Length-weight relationship and condition of Mystus cavasius (Hamilton) from lower Indus River at Thatta District, Sindh, Southern Pakistan

Mystus cavasius a Bagirid catfish is one of the commercially important fish. Paper presents the first report on any biological aspect of this important catfish. Studies on Length-weight relationship and condition factor of M. cavasius at downstream of Indus River near Thatta District were carried out from March to July 2013. A total of 391 specimens including 177 male and 214 female were used for the study. The total length of male population ranged between 7.5 to 18.5 cm and in female population ranged 7.8 to 23.5 cm. The female population dominated over the male in the number, and it also attains larger size than male. The exponent b values of male, female and combined population were calculated as 2.51, 2.57 and 2.54 respectively, that indicate the negative allometric growth. This research reports the first study on Length-weight relationship of M. cavasius from Indus River.

Keywords: Mystus cavasius, Catfish, Length-weight relationship, condition factor, Indus River.