Breeding and Seed Production of the Ganga River Prawn Macrobrachium gangeticum (Bate) Under Captive Conditions

摘要

The Ganga river prawn Macrobrachium gangeticum (Bate 1868) inhabits the rivers Ganga and Brahmaputra in the Northeast region of India. The post-larvae (PL) production and grow-out culture techniques developed for M. rosenbergii and M. malcolmsonii arebeing practiced all over the country but hatchery technology for PL production of M gangeticum is currently lacking. This work was conducted at Central Institute of Freshwater Aquaculture (CIFA) Kausalyaganga, Bhubaneswar during 2000 to develop mass culture of M gangeticum post-larvae. The juveniles, adults and berried females were transported by land from the collection sites on the river Ganga (at Patna and Farakka) and its tributary, the Padma (at Lalgola). The juveniles and adult prawns were rearedunder laboratory and out-door conditions using air-lift bio-filter recirculatory system. Females attained maturity at 85 mm (8g) size and bred and spawned under captive condition. The hatching of zoeae occurred within 12-13 days of spawning. First stagezoeae were reared in brackish water of 10-18 ppt salinity for larval growth and development. The zoea first larvae passed through 18 molts, showing the characteristics of 11 distinct larval stages before attaining post-larval stage within 22 - 26 days.A total number of 7,997 post larvae was produced in four rearing trials lasting 60 days. The number of PL's produced, percentage of PL recovery and the rate of production (PL/1) at the end of 60 days was: Trial 1: 2798 PL, 96.05%, 9.3 PL/1; Trial 2: 2042 PL, 98.98%, 6.75 PL/1; Trial 3: 2487 PL, 80.09%, 8.64 PL/1; Trial 4: 670 PL, 94.49%, 2.22 PL/1. These results indicated commercial culture potential of this species.