Abstract
It is proposed to name the Atlantic holothuria Psolidium complanatum Cherbonnier, 1969, whose denomination is already occupied by Psolidium complanatum (Semper, 1867) from the Philippines, as Psolidium bathygalego nom. nov. 843 specimens of Psolidium bathygalego nom. nov., collected between 417 and 1191 m deep in the NW and W of Galicia and in the Galicia Bank, were studied. A detailed description of the external and internal anatomy of Psolidium bathygalego nom. nov. is made by studying the ossicles and the skeletal structure by means of scanning electron microscopy (SEM) as well as the introvert, calcareous ring, retractor muscles, water-vascular system, digestive system, respiratory trees, and reproductive system by means of micro-computed tomography (micro-CT). The habitat, feeding system, and geographical distribution of Psolidium bathygalego nom. nov. are also described.