Length-Weight Relationship and Condition Factor of Mrigal Cirrhinus mrigala (Hamilton) Reared in Bheries of 24-South Paraganas District in West Bengal

An attempt was made to study length-weight relationship and condition factor of Indian major carp, mrigal (Cirrhinus mrigala) reared in bheries at Bhamanghata of 24-South Parganas district in West Bengal. Samples of 323 fishes having size range of 127 mm to 334 mm were taken to estimate length-weight relationship. The regression equation was found as logW = -4.239 + 2.753 logL (r = 0.885) for male, logW = -4.388 + 2.823 logL (r = 0.871) for female and logW = -4.372 + 2.797 logL (r = 0.876) for pooled sample and it exhibited significant correlation (P<0.05) between length and weight. It was found that the exponent 'b' value varied significantly from '3' indicating allometric growth. The mean relative condition factor (Kn) was found to vary from 0.94 to 1.14 during the period of investigation. It varied significantly (F_{11, 11}= 3.37, P<0.05) during different months which were attributed to food and feeding habit of fish. The variations in exponent and dynamics of relative condition factor of fish are discussed referring earlier works.