Population dynamics of Randall’s threadfin bream <i>Nemipterus randalli </i> from Pakistani waters, Northern Arabian Sea

Abstract

The <i>N. randalli </i> fish data consist of 1141 pair of length weight relationship and 24312 length frequencies were measured during 2009 - 2010 survey. The maximum length and weight were 25 cm and 251 g, respectively. The length-weight relationship were <i>a </i> = 0.035, <i>b </i> = 2.744 and <i>R</i>² = 0.972. The asymptotic length (<i>L_∞</i>) and growth coefficient (<i>K</i>) were estimated to 26.25 cm and 0.320 year^-1, respectively. The total mortality (Z) was 1.25 year^-1. The natural mortality (M) was 0.863, hence the fishing mortality (F) was Z–M = 0.387 year^-1 for <i>N. randalli</i>. The yield per recruit analysis indicated that when t_c was assumed to be 2, F_max was estimated at 1.3 and F_0.1 at 1.3; while t_c was assumed to be 1, F_max was estimated at 1.1 and F_0.1 at 0.95. Currently age at first capture is about 1 year and F_current was 0.387, therefore, F_current was smaller than F_0.1 and F_max. The results during present study indicate that current fishery stock is in sustainable state. However, it is suggested that take some management steps to maintain the stock of <i>N. randalli </i> in Pakistani waters, Northern Arabian Sea.