Alburnoides qanati, Coad & Bogutskaya, 2009

Coad, Brian & Bogutskaya, Nina, 2009, Alburnoides qanati, a new species of cyprinid fish from southern Iran (Actinopterygii, Cyprinidae), ZooKeys 13 (13), pp. 67-77 : 68-74

Alburnoides qanati sp. n.

urn:lsid:zoobank.org:act:EE6B0CF8-3FF5-459F-8484-B3048878C9CF

Figs 1-2

Holotype. CMNFI 1977-0509 . Female. 81.5 mm TL, 65.0 mm SL, Iran, Fars, at source and along stream of a qanat at Naqsh-e Rostam, Pulvar River system, 29°59’30”N, 52°54’00’’E, 1660 m altitude, 6 October 1976, coll. Brian W. Coad, Sylvie Coad and John M. Gunn.

Paratypes. CMNFI 1977 -0510, 178 specimens, 24.9-72.5 mm SL, 15 males 50.0-72.0 mm SL and 15 females 54.0- 72.5 mm SL counted and measured, same data as holotype.

Diagnosis. The species is distinguished by a combination of characters which includes a large eye, the orbit width exceeding both the snout length and the interorbital width, a scaled ventral keel behind the pelvic fins along the abdomen to the anus, commonly 43-47 lateral line scales to posterior margin of hypurals, 2.5-4.2 pharyngeal teeth, commonly 8½ branched dorsal-fin rays, 10-12½ branched anal-fin rays, 40-41 total vertebrae, andthe caudal vertebral region equal or longer then the abdominal region (vertebral formulae 20+20 or 20+21).

Description of holotype. A ventral keel between the pelvics and the anal fin is developed but is completely covered by scales. There is a pelvic axillary scale and scales extend over the proximal bases of the anal fin. The lateral line is decurved and only the last few scales are elevated and on the mid-caudal peduncle. Dorsal fin rays are 3 unbranched and 8½ branched, anal fin rays are 3 unbranched and 12½ branched, branched pectoral fin rays are 15, pelvic fin branched rays are 7. The anal-fin origin is behind the posterior end of the dorsal-fin base. Lateral line scales to posterior margin of hypurals number 46, scales above lateral line to dorsal fin origin are 9, scales below lateral line to anal fin origin are 4, scales below lateral line to pelvic fin origin are 4, and total vertebrae are 41 (including 4 Weberian vertebrae and last complex centrum), comprising 20 abdominal and 21 caudal vertebrae.

The upper body profile is straightened while the lower profile is considerably convex. The snout is short and slightly pointed. The mouth is upturned, the tip of the mouth cleft is on a level with the upper margin of the pupil. The body depth enters standard length 3.6 times, head length enters 3.8, predorsal length 2.0, postdorsal length 2.8, caudal peduncle depth 8.6, caudal peduncle length 4.6, length of longest dorsal fin ray 4.4, and length of longest anal fin ray to scale sheath 6.3. Orbit width enters head length 3.2 times, snout length enters 3.3, and interorbital width 3.3. Pectoral fin length enters pectoral fin origin to pelvic fin origin distance 1.1 times, and pelvic fin length enters pelvic fin origin to anal fin origin distance 1.3 times.

Pigmentation of the holotype in 5% formalin consisted of a dark lateral line dividing the hypaxial and epaxial muscle masses and a weakly developed stripe of black pigment on mid-flank prominent posteriorly on the caudal peduncle but fading over the pectoral fin and often interrupted anteriorly. The lateral line pores were lined by pigment dorsally and ventrally. A mid-dorsal line was apparent before the dorsal fin, weakly developed behind the fin. The fins were mostly hyaline with some black pigment lining the fin rays of the dorsal and caudal fins, the dorsal rays of the pectoral fins and the anterior rays of the anal fin.

Description of paratypes. The following description is based primarily on the 15 males and 15 females listed above.

