Growth and mortality parameters of Indian squid Uroteuthis (Photololigo) duvaucelii (D'Orbigny,1835) from Pakistani waters(Arabian Sea) based on length frequency data.

Abstract

Present study was carried out to understand the Growth and Mortality parameters of commercially important Indian Squid Uroteuthis Duvauceli (D’ Orbigny.1985) based on length frequency data from Pakistani waters. The pooled n=1138 pair length-weight data of both sexes combined were used to calculate the length weight relationship as: W=0.278*L2.122 (R2=0.9520) length frequency data n=10008 were used to estimate VBGF growth parameters as =26.25(ML-cm) and K= 0.270 year-1 with goodness of fit model were estimated at Rn=0.335. The t0 value was calculated at t0=-0.442. Length converted catch curve analysis gave a Z value of 1.14 year-1. Natural mortality (M) obtained from Srinath’s method using empirical formula M = 0.4603+1.4753K, M=0.853 year-1. Fishing mortality was calculated as F=Z-M = 0.287 year and the exploitation rate (E) was calculated from F/Z = 0.251 year because the exploitation rate in present study is lower than 0.5.