An overview of Hexabathynella (Crustacea,Syncarida, Parabathynellidae) with the description of a new species

A new species of the cosmopolitan genus Hexabathynella is described from Spain. This new species has four setae on the expopod of the uropod, the rest of the species in the genus have between one and three. The endopod of the uropod has two smooth setae of similar length and one plumose seta, these characters only appear in the new species within the genus. The antennal organ in the males is shown to be a new unique character for the genus. It is the third species of this genus that has been found in Spain. To date the genus consists of 18 species in the world. A key for identification of the 18 species of Hexabathynella is provided. It is the only cosmopolitan genus of Bathynellacea and it is distributed in Europe (nine species), Africa (one species), South America (two species), North America (three species) and Australia and New Zealand (three species).