Some aspects of biology of Stolephorus bataviensis Hardenberg, from Mangalore area, Dakshina Kannada

Abstract

The growth parameters of S. bataviensis are estimated by Gulland and Holt method. The parameters are £α=116 mm, k=0.0054/day and to=—20 days. This species reaches a length of 77 mm at six months and 101 mm at the end of one year. The length-weight regression equations of the males and females differ significantly. The sexes are uniformly distributed over most of the study period. The length at first maturity is estimated as 77 mm. The major spawning period is from November to March. Mature fish are found through out the year. Juveniles occur abundantly from April to June. Fecundity estimates are poorly correlated to the total length of the species. Fluctuating Kn values beyond the length at first matuity may be due to protracted spawning season of the species. S. bataviensis mainly feeds on zooplankton dominated by copepods.