Alburnoides diclensis, Turan, Davut, Bektaş, Yusuf, Kaya, Cüneyt & Bayçelebi, Esra, 2016

Turan, Davut, Bektaş, Yusuf, Kaya, Cüneyt & Bayçelebi, Esra, 2016, Alburnoides diclensis (Actinopterygii: Cyprinidae), a new species of cyprinid fish from the upper Tigris River, Turkey, Zootaxa 4067 (1), pp. 79-87 : 81-84

Alburnoides diclensis , new species

( Fig. 2 a, b)

Holotype. FFR 01118, 78 mm SL; Turkey: Hakkari Prov.: Eziki Stream, Tigris River drainage (37°40'38" N, 43°51'84" E); coll. C. Kaya and F. Kaya, 0 4 June 2014.

Paratypes. FFR 01119, 35, 53– 81 mm SL; same data as holotype. FFR 01056, 4, 42- 67 mm SL; Turkey: Hakkari Prov.: Eziki Stream, Tigris River drainage (37°40'38" N, 43°51'84" E); coll. C. Kaya and F. Kaya, 0 7 Aug. 2011. FFR 01055, 4, 35– 72 mm SL; Turkey: Hakkari Prov.: Zap Stream, Tigris River drainage; 37°41'28" N, 44°03'37" E; coll. C. Kaya and F. Kaya, 0 7 Aug. 2011.

Diagnosis. Alburnoides diclensis is distinguished from all species of Alburnoides in adjacent waters by the following combination of characters (none unique to the species): a poorly developed ventral keel between pelvic and anal fins, completely scaled or rarely without one scale in front of anus; body depth at dorsal-fin origin 25– 30% SL; caudal-peduncle depth 11–12% SL; head length 24–27% SL, its upper profile convex on snout; mouth terminal, with a marked chin; tip of upper lip not projecting beyond the lower lip (tip of both lips are equal to or upper lip slightly longer than lower lip); snout rounded, its length equal to or greater than eye diameter but smaller than interorbital distance; dark grey stripe clearly distinct on both anterior and posterior part of body but slightly distinct immediately behind the head, its width greater than eye diameter; pigmentation of lateral line distinct along anterior part of body, slightly distinct in posterior part of body; 48–53 lateral-line scales, 9–11 scale rows between lateral line and dorsal-fin origin, 4–6 scale rows between lateral line and anal-fin origin, 7½–9½ branched dorsalfin rays; 12½–15½ branched anal-fin rays; pharyngeal teeth 2.5–4.2, markedly hooked; number of total vertebrae 41–42 (mode of 41), comprising 20–21 (mode of 21) abdominal and 20–21 (mode of 21) caudal vertebrae.

Description. Maximum known size 81 mm SL. General appearance is shown in Figure 2 a, b; morphometric and meristic data are given in Tables 1 and 2 . Body moderately deep and its depth at dorsal-fin origin 3.3–4.0 times in SL, markedly compressed laterally. Caudal-peduncle depth 1.7–2.1 times in its length. Dorsal profile convex, ventral profile equal to or slightly convex than dorsal profile. Predorsal length 1.8–1.9 times in SL. Prepelvic length 2.1–2.2 times in SL. Head short, its length smaller than body depth at dorsal-fin origin (head length 0.8–1.0 times in body depth at dorsal-fin origin), dorsal profile straight or slightly concave at interorbital area, convex on snout. Snout long, with rounded tip, its length greater than eye diameter but smaller than interorbital distance. Mouth terminal, with marked chin, the tip of mouth cleft between level of middle of pupil and lower margin of pupil. The tip of upper lip commonly not projecting beyond the lower lip (tip of both lips are equal or upper lip slightly longer than lower lip). Lower jaw-quadrate junction almost reaching to anterior margin of eye. Dark grey stripe distinct both in anterior and posterior part of body, its width greater than eye diameter. The ventral keel poorly developed, completely scaled or rarely without one scale in front of anus.

Lateral line with 48 (3), 49 (6), 50 (6) and 51 (11), 52 (11) and 53 (6) scales; 9 (5), 10 (32) and 11 (6) scale rows between lateral line and dorsal-fin origin; 4 (2), 5 (38) and 6 (3) scales between lateral line and anal-fin origin. Gill rakers 2 + 4–5 = 6 (16) – 7 (4) on left side of first gill arch. Dorsal-fin height 0.9–1.1 times in HL, with 3 simple and 7½ (2), 8½ (37) and 9½ (4) branched rays, outer margin slightly convex, its origin markedly in front of mid-point of pelvic-anal distance. Pectoral fin somewhat long, not reaching pelvic-fin origin, outer margin convex, with 1 simple and 14 (4), 15 (23) and 16 (11) branched rays. Pelvic fin long, almost reaching the origin of anal fin, with 1 simple and 7 branched rays, outer margin slightly convex. Anal fin depth 1.2–1.4 times in HL, with 3 simple and 12½ (14), 13½ (25), 14½ (2) and 15½ (2) branched rays, outer margin concave. Caudal fin long, deeply forked, lobes pointed.