The body is markedly compressed. The upper body profile is convex or, in larger specimens, slightly to markedly straightened while the lower profile is considerably convex. The ventral keel between the pelvics and anal fin is not sharp and is completely covered by scales in all specimens but four possessing a short scaleless portion of keel (about ¼ of keel length) just in front of the anus. The anal-fin origin is behind the posterior end of the dorsal-fin base. The snout is short and slightly pointed. Themouth is terminal to upturned, with the tip of the mouth cleft on a level from slightly above the middle of the eye to the upper margin of the pupil. The mouth cleft is always turned upward, never horizontal, the lower jaw slightly to moderately projecting relative to the upper jaw, and the junction of the lower jaw and the quadrate is on about a vertical through the anterior eye margin.

Body depth enters standard length 3.3-3.9 times (mean 3.6, standard deviation 0.14), predorsal length 1.8-2.3 (2.0, 0.09), postdorsal length 2.6-3.1 (2.8, 0.12), caudal peduncle depth 7.9-9.4 (8.7, 0.36), caudal peduncle length 4.0-5.3 (4.5, 0.28), length of longest dorsal fin ray 3.9-5.1 (4.4, 0.27), and length of longest anal fin ray to scale sheath 5.6-6.7 (6.3, 0.30). Orbit width enters head length 2.9-3.5 (3.2, 0.14) times, snout length 3.1-4.0 (3.5, 0.17), and interorbital width 3.0-3.8 (3.4, 0.18).

Head length is longer in males than in females (p<0.05>0.025), in standard length for males 3.3-3.9 (3.6, 0.17) and for females 3.5-3.9 (3.8, 0.11). Pectoral fin length and pelvic fin length are also longer in males. Pectoral fin enters pectoral fin origin to pelvic fin origin distance for males 0.9-1.1 (1.0, 0.07) and for females 1.0-1.2 (1.1, 0.08), and pelvic fin length enters pelvic fin origin to anal fin origin distance for males 0.9-1.2 (1.1, 0.08) and for females 1.1-1.3 (1.2, 0.06).

Dorsal fin unbranched rays commonly 3, 4 in 3 specimens, dorsal fin branched rays 7½ (3) or 8½ (27) (mean 7.9, standard deviation 0.25), anal fin unbranched rays 3, anal fin branched rays 10½ (3), 11½ (22), 12½ (5) (11.1, 0.49), branched pectoral fin rays 13(4), 14(20) or 15(6) (14.1, 0.58), pelvic fin branched rays 7(30). A pelvic axillary scale is present and the anal fin base is proximally overlain by flank scales. The dorsal fin outer margin is truncate to slightly rounded and the anal fin outer margin is truncate to slightly concave.

The lateral line is complete with none, 1 or 2 unpored scales at the posterior end of the lateral series; lateral line scales to posterior margin of hypurals 41(1), 42(1), 43(5), 44(6), 45(3), 46(7), 47(5) 48(1) or 49(1) (45.0, 1.88); scales above lateral line to dorsal fin origin 9(9), 10(18) or 11(3) (9.8, 0.61), scales below lateral line to pelvic fin origin 3(4), 4(19) or 5(7) (4.1, 0.61), and scales below lateral line to anal fin origin 4(16), 5(13) or 6(1) (4.5, 0.57). Total scale radii 8(1), 9(1), 10(4), 11(8), 12(20), 13(17), 14(16) 15(12), 16(7), 17(3) or 18(1) (13.2, 1.91); scale radii are restricted to the posterior field encroaching laterally, circuli are eccentric and the focus is anteriorly located. Total gill rakers in the outer row on first left arch number 6(4), 7(4), 8(21) or 9(1) (7.6, 0.76); gill rakers are very short and widely spaced, not touching the adjacent raker when appressed. Total vertebrae including 4 Weberian vertebrae and last complex centrum number 40(16) or 41(14) (40.5, 0.51). Abdominal vertebrae (including intermediate ones; precaudal vertebrae auctorum) number 20 (in 28 specimens) or 21(12) (mean 20.1). Predorsal vertebrae (anterior to first dorsal pterygiophore) number 13 (24) or 14 (6) (13.2). Caudal vertebrae number 20 (18) or 21 (12) (20.4). The vertebral formula is 20+20 (16), 20+21 (12) or 21+20 (2). Thus, the caudal vertebral region most commonly (in 93% of examined specimens) is equal to or slightly longer then the abdominal region, the mean difference between abdominal and caudal counts being -0.3. A radiograph of a specimen with a vertebral formula 20+21 is shown in Fig. 2 .

