Turcinoemacheilus ekmekciae, Kaya & Yogurtçuoglu & Aksu & Bayçelebi & Turan, 2024

Kaya, Cüneyt, Yogurtçuoglu, Baran, Aksu, Ismail, Bayçelebi, Esra & Turan, Davut, 2024, Turcinoemacheilus ekmekciae, a new dwarf loach from upper Tigris and Euphrates (Teleostei: Nemacheilidae), Journal of Fish Biology 104 (1), pp. 227-239 : 230-232

3.2 | Turcinoemacheilus ekmekciae , new species

3.2.1 | Holotype

FFR 3608 , 36 mm SL; Türkiye: Muş Prov.: stream Kaynarca at Kalecik, Murat drainage, 39.1519N 41.3534E .

3.2.2 | Paratypes

FFR 3624 , 7, 31 – 37 mm SL; FFR 3615 , 14, 31 – 46 mm SL; FFR 3617 , 5, 27 – 33 mm SL: same data as holotype. — FFR 3603 , 7, 48 – 54 mm SL: Türkiye: Bitlis Prov.: stream Çıratan at 3 km southwest of ÜÇadım , Yanarsu drainage, 38.3547N 41.7814E. — FFR 3604 , 1, 48 mm SL; FFR 3611 , 7, 35 – 47 mm SL; FFR 3616 , 5, 36 – 45 mm SL; Türkiye: Şırnak Prov.: stream Nerduş about 7 km south-west of Şırnak, 37.4755N 42.3739E. — FFR 3610 , 1, 29 mm SL; FFR 3618 , 3, 29 – 30 mm SL; Türkiye: Batman Prov.: stream Sason (Han) at Cevizli , Batman drainage, 38.2885N 41.2879E. — FFR 3613 , 4, 29 – 50 mm SL; Türkiye: Bitlis Prov.: stream Destumi at Tanrıyar, Botan drainage, 38.2258N 41.8825E .

3.2.3 | Additional material

FFR 3602 , 2, 52 – 55 mm SL; Türkiye: Bitlis Prov.: stream Oraniz at Ekinli , 38.1386N 42.4303E . — FFR 3609 , 1, 55 mm SL; Türkiye: Bitlis Prov.: stream Oraniz at Dönertas ¸, Botan drainage, 38.3158N 42.5653E .

3.2.4 | Genetic material

FFR DNA-Tur1; Türkiye: Bitlis Prov.: stream Çıratan at 3 km southwest of ÜÇadım, Yanarsu drainage, 38.3547N 41.7814E (GenBank accession number: OQ 758274). FFR DNA-Tur7, 9; Türkiye: Bitlis Prov.: stream Destumi at Tanrıyar, Botan drainage, 38.2258N 41.8825E (GenBank accession numbers: OQ 758275, OQ 758279). FFR DNA-Tur18, 19; Türkiye: Şırnak Prov.: stream Nerduş about 7 km south-west of Şırnak, 37.4755N 42.3739E (GenBank accession numbers: OQ 758276, OQ 758283). FFR DNA-Tur11, 38; Türkiye: Batman Prov.: stream Sason (Han) at Cevizli, Batman drainage, 38.2885N 41.2879E (GenBank accession numbers: OQ 758278, OQ 758282). FFR DNA-Tur4, 5, 6; Türkiye: Muş Prov.: stream Kaynarca at Kalecik, Murat drainage, 39.1519N 41.3534E (GenBank accession numbers: OQ 758280, OQ 758281, OQ 758277).

3.2.5 | Diagnosis

Turcinoemacheilus ekmekciae is distinguished from its congeners from upper Tigris and Euphrates drainages by a combination of characters. The new species is distinguished from T. minimus from Göksu and Kahta drainages by having a deeper caudal peduncle (7% – 9% SL v. 6 – 7), and 5 – 6 mandibular pores in mandibular canal (v. 4 – 5). T. ekmekciae is distinguished from T. kosswigi from upper Greater Zab by having a greater pre-pelvic distance (50% – 53% SL v. 47 – 50), a shorter upper caudal fin lobe (14% – 18% SL v. 18 – 21), and a shorter maxillary barbel (15% – 21% HL v. 21 – 26). The new species is further distinguished from T. kosswigi by having a dark stripe broader than the eye diameter along the lateral line, only in one population possessing roundish blotches (v. a dark-brown mid-lateral stripe narrower than the eye diameter).

Turcinoemacheilus ekmekciae is distinguished from the two Iranian Turcinoemacheilus , T. bahaii and T. hafezi , by the position of the anus, which is situated in the middle or in front of midpoint between pelvic and anal fins ( v. situated behind the midpoint between pelvic and anal origins). The new species is further differentiated from T. bahaii by the lack of dark-brown blotch on each side of the anal-fin base ( v. present ). T. ekmekciae is further distinguished from T. hafezi by having a smaller head (17% – 20% SL, v. 20 – 23), a slenderer body (body depth at dorsal-fin origin 11% – 14% SL, v. 15 – 17), and a shorter and slenderer caudal peduncle (its length 16% – 19% SL, v. 19 – 23; its depth 7% – 9% SL, v. 9 – 11).

