Paracobitis abrishamchiani, Mousavi-Sabet & Vatandoust & Geiger & Freyhof, 2019

Mousavi-Sabet, Hamed, Vatandoust, Saber, Geiger, Matthias F. & Freyhof, Jörg, 2019, Paracobitis abrishamchiani, a new crested loach from the southern Caspian Sea basin (Teleostei: Nemacheilidae), Zootaxa 4545 (3), pp. 375-388 : 377-387

Paracobitis abrishamchiani , new species

( Figs. 3–7 )

Holotype. VMFC PCAB-H, 95 mm SL; Iran: Mazandaran prov.: a tributary of Babol River, upstream of Lafour reservoir, near Galeshkola , 36°12'33"N 052°46'16"E; S. Vatandoust & H. Mousavi-Sabet.

Paratypes. All from Iran: Mazandaran prov .: VMFC PCAB-P1 , 5 , 43–68 mm SL ; VMFC PCAB-P2 , 16 , 46– 85 mm SL ; VMFC PCAB-P3 , 7 , 48–89 mm SL; same data as holotype .

Additional materials. All from Iran: Mazandaran prov.: VMFC PCAB-P4, 13, 34–84 mm SL; a tributary of Siah River at Seyed-Abu-Saleh, 36°25'0.22"N 53°1'5.81"E; H. Mousavi-Sabet & S. Vatandoust.—FSJF 4058, 2, 86–92 mm SL; VMFC PCAB-P5, 3, 89–110 mm SL; VMFC PCAB-P6, 14, 46–94 mm SL; VMFC PCAB-P7, 5, 68–97 mm SL; stream Shirin at Ali-Abad, at the road from Sari to Damghan, a tributary of Tajan River, 36°27'28"N 053°07'35"E; H. Mousavi-Sabet & S. Vatandoust.—VMFC PCAB-P8, 2, 96–97 mm SL; stream Kashpal, near Chamestan, 36°28'22.05"N 52°5'46.08"E; H. Mousavi-Sabet & S. Alavi-Yeganeh.—VMFC PCAB-P9, 3, 78–90 mm SL; a tributary of Talar River, at Zirab, 36°11'74"N 053°00'92"E; H. Mousavi-Sabet & S. Vatandoust.

Material for molecular genetic analysis. FSJF DNA-2754 , FSJF-DNA2755 ; Tajan River at Ali-Abad, 36°27'28"N 053°07'35"E (GenBank accession numbers: MK238773 , MK238774 ) .— FSJF DNA-2756 ; Babol River at Galeshkola, 36°12'33"N 052°46'16"E (GenBank accession numbers: MK238770 , MK238771 ) . — FSJF DNA-2757 ; stream Kashpal , at Chamestan, 36°28'22.05"N 52° 5'46.08"E (GenBank accession number: MK 238772 ) .

Diagnosis. Paracobitis abrishamchiani is distinguished from the other species of Paracobitis in the Middle East by a combination of characters, none of them unique. It is distinguished from P. hircanica and P. atrakensis , two other species found in rivers of the eastern Caspian Sea basin, by having scales on the flank posterior to the dorsal-fin origin, sparsely set on the flank between the dorsal-fin origin and the anal-fin base, densely set on the caudal peduncle (vs. scales absent) and the caudal-fin rays hyaline with an irregular pattern of dark-brown or black spots and elongated blotches often organised in 1–2 wide, irregularly-shaped bars (vs. caudal-fin rays dark-brown or black, having a hyaline base and a hyaline posterior margin in P. hircanica ). The base and posterior caudal-fin margin is also hyaline in P. abrishamchiani . Paracobitis abrishamchiani is further distinguished from P. hircanica by having many, pale- or dark-brown blotches and spots on the body. In individuals larger than 60 mm SL, the blotches are usually roundish or vertically elongated, some are fused to each-other. The blotches are commashaped along the lateral midline in smaller individuals forming a densely-set row (vs. a mid-lateral row of spots and small blotches, fused to an incomplete, irregularly shaped stripe along the lateral line in most individuals in P. hircanica ). Paracobitis abrishamchiani is further distinguished from P. atrakensis by having a well-developed axillary pelvic lobe (vs. absent).

