Cladocera (Branchiopoda, Anomopoda, Ctenopoda, and Onychopoda) from Sicilian inland waters: an updated inventory

An extensive survey aimed at updating and increasing the knowledge on species richness and distribution of Cladocera (Branchiopoda) in Sicily has been carried out in the period 2000-2004. More than 250 water bodies, mainly temporary, have been sampled on the whole Sicilian territory and the circum-Sicilian islands. This sampling effort led to the discovery of several species new to the fauna of the island and, coupled with a careful bibliographic review, allowed the realization of an updated checklist that includes 57 species definitely present on the island (only 33 were formerly known), and two more, whose actual presence in Sicily is dubious and needs confirmation. The chorological spectrum of the Sicilian cladoceran fauna shows a predominance of taxa with a wide distribution, but several others with a strictly Mediterranean range are also present. A slightly major affinity of the Sicilian cladoceran fauna with the Tunisian one, rather than with that inhabiting the water bodies of the Italian mainland, was observed. Moreover, the lack of detailed information on cladoceran species richness and composition in Tunisia does not allow to determine a definitive outline of the affinities and origins of the fauna on the island. Nevertheless, the island, located in the middle of the Mediterranean basin, represents a pivotal point in this area, characterized by high biodiversity indices.