Effect Of Photoperiod On Hatching Success Of Eggs And Early Fry Performance Of Clarias Gariepinus (Siluriformes, Burchell 1822)

The present study investigated the effect of egg exposure to three light and dark regimes: 00D: 24L; 24D: 24L; and 12D: 12L on hatching and early growth of Clarias gariepinus larvae. Incubation was carried out in 30L black cylindrical plastic bowls. Hatching rates were determined 24hours post incubation while growth and survival were determined every three days for two weeks. Results obtained reveal no significant difference (P>0.05) in fertilization rate of eggs assigned to various photoperiods and no effect of photoperiod on mean final weight, mean weight gain, and specific growth rate of fry. However hatching rate and survival rate were significantly affected by light regime (P<0.05) with fry raised under the light regimes of 12L: 12D and 24L: 00D having significantly higher hatching (84%) and survival (54%) rates. A favorable temperature as well as better vision in search and capture of food aided fish under these treatments to perform better. Photoperiod can therefore be used to enhance incubation, hatching and early growth of C. gariepinus with potential to maximize hatching from egg