Lengths, length-length relationships and condition factor of Indian catfish Gagata cenia (Hamilton, 1822) from the Padma River, Bangladesh

This study described some biological parameters including lengths, length-length relationships and Fulton’s condition factors of Gagata cenia in the Padma River of Bangladesh, based on 1120 specimens collected from May to November, 2012. Maximum 39.78% female fishes were belonging to the length category of 55-60 mm whereas 51.06% male were belonging to 50-55 mm. The highest mean total lengths were found 66.51±10.28 mm (combined sex), 70.12±09.49 mm (female) and 61.08±09.45 mm (male) in the month of June. Similar findings are also presented for standard length, fork length, body depth, dorsal length, pectoral length, pelvic length and anal length. Linear relationships were also studied among mentioned lengths. Strong positive correlations were observed in all cases. Speraman’s Rank test indicated that there was a strong, positive correlation between total length and condition factor in female, which was statistically significant (rs=0.210, P=0.044). In male, there was no significant correlation between these two (rs=0.167, P=0.262). The Mann-Whitney U-test showed that the female individuals had the highest condition factor (Mean rank of 79.76). There was a statistically significant differences in the Fulton’s condition factor between males and females (two tailed, Mann-Whitney U = 1324)