INDUCED SPAWNING PRACTICES OF DIFFERENT FISHES IN THE HATCHERIES OF BARISAL DISTRICT, BANGLADESH
Present investigation was conducted to investigate the induced spawning practices in 21 hatcheries of 7 Upazilas of Barisal District in Bangladesh. It was observed that, 5 native fish species viz. rui (Labeo rohita), catla (Catla catla), mrigal (Cirrhina mrigala), bata (Labeo bata), sarpunti (Puntius sarana) and 5 exotic fish species namely silver carp (Hypophthalmichthys moltrix), bighead carp (Aristichthys nobilis), grass carp (Ctenopharyngodon idella), common carp (Cyprinus carpio) and
... s carpio) and mirror carp (Cyprinus carpio var. specularis) were used in the surveyed hatcheries for induced spawning purpose. The weight of different brood fish was ranged from 0.25 kg to more than 8kg and age was ranged from 1 to 10 years for different fishes. Two types of hormone injections like PG (pituitary gland) and HCG (human chorionic gonadotropin) were used for induced spawning. The rate of 1 st doses of injections of PG were from 1 to 4 mg/kg and HCG from 150 to 500 IU/kg and the rate of 2 nd doses of injections of PG for native and exotic species were from 4 to 8 mg/kg and 4 to 10 mg/kg, respectively. The ovulation period and hatching rate in different fish species varied from 1.5 to 6 hours and 47% to 86%, respectively.