SOME ASPECTS OF REPRODUCTIVE BIOLOGY OF GANGETIC AILIA, Ailia coila (HAMILTON, 1822) IN BANGLADESH.

The present study was conducted by Bangladesh Fisheries Research Institute, Floodplain Substation to investigate the reproductive biology of Ailia coila in the northern region of Bangladesh. A total number of 100 fish samples were collected on a monthly basis from the Atrai River and Jamuna River during the period from January 2022 to December 2022. The highest mean value of the gonado-somatic index (GSI) was recorded in July (8.78 ± 1.95%), whereas the lowest was found in December (0.15 ± 0.09%). The highest individual fecundity (2,450 ± 570) and ova diameter (0.38 ± 0.07 mm) was also observed in July. From the histological observation of the ovary, the highest percentages (75%) of mature oocytes were observed during the month of July. Based on the GSI, fecundity and gonadal histology, the breeding season of A. coila was observed from June to August with a remarkable peak in July. In the case of length weight relationship (LWR), the coefficient of determination value (r2) was found 0.96 and the slope was found b = 1.50 which indicated the pattern of negative allometric growth of this species as b < 3. In contrast, an increase was recorded in the fecundity associated with the rise of total length, body weight and gonad weight showed a significant linear relationship. This study would assist in the development of induced breeding techniques and provide valuable information for the sustainable management of this population in the inland open ecosystem. [ABSTRACT FROM AUTHOR]