Oxynoemacheilus kentritensis, a new species from the upper Tigris drainage in Turkey with remarks on O. frenatus (Teleostei: Nemacheilidae) Freyhof, Jörg Kaya, Cüneyt Turan, Davut Zootaxa 2017 4258 6 551 560 [151,515,1036,1062] Actinopterygii Nemacheilidae Oxynoemacheilus Animalia Cypriniformes 1 552 Chordata species kentritensis sp. nov.     Holotype. FFR0 1566, 67 mm SL; Turkey: Bitlisprov.: stream Kesanabout 1 kmsouth of Güntepe, 38°21'24''N 42°37'39''E; C. Kaya& F. Kaya,  21.09.2010.    Paratypes. FFR0 1403, 3, 57–68 mmSL; same data as holotype.—   FSJF3645, 3, 65–79 mmSL; Turkey: Bitlisprov.: stream Horozdereeast of Hizan, 38°14'41''N 42°28'45''E; C. Kaya& F. Kaya,  21.09.2010.—   FSJF3646, 2, 68–70 mmSL; Turkey: Bitlisprov.: stream Oranizabout 1 kmeast of Dönertaş, 38°18'51''N 42°33'56''E; C. Kaya& F. Kaya,  21.09.2010.  Additional material (non-types).FFR 0 1412, 5, 31–56 mmSL;   FSJF3647, 4, 39–55 mmSL: Turkey: Şırnakprov.: stream Nerduşat northwest of Toptepe, 37°28'26''N 42°22'49''E.—   FSJF3647, 9, 47–53 mmSL; Turkey: Şirnakprov.: stream Hezilwest of Bağlica, 37°26'28''N 42°44'54''E.   Diagnosis.  Oxynoemacheilus kentritensisis distinguished from the other species of  Oxynoemacheilusin the Tigris drainage by a combination of characters, none of them unique.  Oxynoemacheilus kentritensisbelongs to a group of species (  O. chomanicus,  O. frenatus,  O. hazarensis,  O. kiabii,  O. zagrosensis,  O. gyndes) which lack a suborbital groove in males (vs. present in  O. bergianus,  O. euphraticus,  O. hanae,  O. longipinnis,  O. karunensis,  O. kurdistanicusand  O. parvinae) and have a slightly emarginate or truncate caudal fin (vs. deeply emarginate or forked in  O. bergianus,  O. euphraticus,  O. hanae,  O. longipinnis,  O. karunensis,  O. kurdistanicusand  O. parvinae). The new species occurs adjacent to  O. frenatusfrom the upper Tigris and  O. chomanicusand  O. zagrosensisfrom the Lesser Zab. It is distinguished from  O. frenatusby having distinct bars or vertically elongated blotches on the flank behind the dorsal-fin origin (vs. mottled or marbled pattern), the maxillary barbel reaching beyond the middle of the eye, usually to posterior eye margin (vs. to anterior eye margin or middle of eye), a complete lateral line (vs. incomplete) and the colour pattern on the anterior part of the flank not interrupted by an unpigmented zone along the lateral line (vs. usually interrupted on anterior part of flank). It is distinguished from  O. chomanicusand  O. zagrosensisby having longer barbels, the maxillary barbel is reaching beyond the middle of the eye, usually to the posterior eye margin (vs. to anterior eye margin or middle of eye), distinct bars or vertically elongated blotches on the flank behind the dorsal-fin origin (vs. very indistinct, fuzzy bars on caudal peduncle in  O. chomanicus, mottled pattern in  O. zagrosensis), a smaller interorbital distance (interorbital distance 1.6–1.9 times in snout length vs. 1.4–1.5) and a deeper caudal peduncle (caudal peduncle depth 1.2–1.3 times in caudal peduncle length vs. 1.3–1.4).  Oxynoemacheilus kentritensisis further distinguished from  O. zagrosensisby having the posterior process of the bony air-bladder capsule directed posteriorly (vs. directed laterally).   Oxynoemacheilus kentritensisis distinguished from  O. kiabiiby the presence of a central pore in the supratemporal canal (vs. absence), three pores in the supratemporal canal (vs. 4–6 pores), a shorter head (length 24% SL vs. 26–30), a larger predorsal distance (51–54% SL vs. 48–52) and a complete lateral line (vs. incomplete). The new species is distinguished from  O. hazarensisand  O. gyndesby having scales on the back and flank in front of the anus (vs. absent), distinct bars or vertically elongated blotches on the flank behind the dorsal-fin origin (vs. mottled pattern or with stripes) and a complete lateral line (vs. incomplete).   