An Annotated Checklist of Ichthyofaunal Diversity of the Potamon Zone of Thamirabarani River, South India

Thamirabarani is a major east-flowing river originates from the Pothigai Hills of Southern Western Ghats (8°36'07.1"N 77°15'50.9"E) at an altitude of 2074 m with a catchment area of 5482 km² and meanders through a distance of 120 km (24 km in hilly terrain and 96 km in plains) in Tirunelveli and Tuticorin districts and drains into the Bay of Bengal. Present paper provides information on abundance, distribution, human utility, Trophic level, L_m and IUCN status of the Thamirabarani River.

The present study was conducted by monthly intervals on Ichythyofaunal diversity of the Potamon Zone of Thamirabarani River from November 2019 to October 2021, selecting seven sampling stations viz Cherenmahadevi, Vannarpettai, Murappanadu, Karungulam, Srivaikuntam, Eral and Authoor.

In the present study, a total of 57 species comprising 11 orders, 19 families and 38 genera were documented from downstream stretch of Thamirabarani River, of which three fish species namely Horadandia atukorali; Oreochromis mossambicus and Wallago attu are under vulnerable category and three fish species namely are Hypselobarbus dubius; Labeo fisheri and Dawkinsia tambraparniei endangered listed in the International Union for Conservation of Nature red list. Among the 11 orders reported, the order Cypriniformes (52%) was observed to have the highest contribution to the Ichthyofaunal diversity and the family Cyprinidae (32%) was recorded the highest contribution to the finfish diversity. The trophic level community structure of recorded fish species revealed the dominance of mid-level carnivores (48%). The human utility of recorded finfishes was found to be the highest was observed as edible (72%) and IUCN status was the highest with least concern (72%).