CEPF Western Ghats Special Series: Length-weight relationship and condition factor of an endemic stone sucker, Garra gotyla stenorhynchus (Jerdon, 1849) from two opposite flowing rivers in southern Western Ghats

Abstract

Length weight relationship (LWR) and condition factor were studied in Nilgiri Garra, Garra gotyla stenorhynchus (Jerdon), from the rivers Chaliyar and Bhavani flowing through the Western Ghats Biodiversity Hotspot. The regression equation for LWR of the Nilgiri Garra from Chaliyar River was estimated as Log Wt = 2.920 Log L - 1.854, while those from Bhavani River as Log Wt = 2.594 Log L - 1.538. Although, the ‘b’ value observed from west flowing Chaliyar River (2.920) was higher than that from east flowing Bhavani River (2.594), they were statistically insignificant. Similarly, the Condition Factor (K) was higher in Bhavani populations (2.177) compared to Chaliyar (2.087), but were also statistically insignificant. The results indicated that populations of G. gotyla stenorhynchus in Chaliyar River followed an isometric like growth pattern with ‘b’ values close to cubic law. However local populations of the same species in Bhavani River are under stress as indicated by comparatively lower ‘b values. This difference in ‘b’ value between the two river populations may be due to the differences in physical habitat features of the locations from where they were sampled, including altitude, physical habitat features, water quality and their combined influence on the availability of food materials as well as stock/population differences and yet to be identified stressors.