Abstract
The fish Cabdio morar (Hamilton, 1822) is a member of the family Cyprinidae, commonly known as morari in Bangladesh and Aspidoparia in India. This fish was previously known as Aspidoparia morar and is widely distributed in Bangladesh, India, Myanmar, Nepal, Pakistan, and Thailand. The present study describes the temporal variations of sex ratio (SR), length-frequency distributions (LFDs), length-weight relationship (LWRs), and Fulton's condition factor (K-F) of the C. morar. A total of 1200 specimens (male = 552, female = 648) ranging from 4.06-12.84 cm TL and 0.53-16.75 g BW were analyzed. The overall SR showed significant differences from the expected value of 1:1 (male: female) (chi(2) = 7.68, P > 0.01), and there was also a significant difference in LFD between the sexes (P < 0.05). The allometric co-efficient (b) for the overall LWR indicated positive allometric growth (> 3.00) in males and isometric growth in females (similar to 3.00). Hence, LWRs were significantly different between males and females (ANCOVA, P < 0.001). K-F showed significant variation (P < 0.01) between the sexes, with better performance by females (0.88 +/- 0.14) than for males (0.86 +/- 0.15). In addition, our study uniquely discovered the spawning season based on lower values of allometric co-efficient (b) for C. morar during December to March in the Jamuna River. These results will help further studies on population assessment and stock management of C. morar in the Jamuna River ecosystem.