Preliminary investigations on stock analysis of tigertooth croaker (Otolithes ruber) from balochistan coast, Pakistan

Abstract

Length-weight relationship, growth and mortality rate parameters of Tighertooth croaker (Otolithes ruber) were estimated using length-weight and data length frequency distributions, samples gathered from different fish landing sites of Balochistan coast, Pakistan. A total of 278 pairs of length-weight relationship and 4062 samples of length frequency distribution were measured during current study. Length-weight relationship was at a =0.016, b =2.829 (R²= 0.969). ELEFAN method was used to evaluate the growth rate where L∞= 34.65 cm and K =0.83 yr-1 and t0=-0.185, growth performance index was at 2.608 yr-1. Length converted catch curve was used to estimate total mortality which was Z =3.18 yr-1, whereas, fishing and natural death of fish evaluated at 1.465, 2.171 yr-1 respectively, however, exploitation rate (E) was at 0.682 yr-1. Pursuant to Gulland (1971, 1979) exploitation rate would be less than 0.5 and Patterson (1992) reported exploitation rate may retained at 0.4 level for sustainable fishery resources. Considering above facts, stock of O. ruber from Pakistani waters (Balochistan coast) is in overexploitation state. It may be suggested to government agencies to initiate rules and regulations to sustain the stock of this fishery from Pakistani waters for future.