M. Rajkumar, R. Aravind, J. Praveen Raj, N. Artheeswaran and Amith P. Pandey
Abstract
The association of juvenile of carangids with jellyfish as a temporary commensalism to protect the fishes from predators. The study were carried out in August 2012 in the Mandapam region of Palk Bay at 79° 17' E to 79° 8' E longitudes and 9° 17' N latitude. We reported that juveniles of carangid (Caranx sp.) association with scyphozoan jellyfish (Rhopilema sp.) in the coral reef habitats of Palk Bay. The juvenile Caranx sp. and jellyfish (Rhopilema sp.) association were observed in a 45 minutes session of SCUBA diving in a depth range from 9 to13 m. In order to avoid predation of juvenile carangids by predators, it hides in the vicinity of jellyfish tentacles as a shield. It was also observed and recorded that juvenile fishes were not found in the jellyfish diet through the gut content analysis. Hence, our observation proved that, the commensal relationship between jellyfish and juveniles of carangid will help to sustain carangid fish stock in the coral reef habitats. The loss of such commensal relationship by overfishing and anthropogenic activities on the coral reef habitats of Palk Bay lead to imbalance effect on ecosystem.