Description.For general appearance see Figs. 1–3. Morphometric data are provided in Table 1. Large-sized and stout species with a blunt head. Body deepest at dorsal-fin origin or about midline between nape and dorsal-fin origin, depth decreasing below dorsal-fin base, staying almost continuously towards caudal-fin base. No hump at nape, usually a shallow hump in front of dorsal-fin origin. Greatest body width at pectoral-fin base. Section of head roundish, flattened on ventral surface. Cheeks enlarged. Caudal peduncle compressed laterally, 1.2–1.3 times longer than deep. No or a very shallow, usually roundish axillary lobe at base of pelvic fin, fully attached to body. Pelvic-fin origin below first or second branched dorsal-fin ray. Anal-fin origin slightly behind vertical of middle between dorsal and caudal-fin origins. Pectoral fin reaching approximately 60–70% of distance from pectoral-fin origin to pelvic-fin origin. Pelvic fin not reaching vertical of tip of last dorsal-fin ray, reaching to or to a short distance in front of anus. Anus about 0.9–1.4 eye diameter in front of anal-fin origin. Anal fin not reaching caudalfin base. A shallow dorsal and ventral adipose crest on caudal peduncle. Margin of dorsal fin straight or slightly convex. Caudal fin slightly emarginate. Largest known specimen 79 mmSL. Dorsal fin with 8½ (n=8)–9½ (n=1) branched rays. Anal fin with 5½ (n=9) branched rays. Caudal fin with 10+9 (n=2), 9+9 (n=5) or 9+8 (n=1) branched rays. Pectoral fin with 12–13 and pelvic fin with 6–8 rays. Body covered by embedded scales on flank and back, usually isolated and deeply embedded on back and flank in front of dorsal-fin origin. Nape without scales. Lateral line complete, reaching to caudal-fin base. One or two lateral pore in supratemporal canal, one central pore. Anterior nostril opening at end of a low, pointed and flap-like tube. Posterior tip of anterior nostril overlapping or almost overlapping posterior nostril when folded backwards. No suborbital groove in males. Mouth large, arched ( Fig. 4). Lips thin with small furrows. A shallow median interruption in lower lip. Median incision in upper lip absent or a very shallow groove. Processus dentiformis narrow and pointed. A median notch in lower jaw. Barbels long, inner rostral barbel reaching to base of maxillary barbel; outer one reaching to vertical of anterior eye margin or to a point slightly in front of eye margin. Maxillary barbel reaching beyond middle of eye. Male with longer pectoral fin.  Coloration.Body yellowish with coarse, dark-brown marmorate pattern. Head and cheeks brown on top with many minute yellowish spots and vermiculation, cheeks without colour pattern ventrally. A marmorate pattern or narrow, irregularly shaped bars on flank in front of dorsal-fin origin. Flank behind dorsal-fin origin with irregularly shaped and spaced dark-brown bars, dissociated into vertically elongated blotches in most individuals, bars or blotches reaching to ventral midline. Colour pattern on flank not interrupted by lateral line. Back with 2–4, darkbrown saddles, irregularly shaped and set, wider than interspaces, not fused to lateral bars. A large, roundish, dark brown blotch at dorsal fin-origin and below posterior half or dorsal-fin base. Three to