New insights into the phylogeny of Carasobarbus Karaman, 1971 (Actinopterygii, Cyprinidae) with the description of three new species

Abstract Fishes from the genus Carasobarbus , widely distributed throughout the river systems of North Africa and West Asia, are commonly referred to as Himris. In the Persian Gulf basin, they are widespread and are also found in fast-flowing rivers or the deeper regions of lakes. In this region, representation of these fishes in scientific collections is scarce, and except for C. luteus , the other species are very poorly documented and frequently misidentified due to their similarities. In this study we analysed the relationships among Carasobarbus species using mitochondrial genes (Cyt b , COI) and present morphological characters based on examinations. Our results revealed three new species which we describe here. Carasobarbus doadrioi, new species, is distinguished by 40–44 scales on the lateral line and a prominent black blotch on end of caudal peduncle in specimens < 85 mm SL. Carasobarbus hajhosseini , new species is distinguished by 32–34 scales on the lateral line and long head length (20–24% SL). Carasobarbus saadatii , new species, is distinguished by 38–40 scales on the lateral line and short head length (19–20% HL). In the Persian Gulf basin, Carasobarbus species exhibit uncorrected genetic distances of 1.6 to 5.5% in the COI barcode region and 2.6% to 9.9% in the Cyt b gene. This study highlights the importance of investigating the unexplored diversity that exists within poorly sampled and understudied freshwater fish group. Such investigations are essential for developing a comprehensive understanding of the true extent of biodiversity, which is critical for informing effective conservation and protection strategies.