Document Repository and Sectoral Scope Summary

Abstract

Fish stocking or restocking in natural water bodies, whereby production is generally extensive, can be an option in the attempt to compensate the dearth in fish production related to stock depletion in capture fisheries and high feed costs in aquaculture. While a major objective in fish production in aquaculture is the procurement of fast-growing strains through hybridization, survival rate is a major metric to evaluate the effectiveness of fish stocking programs. Consequently, 600 hatchery-bred Clarias gariepinus hybrid fry of mean total length 1.46±0.16 cm and mean weight 0.097±0.011 g were stocked in a wetland for 180 days, without supplementary feeding and protection from predators. Mean length gain was 49.85±13.27 cm, mean weight gain 1,334.79±1088.268 g with males recording higher mean final weight than females (P<0.05), and growth hypoallometric. Survival rate was 7.17%, with the females outnumbering the males (P<0.05). This effort showed a relatively significant growth and recovery rate of stocked C. gariepinus seed, indicating that there is a potential for an even higher growth and survival if the habitat is manipulated to preclude predation and if both stocking and harvesting are timed aptly.

Keywords: Fish stocking, Extensive production, Hybridization, Survival, Wetland