Demographic patterns of an endemic cichlid, Etroplus suratensis, across five rivers in the Western Ghats Biodiversity Hotspot, India

Etroplus suratensis (Cichlidae), a commercially important food fish endemic to the Western Ghats (WG) biodiversity hotspot in India, has shown a marked decline in population due to excessive exploitation. To assess the impacts of overexploitation on E. suratensis, as detailed information on the fishery and current population status is lacking. The study examined the fishery, length-weight relationships (LWRs), growth patterns, mortality rates, and exploitation status of E. suratensis across five major rivers in the Western Ghats of India. The annual catches of E. suratensis ranged from 1.3 to 4.75 tons/year. Total mortality ranged from 0.93 yr-1 to 2.16 yr-1, while fishing mortality varied from 0.36 yr-1 to 1.37 yr-1. The length at first capture (Lc) was lower than the length at first maturity (Lm), indicating that more than half of the E. suratensis population is harvested before attaining reproductive maturity. The stock of E. suratensis in most rivers appears to be approaching full exploitation under the current fishing levels. Implementing management measures such as seasonal fishing closures, mesh size regulations, establishment of fish sanctuaries, and adoption of quota systems could help promote the sustainable utilisation and conservation of E. suratensis populations.