Oxynoemacheilus cilicicus, Kaya & Turan & Bayçelebi & Kalayci & Freyhof, 2020

Kaya, Cüneyt, Turan, Davut, Bayçelebi, Esra, Kalayci, Gökhan & Freyhof, Jörg, 2020, Oxynoemacheilus cilicicus, a new nemacheilid loach from the Göksu River in southern Anatolia (Teleostei: Nemacheilidae), Zootaxa 4808 (2), pp. 284-300 : 289-297

Oxynoemacheilus cilicicus , new species

( Figs 2–5 )

urn:lsid:zoobank.org:act:7CC03542-0FE9-4E1F-84D4-60ADAA09A1E2

Holotype. FFR 15579, 54 mm SL, Turkey: Mersin prov.: irrigation canal 6 km southeast of Silifke , 36.3465 33.9806.

Paratypes. FFR 15560, 18, 43–55 mm SL; FSJF 4098 , 5 , 44–49 mm SL; same data as holotype .

Additional materials. FFR 15500, 20, 33–44 mm SL; Turkey: Kahramanmaraş prov.: a tributary of stream Aksu 2 km southwest of Kuyumcular , 37.4122, 36.9097.—FFR 15559, 6 , 41–49 mm SL; Turkey: Adana prov.: stream Eğlence 1 km southeast of Eğlence , 37.2922, 35.2252.—FFR 15576, 6 , 28–52 mm SL; Turkey: Adıyaman prov.: Lake Gölbaşı at Gölbaşı , 37.7978, 37.6611.—FFR 15578, 1 , 46 mm SL; Turkey: Kahramanmaraş prov.: stream Aksu 4 km north of Pazarcık , 37.5256, 37.3119.— FFR 1415 , 5 , 30–52 mm SL; Turkey: Adana prov.: stream Üçürge 2 km southeast of Karaisali , 37.2377, 35.0890.— FFR 1491 , 6 , 31–53 mm SL; Turkey: Adana prov.: stream Üçürge at Karaisali , 37.2611, 35.0669.— FFR 1489 , 2 , 40–47 mm SL; Turkey: Kahramanmaraş prov.: stream Aksu 7 km northeast of Pazarcık , 37.5399, 37.3477.— FSJF 2324 , 4 , 49–50 mm SL; Turkey: Adana prov.: stream Çakıt south of Salbaş , 37.0961, 35.1170.— FSJF 2432 , 6 , 29–48 mm SL; Turkey: Adana prov.: Seyhan River below water regula- tion doors at Yüreyir , south of Adana, 36.9757, 35.3354.— FSJF 2477 , 2 , 46– 40 mm SL; Turkey: Kahramanmaraş prov.: spring Evri south-west of Çöçelli , south of Kahramanmaraş, 37.2662, 37.1017.— FSJF 2507 , 1 , 53 mm SL; Turkey: Adıyaman prov.: river connecting Lakes Gölbaşı and Azaplı south of Gölbaşı , 37.7904, 37.6263.— FSJF 2569 , 13 , 46–58 mm SL; Turkey: Adıyaman prov.: stream Çelik at road south of Gölbaşı , 37.6239, 37.5034.— FSJF 2606 , 20 , 32–54 mm SL; Turkey: Kahramanmaraş prov.: spring Çöçelli north of Çöçelli south of Kahramanmaraş, 37.2811, 37.1248.— FSJF 2940 , 2 , 47–48 mm SL; Turkey: Adana prov.: lower part of stream Ecemiş east of Salbaş , 37.1390, 35.1423 .

Material used in molecular genetic analysis. FFR DNA Oxy-7-13; Turkey: Mersin prov.: irrigation canal 6 km southeast of Silifke , 36.3465 33.9806. (GenBank accession numbers: MT 513925 - MT 513930 )— FFR DNA Oxy-305-309 ; Turkey: Adıyaman prov.: Lake Gölbaşı at Gölbaşı , 37.7978, 37.6611 (GenBank accession numbers: MT 513931 - MT 513935 )

Diagnosis. Oxynoemacheilus cilicicus is distinguished from other species of the O. galilaeus species group by a combination of characters, none of them unique to the species. It is distinguished from O. ceyhanensis , which is also found in the Ceyhan, by possession of an incomplete lateral line terminating anterior to the dorsal-fin origin or below the dorsal-fin base (vs. complete), a deeper caudal peduncle (its depth 1.0–1.4 times in its length, vs. 1.4–1.6), a deeper body (20–24% SL vs. 18–20), and a shorter head (head length 22–25% SL vs. 25–27).

