Disentangling an Asian puzzle: Two new bathynellid (Crustacea, Syncarida, Parabathynellidae) genera from Vietnam

Abstract

In this paper the 17 asiatic species of the family Parabathynellidae are reviewed from a taxonomic point of view using bibliographic data. Two new genera and two new species are described from caves in Vietnam. Paraeobathynella n. g. presents a unique combination of characters (antennule: seven segments; antenna: six segments; mandible: pars incisiva with five teeth and pars molaris with 10 teeth; maxillule: distal endite with seven claws; exopod of the thoracopods with three or more segments and epipods present in thoracopods 3–7; pleopods absent; endopod of the Th 8 male with two setae; seven spines on the sympod and two spines on the endopod of the uropod and the small minimum size of the adult body) and exclusive characters like the Th 8 female having two small spines and one long seta and the general size and aspect of the Th 8 male and its lobes. Sketinella n. g. presents a unique combination of characters (antennule: eight segments; antenna; six segments; mandible: pars incisiva with six teeth and pars molaris with eight teeth: maxillule: distal endite with seven claws; exopod of the thoracopods with three or more segments and epipods present in Th 3–7; endopod of the thoracopod 8 male with two setae; 12 spines on the sympod and two spines on the endopod and seven setae on the exopod of the uropod) and characters exclusive to the asiatic species are: a pair of pleopods reduced to a single seta; a very distinctive basipod and outer lobe of the Th 8 male and an exopod of the Th 8 male with a small tooth or protuberance. This is the first time that the Parabathynellidae has been found in Vietnam, this find extends the range of distribution of this family in Asia.

Keywords:

• Parabathynellidae
• subterranean waters
• Syncarida
• Vietnam

Acknowledgements

We gratefully acknowledge B. Sket and P. Trontelj, who have provided the material which has made this work possible. C. Puch and A. G. Valdecasas who have helped us in different ways. We thank Mark Creb who helped us with the English translations. This work was supported by project EVK2‐CT‐2001‐00121 (European Projects PASCALIS) and Convenio Junta de Castilla y León and CSIC.