Size at sexual maturity and fecundity of the mola carplet Amblypharyngodon mola (Hamilton 1822) (Cyprinidae) in the Ganges River, Bangladesh

摘要

Amblypharyngodon mola Hamilton 1822 is widely distributed in the freshwaters of Southeast Asia and is commercially important. We studied the size at sexual maturity (TL50) of A mola in addition to its fecundity indices using samples collected from theGanges River, Bangladesh. A total of 1200 individuals of A mola were examined comprising 373 males and 827 females. Based on the relationship between gonadosomatic index (GSI) and total length (TL), males with a GSI > 2.31% and females with a GSI > 4.66% could roughly be defined as mature. The TL50, the TL at which 50% of individuals become mature, was estimated by logistic equation as 5.85 cm in males and 5.97 cm in females. The total fecundity (FT) ranged from 1652 to 15,985 (6255 ± 3640). Both thestudied variables (TL and body weight, BW) were highly correlated with FT and can be used to estimate the total potential fecundity, although BW performed better. Our results provide an insight into the TL50 and reproductive potential of A. mola, which would be helpful to set the mesh-size restriction and to estimate potential recruitment and population growth rate for their sustainable management.