First record of important biological parameters of Badis badis: A small indigenous species in Bangladesh

A total of 286 Badis badis were collected from the Sutiyahali Reservoir in Mymensingh from January to December 2022, and their sex ratios, first sexual maturity, length-weight relationships and condition factors were evaluated. The weight and length of B. badis varied from 0.81 to 1.01g (0.89±0.30) and 4.08 to 4.60cm (4.36±0.31), respectively. Logistic curves depicting a sex ratio and 50% maturity (L50) estimated at 4.5cm for females and 4.05cm for males, as well as males reaching first sexual maturity with a shorter length than females. Regression coefficients in every month differ significantly (p<0.05), according to the regression equations. Each month, the values of the exponent b were less than 3 (b<3), with the highest value of b recorded in August (2.80) and the lowest value recorded in January (2.33). This led to a monthly negative allometric growth being seen. A strong positive relationship is evident from the coefficient of determination (r2) values, which ranged from 0.92-0.98 with an average of 0.961. During the study, the average condition factor (Kn) value for B. badis was found to be 1.02±0.13, which is a positive indicator of the fish's physical well-being. The condition factor values varied between 0.84 to 1.39, making it abundantly clear that B. badis are in good health and the waterbody is an ideal habitat for their survival. Relative condition factor (Kr) values, which varied between studies and ranged from 0.78 to 1.01, also exhibited a noteworthy difference (p<0.05). For its long-term management, the above findings will be very helpful.