Population parameters and exploitation status of endemic Garra mullya (Sykes, 1839) in relation to environmental variables, in a tropical river of Western Ghats, India.

Endemic cyprinid, Garra mullya, is an important bioindicator species for assessing anthropogenic impacts in the rivers of Western Ghats. Ulhas River is an important perennial river in Maharashtra, originating from the Western Ghats. Based on the length frequency data collected during April 2024 to March 2025 from the Ulhas River in the northwestern Ghats, the growth, mortality, and exploitation status of G. mullya are reported in the present communication. The length-weight relationship of G. mullya revealed an isometric growth pattern. Length-frequency analysis was performed using the R-TropFishR package. The growth parameters estimated were L∞ = 19.5 cm, K = 0.53 year-1, and t0 = -0.35 year. The growth performance index (ɸ') was calculated as 2.30. Natural mortality (M) and total mortality (Z) were estimated as 0.97 year-1 and 2.29 year-1, respectively. The current fishing mortality, Fcurr = 1.31 year-1 was less than the predicted Fmax value but greater than F0.1 and F0.5 values. The current exploitation rate (Ecurr) was 0.57. The length at first maturity (Lm) was 9.5 cm against the length at first capture (Lc) estimate of 8.24 cm. The combined estimates of Fcurr, Ecurr, and Lc indicate that the stock is undergoing a potential risk of growth overfishing, highlighting increasing anthropogenic stress in the Ulhas River ecosystem. Environmental analyses revealed spatial and temporal gradients in water quality that provide ecological context for interpreting the observed population status. This is perhaps the first comprehensive study on the growth, mortality, and exploitation status of G. mullya.