ABSTRACT

 Hatchability, survival and growth of fry of Heterobranchus Iongfiilis were evaluated under laboratory conditions in Umudike. Hypophysation was done by hormone inducement (ovaprim at 0.5rn1/kg of fish). After a latency period of I 5hours, the eggs were stripped out, fertilized and incubated. A mean of 679 eggs was estimated as the number of eggs per gram. The number, of hatched larvae was counted immediately after hatching to evaluate hatchability. The mean hatchability was 68.4%. Exogenous feeding with mixed zooplankton started at the 311 day after hatching. A 40% CP supplementary feed was combined with the mixed zooplankton by the 8th day and this lasted for 2 weeks after which the fry were fed solely with 40% CP supplementary feed till the end of the experiment. Weekly mean total length, weight and survival were used for investigation of the growth rate The fry attained mean total length and weight of 2.05cm and 2.16g respectively at the end of the experiment white the mean survival was 2.7% in the rearing troughs used. The experiment lasted for 12 weeks. A regression analysis was made to show the relationship between total length and weight, survival and weight as well as survival and total length. The mean total weight and survival varied significantly (F<0.005) between the weeks. The mean total length, weight increased as weeks progressed while the mean survival decreased as the weeks increased.