Two new Oxynoemacheilus species in western Anatolia (Teleostei, Nemacheilidae)

Oxynoemacheilus sakaryaensis sp. nov. , is restricted to the Sakarya River basin, and O. melenicus sp. nov. , is distributed in both the Sakarya River and Büyükmelen Stream. Oxynoemacheilus sakaryaensis is distinguished by having a flank plain or with numerous irregularly shaped pale brownish bars and a caudal-peduncle depth 2.8–3.2 times in its length. Oxynoemacheilus melenicus is distinguished by having a flank with 10–13 irregular shaped brownish bars or blotches and the caudal peduncle depth 1.9–2.8 times in its length. Oxynoemacheilus banarescui , O. samanticus , O. simavicus , O. fatsaensis , O. sakaryaensis , and O. melenicus are valid, which belong to the O. bergianus species group. O. melenicus and O. sakaryaensis were differentiated from all other Oxynoemacheilus species in western Anatolia by two diagnostic and unique nucleotide substitution sites in the COI barcoding region. Also, species delineation tests (ABGD, GMYC, ASAP) and phylogenetic analyses support the validity of O. melenicus and O. sakaryaensis as distinct species.