A new record of sea star genus Pteraster (Asteroidea: Velatida: Pterasteridae) from the East Sea, Korea

Family Pterasteridae is almost exclusively from deep water and is of worldwide distribution (Clark and Downey, 1992), and is composed of eight genera: Amembranaster Golotsvan, 1998, Benthaster Sladen, 1882, Calyptraster Sladen, 1882, Diplopteraster Verrill, 1880, Euretaster Fisher, 1940, Hymenaster Thomson, 1873, Hymenasterides Fisher, 1911, and Pteraster Müller & Troschel, 1842 (Mah and Hansson, 2015). Species of this family usually have stout thick body, inflated dorsal surface, and supra­ dorsal membrane forming a cover over dorsal surface. They have a hole in the middle of disc called osculum, which can be used to expel mucus for defending against predators, like many other members of the order Velati­ da (Mah, 2010). Genus Pteraster comprises 46 species of which P. tesselatus Ives, 1888 distributed Korea, Ja­ pan, and North Pacific Ocean have been reported in Ko­ rean fauna (Shin, 2010).