Cobitis avicennae, Mousavi-Sabet, Hamed, Vatandoust, Saber, Esmaeili, Hamid Reza, Geiger, Matthias F. & Freyhof, Jörg, 2015

Mousavi-Sabet, Hamed, Vatandoust, Saber, Esmaeili, Hamid Reza, Geiger, Matthias F. & Freyhof, Jörg, 2015, Cobitis avicennae, a new species of spined loach from the Tigris River drainage (Teleostei: Cobitidae), Zootaxa 3914 (5), pp. 558-568 : 558-568

Cobitis avicennae , n. sp.

( Fig. 3–5 )

Holotype. GUIC CC1462MA; 68.4 mm SL, Iran, Hamedan prov., Gamasiab River at Dehno, a tributary to Karkheh, 34°10’15"N, 48°21'19"E, altitude 1610 m, 20 September 2011, S. Vatandoust, H. Mousavi-Sabet.

Paratypes. GUIC CC1462M; 6, 65.2 – 98.2 mm SL; same data as holotype.

Additional materials. FSJF 3225; 18, 26 – 37 mm SL, Iran, Hamedan prov., Gamasiab River south of Habibabad, a tributary to Karkheh, 34°16'54" N, 48°09'26"E. – FSJF 3231; 10, 31 – 56 mm SL, Iran, Kermanshah prov., Sepidbarg River west of Javanrud, a tributary to Karun (Karoun) 34°48'21.4"N, 46°27'29.2"E.

Diagnosis. Cobitis avicennae is distinguished from all other species of Cobitis in the Persian Gulf, Kor and southern Caspian Sea basins by the combination of the following characters: a single lamina circularis on pectoral fin in males (vs. two in C. elazigensis and C. linea ); 5–6 rows of dark spots on dorsal and caudal fins in individuals larger than 65 mm SL (vs. 3–4 in C. faridpaki ); sub-dorsal scales with a small focal zone (vs. large in C. amphilekta and C. taenia ); Z4 consisting of 12–17 distinct, large, dark-brown blotches (vs. small, indistinct blotches in C. kellei ); a small comma-shaped black spot on the upper caudal-fin base (vs. a large spot in C. keyvani ; two spots in C. melanoleuca ), and Z4 consisting of 12–17 dark-brown large blotches (vs. 20–30 in C. faridpaki ).

Description. See Figures 3–5 for general appearance and Table 2 for morphometric data of holotype and six paratypes. Greatest body depth at or slightly in front of dorsal-fin origin, decreasing towards caudal-fin base. Head profile slightly convex, head length 1.0–1.2 times in body depth. Snout slightly pointed, its length 1.2–1.4 times in postorbital length. Eye diameter 3.4–4.7 times in head depth at eye, 1.2–1.5 times in interorbital width. Caudalpeduncle length 0.9–1.0 times in its depth. Caudal peduncle relatively high (8.9–10.9 % SL) and short (8.9–10.6 % SL). Suborbital spine simple, without laterocaudal process in types, with a laterocaudal process in additional materials, reaching slightly beyond centre of eye. Dorsal-fin origin equidistant from base of caudal fin and tip of snout. Pelvic fin short, not reaching anus. Pelvic-fin origin below vertical through base of first or second branched dorsal-fin ray. No pelvic axillary lobe. Margin of dorsal and anal fins straight. Caudal fin truncate. Anal fin not reaching caudal-fin base. No dorsal or ventral keels on caudal peduncle. Largest recorded specimen 98.2 mm SL.

Dorsal fin with 6½ branched rays. Anal fin with 5½ branched rays. Caudal fin with 7+7 (6) or 8+7 (1) branched rays. Pectoral fin with 7 (2) or 8 (5) branched rays and pelvic fin with 5 (5) or 6 (2) branched rays. Body completely covered by embedded scales. Subdorsal scales rounded, with reduced and eccentric focal zone. Mouth arched. Lips thin, furrowed, mental lobes short. Lower lip interrupted at middle ( Fig. 5 ). Rostral barbel reaching base of mandibular barbel. Mandibular barbel reaching to or slightly beyond vertical from nostril. Maxillary barbel reaching vertical from front border or middle of eye. Focus of scale clear, located in posterior region of scale ( Fig. 6 ).

TABLE 2. Proportional morphometry of Cobitis avicennae . Values for holotype and paratypes.

Holotype Paratypes

Male Males Females

Standard length (mm) 68.4 65.8 65.2 80.9 93.8 98.2 98.0 In percent of standard length

Sexual dimorphism. Males with a single lamina circularis at base of first branched pectoral-fin ray ( Fig. 7 ). Lamina circularis almost ovoid reaching posterior to 3rd segment of first branched pectoral-fin ray ( Fig. 7 ). Lamina circularis absent in females. Females larger than males, males with a longer pectoral fin (pectoral-fin length 17-19 % SL vs. 10–12% in females).

