Ichthyofaunal Diversity of Korappuzha and Kanayankode Rivers, Kozhikode, Kerala, India

The present study documents the fish diversity of the Korappuzha and Kanayankode rivers in Kozhikode district. Collections were conducted over a period of six months, from January to June 2024, using cast nets, drift nets, and hooks and lines. A total of 21 species, belonging to 8 orders and 18 families, were recorded, with the order Perciformes exhibiting the highest diversity. Gerres filamentosus was the most abundant species in the Korappuzha River, while Etroplus suratensis dominated in the Kanayankode River. The Shannon–Wiener biodiversity index (2.26–2.86) indicated a high level of diversity in both rivers. Notably, Horabagrus brachysoma and Hyporhamphus xanthopterus, species classified as Vulnerable by the IUCN, were also recorded. This study highlights the biodiversity and conservation significance of these river ecosystems.