Life- History Traits and Decadal Trends in the Growth Parameters of Golden Mahseer Tor putitora (Hamilton 1822) from the Himalayan Stretch of the Ganga River System.

Year 2008, Volume: 8 Issue: 1, - , 01.02.2008

Prakah Nautiyal *(1) Anees Fatma Rizvi (2) P. Dhasmanaa (1)

Abstract

Life-history traits such as age and body growth patterns of Tor putitora (Hamilton 1822), inhabiting the lesser Himalayan stretch of the Ganga river system in the Garhwal region were examined during 1994 and 1995. The maximum age was recorded 17+ whereas harvestable size was 65.6 cm. The asymptotic length (L) was found to decline from 1980-81 (272 cm, K = 0.055 year-1) to 1994-95 (216, K = 0.056) resulting in the increase of the growth coefficient (K). The total, natural and fishing mortality coefficients also exhibited a similar pattern 0.366, 0.084 and 0.28 and 0.58, 0.086, 0.494, respectively during 1980-81 and 1994-95. This was reflected in the exploitation rate and ratio also, 0.23 and 0.76 and 0.37 and 0.85 respectively for 1980-81 and 1994-95.

Keywords

Age, Growth, Asymptotic length, Mortality, Exploitation, Decadal trends