New Records of Species of Holophryxus Richardson, 1905 (Crustacea: Isopoda: Dajidae) from the Atlantic and Pacific Oceans with Comments on Taxonomic Issues in the Genus

Abstract The dajid parasite Holophryxus alaskensis Richardson, 1905a is reported from Pasiphaea pacifica Rathbun, 1902 collected at 1,200 m depth near Baja California, Mexico. This represents the southernmost record for this species at approximately twice the depth of prior records. A juvenile specimen of Holophryxus attached to Parapasiphae sulcatifrons Smith, 1884 collected at 1,625 m depth from the Bear Seamount (an underwater volcano in the western Atlantic Ocean) was found to be similar in morphology to juveniles of H. alaskensis. However, it is also not possible to determine whether it is conspecific with either of the known Atlantic species of Holophryxus (H. acanthephyrae Stephensen, 1912a and H. richardi Koehler, 1911). This is the first record of P. sulcatifrons as a host for any epicaridean. Finally, H. acanthephyrae is reported for the first time from off the Bahamas, where it was found on Acanthephyra pupurea A. Milne-Edwards, 1881 collected at 2,134 m depth. A discussion of the global distribution and taxonomic issues in the genus Holophryxus is provided.