five wide dark-brown saddles on upper caudal peduncle, fused with blotches or bars on flank in few individuals. A wide, dark-brown, irregularly shaped bar at caudal-fin base. Dorsal-fin usually with many elongated, dark-brown blotches on rays, forming two bands in some individuals. Caudal-fins with many elongated, dark-brown blotches on rays, forming 2–4 wide, irregularly shaped, dark-brown bands in some individuals. Pectoral fin hyaline, with dark-brown elongated blotches on rays. Anal- and pelvic-fin with few dark-brown spots on rays or 1–2 large, dark-brown blotches.   Distribution.  Oxynoemacheilus kentritensiswas found in headwaters of the Botan River in Turkey. The Botan is a left side tributary to the upper Tigris joining the Tigris at the village of Çattepe in the Turkish Siirt Province. The Botan River drains the area south of Lake Van. Kaya et al.(2016)also found this species in the Hezil and Nerdus Rivers, which are small rivers entering the Tigris in the border area of Turkey, Iraqand Syria.   Etymology.  Oxynoemacheilus kentritensisis named for the Kentrites, the historic name of the Botan River. The Greek historian Xenophon (ca. 431–355 BC) mentions the crossing of the Kentrites in his  Anabasis. An adjective.    Remarks.  Oxynoemacheilus kentritensisis described from within the distribution area of  O. frenatus. Oxynoemacheilus frenatuswas described from Mosul in Iraq, an area that can actually not be accessed for safety reasons. As there are only small tributaries flowing to the Tigris in the area of Mosul, the syntypesof  O. frenatusmust have been collected from these tributaries or from the Tigris itself. We exclude the possibility that all six syntypesmight have been washed downriver by a flood.  Freyhof et al.(2011)as well as  Freyhof& Özuluğ(2017)identified fishes from the upper Tigrisin Turkeyas  O. frenatusand treat  O. afrenatusas a synonym.  Oxynoemacheilus afrenatuswas described from small tributaries to the Tigrisaround the Turkishcity of Diyarbakır. Mosul is about 400 kmdownstream from Diyarbakır.  Diyarbakıris the lowermost point in the Tigris Riveritself, where we found loaches identified as  O. frenatus. But this species is also known from headwaters of the BatmanRiver, which enters the Tigris 80 kmdownstream of Diyarbakır( Kaya et al.2016). Despite its quite ubiquitous habitat choice in the uppermost Tigris, it has not been found in the tributaries of the Tigris downstream of the BatmanRiver as the Botan, the Khabur, the Greater Zab or any of the more southern tributaries of the Tigris. JFdid find this species in the Tigris in Diyarbakırand above but failed to find it in the Tigris in Hasankeyf. Kaya et al.(2016)did not find it in the main stream of the Tigris in Turkeyand K. Borkenhagen(pers. comm.), who visited the Tigris at the border between Syria and Turkey, did not record this species or any other  Oxynoemacheilus.   FIGURE 3.  Oxynoemacheilus kentritensis, FSJF 3645, paratypes, 79 mm SL, 77 mm SL, 65 mm SL; Turkey: stream Horozdere east of Hizan. The question is, had  O. frenatusbee continuously distributed in the Tigris downriver from Diyarbakırat least until Mosul, maybe still in the middle of the 19th century? If so, it might have vanished from the Tigris below Diyarbakır, maybe due to pollution, which is considerable in that area. Between Diyarbakırand Mosul, the Botan River and the small rivers Hezil and Nerdus enter the Tigris and are inhabited by  O. kentritensis, a species described above.  