Length-weight relationship and population structure of pool barb (Puntius sophore) from Jashore, Bangladesh

The pool barb, Puntius sophore, is a small indigenous freshwater fish species with food and ornamental value, belonging to the family Cyprinidae. Size structure, length-weight relationship, and condition factor were studied by examining a total of 86 specimens randomly collected from the Jashore region. The sampled species mostly (78%) belonged to the size class 65-98 mm; total length ranged from 116 mm to 45 mm, average of 82±14.69 mm, and body weight ranged from 12.85g to 4.25g, average of 8.165 1.74 g, respectively. The female-to-male ratio was 1.36. The mean Fulton’s condition factor (K) was 1.84 ± 0.81 for the overall population. The mean K value was 2.02 ± 0.92 in males and 1.70 ± 0.70 in females. The largest female was recorded from the monsoon, with 116 mm TL and 12.85 g BW, while the largest male was 98 mm TL and 10.5 g BW. Again, the smallest female was observed in summer with 49 mm TL and 4.75 g BW, while the smallest male belonged to a size of 45mm TL and 4.25 g BW. Positively Linear and highly significant relationships were obtained between TL and BW for all fishes in different seasons, with the regression equation BW = 0.1112TL – 0.5522 (r² = 0.8803). The result of the length-weight relationship for male specimens was BW= 0.0878TL + 0.943, and the value of the regression r2=0.9277. The calculated length-weight relationship for females is expressed by BW = 0.1182TL – 0.9441, and the value of the regression r2=0.8886.