Origin of the interstitial isopod Microcharon (Crustacea, Microparasellidae) from the western Languedoc and the northern Pyrenees (France) with the description of two new species

The interstitial groundwater genus Microcharon (Crustacea, Isopoda, Microparasellidae) is highly diversified in southern France. A new species, Microcharon boulanouari n. sp. is described from the Aude River, whereas specimens from the Lachein River in the central Pyrenees are reassigned to another species, M. ariegensis new to Science. Microcharon boulanouari n. sp. is closely related to the species of the group rouchi and may belong to the phylogenetic western Mediterranean lineage. The two-step model of colonization and evolution provides an understanding of the origin and age of this stygobite. Microcharon boulanouari n. sp. is derived from marine ancestors that lived in the interstitial littoral shallow bottoms of the Atlantic embayment which covered southwestern France at the very beginning of the early Eocene period. Both the regression of this gulf at the start of the Eocene and the Pyrenees uplift may have played a major role in the evolutionary history through vicariance of Microcharon boulanouari n. sp. and of the northern Pyrenean species of the group rouchi

Origin of the interstitial isopod Microcharon (Crustacea, Microparasellidae) from the western Languedoc and the northern Pyrenees (France) with the description of two new species

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New records of rare males of Cryptocandona vavrai Kaufmann, 1900 (Crustacea, Ostracoda), with further additions to the description of the species

Three males of Cryptocandona vavrai were discovered in geographically distant sites (UK, France, Romania), representing different environments (surface and underground waters). The species may be considered a parthenogen with rare occurrence of single males, the morphology of which was hitherto poorly known. The first complete description of males is given, which, together with comparative descriptions of females from surface waters at the UK site and underground waters at an additional site in eastern France, as well as consideration of the shape and size of the last juvenile stages, permits the presentation of a more complete description and an amended diagnosis of the species. Cryptocandona vavrai takes an intermediate position in the genus, lodged between stygobitic species and the cluster of more primitive C. reducta and C. brehmi. Due to a number of traits (broad calcified inner lamella of the valves, 3rd ramus podomere of the antennule lacking the posterior seta, hook-like shortest terminal seta of the cleaning leg, specific morphology of the male prehensile palps and hemipenis lobes) C. vavrai is fairly easily recognised, although there seems to be considerable intraspecific variation. The comparison between females from surface and underground waters revealed substantial elongation of the apical antennal claws, aesthetascs and the distal claw of the walking leg in the latter population. The major difference recorded among the compared males is the underdevelopment of the external claw z2 on the 3rd endopodial podomere of the antenna in the male from the underground waters in Romania. The revealed variation could indicate that some populations may deserve a separate (sub-specific) taxonomic status. Finally, available data on the distribution and ecology of this species are summarised