M.M. Parvez, M.K. Alam, N.G. Das
Successful re-maturation and spawning of the hatchery used wild spawners of Penaeus monodon were performed in the Pioneer Hatchery of Cox's Bazar, Bangladesh. Eye-stalk ablation, maturation and first spawning of wild caught brooders took place inside the 'Green House' of the Hatchery. After first spawning seven healthy spawners were directly stocked in the re-maturation tanks whereas another seven spawners were reared in an out-door tank for spawners of first phase compared to that of second phase. In the first phase re-maturation was repeated for six times of spawning but hatching success was observed only upto fifth spawning. Out of seven selected spawners, 100% spawned for first and second times, 85.71% for third, 42.86% for fourth, 28.57% for fifth and only 14.29% for six times. Total spawners were 1,13,50,000 and 63,90,000 respectively. Spawning and hatching rates gradually decreased with each consecutive spawning but fertilization rate was almost uniform. In the second phase re-maturation was possible only for two times, but hatching success was occurred one time only. Out of the seven selected spawners, 71.43% spawned for first time and only 42.86% for second time. The spawner laid 55,70,000 eggs and the corresponding eggs produced 30,40,000 nauplii. Spawning, fertilization and hatching rates rematured under the controlled aquatic conditions and feed with fresh frozen meal of squid, clam, cockle, crab at 15% of the body weight.
(International Resource Development and Management, Dhaka, Bangladesh)