An overview of ichthyofaunal diversity in Nun River: A preliminary survey

This study aims to investigate and document the ichthyofaunal diversity of the Nun River, a previously unexplored tributary of the River Tons in the District of Dehradun, to assess its ichthyofaunal diversity and identify potential conservation needs. Fish samples were collected from several sampling locations with the help of local fishermen, who are regularly engage in fishing activities at these locations, using a variety of fishing nets (mesh size: 20–40 mm) and traditional equipment. However, some fish were also procured from the local fishermen at different sampling sites. Over the course of the study period (August 2022–April 2023), the fish fauna of the Nun River was investigated. Overall, a total of 12 species belonging to 4 orders, 6 families, and 12 genera were recorded. Several anthropogenic stressors such as pollution from agricultural sources, human settlements, and sewage cause severe threats to the fish fauna and aquatic diversity of rivers. Nun River has not been explored earlier for its fish fauna. This is the first attempt made to explore the fish faunal diversity of Nun River. Since this small study area is rich in aquatic faunal diversity, hence its conservation must be given priority.