The new species is distinguished from T. saadi by having a dark stripe broader than the eye diameter along the lateral line, only in one population possessing roundish blotches (v. 7 – 9 distinct saddles on flank, lateral stripe, or row of blotches absent along lateral midline). It further differs from T. saadi by having a longer pre-dorsal length (55% – 59% SL, v. 52 – 55), a shorter post-dorsal length (32% – 37% SL, v. 37 – 40), and a longer pre-anal length (75% – 78% SL, v. 70 – 75).

3.2.6 | Description

For general appearance see Figures 1 – 4; morphometric data are provided in Table 2. Small-sized and slender species. Head short, body depth at dorsal-fin origin 1.3 – 1.7 times in HL. Pre-dorsal profile slightly convex, pre-pelvic profile straight. Body deepest and widest at mid-point of pre-dorsal distance, depth decreasing toward caudal-fin base. No hump at nape. Section of head roundish, flattened on ventral surface, straight or slightly convex in interorbital space, distinctly convex on snout. Snout pointed. Caudal peduncle compressed laterally, 1.8 – 2.7 times longer than deep. Pelvic axillary lobe present, its tip not attached to body. Pelvic-fin origin in front of dorsal-fin origin. Pectoral fin reaching 41% – 55% of distance from pectoral-fin origin to pelvic-fin origin. Pelvic fin reaching beyond anus. Distance from anus to anal-fin origin 0.4 – 0.5 times in distance from pelvic-fin to anal-fin origins. Anal-fin origin posterior to vertical to tip of dorsal fin when folded backwards. Anal fin not reaching to middle of caudal peduncle. No adipose crest on caudal peduncle. Margin of dorsal fin straight. Caudal fin slightly emarginate. Largest known specimen 55 mm SL.

One central and one lateral pores on each side of supratemporal canal, 6 – 8 pores in anterior infraorbital canal, 3 – 4 pores in posterior infraorbital canal, 7 – 9 pores in supraorbital canal, and 5 – 6 pores in mandibular canal. No suborbital flap or groove in male.

Dorsal fin with 6 – 7½ (usually 6½) branched rays. Anal fin with 5½ branched rays. Caudal fin with 8 + 8 or 8 + 7 branched rays. Pectoral fin with 8(9) and pelvic fin with seven branched rays. Body without scales. Lateral line incomplete, with 18 – 28 pores, usually extends to the midpoint of area between tip of pectoral fin and dorsal-fin origin. Anterior nostril opening at end of a pointed flap-like tube. Posterior nostril oval, posterior tip of anterior nostril not, or just overlapping posterior nostril when folded backwards. Mouth small, slightly arched (Figure 1). Lips moderately thick. A median interruption in lower lip. Upper lip without median incision. Processus dentiformis small and blunt. No median notch in lower jaw. Barbels short, inner rostral barbel not reaching base of maxillary rostral barbel; outer one reaching to base of maxillary barbel. Maxillary barbel reaching vertical of anterior part of eye. No external sexual dimorphism observed.

3.2.7 | Colouration

Yellowish or cream background in life and formalin preserved individuals. In Yanarsu population, a row of large, irregular, brown blotches along the lateral line and is not in form of a stripe, often fused into a prominent irregular lateral stripe, in other populations, a stripe broader than the eye diameter along the mid-lateral line. Generally, there are no saddles on the back. If present, they are large and brown, connected to lateral blotches along the body. On the pre-dorsal back and upper part of the flank sometimes completely covered by pigments and no saddles appear. Flank below lateral stripe without pigmentation. An irregularly shaped, dark-brown or black bar at caudal-fin base.

Dorsal and caudal fins hyaline, with elongated spots on rays, forming one wide row, approximately in median part of the rays. Last unbranched dorsal-fin ray hyaline at base, black at anterior half and hyaline on posterior half. Caudal, anal, and anterior pectoral fins are yellowish or hyaline. Proximal and median part of the rays of caudal and anal fins, and sometimes anterior half of pectoral fin with dark-brown pigments.

Cheeks and ventral surface of head cream or yellow, head above cheeks plain brown to brown.

3.2.8 | Distribution

The new species is currently known from Kaynarca Stream (upper Murat River drainage) as well as from Yanarsu, Botan, Nerdus¸, Batman River drainages (all upper drainages of the Tigris River). It usually prefers fast-flowing, shallow and clean streams with stone or pebble substrate (Figure 5).

3.2.9 | Etymology

The species is named for Fitnat Güler EkmekÇi for her contribution to the knowledge of the ichthyofauna of Türkiye. A noun in genitive, indeclinable.