First reliable record of the blue-lined octopus, Hapalochlaena fasciata (Hoyle, 1886) (Cephalopoda: Octopodidae), from Jeju Island, Korea

A specimen of the blue-lined octopus, Hapalochlaena fasciata (Hoyle, 1886) was collected from a tidal pool on the southern coast of Jeju Island, Korea, on 10 September 2015 and identified by DNA barcoding. This species is characterized by its blue middle lines on dorsal and lateral mantle and head, with development of numerous small papillae on the mantle, head, and arms. A molecular analysis of the mitochondrial DNA cytochrome oxidase subunit I gene showed that the specimen belonged to H. fasciata with 98.8% sequence similarity. The proposed Korean name is “Pa-ran-seon-mun-eo”. The present study far expanded the geographic distribution of H. fasciata, and further monitoring is to be made for this venomous octopus species.