Demographics of the endemic and threatened small cyprinid Pethia setnai from the Northern Western Ghats, India

The indigo barbPethia setnaiis a threatened small cyprinid endemic to the Western Ghats biodiversity hotspot of India. In this study, the length-weight relationship and length-frequency-based population dynamics of this species, which are important prerequisites for effective fisheries management, were investigated for the first time based on specimens collected from the Mhadei River in the northern part of the Western Ghats. Estimated von Bertalanffy growth parameters were as follows: theoretical maximum length,L-infinity, 70.88 mm; growth coefficient,k, 1.50 year(-1); and theoretical age at length 0,t(0), -0.016 years. Natural mortality ofP. setnaiwas higher than fishing mortality, and the present exploitation level (0.37) was less than 60% of the predicted maximum exploitation, suggesting that the species is not exploited to a level that is detrimental to the local population.