Oxynoemacheilus eliasi, Yoğurtçuoğlu & Kaya & Freyhof, 2022

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 : 478-481

Oxynoemacheilus eliasi , new species

( Figs. 18–20 )

Holotype. FFR 15619, 51.4 mm SL; Turkey: Izmir prov.: inlet of Tahtalı Reservoir, under Şaşal bridge, 38.1990 27.1705.

Paratypes. FFR 15581, 21, 35–43, same data as holotype.— FSJF 1878 , 6 , 28–56 mm SL; Turkey: Izmir prov.: Şaşal stream south of Şaşal, a tributary of Tahtalı reservoir, 38.1991 27.1358 .

Additional material. FSJF 2016 , 15 , 45–56 mm SL; Turkey: Manisa prov.: Gördeş stream at Gölmarmara , 38.7434 27.9293 .— FSJF 2324 , 4 , 49–50 mm SL; Turkey: Manisa prov.: stream between Salihli and Ahmetli, about 6 km southwest of Salihli , 38.4702 28.0579 .— FSJF 3699 , 2 , 37–45 mm SL; Turkey: Izmir prov.: Den stream 1.5 km south of Küner , 38.1991 27.1358 .— FSJF 3704 , 48 , 32–64 mm SL; Turkey: Izmir prov.: Tire stream 20 km west of Ödemiş , 38.2354 27.7435 .

New material used in molecular genetic analysis. FSJF-DNA 273 ; Turkey: Manisa prov.: stream between Salihli and Ahmetli, about 6 km southwest of Salihli , 38.4702 28.0579 (GenBank accession numbers: ON123681 ) .— FSJF-DNA 2829 ; İzmir prov.: Den stream 1.5 km south of Küner , 38.1991 27.1358 (GenBank accession numbers: ON123693 , ON123694 , ON123695 ) .— FSJF-DNA 2856 ; Turkey: İzmir prov.: Develi stream 1 km south of Develi , 38.2004 27.1713 (GenBank accession numbers: ON123701 ) .— FSJF-DNA 2882 ; Turkey: İzmir prov.: Tire stream 20 km west of Ödemiş, a tributary of Küçük Menderes flowing into the Zeytinova Reservoir, 38.2354 27.7434 (GenBank accession numbers: ON123703 , ON123704 , ON123705 ) .

Diagnosis. Oxynoemacheilus eliasi is distinguished from other species of O. angorae group by a combination of characters, none unique. It is distinguished from O. theophilii by having a decreasing body depth between the dorsal- and caudal-fin bases (vs. almost uniform), the depth of the caudal peduncle is 79–87% of the body depth at the anterior-most dorsal fin base in O. eliasi (vs. 87–99 in O. theophilii ).

Oxynoemacheilus eliasi is distinguished from O. germencicus by having a stouter caudal peduncle (caudal peduncle depth 1.3–1.5 times in its length vs. 1.5–1.8), small, isolated and embedded scales on the belly usually reaching from between the pelvic fin bases to the midline between the pectoral- and pelvic-fin origins (vs. scales on belly restricted between pelvic fin bases, rarely exceeding slightly to the front).

The new species is distinguished from O. anatolicus , O. angorae , O. eregliensis , O. axylos and O. mediterraneus by possessing an emarginate caudal fin in which the middle caudal-fin ray 71–84% of the length of the longest caudal-fin ray (vs. almost truncate, 84–93 in O. anatolicus , 88–92 in O. angorae , 83–91 in O. eregliensis , 88–98 in O. axylos , and deeply emarginate 65–76 in O. mediterraneus ). It is further distinguished from these species by having small isolated scales on the belly (vs. absent) and from O. angorae by the caudal peduncle depth 1.3–1.5 times in its length (vs. 1.5–1.8), and irregularly shaped and set blotches on the flank, forming a mottled or marbled pattern (vs. a series of dark-brown midlateral blotches usually fused into a wide, irregular shaped midlateral stripe, rarely a mottled pattern), and no depigmented stripe along the anterior part of the lateral line (vs. usually present).

Oxynoemacheilus eliasi is further differentiated from O. eregliensis by the caudal peduncle depth 1.3–1.5 times in its length (vs. 1.5–1.9), and from O. mediterraneus by the slowly decreasing body depth between the dorsal- and caudal-fin bases (vs. not decreasing).

Oxynoemacheilus eliasi is distinguished from O. isauricus by having small isolated scales on the belly (vs. absent), the caudal peduncle depth 1.3–1.5 times in its length (vs. 2.2–2.6), a long head (head length 24–26% SL vs. 21–24), and the prepelvic length 52–56% SL (vs. 48–51).

The new species is distinguished from O. nasreddini by the caudal peduncle depth 1.3–1.5 times in its length (vs. 1.5–2.1), and irregularly shaped and set blotches on the flank, forming a mottled or marbled pattern (vs. a series of vertically elongated midlateral blotches).

