Population selection-strategies in the wedge clam, Donax-incarnatus (Gmelin) from Panambur beach, Mangalore

Abstract

Correlates of r- and K-selection strategies were examined in an intertidal population of D. incarnatus. Settlement extended from November to May. Zero year class dominated the population. Instantaneous total mortality ranged from 0.1824 (January 1985) to 0.3963 (March 1984). Growth rate showed variability, being faster (3.22 mm per month) during the first 6 months than during the rest of the year (1.77 to 0.3 mm per month). L(max) was 26.1 mm. The von Bertalanffy equation for length was L(t) = 30.94[1-e-0.1612(t + 0.04)]. A life table of a cohort of 1000 individuals was prepared. The life span was < 15 months. Survivorship curve belonged to type Ia of Deevey [Quart Rev Biol, 22(1947)283]. Selection attributes indicated that this species is a K-strategist in this study area.