The starfish Phataria unifascialis is widely distributed in the eastern cost of the Pacific Ocean, found on rocky bottoms, at depths between 0 and 50 m. The original description of P. unifascialis made by Gray in 1840 was brief and inaccurate in some important aspects, such as distribution area, plate arrangement and ambulacral spines. Here, we improve the description of P. unifascialis with SEM images and description of its mesodermal skeleton on the basis of a large sample. Rev. Biol. Trop. 65(Suppl. 1): S258-S271. Epub 2017 November 01.

Keywords: Asteroidea, Ophidiasteridae, Phataria unifascialis, redescription, SEM, Eastern Pacific.