Oxynoemacheilus isauricus Yoğurtçuoğlu, Kaya, Özuluğ & Freyhof 2021

(Fig. 10)

Oxynoemacheilus isauricus Yoğurtçuoğlu, Kaya, Özuluğ & Freyhof 2021:372, Figs. 2–4 (type locality: Lake Beyşehir Basin, stream Çeltek at Çeltek, south of Şarkikaraağac, 38.0124 31.3152)

Material examined. IUSHM 2021-1425, holotype, 63 mm SL; IUSHM 2021-1463, paratypes, 48–53 mm SL; Turkey: Isparta prov.: Çeltek stream at Çeltek, south of Şarkikaraağaç, 38.0124 31.3152 .— FFR 1534, 9, 46–56 mm SL; Turkey: Konya prov.: Akçay stream at Gökçehüyük, 3 km west of Seydişehir, 37.4396 31.8000 .

Diagnosis. Oxynoemacheilus isauricus is distinguished from all other species of the O. angorae group by having a very slender caudal peduncle (caudal peduncle depth 2.2–2.6 times in its length vs. 1.3–1.6 in O. anatolicus, 1.5–1.8 in O. angorae and O. germencicus, and 1.5–1.9 in O. eregliensis; see details for other species below). It is further differentiated from O. anatolicus, O. angorae and O. eregliensis by possession of a shorter head (head length 21–24% SL vs. 24–27 in O. anatolicus; 23–26 in O. angorae and 24–26 in O. eregliensis), a moderately deep emarginate caudal fin (vs. slightly emarginate or almost truncate) in which the shortest middle caudal-fin ray is 71–85% of the longest ray of the upper caudal-fin lobe (vs. 84–93 in O. anatolicus; 88–92 in O. angorae and 83–91 in O. eregliensis), and no depigmented stripe along the anterior part of the lateral line (vs. present in O. angorae). Oxynoemacheilus isauricus is further distinguished from O. germencicus by lacking scales on the belly (vs. present).

Distribution. Oxynoemacheilus isauricus is known from Lake Beyşehir and Suğla basins in Central Anatolia

Remarks. Based on DNA barcoding, O. isauricus is well separated by a minimum K2P sequence divergence of 7.5% and 8.0% in the mtDNA-COI barcode region from O. axylos and O. eregliensis, its closest relatives. It is also supported to be a distinct species by the PTP approach, and by the mPTP delimitation.