POPULATION STRUCTURE AND DYNAMICS OF WARTY VENUS, VENUS VERRUCOSA (BIVALVIA, VENERIDAE), IN NORTH AEGEAN SEA, TURKEY

The growth, reproduction, and density of warty venus clams (Venus verrucosa) were studied at a depth of 2-5 m in Baklaburnu Bay in the North Aegean Sea, Turkey. Samples were collected monthly between September 2012 and August 2013. The average density of the studied population ranged between 152 individuals m(-2) (October) and 310 individuals m(-2) (June). The shell length at first capture (L-50%) by hand rake was 37 mm. von Bertalanffy growth parameters using the length-frequency distribution of V. verrucosa were estimated at L-infinity = 57.65 mm, the rate at which the asymptotic length (L-infinity) is approached (K) = 0.25 y(-1), theoretical age (y) when the length = 0 (t(0)) = -0.211, and seasonal oscillation in the growth rate was 0.30. Growth was rapid during the first 4 y of life (similar to 40 mm) and decreased after the 4th y. The slowest growth period was in January (winter point = 0.03). Overall growth performance, growth performance index, and potential longevity derived from seasonal parameters were calculated as 4.68, 2.92, and 12.0 y, respectively. The growth pattern showed isometric growth (slope [b] = 3.09) and the spawning period occurred from mid-June to August.