A Study on Length-Weight Relationships (LWR) and Growth Responses of Major Carps Exposed to Lead (Pb)

Abstract

A group of Catla catla, Labeo rohita and Cirrhina mrigala, was exposed to sub-lethal concentrations of lead, separately, in glass aquaria whereas other another group was kept un-stressed as a control. The duration of trail was for 30 days. Both stressed and unstressed fish species were transferred to earthen ponds to rear, separately, for six months. After this exposure period, their growth performance in terms of weight, fork and total length were investigated at final harvest. Analysis of Variance and regression were applied to find out length and weight relationship of three fish species. Among three fish species Cirrhina mrigala gained maximum weight of 53.76± 7.39 g that varied significantly (p<0.05) from that of Labeo rohita (41.7± 9.48 g) but similar to the weight gains of Catla catla (52.65± 9.40 g). Fork and total length increments were observed significantly (p<0.05) higher in Cirrhina mrigala followed by that of Catla catla and Labeo rohita. Regarding length-weight relationship, all the three lead stressed fish species showed allometric growth. It was concluded that this investigation could stoutly be supportive to the researchers and policy makers for the preparation of very effectual sustainable management plans of fishery resources for the riverine systems.