Pharyngeal tooth counts are 2.5-4.2 in 10 fish examined with one additional fish being a variant with 2.4-4.0. Teeth are hooked at the tip and not serrated below it. The gut shape is a simple “S” with an occasional specimen showing a slight flexure to the left of the anterior loop. Th e peritoneum is rarely dark brown but usually is white-grey to light brown with black spots. A postcleithrum bone is present and reduced, or absent, in the pectoral fin skeleton.

The general topography of cephalic sensory canals and numbers of pores is typical of most Alburnoides , as described by Bogutskaya (1988). Th e supraorbital canal is not lengthened in its posterior section and has 7-11, commonly 8-10 pores (9 in 57% of canals; mean 8.8), with 2-4 (3 in 90%) and 5-7 (6 in 73%) canal openings on the nasal and frontal bones, respectively. Th e infraorbital canal has 10-15 pores (13 in 38%, 12 in 30%; 12.8) with 4 (93%) or 5 canal openings on the first infraorbital. The preopercular-mandibular canal is complete, with 11-17, modally 13-16, pores (14 in 38%; 14.4) with (3)4-6 (5 in 77%) and 7-10 (8 in 62%) canal openings on the dentary and preoperculum, respectively. Th e supratemporal canal is complete, with (4)5-7 (7 in 54%; 6.20) pores.

Overall colouration is silvery with the bases of the pectoral, pelvic and anal fins pink in life. An orange line parallels the anal fin base and the lateral line, lying midway between the two. The ventral surface of the head between the dentaries may be yelloworange and similarly coloured spots may be found on either side of the dorsal mid-line extending along the whole body. Faint yellow spots occur in rows along the flanks also.

Pigmentation in preserved fish is as described for the holotype although the lateral stripe is weakly-developed in some specimens, the mid-flank band of spots of black pigment may be variably developed, and the lateral line may be clearly or only faintly edged by pigment.

Etymology. The species is named for the qanat habitat in which it was found, now fast disappearing with the use of pump wells, and in recognition of the contribution to civilization made by the Iranian people through this innovative irrigation technique.

Distribution and habitat. To our knowledge, Alburnoides qanati is the southernmost Alburnoides species.This species is only found in the internal, endorheic drainage basin of the Kor [Kur] River which terminates in the salt lakes Tashk and Bakhtegan which are variably connected and distinct, with Tashk being the northern basin receiving the Kor River ( Fig. 3 ). The Pulvar [Polvār] River is the principal tributary to the Kor River (the classical Araxes) which rises in the Zagros Mountains. The type series was collected from a small stream which issues from a qanat ( Fig. 4 ) near the archaeological site of Naqsh-e Rostam to the northeast of Persepolis.

The qanat taps groundwater through an adit and is used to irrigate fields flanking the Pulvar River, without the need to raise water from the incised river bed. Qanat streams flow into the nearest watercourse, enabling fish to colonise them. Some are stocked with fish from the nearest natural water body ( Coad 1996). This qanat stream at 15.00 hours on 6 October 1976 had clear and colourless water, a temperature of 21°C, pH 6.8, conductivity 0.475 mS, the current was slow to medium, stream width was about 2 m and maximum depth was up to 1 m, the shore was grassy, plant life in the stream consisted of encrusting and submergent types, and the stream bed was gravel and mud. Other species caught in the stream were Alburnus cf. mossulensis , Capoeta cf. damascina and Paracobitis cf. malapterura . Barbus luteus is also found here.

