Pongycarcinia xiphidiourus n. gen. n. sp., a new Brazilian Calabozoidae (Crustacea Isopoda)

The discovery of a second species of Calabozoidae, in a cave of an ancient karstic zone of the Bahia State (Brazil), provides new insights into the suborder Calabozoidea, described by VAN LIESHOUT in 1983 and represented until now by a single species Calabozoa pellucida Van Lieshout 1983 inhabiting the subterranean waters of Venezuela. The new finding expands the distribution range of the suborder and permits further studies to clarify its uncertain phylogeny. It also demonstrates a greater diversity of the isopod taxa in Brazilian subterranean waters than previously known. This suggests that a more detailed search would increase the chances of finding further interesting specimens of Crustacea in this region. The belonging of the newly discovered specimens to a new genus and species Pongycarcinia xiphidiourus is justified by the presence of peculiar characters, such as the shape of the second male pleopod and of some structures of the stomach. The two theories of the phylogeny of this isopod taxon, one linking it to the suborder Asellota through common ancestors, the other considering it more closely related to Oniscoidea, are discussed.