Description. See Figures 18–20 for general appearance and Table 4 for morphometric data. Small-sized and slender species. Head long, body depth at dorsal-fin origin 1.2–1.4 times in head length. Body deepest at behind vertical of midline between dorsal-fin origin and nape and widest at pectoral fin base. Body depth slowly decreasing between dorsal- and caudal-fin bases. Section of head roundish, flattened on ventral surface, slightly convex in interorbital space, convex on snout. Snout roundish. Caudal peduncle compressed, 1.3–1.5 times longer than deep. No, or a very rudimentary pelvic axillary lobe, fully attached to flank. Pelvic-fin origin below first or second branched dorsal-fin ray. Anal-fin origin at in front of vertical of midline between dorsal and caudal-fin origins. Pectoral fin reaching to approximately 70–95% of distance from pectoral-fin origin to pelvic-fin origin. Pelvic fin usually reaching anus, reaching to genital papillae; reaching vertical of tip of last dorsal-fin ray. Anus about 40–70% of an eye diameter anterior to anal-fin origin. Anal fin not reaching caudal-fin base. An elevated, short dorsal and ventral adipose crest on caudal peduncle behind vertical of posterior anal-fin base in some individuals, shallow or absent in other individuals. Largest known individual 64 mm SL.

Dorsal fin with 7½ (21), 8½ (1) branched rays, outer margin slightly concave. Anal fin with 5½ (22) branched rays, outer margin straight or slightly concave. Pectoral fin with 8 (16), 9 (4) and 10 (1) branched rays, outer margin straight. Pelvic fin with 5 (15), 6 (6) branched rays, outer margin straight or slightly convex. Caudal fin emarginate, shortest middle caudal-fin ray 71–84% of longest ray of upper caudal-fin lobe. Caudal fin with 8+8 (2), 9+8 (18) and 9+9 (1) branched rays. Flank and back covered by scales, scales irregularly set on predorsal back, densely set on flank below lateral line. Few scales on belly, chest without scales. Lateral line usually complete, with 55–85 pores, terminating on hypural complex, sometimes interrupted between anal-fin base and hypural complex.Anterior nostril opening at end of a low, ovoid, flap-like tube. Posterior tip of anterior nostril overlapping posterior nostril when folded backwards. One central pore and one or two lateral pores on each side of supratemporal head canal, 9–11 pores in infraorbital canal, 5–7 pores in supraorbital canal, and 9–11 pores in preoperculo-mandibular canal. One out of 21 individuals without a central pore. A shallow suborbital groove in male, often indistinct in individuals smaller than 50 mm. Mouth small, arched. Lips smooth, without furrows. Lower lip thicker than upper lip. A median interruption in lower lip. Upper lip without, or with very shallow median incision in some individuals. Processus dentiformis narrow and rounded. Lower jaw rounded, without median notch. Barbels moderately long; inner rostral barbel reaching or not reaching base of maxillary barbel, outer rostral barbel reaching to or slightly behind the anterior eye margin. Maxillary barbel reaching to, or rarely slightly behind vertical through posterior eye-margin.

Coloration. Background colour beige or yellowish with brown or dark-brown pattern in life and preserved individuals. Flank mottled or marbled, predorsal back with 0–4, very irregularly shaped, often-indistinct saddles. Back with fine, dark-brown, mottled pattern in some individuals. At back behind dorsal-fin base, 2–5 irregularly shaped saddles, connected to midlateral blotches in some individuals, forming short bars on caudal peduncle. Blotches along midlateral line often darker and forming a stripe in some preserved individuals. Two irregularly shaped, dark brown blotches on caudal-fin base, rarely connected to each other. Cheeks and head above cheeks with small brown spots sometimes fused into a mottled pattern. Ventral surface of head and belly pale yellow. Dorsal, caudal and pectoral fins with many elongated blotches on rays, forming 2–3 dark vertical rows in dorsal and caudal fins, rows not evident in pectoral fins. Anal and pelvic fins hyaline.

Distribution. Oxynoemacheilus eliasi is known from the Gediz, Küçük Menderes and Tahtalı River drainages in the western Anatolia.

Etymology. The species is named for Elias Freyhof, the son of the senior author, who always suffered from the absence of his father being in the field to search for loaches. A noun in genitive, indeclinable.

Figures

FIGURE 18. Oxynoemacheilus eliasi, FFR 15619, holotype, male, 51 mm SL; inlet of Tahtalı Reservoir.

FIGURE 19. Oxynoemacheilus eliasi, FFR 15581, paratypes, from top, 40 mm SL; 43 mm SL; 40 mm SL; inlet of Tahtalı Reservoir.

FIGURE 20. Oxynoemacheilus eliasi, FSJF 3699, 45 mm SL; not preserved, about 55 mm SL, same place as FSJF 1878; Şaşal stream; not preserved, about 55 mm SL, same place as FSJF 2016