Oxynoemacheilus cilicicus is distinguished from O. galilaeus , O. panthera and O. leontinae by having a deeply emarginate caudal fin (vs. slightly emarginate or truncate), the flank and back posterior to the dorsal fin base covered by scales (vs. very few isolated scales on caudal peduncle, no scales in O. galilaeus ), and a series of regularly or irregularly-shaped flank bars (vs. irregularly-marbled or mottled in O. galilaeus and O. panthera ). Oxynoemacheilus cilicicus has usually one, rarely two, central pores in the supratemporal canal (vs. central pore usually absent in O. panthera ).

The new species is distinguished from O. namiri by having a shorter lateral line, usually terminating anterior to the dorsal-fin origin or slightly posterior to the dorsal-fin base (vs. lateral line terminating posterior to the dorsal-fin base, at the caudal-fin base in some individuals), a deeper body (body depth at dorsal-fin origin 20–24% SL, vs. 16–20), a deeply emarginate caudal-fin with middle ray 1.3–1.5 times in the length of the longest unbranched ray in the upper caudal-fin lobe (vs. slightly forked, 1.2–1.3), and flank bars narrower than interspaces in most individuals, rarely as wide as interspaces (vs. wider than interspaces).

Description. See Figures 2–5 for general appearance and Table 3 for morphometric data. Medium-sized and stout species. Body deepest at about midline between nape and dorsal-fin origin. Body width greatest at pectoral-fin base in male, slightly anterior to dorsal-fin origin in female. Section of head roundish, flattened on ventral surface, straight in interorbital space, convex on snout. Snout roundish. Caudal peduncle compressed laterally, 1.0–1.4 times longer than deep. No pelvic axillary lobe. Pelvic-fin origin below second or third branched dorsal-fin ray. Anal-fin origin about vertical of midline between dorsal and caudal-fin origins. Pectoral fin reaching to approximately 60– 70% of distance from pectoral-fin origin to pelvic-fin origin. Pelvic fin not reaching anus, not reaching vertical of tip of last dorsal-fin ray. Anus about 50–70% eye diameter anterior to anal-fin origin. Anal fin not reaching caudal-fin base. A shallow dorsal and ventral adipose crest on caudal peduncle, elevated in some individuals ( Figure 2 and 5b ). Dorsal adipose crest reaching to vertical through posterior anal-fin base. Largest known individual 55 mm SL.

Dorsal fin with 8½ branched rays, outer margin straight. Anal fin with 5½ branched rays, outer margin convex. Pectoral fin with 10–12 rays, outer margin slightly convex. Pelvic fin with 7 rays, outer margin straight or slightly convex. Caudal fin deeply emarginate. Flank and back behind dorsal-fin base covered by cycloid scales. Lateral line incomplete, with 13–23 pores, terminating at midline between pectoral- and dorsal-fin bases, slightly posterior to dorsal-fin base in some individuals. Anterior nostril opening at end of a low, pointed and flap-like tube. Posterior tip of anterior nostril reaching to posterior nostril when folded backwards. One, rarely two central pores and one lateral pore on each side of supratemporal head canal, 8–10 pores in anterior infraorbital canal, 3–4 pores in posterior infraorbital canal, 7–10 pores in supraorbital canal and 7–10 pores in mandibular canal. No suborbital groove or flap in male. Mouth small, slightly arched. Lips thick without furrows, lower lip thicker than upper lip. A median interruption in lower lip. Upper lip sometimes with a small and short median incision. Processus dentiformis wide and rounded. Lower jaw rounded, without median notch. Barbels long; inner rostral barbel almost reaching base of maxillary barbel, outer reaching to anterior margin of eye. Maxillary barbel reaching beyond vertical through posterior margin of eye.

Coloration. Body with yellowish or pale brown background and a dark-brown pattern in live and preserved individuals. Dorsal head and cheek with many spots forming a mottled or marbled pattern, ventral surface of head without pattern. Flank with 9–13 dark-brown bars, narrower than interspaces in most individuals, rarely as wide as interspaces. Flank bars often anastomosed into large and small blotches especially behind vertical of dorsal-fin base. Some populations, especially in Ceyhan River drainage, with a fine brown mottled pattern ( Fig. 5d ), often overlaying flank bars. Back usually with 5–7 large, irregularly-shaped brown blotches or saddles, narrower than or as wide as interspaces, back rarely without pattern or with a fine mottled pattern. Saddles on back usually separated from bars on flank, single saddles and bars confluent in some individuals. Many individuals with a dark-brown bar on caudal-fin base. Bar dissociated into two blotches or only one blotch at lower caudal-fin base. Dorsal and pectoral fins with many, small black blotches on rays, forming 1–3 narrow bands. Caudal fin with many small black blotches on rays and membranes, forming 2–4 ‘M’-shaped bands. Pectoral, anal and pelvic fins hyaline in small individuals, pectoral fin with dark brown blotches on rays in larger individuals.

