Oxynoemacheilus mediterraneus ( Erk‘akan, Nalbant & Özeren 2007 )

Yoğurtçuoğlu, Baran, Kaya, Cüneyt & Freyhof, Jörg, 2022, Revision of the Oxynoemacheilus angorae group with the description of two new species (Teleostei: Nemacheilidae), Zootaxa 5133 (4), pp. 451-485 : 468-469

Oxynoemacheilus mediterraneus ( Erk‘akan, Nalbant & Özeren 2007)

( Fig. 11 )

Barbatula mediterraneus Erk‘akan, Nalbant & Özeren 2007: 74, Fig. 5 (type locality: Eğirdir, Çandir, Aksu Stream, 37°38‘N, 30°31‘E, Turkey)

Material examined. FFR 1529, 15, 53–73 mm SL; Turkey: Isparta prov.: Gökdere stream 5 km downstream of Lake Kovada , 37.5766 30.8120 .— FFR 1367, 4, 50–62; FFR 15605, 4, 65–66 mm SL; Turkey: Antalya prov.: Gökdere stream 8 km southeast of Aşağıyumrutaş , 37.5209 30.7844 .— FFR 15606, 3, 35–51; FSJF 3111 , 4 , 42–48 mm SL; IUSHM 2021-1431 , 4 , 41–48 mm SL; Turkey: Antalya prov.: Köprüçay at Belkıs, 3 km east of Serik Aspendos bridge, 36.9142 31.1621 .— FSJF 2314 , 1 , 61 mm SL; Turkey: Burdur prov.: Aksu River below bridge north of Kayadibi , 37.2276 30.7989 .— FSJF 3029 , 8 , 40–47 mm SL; IUSHM 2021-1425 , 11 , 32–44 mm SL; Turkey: Antalya prov.: Çığırgan stream 1 km north of Gebiz , 37.1272 30.9131 .

Additional distribution records. Van Neer et al. 2008: 37.2592 30.7881, 37.0872 30.8953; Küçük et al. 2009: 37.7771 30.8725, 37.0100 31.2049; Yoğurtçuoğlu et al. 2021a: 32.1272 30.9131, 32.2276 30.7989; Erk’akan 2012: 37.6333 30.5167; unpublished records: 37.5300 31.2700.

Diagnosis. Oxynoemacheilus mediterraneus is distinguished from all species of the O. angorae species group by having a deeply emarginate caudal fin in which the shortest middle caudal-fin ray is 65–76% of the longest ray of the upper caudal-fin lobe (vs. moderately emarginate to almost truncate, 84–93 in O. anatolicus , 88–92 in O. angorae , 83–91 in O. eregliensis ; 72–82 in O. germencicus , and 71–85 in O. isauricus ; see details for other species below). It is further distinguished by a combination of characters not unique to the species: body depth slightly decreasing or almost uniform between the dorsal- and caudal-fin base (depth of caudal peduncle 85–92% of body depth at anterior-most dorsal fin base vs. 68–79 in O. anatolicus , 70–83 in O. angorae and O. eregliensis , 72–82 in O. germencicus , 60–77 in O. isauricus ), elongated blotches on flank being usually connected to the saddles on the back, meeting contralateral on flank (vs. usually disconnected), caudal peduncle depth 1.2–1.5 times in its length (vs. 1.5–1.8 in O. angorae and O. germencicus , 1.5–1.9 in O. eregliensis , 2.2–2.6 in O. isauricus ). It is further distinguished from O. anatolicus by a narrower interorbital distance (26–35% HL vs. 33–40) and from O. angorae by lacking a depigmented stripe along the anterior part of the lateral line (vs. usually present).

Distribution. Oxynoemacheilus mediterraneus is widespread in the Aksu and Köprüçay drainages in the Gulf of Antalya (Mediterranean basin).

Remarks. Our molecular data suggested that Oxynoemacheilus mediterraneus is separated from O. nasreddini by a minimum K2P distance of only 1.2% in the mtDNA COI barcode region. The two taxa are, however, well distinguished morphologically ( Yoğurtçuoğlu et al. 2021a). In addition, loaches from Lake Eğirdir basin are identified as O. nasreddini , despite the analysis of their mtDNA COI, which placed them within O. mediterraneus . Yoğurtçuoğlu et al. (2021a) suspect that this disagreement between morphological and mtDNA data might be due to a past introgressive hybridization between O. mediterraneus and O. nasreddini .

Figures

FIGURE 5. Oxynoemacheilus eregliensis, from top: FFR 15612, 57 mm SL; Aslandoğmuş spring; FSJF 3116, 64 mm SL; Manavgat River; not preserved, about 60 mm SL, same data as FSJF 2326; stream at Kıreli; not preserved, about 70 mm SL, same place as FSJF 2267; Eflatun Pınarı; FSJF 2003, 48 mm SL; Ibdala stream.

FIGURE 11. Oxynoemacheilus mediterraneus, from top: FSJF 3111, 48 mm SL; Köprüçay; FSJF 3029, 45 mm SL; stream Çığırgan; FSJF 2314, 61 mm SL; Aksu River.