Improving breeding performance of fingerlings of <i>Clarias gariepinus</i> through intraspecific hybridization

Abstract

The scarcity of genetically improved fish seed is a major constraint to rapid development of aquaculture in Nigeria due to inbreeding. The study was conducted to monitor breeding indices from intra-specific mating combinations of wild stocks of Clarias gariepinus. Broodstock of C. gariepinus were collected from Lokoja (LK), Makurdi (MK), Agenebode (AG) and Onitsha (ON) and compared with domesticated strain. 16 mating combinations of parental and intraspecific mating combinations were conducted in triplicates. Results were subjected to one way analysis of variance (ANOVA) (α= 0.05). The results showed collection from Onitsha had highest values of fertilization (95.2%), hatchability (87.6 %) and survival (66.0 %), followed by crosses from female from Onitsha : ♀ON X ♂LK, ♀ON X  ♂MK and ♀ON X  ♂AG having 95.8 %, 91.1 % and 88.8 % (fertilization), 68.7 %, 61.9 % and 60.7 % (hatchability) and 61 %, 57 % and 63 % (survival) respectively. Domesticated strain had least values (81.9 %, 59.4 % and 51 %) fertilization, hatchability and survival respectively. ANOVA (α< 0.05) showed variation in fertilization, hatchability and survival. The better performing strains could be explored for genetic development. However, protein and gene profiling of these natural populations may be necessary to identify the proteins and genes responsible for these variations in breeding performances.

Key Words: Breeding, performance, Clarias gariepinus, hybridization