Distribution. Oxynoemacheilus cilicicus has been collected from the lower Göksu, Seyhan and Ceyhan rivers, including the Gölbaşı Lakes basin ( Figs. 6 and 7 ).

Etymology. The species is named for Cilicia, an ancient name for the southern coastal region of Asia Minor, and which existed as a political entity from Hittite times until the Armenian Kingdom of Cilicia during the late Byzantine Empire. An adjective.

Remarks. Oxynoemacheilus cilicicus belongs to a group of Oxynoemacheilus species in which males lack the suborbital groove present in congeners inhabiting the same river drainages ( O. seyhanicola , O. evreni , O. samanticus , and O. hamwii ). It also has an incomplete lateral line usually terminating midway between the pectoral- and dorsal-fin bases, or slightly posterior to the dorsal-fin base in some individuals (vs. complete, terminating posterior to the anal-fin base in O. seyhanicola , O. evreni , O. samanticus , and O. hamwii ), a deep caudal peduncle (its depth 1.0–1.4 times in its length, vs. 1.5–1.8 in O. seyhanicola , 1.7–2.1 in O. evreni , 2.1–2.5 in O. samanticus , 1.4–1.9 in O. hamwii ), and a scaleless body and back except behind dorsal-fin base (vs. completely covered by scales except on the ventral surface in O. seyhanicola , O. seyhanensis , O. evreni , O. samanticus , and O. hamwii ). Oxynoemacheilus cilicicus is further distinguished from O. seyhanensis by usually having with 9–13 narrow, irregularly-shaped and spaced dark-brown bars on flank or at least on the caudal peduncle, narrower than interspaces in most individuals or rarely as wide as interspaces (vs. mottled or marbled).

While O. cilicicus populations from the Seyhan and Ceyhan Rivers have been considered a potentially undescribed species for a number of years (e.g. Geiger et al. 2014), its discovery in the Göksu drainage was unexpected. The Göksu River had a biogeographic connection to the Lake Beyşehir basin in Central Anatolia, evidenced by the shared presence of the fish species Gobio microlepidotus and Seminemacheilus tubae ( Turan & Bayçelebi 2019, Yoğurtçuoğlu et al. 2020). But the timing of this connection and any details are unknown. Oxynoemacheilus atili is the only a member of the genus Oxynoemacheilus present in the Lake Beyşehir basin, and it also occurs in the Manavgat River, which drains to the Mediterranean Sea. But O. atili has not been found so far in the Göksu River drainage. At the same time, the Göksu is inhabited by several endemic freshwater fish species with close relationships to species of the Levant and Mesopotamia. Capoeta caelestis from the Göksu is related to the widespread C. damascina species group in the Levant and Mesopotamia, Chondrostoma toros from the Göksu is related to C. ceyhanensis , C. kinzelbachi and C. regium , and Luciobarbus pectoralis is found from the Göksu east to the Orontes. Oxynoemacheilus cilicicus and Luciobarbus pectoralis are both found in the Göksu, Seyhan and Ceyhan Rivers, and L. pectoralis even ranges further to the Orontes drainage.

Figures

FIGURE 2. Oxynoemacheilus cilicicus, FFR 15579, holotype, 54 mm SL; Turkey: Göksu delta.

FIGURE 3. Oxynoemacheilus cilicicus, FFR 15560, paratypes, from the top, 55 mm SL; 55 mm SL; 55 mm SL; 52 mm SL; Turkey: Göksu delta.

FIGURE 4. Oxynoemacheilus cilicicus, from the top: FSJF 2324, 50 mm SL; Turkey: stream Çatkıt; FSJF 2569, 55 mm SL; Turkey: stream Çelik; FSJF 2507, 53 mm SL; Turkey: river connecting Lakes Gölbaşı and Azaplı; FSJF 2606, 50 mm SL; Tur- key: spring Çöçelli.

FIGURE 5. Oxynoemacheilus cilicicus; FFR 15560, paratype, a, 55 mm SL; b, paratype, 52 mm SL, Göksu delta; c, FFR 15559, 49 mm SL, stream Eğlence; d, FFR 1395, 48 mm SL, stream Çelik.

FIGURE 6. Distribution map of the Oxynoemacheilus galilaeus group in the Levant and the upper Tigris.

FIGURE 7. Turkey: irrigation canal in the Göksu delta, type locality of Oxynoemacheilus cilicicus.