Updated checklist and distribution of large branchiopods (Branchiopoda: Anostraca, Notostraca, Spinicaudata) in Tunisia

Abstract

Temporary ponds are the most peculiar and representative water bodies in the arid and semi-arid regions of the world, where they often represent diversity hotspots that greatly contribute to the regional biodiversity. Being indissolubly linked to these ecosystems, the so-called “large branchiopods” are unanimously considered flagship taxa of these habitats. Nonetheless, updated and detailed information on large branchiopod faunas is still missing in many countries or regions. Based on an extensive bibliographical review and field samplings, we provide an updated and commented checklist of large branchiopods in Tunisia, one of the less investigated countries of the Maghreb as far as inland water crustaceans are concerned. We carried out a field survey from 2004 to 2012, thereby collecting 262 crustacean samples from a total of 177 temporary water bodies scattered throughout the country. Large branchiopod crustaceans were observed in 61% of the sampled sites, leading to the identification of fifteen species. Among these, the halophilic anostracan Branchinectella media is here reported for the first time for the country; conversely, four of the species reported in literature were not found during the present survey. Based on literature and novel data, the known large branchiopod fauna of Tunisia now includes 19 species, showing a noteworthy species richness when the limited extension of the country is considered. For each species, the regional distribution is described and an annotated list of references is provided. Under a conservation perspective, the particular importance of the temporary ponds occurring in the Medjerda river alluvial plain is further stressed. In this location, several large branchiopod taxa with different ecological requirements converge and form unique and species-rich assemblages that should be preserved.