ARTIFICIAL PROPAGATION AND EARLY REARING OF CLARIAS GARIEPINUS IN EGYPTIAN FISH PONDS..

Abstract

This study has been carried out on various phases of induced spawning of Clarias gariepinus broodspawners, fertilization of eggs, egg incubation, hatching and early rearing of the larvae for schedulling and standardizing the process of fingerlings large scale mass production. The number of females used in this study was 135. They were

pretreated under the same environmental and pond mangement conditions in order to minimize the individual variation. They were categorized into three different size groups A, Band C'(45 individuals each), with average individual body weight of 311.6 ± 10.3, 460.5 ± 11.8 and 611.2 ± 8 grams, respectively. Each size group was sorted randomly into nine simillar subgroups (5 femals each). Females of the subgroups A 1. 3, B1•3 and C1. 3 were injected with HCG. Individuals of the subgroups A4-6, B4-6 and C4.6 were iniected with CLPs. However fish of the subgroups A7.9, B1.9 and C7.9 were injected with CPs. Individuals of the

subgroups 1, 4 and 7 from each siz group were then kept separately in aquaria filled with water at a temperature level of22 °C . However, fish of the subroups 2, 5 and 8 of the three siz groups were placed separately in aquaria at water temerature of 25 °C. The water temperature for the 3rd, 6th and 9th •subgroups of the same size groups were maintained at

30°C.

The potency of the three types of spawning inducing agents HC<{, CLPs and CPs at the three.different temperature levels 22, 25 and 30 °C were assessed among individuals of the three different size groups.