Description of a new species of Pericelis (Polycladida, Diposthidae) from sunken wood in the bathyal zone in Japan

We describe Pericelis nivea sp. nov. from sunken wood collected 330 m deep, off the coast of Owase, Japan. This is the first record of Pericelis from the bathyal zone. Unlike other congeners, P. nivea sp. nov. is characterized by the absence of eyespots. We provide a partial sequence of the mitochondrial cytochrome c oxidase subunit I gene as a DNA barcode for the new species. Phylogenetic analyses based on concatenated sequences of nuclear 18S and 28S ribosomal DNA showed that P. nivea sp. nov. was nested in the clade of Pericelis with high support; however, the relationship between P. nivea sp. nov. and other Pericelis species was unclear.