Population dynamics of Nemipterus japonicus (block) In the trawling grounds off Madras

Abstract

Nemipterus japonicus matures at 145 mm total length and has an extended spawning season from June to March with maximum spawning activity in December- March. The length-weight relationship of fish can be expressed as: log W = —4.8665 + 2.9661 log L. The von Bertalanfly parameters of growth are estimated thus: K = 1.004; t„ = 0.2257; Leo = 305 mm. The natural mortality and fishing mortality rates are estimated at 2.5254 and 0.4599, respectively. Both the annual stock (2300 t) and the standing crop (731 t) are higher than the estimated annual catch (336 t), indicating that the present fishing effort can safely be increased without the stock being affected.