Alburnoides qanati sp. n. was also collected from a locality further upriver in the Pulvar River basin ( CMNFI 1979-0060 , 4 , 21.0- 35.4 mm SL, Iran, Fars, spring and irrigation channel, 7 km north of Sa’adatabad , 30°06’N, 53°12’E; 18 April 1976; coll. B. W. Coad and S. Coad ). This material was not included into the paratypes because of the small size of the individuals.

Comparative remarks. The new species differs from most species of the genus, e.g. A. bipunctatus (Bloch, 1782) , A. eichwaldii , A. fasciatus (Nordman, 1840) , A. kubanicus Berg, 1932 , A. ohridanus , A. rossicus Berg, 1924 , A. smyrnae Pellegrin, 1927 , Alburnoides sp. from Amu Darya drainage, Alburnoides sp. from Danube drainage, and Alburnoides sp. from Eastern Ciscaucasus, by its completely or almost scaled ventral keel (vs. scaleless).

A completely scaled keel is also found in A. oblongus Bulgakov, 1926 distributed in the lower reaches of the Syr Darya and Alburnoides sp. from Orumiyeh Lake. Alburnoides oblongus also shares with A. qanati sp. n. such characters as a low number of anal-fin branched rays (9-11½) and a slightly upturned mouth. However A. oblongus is clearly distinguished from the new species by having smaller scales (49-54 lateral line scales to posterior margin of hypurals vs. 41-49), 21+19 or 22+19 vertebrae (vs. commonly 20+20 or 20+21), 2.5-5.2 or 1.5-5.1 pharyngeal teeth (vs. 2.5-4.2), 14-15 predorsal vertebrae (vs. 13-14, usually 13), more numerous gill rakers (10-13 vs. 6-9), a concave margin of the dorsal fin (vs. truncate or rounded), and a rounded anterior part of the anal-fin margin (vs. the whole margin clearly concave). Alburnoides sp. from Orumiyeh Lake differs, besides some other characters, by fewer dorsal-fin branched rays (commonly 7½ vs. 8½), fewer anal-fin branched rays (8-10½, commonly 9½, vs. 10-12½, commonly 11½) and 21+19 or 21+20 vertebrae (vs. 20+20 or20+21) the difference between abdominal and caudal counts averaging +1.4 (vs. -0.3).

The keel is variably scaled in A. taeniatus (Kessler, 1874) from Amu and Syr Darya, and two undescribed species of Alburnoides from Tigris River system in Iran. Alburnoides taeniatus differs from A. qanati sp. n. by having larger scales (36-42, commonly 38-40, lateral line scales to posterior margin of hypurals vs. 41-49, commonly 43- 47), 2.5-5.2 or 1.5-5.1 pharyngeal teeth (vs. 2.5-4.2), and 19+19, 19+18 or 20+18 vertebrae (vs. 20+20 or 20+21) the difference between abdominal and caudal counts averaging +0.8 (vs. -0.3). Both species from the Tigris as compared to A. qanati sp. n. have fewer vertebrae (37-40, averaging 38.9 and 39.0, vs. 40 or 41, averaging 40.5). Geographically close Alburnoides sp. from the Namak Lake basin, which is similar to A. qanati sp. n. in having commonly 20+20 vertebrae and 10-12½ anal-fin branched rays, is clearly different in having a very sharp scaleless ventral keel (vs. scaled) and fewer predorsal vertebrae (averaging 12.2 vs. 13.2).

Unnamed Alburnoides species mentioned above represent to our opinion unnamed distinct species we describe in a separate paper (Bogutskaya and Coad in press), so, we do not provide here their specific names to avoid using them in an unavailable way.

Figures

Figure 1. Alburnoides qanati sp. n., female holotype, 65.0 mm SL.

Figure 2. Alburnoides qanati sp. n., radiograph of a paratype, SL 58 mm SL. Arrow shows first caudal vertebra.

Figure 3. Map showing the type locality of Alburnoides qanati sp. n.: Pulvar River system, 29°59’30”N, 52°54’E.

Figure 4. Type locality of Alburnoides qanati sp.n., mouth of qanat and stream origin (photo by B.W. Coad).