It is distinguished from P. basharensis by having an emarginate caudal fin (vs. truncate or slightly emarginate), the dorsal-fin origin usually slightly behind a vertical through the pelvic-fin origin, rarely above or in front (vs. about one eye diameter behind a vertical through the pelvic-fin origin in P. basharensis ) and a mid-lateral series of comma-shaped, pale-brown blotches in individuals smaller than 60 mm SL (vs. many brown, medium sized, widely spaced and irregularly shaped blotches forming a mottled pattern on predorsal back and on flank).

In individuals larger than 60 mm SL, P. abrishamchiani is distinguished from P. malapterura and P. persa by having many, pale- or dark-brown, roundish or vertically elongated, widely spaced blotches and spots on the body, some fused to each-other (vs. a densely set pattern of dark-brown vermiculations on flank in P. malapterura , coarse brown marbling and a prominent lateral series of blotches or a midlateral stripe in P. persa ). In individuals smaller than 60 mm SL, P. abrishamchiani is distinguished from P. malapterura and P. persa by having a mid-lateral series of comma-shaped, pale-brown blotches (vs. a mid-lateral row of spots, small and large blotches fused to an incomplete, irregularly shaped, stripe along the lateral line in most individuals). Paracobitis abrishamchiani is further distinguished from P. malapterura and P. persa by having 77–85 lateral line pores (vs. 87–96 pores in P. malapterura and 85-91 pores in P. persa ). Paracobitis abrishamchiani is further distinguished from P. malapterura by a deeper head, its depth at eye being 48–52% HL (vs. 46–48% in P. malapterura ). Paracobitis abrishamchiani is further distinguished from P. persa by a deeper caudal adipose crest, its depth at the highest point being 3.2– 3.6% SL (vs. 2.1–3.2% in P. persa of same size), and the tube of the anterior nostril fully overlapping the posterior nostril when folded back (vs. not reaching beyond the posterior tip of the posterior nostril when folded back in P. persa ).

The new species is distinguished from P. molavii by having an emarginate caudal fin (vs. truncate), and a colour pattern of many, widely spaced, brown spots and blotches, organised in a midlateral series of comma-shaped spots in individuals smaller than 60 mm SL (vs. small, irregularly shaped and closely set brown blotches often forming a dense mottled pattern on the predorsal back and on flank).

Paracobitis abrishamchiani is distinguished from P. zabgawraensis by having a colour pattern of many widely spaced brown spots and blotches in individuals larger than 60 mm SL, organised in a midlateral series of commashaped spots in individuals smaller than 60 mm SL (vs. almost plain brown with a yellowish, narrow reticulate pattern).

It is distinguished from P. longicauda , P. rhadinaea and P. vignai by having a roundish posterior narial opening (vs. slit-like) and the scales on the flank present posterior to the dorsal-fin origin, sparsely set on the flank between the dorsal-fin origin and the anal-fin base, densely set on the caudal peduncle (vs. flank fully covered by scales in P. longicauda , the flank without scales in P. vignai ).

The new species is further distinguished from the other species discussed above (with the exception of P. basharensis ) by the position of the dorsal-fin origin, which is usually situated behind a vertical through the pelvicfin origin (vs. in front of the vertical through the pelvic-fin origin). While this is the case in most individuals of P. abrishamchiani , some individuals have the dorsal-fin origin above the pelvic-fin or in front of the pelvic-fin origin. This character is therefore helpful to identify larger series of P. abrishamchiani , but not fully diagnostic for the species.

