Xiphoarcturus - A new genus and two new species of the family Antarcturidae (Isopoda: Valvifera) from the Mar del Plata submarine canyon and its phylogenetic relationships

Abstract

Xiphoarcturus kussakini gen.n., sp.n. and Xiphoarcturus carinatus gen.n., sp.n. are described from the Mar del Plata submarine canyon, South-West Atlantic Ocean. The new genus Xiphoarcturus has an elongate endopod of the uropod that extends to the end of the acuminate pleotelson; this elongate endopod is a novel character for the family Antarcturidae. A parsimony analysis based on 40 morphological characters for 20 species of the family Antarcturidae was performed. The consensus tree clusters Xiphoarcturus gen.n. with the genera Mixarcturus, Chaetarcturus, Fissarcturus and the species Acantharcturus acutipleon. The relationships among the genera Acantharcturus, Cylindrarcturus, Chaetarcturus, Fissarcturus, Furcarcturus, Glaberarcturus, Globarcturus and Mixarcturus are discussed. Monophyly was recovered to all the genera except for Acantharcturus, which resulted paraphyletic in all the trees obtained.