LENGTH-WEIGHT RELATIONSHIP AND RELATIVE CONDITION FACTOR OF GOLDEN MASHEER (TOR PUTITORA HAMILTON 1882) UNDER POND-REARED CONDITION IN SOUTHERN FOOTHILLS OF BHUTAN

Abstract

A study was conducted with the objective to establish the first ever length-weight relationship and evaluate the physical robustness of the endangered Golden Mahseer (Tor putitora Hamilton 1822) in Bhutan. The study samples were from populations reared in fertilized earthen ponds at National Research and Development Centre for Aquaculture (NRDCA), Gelephu. Data on total length and total weight of 120 juvenile and adult specimens of fish were collected in November, 2017. To enable simple linear regression analysis for estimating the coefficient of total length in describing total weight, the linear growth model (ln W = ln a+b. ln L) was used. An indicator of physical robustness was estimated using Le Cren’s formula for relative condition factor (Kn) (Kn = W Ŵ ). Length-weight relationships and relative condition factors were estimated separately for two different groups of juveniles, adult males, adult females and pooled data. The relationships between total weight and total length across groups and for the pooled data were highly significant at 99% significance level. The length-weight relationships and relative condition factors (mean values) were: ln W= -2.581+1.749 ln L and 1.044 for 9-month-old juveniles; ln W= -4.062+2.782 ln L and 1.025 for 13-month-old juveniles; ln W= -4.385+2.946 ln L and 1.066 for adult males; ln W= -5.420+3.195 ln L and 1.113 for adult females; and ln W=-3.979+2.822 ln L and 1.064 for pooled data.