Alburnoides damghani, Roudbar, Arash Jouladeh, Eagderi, Soheil, Esmaeili, Hamid Reza, Coad, Brian W. & Bogutskaya, Nina, 2016

Roudbar, Arash Jouladeh, Eagderi, Soheil, Esmaeili, Hamid Reza, Coad, Brian W. & Bogutskaya, Nina, 2016, A molecular approach to the genus Alburnoides using COI sequences data set and the description of a new species, A. damghani, from the Damghan River system (the Dasht-e Kavir Basin, Iran) (Actinopterygii, Cyprinidae), ZooKeys 579, pp. 157-181 : 162-170

Taxon classification Animalia Cypriniformes Cyprinidae

Alburnoides damghani sp. n. Figs 3, 4, 5, 6

Type locality.

Cheshmeh Ali (Ali Spring), Damghan River tributary, Iran.

Holotype.

CMNFI 2015-0091, female, 67.0 mm SL, Iran, Semnan Prov., Cheshmeh Ali, Damghan River tributary, near Damghan city, Dasht-e Kavir Basin, 36°16'45.6"N, 54°05'01.6"E, altitude 1569 m, 22 August 2011, coll. H.R. Esmaeili, A. Gholamifard, G. Sayyadzadeh, R. Zamaniannejad.

Paratypes.

ZM-CBSU 2011-1, 15 specimens, 57.1−79 mm SL, same data as holotype; CMNFI 2015-0091A, 24 specimens, 54.6−84.4 mm SL, same data as holotype; ZM-CBSU 2012-1, 3 specimens, 83.9−89.7 mm SL, same data as holotype, 06 July 2012, coll. S. Eagderi.

Diagnosis.

Alburnoides damghani sp. n. is distinguished by having a combination of character states which includes a weakly-developed, variably-scaled, ventral keel from completely scaleless to completely scaled; a stout short snout with tip of the mouth cleft on a level with the lower margin of the pupil or lower; a small eye (eye horizontal diameter slightly to markedly less than interorbital width); commonly 8½ branched dorsal-fin rays; commonly 11− 12½, branched anal-fin rays; 40−46(47) total lateral-line scales (40-46 scales to posterior margin of the hypurals); 2.5-4.2 and 2.5-4.1 pharyngeal teeth; 6−8 total gill rakers in outer row on first left arch; 39−41, commonly 40, total vertebrae; 12−14, commonly 13, predorsal vertebrae; abdominal vertebral region most commonly equal to or longer than caudal region (vertebral formulae 20+20 and 21+19).

Description.

Description of holotype (Fig. 3). The caudal-fin lobes are rounded and the fin is shallowly forked. A ventral keel between the pelvics and the anal fin is scaleless for 1/3 of the length in front of the anus. There is a pelvic axillary scale and scales extend over the proximal bases of the anal fin forming a sheath. The upper body profile is convex, similar to the lower profile. The body is relatively thick and the caudal peduncle short and deep (its depth enters the length 1.7 times).

The eye is small, its horizontal diameter enters interorbital width 1.2 times. The snout is short and stout, its length only slightly exceeds the eye diameter. The upper jaw slightly projects over the lower jaw. The mouth is small, terminal, the mouth cleft is slightly curved, and the tip of the mouth cleft is on a level with the lower margin of the pupil. The posterior end of the lower jaw is on a vertical with the anterior margin of the pupil. The body depth enters SL 3.2 times, HL enters 3.7, predorsal length 1.8, caudal peduncle depth 7.7, caudal peduncle length 4.7, length of longest dorsal fin ray 4.4, and length of longest anal-fin ray to scale sheath 6.6. Eye horizontal diameter enters HL 3.9 times, snout length enters 3.4, and interorbital width 3.2. Pectoral-fin length enters pectoral-fin origin to pelvic-fin origin distance 1.2 times and pelvic-fin length enters pelvic-fin origin to anal-fin origin distance 1.1 times.

Dorsal-fin rays are 4 unbranched and 8½ branched, anal fin rays are 3 unbranched and 12½ branched, pectoral-fin branched rays are 13, and pelvic-fin branched rays are 7. The anal-fin origin is on a vertical from the posterior end of the dorsal-fin base. Total lateral-line scales number 46 and those to posterior margin of hypurals 44, scales around caudal peduncle 17, 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 midline predorsal scales are 27. Pharyngeal teeth 2.5-4.2. Gill rakers number 6, they are short and stubby, the longest touching the adjacent one when appressed. Total vertebrae number 40 (abdominal vertebrae 20, caudal vertebrae 20). Predorsal vertebrae number 13.