Alburnoides diclensis

Basin Persian Gulf Basin

Drainage Eziki Stream (a drainage of Tigris River)

Province Hakkari

Number of specimens 30

Pharyngeal teeth 2.5–4.2, markedly hooked. Number of total vertebrae 41(13) and 42 (10); predorsal vertebrae 13 (8) and 14 (15); abdominal vertebrae 20 (7) and 21 (16), caudal vertebrae 20 (6) and 21 (17); the caudal region approximately equal to the abdominal region, and the difference between the abdominal and caudal counts varies from +1 to –1, vertebral formulae 20+21 (7), 21+20 (6) or 21+21 (10).

Sexual dimorphism. The pectoral fin is longer in the males. In males, it almost reaches to the pelvic-fin origin whereas in the females, it does not approach the pelvic-fin origin ( Fig. 2 a, b).

Coloration. Formalin-preserved adults and juveniles light brown on back and upper part of flank, yellowish on lower part of flank and belly. Caudal, dorsal and anal fins light grey; pectoral and pelvic fins yellowish. Numerous small black spots on rays of dorsal, anal and caudal fins. Spots along lateral line above and below pores distinct in anterior part of body but indistinct on caudal peduncle in most specimens. A dark grey stripe present on upper part of flank from posterior margin of operculum to caudal peduncle, distinct in both anterior and posterior parts of body, its width equal to or slightly greater than eye diameter.

Distribution and notes on biology. Alburnoides diclensis is presently known only from the Great Zap and Eziki streams, upper drainages of the Tigris River ( Fig. 1 ). It inhabits swift and clear flowing water, with cobble and pebble substrates. Glyptothorax armeniacus , G. kurdistanicus , Capoeta umbla , Barbus lacerta , Oxynoemacheilus frenatus , Paracobitis zabgawraensis, Turcinoemacheilus kosswigi, Alburnus mossulensis and Garra rufa have been collected with A. diclensis . Its maximum known size is 81 mm SL.

Etymology. The name of the species is derived from the Turkish name (“Dicle”) for the Tigris River.

Figures

FIGURE 1. Distribution of named Alburnoides species in Turkey: A. emineae (+), A. velioglui (□), A. recepi (D), A. fasciatus (■), A. eichwaldii (x), A. manyasensis (∆), A. cf. smyrnae (▲) A. tzanevi (O), and A. diclensis (★).

FIGURE 2. Alburnoides diclensis; a, holotype, FFR 01118, male, 78 mm SL; b, paratype, FFR 01119, female, 79 mm SL; Turkey: Hakkari Province: Eziki Stream, Tigris River drainage.

Tables

TABLE 2. Frequency distribution of meristic characters of six species of Alburnoides in Tigris and Euphrates rivers.

			Lateral-line scales
diclensis , n=43 idignensis , n=13 nicolausi , n=60 emineae , n=20 velioglui , n=25 recepi , n=34	39 40 41 42 43 3 2 1 2 11 1 1 1 2 4	44 4 15 4	45 46 47 48 49 50 51 52 53 54 55 56 57 3 6 6 11 11 6 1 2 6 13 7 2 2 2 7 1 3 5 6 5 1 1 2 1 2 3 1 10 3 6 4 3 1	58 1	Mean 50.9 43.3 45.0 43.4 49.6 53.1
	Scales above lateral line		Scales below lateral line Branched anal-fin rays
diclensis , n=43 idignensis , n=13 nicolausi , n=60 emineae , n=20 velioglui , n=25 recepi , n=34	8 9 10 11 12 5 32 6 1 11 1 2 30 25 2 9 11 4 15 6 3 24 7	13	Mean 3 4 5 6 Mean 8 9 10 11 12 13 10.0 2 38 3 5.0 14 25 9.0 5 7 1 4.7 1 8 4 9.5 1 27 28 3 4.6 2 13 32 12 9.6 3 17 4.9 10 10.1 10 15 4.6 7 16 2 11.1 10 24 4.7 7	14 2 9 16	15 16 Mean 2 12.8 11.2 10.0 1 13.5 11.8 9 2 14.2
	Total vertebrae		Abdominal vertebrae Caudal vertebrae
diclensis , n=23 idignensis , n=46 nicolausi , n=42 emineae , n=20 velioglui , n=20 recepi , n=24	37 38 39 40 41 13 1 7 30 8 9 28 5 16 2 3 16 5	42 10 4 18	43 Mean 18 19 20 21 22 Mean 18 19 20 41.4 7 16 20.7 6 39.0 1 21 24 19.5 1 22 23 38.9 12 28 2 19.8 7 22 13 41.2 2 18 20.9 14 41.9 2 13 5 21.1 4 39.1 4 19 1 19.9 2 18 4	21 17 6 16	Mean 20.7 19.5 19.1 20.3 20.8 19.1