Oxynoemacheilus frenatusmight also occur in these rivers, but has not yet been recorded. This is the most likely explanation, as  O. frenatusis found in all kinds of streams in the upper Tigris and should therefore inhabit also streams, and not only the main river, downstream. But we can also not exclude that  O. frenatusmight correspond to a yet undiscovered additional species in the Tigris. The syntypesof  O. frenatuscannot be distinguished from the fishes from the upper Tigris by the characters examined in this study (body shape, position of fins, colour pattern, length of lateral line, pattern of scale cover). All syntypesof  O. frenatusare diagnosed by having an incomplete lateral line, reaching to a vertical between the pectoral-fin tip and the anal-fin origin and a mottled flank pattern without bars or large, vertically elongated blotches on the caudal peduncle. Even the prominent dark-brown stripe between the snout and the eye ( Fig. 5), which inspired Heckel (1843)to apply the name “  frenatus”, is well visible in the fishes from the upper Tigris. The only difference between the fishes from the upper Tigris and the syntypesmight be the colour pattern on the anterior part of the flank, which is interrupted by an unpigmented zone along the lateral line in fishes from Turkey. This unpigmented zone is not visible in the figure of  Cobitis frenataby Heckel (1843)( Fig. 5) but visible in the syntypes( Fig. 6). The syntypeon the figure by Heckel (1843)( Fig. 5) has a deeper emarginate caudal fin than the fishes from the upper Tigris, in which the caudal fin is almost truncate. Sadly, the caudal fin is damaged in all syntypesof  O. frenatus. Therefore, we have no case to treat the fishes from the upper Tigris as a distinct species (  O. afrenatus). If it might be possible to visit Mosul in the future, it might turn out that there are additional characters which might distinguish  O. afrenatusfrom  O. frenatusbut until then we keep  O. afrenatusas a synonym of  O. frenatus.   FIGURE 4.  Oxynoemacheilus kentritensis, FSJF 3645, paratype, 79 mm SL; Turkey: stream Horozdere east of Hizan. Left maxillary barbel lost in this individual.   FIGURE 5.  Oxynoemacheilus frenatus, syntype; Iraq: Tigris River at Mosul. Modified from Heckel (1843).   FIGURE 6.  Oxynoemacheilus frenatus, NMW 48552, syntypes, 70 mm SL, 43 mm SL; Iraq: Tigris River at Mosul.   FIGURE 7.  Oxynoemacheilus frenatus, FSJF 2614, 70 mm SL; Turkey: River Tigris south of Diyarbakır. Gozianpour et al.(2011) as well as Jouladeh-Roudbar et al.(2016)reported  O. frenatusfrom Iran. Following the results of this study, it is possible that  O. frenatusoccurs in Iranian rivers. The species reported by Gozianpour et al. (2011) and Jouladeh-Roudbar et al.(2016)should be carefully re-examined. 1499986403 2010-09-21 FFR C. Kaya & F. Kaya Turkey 38.356667 Guntepe 19 42.6275 Kesan 1 552 1 Bitlis holotype 1499986401 [199,961,1215,1240] 2010-09-21 FFR C. Kaya & F. Kaya Turkey 38.356667 Guntepe 19 42.6275 Kesan 1 552 1 Bitlis paratype 1499986399 2010-09-21 FSJF C. Kaya & F. Kaya Turkey 38.244724 Hizan 19 42.479168 Horozdere 1 552 FSJF 3645, 3 1 Bitlis paratype 1499986400 2010-09-21 FSJF C. Kaya & F. Kaya Turkey 38.314167 Donertas 19 42.565556 Oraniz 1 552 FSJF 3646, 2 1 Bitlis paratype 1499986404 FSJF Turkey 37.47389 Toptepe 19 42.380276 Nerdus 1 552 FSJF 3647, 4 1 Sirnak 1499986398 FSJF Turkey 37.441113 Baglica 19 42.748333 Hezil 1 552 FSJF 3647, 9 1 Sirnak 1499986402 Iraq Freyhof 5 556 Ozulug Freyhof 4 555 2 Diyarbakir syntype 1499986396 [286,892,151,176] Iraq Diyarbakir 5 556 1 Diyarbakir syntype 1499986397 Tigris. JF & K. Borkenhagen Turkey Tigris River 5 556 1 Diyarbakir syntype