Two new species of Thermosbaenacea (Peracarida, Halosbaenidae and Monodellidae) from southern France

Abstract

Two new species of Thermosbaenacea are described from various locations in southern France. One species is Limnosbaena occidentalis n. sp., a species that has been known since 1967 and has long been awaiting a formal description, the other is Tethysbaena exigua n. sp., a very small species that represents a new species-group within the genus and has more morphological affinities with the Caribbean Tethysbaena sanctaecrucis species-group than with any other group. Furthermore, some considerations about the origin and ecology of these species are given. Three species distributed over the families of Halosbaenidae and Monodellidae are now known in France within a radius of 80 km around Marseille, one of which has also been identified in the alluvial aquifer of the Dordogne river. Two new species of Thermosbaenacea are described from various locations in southern France. One species is Limnosbaena occidentalis n. sp., a species that has been known since 1967 and has long been awaiting a formal description, the other is Tethysbaena exigua n. sp., a very small species that represents a new species-group within the genus and has more morphological affinities with the Caribbean Tethysbaena sanctaecrucis species-group than with any other group. Furthermore, some considerations about the origin and ecology of these species are given. Three species distributed over the families of Halosbaenidae and Monodellidae are now known in France within a radius of 80 km around Marseille, one of which has also been identified in the alluvial aquifer of the Dordogne river.