Description. For general appearance see Figs. 3–7 ; morphometric data are provided in Table 2. Medium sized and elongate species with laterally compressed caudal peduncle. Predorsal profile convex, prepelvic profile straight. Body deepest at about dorsal-fin origin or slightly anterior to it, depth decreasing towards caudal-fin base. No hump at nape, or only a slight hump at nape in some individuals (in population from Tajan River). Greatest body width at pectoral-fin base, body almost uniformly wide until dorsal-fin origin, tapering towards caudal-fin base. Section of head roundish, flattened on ventral surface; slightly depressed, almost conical. Head length 1.5– 1.8 times in body depth. Snout rounded, its length 0.9–1.0 times in postorbital head length. Eye relatively small, eye diameter 3.1–5.0 times in head depth at eye, 1.6–3.1 times in interorbital width. Eye located on anterior half of head or at mid-head. No suborbital flap or groove in male. Nares rounded, located just anterior to eye. Anterior narial opening developed as a low, pointed, flap-like tube. Posterior naris narrow; nares adjacent, posterior tip of anterior naris reaching to posterior naris when folded down. Mouth small, distinctly arched ( Fig. 8 ). Lips moderately thick, well furrowed. Lower lip interrupted medially ( Fig. 8 ). No median notch in lower jaw. Upper lip without median incision. Processus dentiformis large, blunt ( Fig. 8 ). Maxillary barbel long, reaching to posterior margin of eye or beyond. Outer rostral barbel reaching beyond vertical through posterior nostril, to vertical through anterior eye margin in some individuals. Inner rostral barbel not reaching origin of maxillary barbel. Caudal peduncle 1.6–2.8 times longer than deep (crest not included). Dorsal adipose crest on caudal peduncle welldeveloped, not reaching posterior part of dorsal-fin base, reaching to caudal-fin base. Flank behind dorsal-fin origin covered by minute scales with an eccentric, relatively small focal zone; scales sparsely set on flank between dorsalfin origin and anal-fin base, densely set on caudal peduncle. Lateral line straight, complete, with 77–85 pores, reaching to, or almost to caudal-fin base, pores often irregularly set. One central and one lateral pore in supratemporal canal, 10 pores in anterior infraorbital canal, four pores in posterior infraorbital canal, 8–9 pores in supraorbital canal and 9–11 pores in preoperculo-mandibular canal. No external sexual dimorphism observed. Largest known individual 110 mm SL.

Dorsal fin with 6½–7½ branched rays. First unbranched rays deeply hidden in skin. Dorsal-fin origin usually slightly behind vertical through pelvic-fin origin, rarely above or in front. Margin of dorsal fin straight or slightly convex. Dorsal fin reaches to or slightly beyond anterior-most tip of adipose crest when folded backwards. Anal fin with 5½ branched rays. First unbranched rays deeply hidden in skin. Anal fin not reaching caudal-fin base. Anus about one eye diameter in front of anal-fin origin. Pectoral fin with one simple and 8 (10), 9 (10) or 10 (8) branched rays. Pectoral fin reaching approximately 50–70% of distance from pectoral-fin origin to pelvic-fin origin. Pelvic fin with one simple and 7 (20) or 8 (8) branched rays. Pelvic fin not reaching anus. A distinct axillary lobe at pelvic-fin base, its posterior part free from body in large individuals, fully attached in small individuals. Caudal fin emarginated (length of middle ray 79–88% of longest branched ray in upper lobe), with 9+8 (7), 9+9 (19) and 10+9 (2) branched rays.

Coloration. In preserved individuals, background colour on head and body pale yellow to whitish with brown pattern. Dorsal surface of head pale yellowish with a fine marbled or vermiculate, brown pattern. Cheeks pale yellowish or whitish. Anterior part of flank and back with many pale- or dark-brown blotches and spots, often forming a marmorate pattern. Flank pattern denser and blotches smaller on flank anterior to dorsal-fin base, coarser posterior to dorsal-fin base, pattern extending onto adipose crest. In individuals larger than 60 mm SL, blotches usually small and roundish, irregularly shaped or vertically elongated, some fused to each-other. Blotches usually comma-shaped along lateral midline in smaller individuals, forming a densely set row. Adipose crest with a darkbrown or black margin in few individuals, pale creamy in others. Belly yellowish-beige, in some individuals with little dark-brown dots, small dark-brown dots also around anal-fin base and on caudal peduncle. Lateral line beige, in contrast to colour pattern on mid-lateral flank. A faint brown stripe from eye to snout. A bold and wide darkbrown or black, irregularly shaped bar at caudal-fin base. A bold black or dark-brown blotch at base of unbranched and branched dorsal-fin rays, base of branched rays 2–3 beige and base of rays 4–7 black or dark brown. Darkbrown or black spots or blotches on dorsal-fin rays, membrane hyaline. Caudal-fin rays hyaline with an irregular pattern of dark-brown or black spots and elongated blotches often organised in 1–2 wide, irregularly shaped bars. Anal, pectoral and pelvic fins usually hyaline, with dark-brown spots (anal and pelvic fins without pigmentation in some individuals). Mental lobes of mouth with dark grey pigmentation. Rostral barbel and bases of maxillary barbels with dark brown pigments, maxillary immaculate.

Distribution. Paracobitis abrishamchiani is endemic to Iran where it is known from the rivers Tajan, Siah, Talar, Babol, Haraz and Kashpal in the southern Caspian Sea basin.

Etymology. The species is named in honour of Mir-Jafar Abrishamchian (1930–2018) and his son Ali Abrishamchian (1954–2007), the great benefactors in Guilan Province, to respect their developmental services in support of the University of Guilan and its students.

