Establishment and Efficiency Evaluation of a Simple Mini hatchery for production of Oreochromis niloticus (GIFT strain) seeds

A simple technology mini hatchery was established for small scale farmers to meet their own GIFT seed requirements. Different shapes and sizes of jars were trialed for incubation of eggs and yolk-sac larvae. Concaved bottom round plastic bottles (4 L) and rectangular (3 L) plastic trays gave the best hatchability of eggs and survival of yolk-sac larvae respectively. The best stocking density was 500 eggs/larvae L-1. Optimised flow rate into the incubation bottles and rearing trays were 2.70±0.18 L min-1 and 5.40±0.14 L min-1 respectively. Two gravel filters (15 L and 20 L) made with discarded and low cost material purified the water from the incubation containers and directed into a water recirculation system. Production efficiency of this mini hatchery was compared with a hapa breeding method. Two hapas having 10 m3 size and 1.6 mm mesh were positioned in an earthen pond. Each hapa was stocked with 40 GIFT broodfish at 1:1 female to male ratio. In Phase I of the study (60 days), eggs collected from Hapa I were placed in incubation bottles and hatchability and survival rate were determined. In parallel, free-swimming fry were collected and counted from the Hapa II at every 14 days. The study continued in the same way for Phase II (next 60 days) by interchanging the brood fish between Hapa I and Hapa II. Yield from the mini hatchery (24,000 fry) was significantly different (P≤0.05) from hapa method (4,879 fry) indicating that this established mini hatchery could serve as a productive model to support small scale farmers in GIFT seed production