The peritoneum is silvery with fine melanophores. The lateral line is clearly delineated by darker pigment above and below, but this is obscured on the caudal peduncle by the flank stripe. Some pigment on flank scales above the lateral line give the impression of stripes. A mid-flank stripe is evident, darkest on the caudal peduncle. The back and top of the head are dark, the belly is light with almost no melanophores. Melanophores are dense dorsally on the flank becoming progressively less ventrally. All fins have melanophores lining the rays, and the dorsal, anal and caudal fins have melanophores on the membranes, with very few melanophores on the pectoral- and pelvic-fin membranes. The unbranched pectoral-fin ray is lined with melanophores on its inner margin.

Description of paratypes. General appearance of body is shown in Figures 2-4 and morphometric data are given in Table 3. Body compressed but thick, upper body profile clearly convex, similar to the lower profile. The eye is small, always less than interorbital width (eye horizontal diameter enters interorbital width 1.1−1.4 times). Snout short and stout, only slightly pointed, snout length about equal to eye horizontal diameter. Mouth short, posterior end of upper jaw commonly in front of vertical with anterior margin of eye, posterior end of lower jaw on about vertical with anterior margin of pupil. Mouth terminal, but mouth cleft more or less markedly curved and tip of mouth cleft is on or below a level from lower margin of the pupil. Upper jaw slightly produced over lower jaw in most specimens, especially larger-sized. Ventral keel between pelvic and anal fin not sharp and weakly pronounced, variably scaled (examined in 24 paratypes): completely scaleless (in 7 specimens), scaleless along 3/4 (4 specimens), 2/3 (4 specimens), 1/2 (5 specimens), 1/4 (2 specimens), 1/5 (1 specimen) of keel length in front of the anus or completely scaled (1 specimen). Pelvic axillary scale present extending over the proximal base of the anal fin. Caudal fin shallowly forked with rounded lobes. Anal-fin origin at the vertical of the posterior end of the dorsal fin base (Fig. 5) or in front of it (Fig. 4). The dorsal-fin outer margin is truncate to slightly convex and the anal-fin outer margin is slightly concave. For measurement and ratios see Table 4.

In 24 paratypes (CMNFI 2015-0091): the lateral line is complete with 1 or 2 unpored scales at the posterior end of the lateral series, total lateral-line scales 40 (1), 41 (1), 42 (4), 43 (3), 44 (7), 45 (3), 46 (2) or 47 (1), lateral-line scales to the margin of hypurals 40 (2), 41 (3), 42 (7), 43 (5), 44 (1), 45 (3) or 46 (1), total gill rakers in the outer row on first left arch number 6 (5), 7 (16) or 8 (3), gill rakers are rather thick, short and widely spaced, not touching the adjacent raker base when appressed, pharyngeal tooth counts are 2.5-4.2 in 19 specimens from 25 examined and 2.5-4.1 in 5 specimens. The general topography of cephalic sensory canals and numbers of pores is typical of most Alburnoides (e.g., Coad and Bogutskaya 2009). The supraorbital canal is not lengthened in its posterior section and has 8-10, commonly 9 pores with 2−4, commonly 3, and 5−7, commonly 6, canal openings on the nasal and frontal bones, respectively. The infraorbital canal has 13−17, commonly 14−15, pores with 4 (rarely 3 or 5) canal openings on the first infraorbital. The preopercular-mandibular canal is complete, with 13-17, modally 14-16, pores and commonly 5 or 6 and 8 or 9 canal openings on the dentary and preoperculum, respectively. The supratemporal canal is complete, with 5 (rarely 6 or 7) pores.

