SOME ASPECTS OF BIOLOGY OF MYSTUS VITTATUS (BLOCH 1794) FROM THE MOURI RIVER, KHULNA, BANGLADESH

Abstract

Length–weight relationship, condition factor (K), relative condition factor (Kn), fecundity and egg diameter of Mystus vittatus (Bloch, 1794) were estimated from 120 individuals collected from the Mouri river of Khulna district, Bangladesh during 7th August to 25th October 2006. The total length (LT) ranged from 7.2 cm (body weight (W) 6.9 g) to 13.4 cm (W=24.2 g) for male and 12.1 cm (W=14.39 g) to 13.6 cm (W=23.29 g) for female. The logarithmic relationship of LT-W and LS-W were strongly positive as estimated , and , . The mean K and Kn varied from 7.24 to 18.49 and 0.44 to 25.81 respectively. The relationship of LT-K was not statistically significant (,) whereas that of LT-Kn produced negative correlation (,). The mean bilobed gonad weight (WG) was 1.41±0.738 g where the left lobe was 0.718±0.375 g and that the right lobe was 0.697 ± 0.367 g. The highest mean egg diameter was 8.75 µm in the left lobe between 13.5 and 13.9 LT and the lowest was 8.15 µm between 13.0 and 13.4. The highest mean egg diameter was 8.27 µm in the right lobe and the lowest was 7.83 µm. The fecundity (F) M. vittatus varied from minimum 1440 to the maximum 5811. The relationship of LT and WG was positively significant () and the LT-F relationship was also significant (). However, the relation of LS and F was highly significant (r2=0.79).