Notes on habitat and conservation. Paracobitis abrishamchiani was collected in streams with clear water and swift current at 317–566 m altitude ( Fig. 9 ). Similar to its congeners, it was found to be rare at the type locality and other sites.

Comparative material. See Freyhof et al. (2014), Esmaeili et al. (2014) and Mousavi-Sabet et al. (2015) for materials of other Paracobitis species examined for this study. New material used in the molecular genetic analysis:

Paracobitis atrakensis , FSJF DNA-2759 ; Iran: Atrak River south of Baba Aman park, 37°28'41.13"N 57°25'58.98"E. (GenBank accession numbers: MK 238762 , MK 238763 ) .

Paracobitis hircanica , FSJF DNA-1984 ; Iran: stream flowing to Gorgan River south of Galikesh, 37°14'58.91"N 55°28'54.14"E. (GenBank accession numbers: MK 238764 , MK 238765 ) .

Paracobitis rhadinaea , FSJF DNA-2486 ; Iran: Chah-Nimeh reservoir south of Zahak, (GenBank accession number: MK238768 , MK238769 ) .— FSJF DNA-2615 ; Iran: Chah-Nimeh reservoir about 50 km south of Zabol, 30°48'02.52''N 61°41'14.35''E. (GenBank accession number: MK 238766 ) .— FSJF DNA-2749 ; Chah-Nimeh reservoir south of Zahak, 30°50'30.53"N 61°42'22.13"E. (GenBank accession number: MK 238767 ) .

Paracobitis zabgawraensis , FSJF DNA-2679 ; Turkey: stream Çıratan about 5 km east of Gümüskanat, 38.38463 41.781780. (GenBank accession number: MK 238776 ) .— FSJF DNA-2640 ; Iraq: stream Choman at Qubay Galala, 36°36'38"N 44°50'17"E. (GenBank accession number: MK 238775 ) .

Paraschistura kessleri , FSJF DNA-2780 ; Iran: stream Dahizva north of Gaxu, 28°30'49.89"N 61°31'29.77"E. (GenBank accession number: MK 238777 ) .

Site-scale records shown in Figure 1 . Previous records (based on Esmaeili et al. 2014, Mousavi-Sabet et al. 2015): 1: 37°29'37.88"N 57°26'25.63"E; 2: 37°28'41.13"N 57°25'58.98"E; 3: 37°40'38.67"N 56°58'12.17"E; 4: 37°23'28.92"N 55°45'11.86"E; 5: 37°14'59.03"N 55°28'53.87"E; 6: 36°53'0.34"N 54°57'31.68"E; 7: 36°50'47.31"N 54°58'54.15"E. New records: 8: 36°27’28"N 053°07'35"E; 9: 36°11’74"N 053°00'92"E; 10: 36°25'0.22"N 53°1'5.81"E; 11: 36°12’33"N 052°46'16"E; 12: 36° 8'54.60"N 52°21'42.96"E; 13: 36°28'22.05"N 52° 5'46.08"E.

Figures

FIGURE 1. Records of Paracobitis in the Caspian Sea basin.

FIGURE 3. Paracobitis abrishamchiani, VMFC PCAB-H, holotype, 95 mm SL; Iran: Babol River.

FIGURE 4. Paracobitis abrishamchiani, VMFC PCAB-P1, paratypes; a–b, 78 mm SL; b–c, 69 mm SL; e–f, 42 mm SL; Iran: Babol River.

FIGURE 5. Paracobitis abrishamchiani, VMFC PCAB-P4, a–b, 84 mm SL; b–c, 68 mm SL; Iran: Siah River.

FIGURE 6. Paracobitis abrishamchiani, FSJF 4058, a–b, 89 mm SL; VMFC PCAB-P6, b–c, 73 mm SL; Iran: Tajan River.

FIGURE 7. Paracobitis abrishamchiani, VMFC PCAB-P3, Babol River, a, female, 81 mm SL, b, male, 61 mm SL; VMFC PCAB-P7, Tajan River, c, male, 68 mm SL, d, female, 76 mm SL; VMFC PCAB-P8, stream Kashpal, e, male, 96 mm SL.

FIGURE 8. Paracobitis abrishamchiani, VMFC PCAB-H, holotype, 95 mm SL; Iran: Babol River.

FIGURE 9. Iran: Babol River, type locality of Paracobitis abrishamchiani.