In 39 paratypes (CMNFI 2015-0091 and ZM-CBSU 2011-1): dorsal-fin unbranched rays 3 or 4 (in 4 specimens only), branched dorsal-fin rays 7½ (5), 8½ (33) or 9½ (1) (mean 7.9 [without ½], sd 0.5). Anal-fin unbranched rays 3, branched anal-fin rays 10½ (2), 11½ (11), 12½ (20) or 13½ (6) (11.8 [without ½], sd 0.8). Total vertebrae number 39 (4), 40 (28) or 41 (7) (40.1, 0.5). Predorsal vertebrae number 12 (5), 13 (26) or 14 (8) (13.1, 0.6). Abdominal vertebrae number 20 (31) or 21 (8) (20.2, 0.4). Caudal vertebrae number 19 (8), 20 (28) or 21 (4) (19.9, 0.5). The vertebral formulae are 20+20 (in 24 specimens, Fig. 6), 21+19 (5), 20+21 (4), 20+19 (3), 21+20 (3), 20+19 (1) or 19+20 (1). Thus, the caudal vertebral region most commonly is equal to the abdominal region (in 23 paratypes) or longer than the latter (in 11), the difference between abdominal and caudal counts being +2 (5), +1 (6), 0 (23) or -1 (5).

Mature males bear tubercles on the unbranched and branched fin rays, in a single row branching into two distally on the branched rays. These are most prominent on the pectoral, pelvic and anal fins. Tubercles line scale margins in a single row of up to six tubercles, in particular over the anal fin and on the lower caudal peduncle. Scales below the dorsal fin are also lined with tubercles but to a much lesser extent than those above the anal fin. Flank scales generally may bear tubercles but many do not and anterior flank scales may have only a single tubercle. Minute tubercles are present on the dorsal and upper head surface.

Coloration of live specimen.

Pigmentation consists of a darker back fading to a silvery white belly, three to four rows of large dark spots above lateral line starting from posterior part of operculum to posterior level of anal fin, continuing with two rows behind anal fin to base of caudal fin, small black spots on the operculum, behind and below the eye, smaller and less dark spots between the eye and upper jaw, a lateral line demarcated by pigment above and below it (the typical “stitched” pattern in many Alburnoides species), base of anal, pelvic, pectoral and dorsal fins almost reddish-orange, caudal-fin base pale or faint yellow. Posterior free margin of dorsal, anal, caudal and pelvic fins whitish hyaline, faint pigmentation on the caudal-fin centre branching distally to follow the inner margins of the fin fork, and fine pigmentation on the proximal part of dorsal- and anal-fin rays, darker in dorsal-fin rays (Figs 3, 4).

Etymology.

The species name links to the type locality, Damghan (Cheshmeh Ali, Damghan River tributary). Proposed common name: Damghan riffle minnow, Mahi-e-Khayateh-e-Damghan (Farsi).

Distribution and conservation.

Alburnoides damghani sp. n. has only been collected from its type locality, Cheshmeh Ali in the Damghan River system, north Dasht-e Kavir Basin (N-Iran) (Fig. 1). Aphanius kavirensis Esmaeili, Teimori, Gholami & Reichenbacher, 2014 which is restricted to this spring, co-exists with Alburnoides damghani sp. n. ( Esmaeili et al. 2010, 2014a, b). Its restricted range, drought in recent years and introduction of the exotic carnivorous fish, Oncorhynchus mykiss (Walbaum, 1792) (personal observation of HRE) may threaten this endemic species.

Habitat

(Fig. 7). At the Cheshmeh Ali sampling site, the spring was about 5−10 m wide, with substrate consisting of coarse gravel and boulders, good riparian vegetation and almost fast-flowing and transparent waters. The physicochemical parameters at the spot were: dissolved oxygen, 7.54 mg/L, total dissolved solids, 318 mg/L, salinity, 0.32‰, conductivity, 552 μm /cm, pH: 7.97 and water temperature 23.25 °C.

Comparative remarks.

Alburnoides damghani sp. n., together with other Iranian species of the genus, belongs to the south-eastern group of species distributed in the eastern area of the genus distribution and characterised by commonly 4 pharyngeal teeth in the long row on the right 5th ceratobranchial ( Bogutskaya and Coad 2009). As most distinguishing characters for species identification are counts (numbers of branched rays in the dorsal and anal fins, gill rakers, lateral-line scales and vertebral counts), a MDS statistical analysis was performed based on mean values of these counts (Table 5) to visualize the level of similarity of individual samples (species) in the Caspian Sea basin localities and adjacent endorheic basins. Frequences of occurrence of individual counts by characters can be found in earlier publications ( Bogutskaya and Coad 2009, Coad and Bogutskaya 2009, 2012, Mousavi-Sabet et al. 2015a, b). The map plotting each sample in two-dimensional space is presented in Fig. 9; stress value is 0.04 (very low) meaning that the results are highly reliable ( Davison 1983). The proximity of the examined samples to each other indicate how similar they are, and Alburnoides damghani sp. n. stands far apart from all other species, being relatively closer to Alburnoides namaki , Alburnoides varentsovi and Alburnoides sp. (Amu Darya River), morphologically.

