Reproductive Biology of Penaeus indicus (H. Milne Edwards, 1837) from the Western Coastal Waters of Sri Lanka

Abstract

The reproductive biology of Penaeus indicus (H. Milne Edwards, 1837) from the western coastal waters of Sri Lanka was studied during the period September 1998 to Decem-ber 1999. Analysis of sex ratios of different size classes indicated that there was a significant deviation of sex ratio from unity for the size range studied. The predominance of males, especially in the size groups from 13.4 to 15.4 cm suggests that females may have a behavioral pattern of separating from males after reaching an age corresponding to size at first maturity. The sizes at 50% maturity for males and females were estimated as 12.