A newly recorded brittle star, Amphiura (Amphiura) digitula (H.L. Clark, 1911)(Ophiuroidea: Amphilepidida: Amphiuridae), from Geoje Island, Korea

A newly recorded brittle star, Amphiura (Amphiura) digitula (H.L. Clark, 1911)(Ophiuroidea: Amphilepidida: Amphiuridae), from Geoje Island, Korea

We describe a newly recorded brittle star to South Korea, Amphiura (Amphiura) digitula (H.L. Clark, 1911), that was collected from Geoje Island, at a depth of 47 m. The species is characterized by a small disk, covered by numerous fine scales, small radial shields that are wider than long, a small stumpy hook at the distal end of the radial shield, two tooth papilla, two adoral shield spines, 2nd adoral shield spine longer than other, tapered dramatically toward dull tip, five arms with four proximal arm spines, and two tentacle scales. We also obtained a 657 bp sequence from COI gene and the amplified sequence matched the general DNA barcoding region. The NJ and ML phylogenetic analyses revealed A. (A.) digitula as monophyletic in the Amphiura clade. This species is clearly distinguished from other Amphiura species by morphological characteristics and the mitochondrial COI sequence, and thus represents the sixth Amphiura species reported to occur in Korea.