Effect of brood stock size on egg fertilization, hatchability and fry survival rate of African catfish (<i>Clarias gariepinus</i>)

Abstract

This experiment was conducted to investigate the effect of size of brood stock on egg fertilization, hatchability and fry survival rate of Clarias gariepinus in an intensive culture system, for a period of four weeks. Larger brood stock size (1200-1500g) produced larger eggs and bigger fry while moderate brood stock size (795-1000)g produced moderate eggs and moderate fry. The mean size of eggs produced and the size of brood stock was however not significantly different (p > 0.05). In addition, larger eggs resulted in larger fry. The survival rate of fry after starvation increased with increase in parent brood stock size. Best on this study it was recommended that for larger eggs and fry production, brood stock of Clarias gariepinus, of average size of (1200-1500g) should be selected for use in fish hatchery operation in Nigeria. There was no significant difference (p> 0.05) in the physiochemical parameters.

Keywords: Broodstock, Egg fertilization, Hatchability, Clarias gariepinus