Effects of Water Replacement Frequency on the Growth and Survival of Heterobranchus Longifilis Valenciennnes, (1980) Fingerlings Reared

Abstract

The effect of water replacement frequency on growth and survival of fingerlings (4.21±0.39 mean weight) of African catfish Heterobranchus longifilis was investigated in concrete tanks of dimension 2m x 2m x1m (4m²)over a period of sixty days. There were five treatments namely: Treatment A = daily water replacement; Treatment B = replacement every two day; Treatment C = replacement every three days; Treatment D = replacement every six day; Treatment E = no water replacement (control). The fish were fed with well balanced artificial diet at 3% body weight daily at 0800hrs and 1700hrs. The results show that fingerlings in treatment D had the best specific growth percentage of 5.32% and feed conversion ratio of 1:3.35 while treatment E was poorest with specific growth percentage of 1.33% and feed conversion ratio of 1: 9.20.Treatment A had 100% survival while treatment E had the least survival rate of 30%. Generally it was observed that the lesser the frequency of water replacement the better the growth performance while the reverse was the case with survival rate of the fish fingerlings. It is recommended that an every six day and upward of water replacement frequency be adopted to avoid the problem associated with stress.

Journal of Agriculture and Food Sciences Vol. 4 (2) 2006: pp. 109-114