Taxonomic diversity of groundwater harpacticoida (Copepoda, crustacea) in southern France. A contribution to characterise Hotspot Diversity Sites

Hotspot Diversity Sites (HDS) are characterised by high taxonomic richness and high numbers of rare (generally endemic) species; for troglobitic fauna the number of stygobitic species is also an important aspect. Additional criteria for definition of HDS are proposed here, based on the taxonomic diversity of entire subterranean faunal assemblages, i.e. the use of the indices of Average Taxonomic Distinctness and the Variation in Taxonomic Distinctness as well as the number of supra-specific taxa such as genera and families. To exemplify our approach we compared assemblages of harpacticoid copepod microcrustaceans as a focal group. We analysed 44 data sets from both groundwater and surface-water sites with special emphasis on 9 sites from southern France (Moulis in Ariège). The origin and development of the taxonomic diversity of the harpacticoid assemblages from Moulis area are analysed using phenetic and cladistic methods. The colonisation process of subsurface habitats within this area is a repetitive process occurring over long periods of time. Four sites in southern France, the Baget and the Goueil di Her (Karstic systems) and the Lachein and the Nert (alluvial interstitial areas) are recognised as HDS; three others are located in non-karstic areas of Central Europe (southern Germany and eastern Austria) and South America (Central Brazil)