When compared to Alburnoides species distributed in the Caspian Sea basin and adjacent endorheic basins in Iran, Alburnoides damghani sp. n. is clearly different from Alburnoides parhami from the Atrek River drainage by having four teeth in the long row on the 5th ceratobranchial (vs. 5). By having five pharyngeal teeth in the long row on the 5th ceratobranchial (this character state is invariably present in all examined specimens), Alburnoides parhami stands apart from all other species in Iran. Besides the number of teeth, Alburnoides damghani sp. n. is distinguished from Alburnoides parhami by having three unbranched dorsal fin rays (vs. often four, found in 13 from 35 examined specimens), commonly a partly scaleless ventral keel (vs. sharp and commonly scaleless), a terminal mouth with the tip of the mouth cleft on or below a level from lower margin of the pupil (vs. an upturned terminal mouth with the tip of the mouth cleft on a level with the upper half of the pupil), and 40−46 lateral-line scales to the margin of the hypurals (vs. 45−51).

Alburnoides damghani sp. n. differs from both Alburnoides petrubanarescui (which is the most morphologically peculiar species in the area possessing the lowest number of anal-fin branched rays) and Alburnoides namaki (a species phylogenetically close to Alburnoides damghani , see Fig. 2) by a slightly pointed snout (vs. markedly rounded), a terminal mouth with the tip of the mouth cleft on or below a level from lower margin of the pupil (vs. subterminal, with the tip of the mouth cleft on or below a level from lower margin of the eye), and 40−46 lateral-line scales (to the margin of the hypurals) (vs. 42−51, commonly 44−48). Alburnoides damghani sp. n. further differs from Alburnoides petrubanarescui by commonly 8½ branched dorsal-fin rays (vs. commonly 7½), commonly 11− 12½ branched anal-fin rays (vs. commonly 9½), abdominal vertebrae commonly 20 (vs. commonly 21), and a ventral keel commonly partly or completely scaleless (vs. completely scaled). From Alburnoides namaki , Alburnoides damghani sp. n. can be further distinguished by a smooth and sometimes partly scaled ventral keel (vs. sharp and completely scaleless) and a higher number of predorsal vertebrae (modally 13 vs. modally 12).

Alburnoides coadi (Fig. 9) is the phylogenetically closest sister to Alburnoides namaki and the two species are rather similar in shape of the head, mouth and body; however, the two species are different by a complex of meristic characters (Fig. 9). Alburnoides damghani sp. n. differs from Alburnoides coadi , first of all, by a lower number of the lateral-line scales to the margin of the hypurals (40−46 vs. 47−51), a higher number of gill rakers (8−10, modally 8 and 9 vs. 6−8, modally 7), and a lower number of total vertebrae (modally 40 vs. modally 41).

Alburnoides damghani differs from Alburnoides holciki and Alburnoides qanati by a relatively small-sized eye with horizontal diameter slightly to markedly less than interorbital width (vs. large eye with eye diameter about equal to or larger than interorbital width), a tip of the mouth cleft on a level with or below the lower margin of the pupil (vs. on a level with the upper half to the upper margin of the pupil), and a shallowly forked caudal fin with rounded lobes (vs. clearly forked caudal fin with pointed lobes). Alburnoides damghani sp. n. is further distinguished from Alburnoides holciki from the Hari River drainage in northeastern Iran by a usually smooth and often partly scaled ventral keel (vs. sharp and scaleless), a lower number of total lateral-line scales (44−47 vs. 47-57), a lower number of anal-fin rays (commonly 11− 12½ vs. 13 –16½), a lower number of total vertebrae (39−41, usually 40 vs. 40-42, usually 41), an abdominal vertebral region most commonly equal to or longer than caudal region, and most common vertebral formulae 20+20 and 21+19 (vs. abdominal region shorter than caudal region, and most common vertebral formulae 20+21, 20+22 and 19+21). Alburnoides damghani further differs from Alburnoides qanati (the Pulvar River drainage of Fars Province in southern Iran) by modally 12½ branched dorsal-fin rays (vs. modally 11½).

