Fertilization, hatchability, survival and larval biometry in interspecific and intergeneric hybrids of Clariid catfishes

Interspecific and intergeneric hybridization studies were carried out in H. longifilis, C. gariepinus and C. anguillaris under controlled hatchery conditions to estimate their aquaculture potential in terms of fertilizability, hatchability and survival. Fertilization rate in all the nine genetic crosses ranges from 60-87.5%, the fertilization rates of the parentals being significantly higher(P<0.05) with highest value of 87.5% obtained in C. gariepinus. The intergeneric hybrids had the lowest rate of fertilization. Hatchability ranges between 75- 88.1 %, with the parental C. anguillaris being slightly significantly higher than the other genetic combinations. C. anguillaris x H. longifilis I had the lowest hatchability and there was no significant difference (P<0.05) in percent hatching among the the interspecific hybrids. The survival of all the nine genetic crosses from hatching up to the end of the two weeks indoor rearing period ranges between 78-89%, which wasn't significantly different among the interspecific and intergeneric hybrids. C. anguillaris and C. gariepinus had the highest percent survival which was significantly different from all the other mating combinations. The intergeneric hybrid larval had significantly greater (P<0.05) length in comparison to the interspecific hybrids. H. longifilis and the hybrids produced from its eggs had greater body weight than that of C. gariepinus and C. anguillaris