Origin, diversity and distribution of freshwater epigean amphipods in Maghreb

Northern Africa, although one of the world hotpots of biodiversity, is poorly studied and the freshwater fauna living in this part of the world remains partly unknown. This study focused on the diversity and distribution of the poorly known epigean freshwater amphipods. We performed an exhaustive analysis of the literature on this group of crustaceans and sampled 106 additional localities from the eastern part of Algeria and in Tunisia. Our results showed an important diversity with 25 species (including the presence of at least three new undescribed species) and a very high rate of endemism with 52% of species occurring at on only 1 or 2 sites. We also highlighted a very low diversity on each site with only 4.4% of sites harboring more than 1 species. The comparative distribution of certain species between Europe and Maghreb and also between the western and eastern part of Northern Africa allow us to discuss some hypotheses about the factors underlying this endemism and the biogeographical origin of species. However, our study revealed a general lack of knowledge in the region, especially in the South of Morocco and Algeria. Hence, more information would be needed to propose adapted conservation strategies of freshwater fauna in Maghreb. Our results showed theimportant diversity of Maghreb despite the scarcity of fresh waters and the weak knowledge on this area. We highlighted a very high rate of endemism with 52% of species occurring at on only 1 or 2 sites. We found enough data to discuss some hypotheses about the factors underlying this endemism and the biogeographical origin of species.