Petroleuciscus, a new genus for the Leuciscus borysthenicus species group (Teleostei: Cyprinidae)

Abstract. Petroleuciscus gen. n. (type species Squalius borysthenicus Kessler, 1859) is erected for 6 species from the former subgenus Squalius of the genus Leuciscus (= Leuciscus cephalus complex sensu Bianco, 1983). It is distinguished by the reduced number of vertebrae (total vertebrae modally 34-38), few sensory cephalic pores (7-10 in the supraorbital canal), relatively small supraethmoid-mesethmoid block, narrow infraorbitals, and deep neurocranium with a normally developed interorbital septum.