Biological and Reproductive Indices of Mystus bleekeri (Day, 1877) in Open Water Body (Dekhar Haor) of Bangladesh

Abstract

Some biological and reproductive aspects of the Mystus bleekeri from Dekhar Haor were investi-gated. From the commercial catches, a total of 600 sample collections were performed on a month-ly basis from July 2017 to June 2018. Total length (TL, cm), body weight (W, g) and individual’s sex were identified between 216 male (36%) and 384 female (64%) fish (ratio 1.00: 1.78). Mean TL and Wofsampleswere14.85±3.38cmand27.54±15.76g,respectively.TheTLofmaleandfemaleranged from 6.9-21.3 and 7.80-24.60 cm, respectively; and W ranged from 5.3-63.3 and 6.70-76.40 g,respectively.Inlength–weightrelationshipofthisfishdepictedanegativeallometricgrowth(b=2.408) with a condition factor (Kn) of 1.04±0.11. Fish of 16.00-16.90 and 10.00-10.90 cm length groups demonstrated the highest (1.45±0.23) and lowest (0.89±0.18) Kn values, respectively which wassignificantlyvariedamongdifferentlengthgroups.MonthlystudyofgonadosomaticindexshowedtwopeaksinthemonthofMay-JuneandNovemberforbothsexes.Theresultsofthisstudy provide baseline data on some biological aspects of M. bleekeri, which would be useful in predicting the responses of M. bleekeri populations in Dekhar Haor.

Keywords

• condition factor
• gonadosomatic index
• length-weight relationship
• mystus bleekeri
• sex ratio