DefinePK

Abstract

Fish seed of the right quality and quantity remain a major challenge facing aquaculture in Nigeria. This study was conducted to evaluate the potentials for culturing the hybrid of Clarias gariepinus xHeterobranchus bidorsalis Heteroclarias to commercial size in earthen ponds. Three earthen ponds 0.02 hectares were stocked each with 330 fingerlings of Clarias gariepinus xHeterobranchus bidorsalis hybrid popularly called Heteroclarias on the 1st February, 2010. Mean weight at stocking was 7.501.50 g. The fish were fed 3 of their body weight two times daily with compounded artificial feed containing 45 crude protein. The changes in length and weight of the fish were measured fortnightly and the feed fed to the fish were accordingly adjusted to reflect the changes in weight. Temperature, dissolved oxygen, pH and total ammonia-nitrogen were measured in each pond. Survival rates, specific growth rate and condition factor were also determined. Survival at harvest 24 weeks after stocking was 97.3 and the mean weight of the fish was 88078.72 g ranged, 610-1150 g. Standing crop at harvest was 282.48 kg0.02 ha 14,124 kg ha-1. Growth of hybrid Heteroclarias was positively correlated with the number of weeks of the study R 0.9. Results demonstrated the potential of Heteroclarias for use in aquaculture and indicate that the fish species can be grown to commercial size within 24 weeks from fingerling stage under semi-intensive pond condition. The best time to selectively harvest the fish for maximum gain in terms of good growth and maximum profit on feed utilization is also 24 weeks.