Hidden in the dark: A new record and species of cave-dwelling Palaumysis (Crustacea, Mysidacea) from Sipadan Turtle Tomb, Malaysia, with identification keys to world species

A new species of the cave-dwelling mysid genus Palaumysis Bacescu & Iliffe, 1986 is described from the marine cave Turtle Tomb, Sipadan Island, Sabah, Malaysia. This represents the first record of the genus from Malaysian waters. The new species belongs to the group of Palaumysis species characterized by a reduced carapace, exposing the last five thoracic somites, but is distinguished from its congeners by the combination of adult body size exceeding 2.5 mm, a 5-segmented inner flagellum of the antennule, and the absence of fine hairs on the male fourth pleopod. Palaumysis jetama sp. nov . is currently known only from the type locality. A revised identification key to all currently known species of Palaumysinae is presented.