Five marine fish host and parasitic isopods genera(Cymothoidae) new distributional record from the Chennai coast, southeast India

The study was conducted along the Chennai coast from March2025 to August 2025 and examined 850 marine fish specimens representing 6 species, and 365 fish were found to be infested with parasitic isopods. They are totalling 250 individuals of 6 cymothoid species. The species identified are Mothocya plagulophora (Haller, 1880), Mothocya collettei (Bruse, 1986), Nerocila sigani (Bowman & Tareen, 1983), Catoessa boscii (Bleeker,1857), Joryma sawayah (Bowman & Tareen, 1983), and Norileca indica (H. Milne Edwards, 1840). Among these, Norileca indica exhibited the highest prevalence, parasitizing species such as Rastrelliger kanagurta and Selar crumenophthalmus. This study shows the variety and specific hosts of cymothoid isopods along the Chennai coast, providing important information for understanding marine parasite in Indian waters.