Macro Symbionts of Jellyfish Reported in the Coastal Waters of Sri Lanka

Both macroscopic vertebrates and invertebrates associated with jellyfishes in Sri Lankan waters were surveyed in 2017, as their interactions had not been studied before. In the survey, young teleost fishes were observed to be swimming together with medusae of Phyllorhiza punctata, and the absence of mesoglea in the stomach contents of the teleost Carangoides praeustus confirmed that the association is not a predatory relationship, but could be commensalism. Similar swimming behaviour was observed in the teleost Gnathanodon speciosus with the medusa, Acromitus flagellatus using underwater footage. Further, an association of the brittle star Ophiocnemis marmorata with jellyfishes, Marivagia stellata and Mastigias sidereus, was also reported in this study from Sri Lankan waters, and this relationship could be kleptoparasitism. Likewise, an assemblage of a copepod, Paramacrochiron sp., with medusae of Lobonemoides gracilis and Rhopilema hispidum was known as parasitism. This study reports, for the first time, the associations of C. praeustus,–P. punctata, G. speciosus,–A. flagellatus, O. marmorata,–M. stellata, O. marmorata,– and M. sidereus.