15 MARCH 1999
REPRODUCTIVE ACTIVITY OF MALE MORPHOTYPES OF MACROBRACHIUM ROSENBERGII (DE MAN) AND THEIR PERFORMANCE IN BROOD STOCK REARING AND LARVAL PRODUCTION
S. Sureshkumar, B.M. Kurup-1998
Journal of Aquaculture in the Tropics, 13(2): 87-94
Abstract:
The study is aimed to delineate the reproductive activities of three male morphotypes of M. rosenbergii viz. blue clawed (BC) males, orange clawed (OC males and small males (SM) and also to optimize the sex ratio in brood stock rearing in order to achieve successful oviposition and maximum viability of eggs. Best results were achieved in respect of oviposition hatchability of egg and survival of larvae in trials conducted with BC males, maintained at 1 male: 4 females ratio. On the contrary, percentage of oviposition was least in treatments with OC males while SM showed intermediary performance at lower ratios. In trials with BC males, extrusion of eggs occurred within 16 days and the period of incubation was 15 to 19 days. BC when maintained at a ratio 1:4, the average prezoea produced and larval survival worked out to 62,000/100 g body weight and 35% respectively and showing this combination to be ideal for brood stock rearing not only among various ratios tried in BC male combinations but also among various morphotypes of M. rosenbergii studied. The success achieved in oviposition and viability of eggs in other stocking ratios of BC as well as in other morphotypes were analysed statistically and discussed.
(School of Industrial Fisheries, Cochin University of Science and Technology, Fine Arts Avenue, Cochin 682 016, India)