Biodiversité comparée et endémisme des Collemboles (HexapodaCollembola) de deux massifs algériens dans un même contexte bioclimatique

Abstract

Several months of prospecting in the forest of Collo allowed us to perform a series of samples in various edaphic environments in order to enrich our knowledge about soil fauna. The results show an exceptional richness in endemic rare species having a large taxonomic and biogeographic interest. Seventy-one species are identified, of which four are new to science and are described in this work and published. Three of the four new species belong to the same genus: Pseudachorutes deficiens, Pseudachorutes labiatus and Pseudachorutes octosensillatus (neanuridae, Pseudachorutinae.). The fourth new species belongs to the genus Deutonura: Deutonura zana (Collembola: neanuridae: Neanurinae) second species of the same genus in Algeria. This species was collected in Edough and more recently in Collo. Our study reveals the existence of cryptic diversity (not apparent morphologically) between populations of Edough and Collo. This genetic divergence is revealed by the sequencing of the mitochondrial gene COI. This is a case in Neanurinae. Several unidentified species are listed in morphospecies or sp. They are in number of 16, representing 22% of the total number of harvested species. Regarding biogeographical membership of harvested wildlife, 45% of species are widely distributed, 16% are rare or possibly endemic species. One of the original features of this work is the presence of an endemic species (Sensillanura austriaca) from the north’s Alpes so far. The wealth of the massif Neanuridae is much higher than most of other Mediterranean regions (excluding Corsica) sampled significantly. Diversity index indicate that Oued Z'hor is the richest of the four areas surveyed. There is a significant difference in species composition between localities, indicating that according to geographical origin, the same habitat does not present the same specific composition. The result of the comparison of the diversity of the Collembola of the Collo massif to those of the bulk of the Edough shows that there are significant dissimilarities in the faunal composition (33 common species between Collo and Edough). Cases of clear vicariances were detected, the most remarkable one between Edoughnura sp., from Collo and the endemic species of the same kind Edoughnura rara from Edough (Deharveng & KrouaHamra, 2007). The second case is an intraspecific level of a genetic divergence between populations of Deutonura zana of the two massifs. This cryptic diversity suggests that a parapatric area may exist in the north of Azzaba.