The occurrence of parasitic copepods and isopods infesting the marine teleost fishes of Kerala coast, India

The present study reports the occurrence of parasitic copepods and isopods infecting marine teleost fishes from the Kerala coast, India. A total of 1795 fishes belonging to 38 species were collected from the fish landing centres across the Kerala Coast for 5 months. The isopod & copepod infection status of these fishes were assessed. The incidents of site-specific infection were documented for all parasites and a fecundity analysis was conducted in randomly selected species. The single or multiple parasitic crustacean infestation and host preference (single or multiple hosts) were also documented. A total of 32 species of copepods and 6 species of isopod were sourced out. However, the maximum prevalence was recorded for the family Lernanthropidae (71.43%) and the maximum intensity (14) was recorded for a Caligid copepod Euryphorus nordmannii. The predominantly targeted region of infection on the host fish appeared to be gill filament (52.15%). The fecundity showed significant differences between the tested species. Fourteen species of fishes showed multiple parasitic crustacean infestation and eight species of parasites infected multiple hosts. The present study demonstrates that over 68% of marine fish species of Kerala coast were under heavy infection either by isopods or copepods.