbles, gravel, coquina, and sand of varying degrees of silting. The size and age composition of clam populations varies depending on the local environment; the shell length of the largest specimen was 98.6 mm, the greatest age was 23 years. In the Vostok Bay, the bivalve grew more slowly than off the coast of Korea and China and reached a commercial size (a shell length of 50 mm) later, at an age of 5–7 years. The von Bertalanffy equation describing the growth of S. purpurata in the aggregate sample of individuals from the Vostok Bay, has the form: L _t = 100.11 ? e^{?0.1675(t ? 0.0504)}]. It is assumed that the boundary of the species range goes north from the Peter the Great Bay, Sea of Japan.