Maternal Age Influence on Fry Survival, Growth and Size Variation in Clarias gariepinus

摘要

Background and Objectives: The maternal attributes could impact on the quality of eggs and life history trajectories of the hatchlings. The work aimed at analyzing the effects of maternal ages on fry quality in Clarias gariepinus. Materials and Methods: Hatchlings were produced from a single male Clarias gariepinus of 3.5 kg and females averaging 1.2 kg and aged 1, 2 and 3 years with 4 replicates of 3 fish in a complete randomized design. The initial, bi-weekly and final weights and number of hatchlings were taken. The survival rates, growth performance and size compositions of the hatchlings were evaluated at the end of 7 weeks experimental periods. The means were analysed with analysis of variance and Duncan Multiple Range Test (p = 0.05). Results: Fry survival rate was significantly higher between 3 and 1, but 3 and 2, and 2 and 1 years old brood stocks. Mean weight gain and specific growth rate were insignificant across the ages though, cumulative weight gain was highest in fry from 2 followed by 3 and least in 3 year old brood stocks. 4 fry size categories viz. A: (100-159), B: (160-359), C: (360-500) and D: (501-2900) were identified and discussed in the context of their significance. Conclusion: Age was found to affect offspring survival rate and size variation among the hatchlings of C. gariepinus greatly, and growth performance marginally.