Paracobitis salihae, Kaya & Turan & Kalayci & Bayçelebi & Freyhof, 2020

Kaya, Cüneyt, Turan, Davut, Kalayci, Gökhan, Bayçelebi, Esra & Freyhof, Jörg, 2020, The westernmost known population of Paracobitis (Teleostei, Nemacheilidae), with the description of a new species from the Euphrates River in southern Anatolia, Zootaxa 4838 (4), pp. 525-534 : 527-532

Paracobitis salihae , new species

( Figs 2–4 )

urn:lsid:zoobank.org:act:8796E0F5-7867-4369-8C50-7F9535567308

Holotype. FFR 3657, 66 mm SL, Turkey: Adıyaman prov.: Göksu River at 2 km east of Aktoprak , 37.8443 N, 37.6703 E.

Paratypes. FSJF 4104 , 1 , 48 mm SL, Turkey: Adıyaman prov.: Göksu River at 7 km northeast of Gölbaşı , 37.8391 N, 37.6974 E .

Material used in molecular genetic analysis. FFR DNA-Para1; Turkey: Adıyaman prov.: Göksu River at 7 km northeast of Gölbaşı , 37.8391 N, 37.6974 E. (GenBank accession number: MT 651606 ) .

Diagnosis. Paracobitis salihae is distinguished from P. zabgawraensis by its greater predorsal length (56–57% SL vs. 49–56), truncate caudal fin (vs. emarginated), greater prepelvic length (54% SL vs. 50–53), and longer barbels (outer rostral barbel 24–32% HL vs. 16–24; maxillary barbel 27–34% HL vs 19–27). It is further distinguished from P. zabgawraensis , its closest relative, by a K2P distance of 3.6%.

Description. For general appearance see Figs. 2–4 ; morphometric data are provided in Table 3. Medium-sized, elongate and slightly compressed laterally, with medium-sized head. Predorsal profile convex, prepelvic profile straight. Body deepest and widest slightly in front of dorsal-fin origin, depth decreasing towards caudal-fin base. No hump at nape. Section of head roundish, flattened on ventral surface, straight in interorbital space, convex on snout. Snout slightly pointed. Caudal peduncle strongly compressed laterally, measured without crest: 1.5 times longer than deep. No axillary lobe at pelvic-fin base. Pelvic-fin origin below dorsal-fin origin. Pectoral fin reaching approximately 40 or 50% of distance from pectoral-fin origin to pelvic-fin origin. Pelvic fin not reaching anus. Moderately high to shallow adipose crest on caudal peduncle. No ventral adipose crest. Dorsal fin reaching or slightly behind to anteriormost tip of dorsal adipose crest when folded down. Anus about 60–90% eye diameter in front of anal-fin origin. Margin of dorsal fin convex. Caudal fin truncate. Largest known specimen 66 mm SL.

Dorsal fin with 7½ branched rays. Anal fin with 5½ branched rays. Caudal fin with 9+8 branched rays. Pectoral fin with 9, pelvic fin with 7 rays. Flank behind vertical through adipose-crest origin covered with small, deeply embedded scales. Back and anterior flank naked. Lateral line complete, reaching to caudal-fin base or middle of caudal peduncle, with 74, 81 pores. Anterior nostril opening as pointed and flap-like tube. Posterior nostril oval, posterior tip of anterior nostril not, or only just overlapping posterior nostril when folded down.

One central and one lateral pore on each side of supratemporal canal, 9 or 10 pores in anterior infraorbital canal, 3 pores in posterior infraorbital canal, 8 or 10 pores in supraorbital canal and 10 pores in preoperculomandibular canal. No suborbital flap or groove in male. No external sexual dimorphism observed.

Mouth small, arched. Lips moderately thick with prominent furrows. A median interruption in lower lip. Upper lip without median incision. Processus dentiformis large, blunt. A median notch in lower jaw in paratype, absent in holotype. Barbels of holotype moderately long, inner rostral not reaching to base of maxillary barbel; outer one reaching vertical through base of maxillary barbel; maxillary barbel almost reaching to vertical through posterior eye margin. Barbels of paratype long, inner rostral barbel reaching to base of maxillary barbel; outer one reaching vertical through middle of eye; maxillary barbel reaching behind vertical through posterior margin of eye.

Coloration. Yellowish green background in live and formalin-preserved individuals. Body with a dark-brown vermiculate or marbled pattern, especially on predorsal back and flank posterior to dorsal-fin base, pale-brown anterior to dorsal-fin base. Colour pattern continues into dorsal adipose crest. Dorsal head and cheek with a vermiculate pattern; ventral surface of head without pattern. Both individuals with a thin dark-brown bar on caudal-fin base. Median part of dorsal-, caudal-, pectoral- and anal-fin rays of holotype, and dorsal- and caudal- fin rays of paratype black, often with black blotches. A few black blotches on pelvic-fin rays of holotype, and on pectoral-, anal- and pelvic-fins of paratype. No or very little pigmentation on fin membranes. Pectoral- and pelvic fins yellowish, others fins grey. Distal margin of fins hyaline. All fins except dorsal reddish in life.

Distribution. Only known from the Göksu River, a tributary of the upper Euphrates ( Figs. 5–6 ).

Etymology. Paracobitis salihae is named in honour of the Saliha Kaya (1939-2015), mother of the first author. A noun in the genitive, indeclinable.

Remarks. Paracobitis basharensis , P. molavii and P. zabgawraensis are the three Paracobitis species known from the Tigris drainage, but only P. zabgawraensis is found in the upper Tigris drainage and this species is related to P. salihae . Paracobitis salihae is distinguished from P. molavii by possessing a longer caudal peduncle (19% SL vs. 14–18) and a dark-brown vermiculate colour pattern on the flank and predorsal back (vs. forming a dense mottled pattern).

Paracobitis salihae is further distinguished from P. basharensis by its dorsal-fin origin being above the vertical through the pelvic-fin origin (vs. about one eye diameter behind), and having a greater prepelvic length (54% SL vs. 50–53), deeper body (maximum body depth 17% SL vs. 12) and shorter caudal peduncle (without crest 1.5 times longer than deep, vs. 2.0–2.3).

As only two individuals of P. salihae could be found, the diagnostic value of all morphometric character states mentioned here should be treated as tentative. But the substantial K2P distance between it and Paracobitis zabgawraensis , to which it has a sister-group relationship ( Fig. 1 ) encourages us to recognise P. salihae as a distinct species. We hope more individuals will become available in the future, allowing a better morphological differentiation of this species against its congeners. We do not wait until that time to make the species name available, however, because this species could be Critically Endangered as a result of the very small size of its known population and range, threatened additionally by dam constructions close to its very small distribution range.

Figures

FIGURE 1. Maximum likelihood tree based on mitochondrial cytochrome oxidase subunit I (COI; 652 bp) gene sequences of Paracobitis spp. Neighbor Joining, Maximum likelihood and Maximum Parsimony analyses resulted in congruent trees. Bootstrap values are shown above nodes on tree if 70% or higher.

FIGURE 2. Paracobitis salihae, FFR 3657, holotype, 66 mm SL; Turkey: Göksu River.

FIGURE 3. Paracobitis salihae, FFR 3657, holotype, 66 mm SL; Turkey: Göksu River.

FIGURE 4. Paracobitis salihae, FSJF 4104, paratype, 48 mm SL; Turkey: Göksu River.

FIGURE 5. Records of Paracobitis salihae and P. zabgawraensis.

FIGURE 6. Göksu River, type locality of Paracobitis salihae.