After ca. 150 years of faunistic and taxonomic research, the branchiopods (Crustacea: Branchiopoda) of Central Asia still remain one of the poorly studied groups, despite their importance for freshwater ecosystems. Within the region, the most actively investigated country is Uzbekistan, containing a large diversity of water bodies. However, to date a large body of published literature devoted to the local branchiopod fauna lacks critical reviews. Here, we aim to summarize the existing knowledge of Uzbek Branchiopoda based on previous studies and original samples collected in twelve regions of Uzbekistan. Of 47 branchiopod taxa collected in this study, two species – Camptocercus uncinatus Smirnov, 1971 and Ilyocryptus spinifer Herrick, 1882 (Cladocera: Anomopoda) – are new records for the local fauna. Also, we confirm the presence of four more rare taxa in Uzbekistan and provide a list of branchiopod records for each province of the country. With the new records, the list of Branchiopoda in Uzbekistan contains 107 species, which are unequally distributed within the country: Karakalpakstan has the richest fauna (82 species), followed by provinces of northeast Uzbekistan (40 or more taxa), while local faunas of Kashkadarya, Khorezm, Navoiy and Syrdarya Provinces include fewer than 25 taxa each. Such inequality might be due to several reasons, of which research effort seems to be the most significant. Faunistic compositions of the species-rich provinces appear to be uniform and are similar to those of West and South Tajikistan, comprising high proportions of cosmopolitan, boreal and thermophilic south temperate/tropical taxa. The best studied cladoceran local faunas of the Karakalpakstan and the Ferghana valley resemble that of Tajikistan and, to a lesser extent, those of the Mediterranean countries. Thus, these local faunas together form West Eurasian cluster, which fits the biogeographic pattern observed in the northern Palearctic. However, final conclusions about Uzbek Branchiopoda and similarity of the local faunas should not be made to date, as our study highlights a lack of research in several regions, taxonomic groups (Anostraca, Notostraca, Spinicaudata) and particular water body types (temporary pools, montane water bodies). Also, faunistic composition might be distorted by cryptic endemism or extinction of some branchiopod species due to environmental changes. We hope that the presented checklist will encourage further faunistic, taxonomic and phylogeographic research in Uzbekistan.
Biogeography, Central Asia, Cladocera, Diversity, Zooplankton
