Biofouling and comparative phylogeographic status of the turtle barnacle Chelonibia testudinaria on various hosts of the Coromandel coast, India

Abstract

Biofouling by the coronuloid barnacle <em>Chelonibia patula </em>(synonimized as<em> C. testudinaria</em>) was observed during the collection and maintenance of live broodstock of a few species of commercially important crustaceans at Mandapam Regional Centre of ICAR-CMFRI located along the Coromandel coast of Tamil Nadu, India. We assessed the genetic identity of <em>C. patula </em>found on the various crustacean hosts (<em>Panulirus polyphagus</em>, <em>Portunus pelagicus</em> and <em>Charybdis natator</em>) and turtle, olive ridley (<em>Lepidochelys olivacea</em>) from the Gulf of Mannar Biosphere Reserve. The phylogeographic studies of turtle barnacles from all potential hosts, carried out across world oceans about their species paradox, do not represent collection record from India and hosts like lobsters and olive ridleys. The mitochondrial Cytochrome <em>c</em> oxidase subunit 1 (COI) analysis of this epibiont from various hosts indicated that species from the south-east coast of India belong to the Indian Ocean/Western Pacific clade of <em>C. testudinaria</em>. The very low K2P genetic distance (0.008) between <em>C. patula</em> and <em>C. testudinaria</em>, on comparison with existing GenBank records, supports this finding. The phylogeographic structuring and evolutionary divergence between the clades of <em>C. testudinaria</em> with COI sequence data indicated that the Indian Ocean/Western Pacific and Eastern Pacific clades are the most divergent.