Population characteristics and biological reference point estimates for two carangid fishes,megalaspis cordyla and scomberoides tol,in the northern arabian sea coast of Pakistan

Torpedo trevally,megalaspis cordyla and needle scaled queenfish,scomberoides tol are important fishery resource in the northern arabian sea coast of pakistan. this study on population characteristics and dynamics of both fishes will provide data for developing strategy for its conservation. fish were sampled from commercial vessels operated in the pakistan coasts between july 2013 and june 2014. the samples included 293 trevally scad,m. cordyla,and 353 needle scaled queenfish,s. tol. the sex ratio of m. cordyla was female biased with 175 females (59.73%) and 118 males (40.27%),this sex difference was not statistically significant (2=11.088,df=1,p= <0.05). the sex ratio of s. tol was also female biased with 222 females (62.9%) and 131 males (37.1%) sampled,but this difference was also not statistically significant (2=23.46,df=1,p= <0.05). von bertalanffy growth function estimated for m. cordyla was lt= 48.3tlcm [1-e - 0.73(t - 0.148)] and for s. tol lt = 70.3tlcm [1 - e - 0.37 (t - 0.152)]. the natural,fishing and total mortalities were estimated for m. cordyla at 1.23,1.38,2.62 and for s. tol 0.71,1.86,2.58. the biological reference points (brp) fopt,flimit were estimated to determine appropriate management measures for sustainable utilization of these species. biological reference points estimates and current catch statistics indicates that these stocks have been fished below the level that would support msy.