Revisiting the species list of freshwater fish in Israel based on DNA barcoding

Israel's region forms a continental bridge; hence, the freshwater fish fauna in Israel consists of unique populations of species that originated from Africa, Asia, or Europe and are often endemic or at the edge of their distribution range. Worldwide, fish biodiversity suffers significantly from pressures and disturbances of freshwater habitats, especially in arid regions, such as in parts of Israel. Biodiversity conservation requires efficient tools for monitoring changes in populations. DNA barcoding, by complementing and enhancing species identification, provides such monitoring tools. In this study, over 200 specimens representing over 28 species were DNA barcoded and together with previously available records, a DNA barcoding database for freshwater fish of Israel was established. Of the 71 distinct barcodes generated, 37% were new, attesting to the uniqueness of fish populations in Israel. For most species, morphological and molecular species identifications agreed. However, discrepancies were found for five genera. Based on DNA barcoding, we propose Acanthobrama telavivensis as a junior synonym for Acanthobrama lissneri. In Garra spp., we propose splitting Garra nana into two species and assigning Garra rufa in the region to Garra jordanica, or possibly to two species. Israeli Pseudophoxinus kervillei is not the same species as in Syria and Lebanon. However, Pseudophoxinus syriacus might not be endangered since it is genetically very similar to Pseudophoxinus drusensis. In Israel, instead of five reported Oxynoemacheilus species, combining DNA barcoding with morphology suggests only three. Genetic and geographic separation suggested that Aphanius mento is likely a species complex. The study provides a thorough barcoding database, suggests significant species reconsiderations in the region, and highlights the Sea of Galilee and the Beit She'an valley streams as biodiversity "hotspots." This study will therefore promote further studying of the fish species in the region and their ecology, as well as the monitoring and conservation of freshwater fish biodiversity in Israel and the region. This study established a DNA barcoding database for freshwater fishes in Israel. Molecular and morphological species identifications were compared, and discrepancies were found for samples in five genera, which suggests significant reconsiderations to the species list in Israel and the region. The results highlight the Sea of Galilee and the Beit She'an valley streams as biodiversity "hotspots," promoting further studying of the fish species in the region and their ecology, as well as monitoring and conservation of freshwater fish biodiversity in Israel and the region.image