The loaches of Iran and adjacent regions with description of six new species (Cobitoidea)

About 31 species in eight genera and two families (Nemacheilidae and Cobiti dae) are reported from Iran and adjacent countries (i.e., Iraq, Turkey, Afg hanistan, and Pakistan). Six new species, five from Iran and one from Afgha nistan, are described. Several Iranian loach genera are also found in weste rn Palearctic region (i.e., Sabanejewia, Cobitis, and Orthrias), or eastern Asia (i.e., Schistura). But other genera such as Paracobitis and Seminemac heilus are endemic to, or exclusive of, Middle Asia. Our investigation conf irms the important role of Iranian drainages as a biogeographic bridge betw een western-Palearctic and Oriental fish faunas.