Biological Considerations in Hatchery Management: A Case Study in a Few Hatcheries in Jessore, Bangladesh

Abstract

The study was carried out from July to November, 2015 to assay the present condition of fish seed production in 10 hatcheries in Jessore, Bangladesh. Questionnaire survey and personal interviews were carried out to collect data on the detail management of hatchery and broods. The average number of manpower at the hatcheries was found to be 8 including 1 Manager, 2 Technicians and 5 Hatchery Assistants. Ninety percent of hatchery owners attended 3-7 days training of DoF, BFRI or Worldfish on hatchery management. Total area of brood ponds used by Ma Fatema Fish Hatchery (MFFH) was 8 with the highest water area of 2310 decimal. However, the range of water areas of the 10 hatcheries surveyed was obtained at 297 to 2310 decimal; the pond number similarly was found to range from 4 to 17. Highest seed production was found in Ma Fatema Fish Hatchery (9000 kg/year) having the production capacity of 14000 kg/year and the lowest production was in Anan Fish Hatchery (733 kg/year) having the production capacity of 8000 kg/year. Brood fishes were mainly collected from Government brood bank and Worldfish as well as used from their own stock. Hatchery owners did not maintain the pedigree history of breeders thus relatedness in the brood was common leading to inbreeding. Stocking size ranged from 10-20 kg/decimal. The yearly exchange rate of brood fish was varied from hatchery to hatchery which was 20 to 40% in different hatcheries. Occurrence of disease, unsuitable weather, poaching, lack of finance and bad communication were the problems faced by hatchery owners. Mainly two types of inducing agents viz. pituitary gland (PG) and Ovaprim were used for induced breeding practices in the surveyed hatcheries. The peak breeding season was April to June. Mean fertilization rate was found to range between 80 to 96.67 % for rohu and 76.67 to 96.67% for Catla; the mean hatching rates in the same hatcheries were ranged between 57.78 and 88.89 % for rohu and 56.67 to 83:33 % for Catla. The weight of the breeders used in spawning in the hatcheries studied was ranged from 3.25 to 8.5 kg female and 2.5 to 5.24 kg male for catla; in rohu the range was 1.79 to 4.17 kg for female and 1.73 to 3 kg for male. Highest Ne, was found at 92.12 in Rupali fish hatchery whose average inbreeding percentage(F) was 0.54 for rohu. For the same species, the lowest Ne, was 10.11 with average inbreeding percentage being 4.95 in Matri fish hatchery. Highest Ne for catla was 21.91 with corresponding inbreeding percentage 2.28 in Rita fish hatchery. The lowest Ne, was only 2 with corresponding inbreeding percentage 25 in Haque fish hatchery. For assurance of quality seed production of the two species the standard of management of hatchery and broods has to be improved with regard to both non-genetic and genetic aspects and for that the government has to strengthen its training and extension services