The new species differs from Alburnoides eichwaldii by a lower number of total lateral-line scales, 44−47 (vs. 44−56, commonly over 47), a lower number of gill rakers, 6−8 (vs. 6−10. commonly 8 and 9), a lower number of total vertebrae, 39−41 with a mode of 40 (vs. (38, 39)40-43 with a modal range of 41−42), a lower number of adbominal vertebrae with a clear mode of 20 (vs. clear mode of 21), a lower number of predorsal vertebrae, 12−14 with a mode of 13 (vs. 13−15 with a mode of 14), and the most common vertebral formulae 20+20 and 21+19 (vs. 21+21, 21+20 and 20+21).

Alburnoides damghani sp. n. can be distinguished from Alburnoides tabarestanensis from the type locality (the Tajan River) by a commonly partly scaled keel (vs. a commonly completely scaleless ventral keel), a lower number of total lateral-line scales (44−47 vs. 47−52), commonly 11− 12½ branched anal-fin rays (vs. 12− 14½, with a mode of 13½, branched anal-fin rays), and a greater head depth at nape (74−84% HL vs. 73−75% HL).

As can be seen from Fig. 8, Alburnoides sp. from rivers in the south of the Talysh Mountains and west of the Safid River (examined samples are mostly from estuarine areas of the rivers in Gilan Province), Alburnoides samiii from the type locality (Safid River drainage), and Alburnoides tabarestanensis from different localities (other than the type one) cannot be clearly discriminated by their meristic character states. Also, they are rather similar by the head and body shape, having most commonly a horizontal, slightly curved mouth, with a tip of the mouth cleft often on a level below the lower margin of the pupil, a slightly to markedly rounded snout, a variably but commonly well forked caudal fin. The ventral keel in these species is partly to completely scaled, considerably varying in and between samples. Discussion on morphological differences between these species/groups of populations is beyond the scope of this paper; Alburnoides damghani sp. n. clearly differs from this complex by having a lower number of lateral-line scales, 40−46 to posterior margin of hypural (vs. 42−56, commonly over 45, averaging 48−49).

Comparative material.

Extensive comparative material is listed in Bogutskaya and Coad (2009) and Coad and Bogutskaya (2009, 2012). Data for Alburnoides coadi (Nam River) and Alburnoides parhami (Baba-Aman stream) from the type localities are taken from Mousavi-Sabet et al. (2015b). Additional material: Alburnoides eichwaldii ZM-CBSU 2007(1386a), 20, Iran, Ardabil Prov., Almas River, Aras River system, Caspian Sea basin, 38°09'31"N, 48°11'37"E, 3 October 2007, coll. H.R. Esmaeili; Alburnoides samiii ZM-CBSU 2009 (1388a), 29, Iran, Gilan Prov., Safid Rud River, at Emamzade Hashem, 37°01'11"N, 49°38'E, 29 June 2009, coll. H.R. Esmaeili, S. Babai; Alburnoides samiii ZM-CBSU A189-210, 21, Iran, Mazandaran Prov., Siah River at Sarookolah, Caspian Sea basin, 36°27'13"N, 52°53'38"E, 29 June 2009, coll. H.R. Esmaeili; Alburnoides cf. tabarestanensis ZM-CBSU 2009(1388b), 15, Iran, Mazandaran Prov., Keslian River, Talar River drainage, at Shirgah, Caspian Sea basin, 36°18'15"N, 52°53'07"E, 31 June 2009, coll. H.R. Esmaeili, H. Mostafavi, Alburnoides Teimori, Alburnoides Gholamifard; Alburnoides cf. tabarestanensis ZM-CBSU 2011(1389), 25, Iran, Mazandaran Prov., Shirin River, Caspian Sea basin, 36°08'59"N, 53°50'02"E, 9 November 2011, coll. H. Mostafavi; Alburnoides cf. tabarestanensis ZM-CBSU 2007(1386b), 10, Iran, Golestan Prov., Gorgan River at Zaringol, Caspian Sea basin, 36°50'39"N, 54°58'24"E, 6 August 2007, coll. H.R. Esmaeili; Alburnoides parhami CMNFI 2016-0050, 25, Iran, Khorasan-e Shomali Prov., Tabarak Dam, Atrak River tributary, Ghoochan, Caspian Sea basin, 37°08'09"N, 58°40'44"E, 25 August 2011 coll. H.R. Esmaeili, Alburnoides Gholamifard, G. Sayyadzadeh, R. Zamaniannejad.