Coloration. Body whitish with a dark-brown pigmentation pattern organised in one mid-dorsal and four lateral zones. Flank with a golden gloss in live specimens. Mid-dorsal pigmentation consisting of a series of 14–17 often fused, irregularly shaped blotches. Zone Z1 with many minute to small spots, narrower than Z2, reaching to caudalfin base. Zone Z2 with 25–30 oblong or roundish spots and blotches about 1–1½ eye diameter, reaching to caudalfin base. Zone Z3 with many very small spots on predorsal flank reaching to anal-fin base in some individuals, to dorsal-fin origin in others. Zone Z4 with 12–17 roundish, irregularly oblong or ovoid blotches ( Fig. 4 ). A small comma-shaped black spot on upper caudal-fin base. An additional smaller, comma-shaped or roundish spot on lower caudal-fin base, absent in some individuals. Upper part of head, opercle and snout covered by small black spots. A dark brown stripe from eye to snout. Fins yellow-orange in live, hyaline in preserved specimens. Dorsal and caudal fins with 5–6 dark-brown, sometimes irregular vertical bars in individuals larger than 65 mm SL, 2–5 bars in smaller fishes. Very small dark brown spots on ventral body between pectoral and caudal-fin base, usually restricted to few spots or no spots anterior to pelvic-fin base. Dark brown, elongated blotches along each fin ray in paired fins. Barbels whitish, rarely pigmented by small dark-brown spots in large specimens.

Distribution. Cobitis avicennae was found in the Gamasiab and Sepidbarg rivers, tributaries of the Karoun. Also mentioned from the Karkheh ( Abdoli 2000) in Hamedan and Kermanshah provinces, western Iran ( Fig. 8 ).

Etymology. The species name avicennae is in honor of the Persian polymath Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā (Persian: Pur-e Sina [ˈpuːr ˈsiːnɑː] "son of Sina "; c. 980 – June 1037), commonly known as Ibn Sīnā or by his Latinized name Avicenna (here used as a noun in the genitive case). Avicenna is regarded as the most influential polymath of the Islamic Golden Age: he wrote almost 450 treatises on a wide range of subjects. His mausoleum is in Hamedan City, near the Gamasiab River where C. avicennae has been collected.

Proposed common name. Zagros spined loach. Loach-e-khardare-e-Zagros (Farsi).

Notes on habitat. At the type locality of C. avicennae , at 1610 m altitude, the Dehno is a shallow and narrow (up to 5 m wide) stream with diverse structures (pools, riffles, gravel bed, sandy shore, etc.). When the fishes were collected, the water was clear with swift current. The specimens were found in shallow water (30–50 cm depth) above gravel ( Fig. 9 ).

Remarks. The Karkheh and Karun rivers, in which C. avicennae was found, flow from the east into the Tigris. To date, Cobitis kellei is the only Cobitis species with a single lamina circularis in males known to occur in the Persian Gulf basin. While there has been intensive field work in the upper Tigris in Turkey, no individual of C. kellei has been found since the collection of the type series (E. Ünlü, pers. comm. 2013). JF and E. Ünlü surveyed the type locality and many adjacent streams also without success. The type material of C. kellei at ISBB (now ITBS) is not accessible. It had been on loan to Teodor Nalbant and could not be located following his death in 2012 (JF: email correspondence with the daughter of T. Nalbant). Therefore, we based our comparison of C. avicennae and C. kellei on the limited information available from the description of C. kellei by Erk'akan et al. (1998). Cobitis avicennae is distinguished from C. kellei by the Z4 consisting of 12–17 roundish or oval blotches, larger than eye diameter (vs. Z4 consisting of minute and rounded spots smaller than eye diameter).

Comparative material. Cobitis linea : ZM-CBSU 4132–4146A; 15, 37.6 – 50.3 mm SL, Iran, Fars prov., stream Ghadamgah, a tributary to Kor River, 30°15'23"N, 52°25'36"E.

Cobitis faridpaki : GUIC CC1403M-1405; paratypes, 25, 48.5 – 67.4 mm SL, Iran, Mazandaran prov., Siahroud River, 36°26'85"N, 52°56'70"E.

Cobitis keyvani : GUIC CC1389MA-CC1391; paratypes, 20, 37.4 – 80.3 mm SL, Iran, Mazandaran prov., stream Keselian in Talar drainage, 36°11′74"N, 53°00′92"E.

Figures

FIGURE 3. Cobitis avicennae, GUIC CC 1462 MA, holotype, male, 68.4 mm SL, Iran, Gamasiab River (above: lateral view in life; below: dorsal view in preservative).

FIGURE 4. Cobitis avicennae, GUIC CC 1462 M, paratypes, lateral and dorsal views, from top to bottom: 65.2, 65.8 and 80.9 mm SL, Iran, Gamasiab River.

FIGURE 5. Cobitis avicennae, GUIC CC 1462 M, paratype, 98 mm SL, Iran: Gamasiab River.

FIGURE 6. Scales of (a), C. avicennae, GUIC CC 1462 M, paratype, 65.2 mm SL; (b), C. amphilekta, ZMMU P- 3751, paratype, 68.3 mm TL (modified from Vasil’eva & Vasil’ev 2012).

FIGURE 7. Cobitis avicennae, first branched ray of pectoral fin showing lamina circularis, right side, dorsal view, GUIC CC 1462 M, paratype, 40.1 mm SL.

FIGURE 8. Records of Cobitis species in the Persian Gulf, Kor and the southern Caspian Sea basins. C. amphilekta, C. avicennae, C. faridpaki, C. kellei, C. keyvani, C. linea.

FIGURE 9. Stream Dehno; type locality of C. avicennae.