Integrated Taxonomic Approach for Identification of Octopus Species from the Southwest Coast of India

ABSTRACT Cephalopods are a commercially important resource for the Indian coast. Species of Octopus alone account for around 10% of the global cephalopod fishery and roughly 3% of Indian fisheries. Proper identification of cephalopods in the field is difficult, and accurate identification of species is important for conservation as well as for sustainable fisheries management of octopus species. With a view to identify and genetically catalogue the octopus species from the southwest Indian coast, 28 specimens were collected from different landing centres in the region and identified morphologically. Molecular characterization was done with partial sequence information from the mitochondrial Cytochrome C Oxidase-I (COI) gene. All the specimens analysed in the study belong to the family Octopodidae. The specimens were identified as four species of Amphioctopus: Amphioctopus neglectus, A. marginatus, A. aegina and A. rex, and two Cistopus: Cistopus indicus and C. taiwanicus, as well as, Octopus vulgaris and Callistoctopus macropus. In the present study, Octopus vulgaris showed genetic similarity with Octopus vulgaris Type III but with 1% divergence from Octopus vulgaris Type II and 3% divergence from Octopus vulgaris Type IV.