Gonad Somatic Index and Feeding Habit of Selected Fish Species of Lake Kalgwaiin Jigawa State, Nigeria

This study investigates gonado somatic index, food and feeding habit of selected fish species of Lake Kalgwai Jigawa State, Nigeria. Samples of fish were collected every fortnight (July 2012-June 2013) at three major landing sites of the lake. The weight of each fish was recorded, gonads were removed, weighed and the gonadosomatic index (GSI) calculated. Stomach was also removed and the content analyzed using frequency of occurrence and point method. Result obtained reveals GSI to range from 2.39±0.08% in Nile perch Latesniloticus [1] to 5.92±0.29% in Nile tilapia Oreochromisniloticus [1]. The stomach content analysis in this study distinguished the fish species into two major groups; Latesniloticus, Mormyrusmacrophthalmus Günther, 1866 and Bayad bagrus bayad Forsskål [2] were observed to exhibit carnivorous feeding habits and feed predominantly on crustacean, fish, fish parts, mollusks, insects and insect larvae, Oreochromisniloticus, African bony tongue Heterotisniloticus [3], Electric catfish Malapteruruselectricus, Synodotisnigrita and North African catfish Clarias gariepinus on the other hand were observed to have an omnivorous feeding pattern with plant parts, insect parts, detritus, crustaceans, snails, worms, fish parts, insects larvae, sand/mud, and algae dominating their diet. Many of the omnivores encountered in this study have good potential as future aquaculture candidate hence the need to further study their biology and their performance under captivity.