Description of the Life Cycle Stages of the Parasitic Cymothoid, Cymothoa indica Schioedte and Meinert, 1884, and Its Prevalence in Commercial Fishes from Chilika Lagoon, India

To study the morphology of all the life stages and the life cycle of the parasitic isopod Cymothoa indica Schioedte and Meinert, 1884, and its prevalence in different commercial fishes in the Chilika Lagoon, India.

From April 2021 to December 2022, different life stages of the said parasites were collected from five different fish species from four localities of the Chilika Lagoon. The parasites were carefully removed from the host with a pair of forceps and then identified following standard literature and description. The morphology of all life stages, life cycle, and prevalence of the isopod C. indica were carried out as per the standard protocol.

A total of 1252 host fishes were analysed. The total prevalence was 44.5%. The host with the highest prevalence of C. indica was Glossogobius giuris, with 58.79% of the hosts parasitized by at least one parasite individual. Followed by the host Datnoides polota (50.98%), Johnius dussumieri (46.25%), Etroplus suratensis (28.45%) and the least prevalence was in Lates calcarifer (14.70%). The description of the life stages is based on the observation of 523 females, 116 males, 46 Juveniles, and 50 embryonic stages of the said parasites.

The description of all the life stages and life cycles certainly helps to identify this species with clarity and ease in understanding the species' biology. In future, this study may be helpful in the effective management towards the improvement of aquaculture productivity.