Oxynoemacheilus chomanicus, Kamangar, Barzan Bahrami, Prokofiev, Artem M., Ghaderi, Edris & Nalbant, Theodore T., 2014

Kamangar, Barzan Bahrami, Prokofiev, Artem M., Ghaderi, Edris & Nalbant, Theodore T., 2014, Stone loaches of Choman River system, Kurdistan, Iran (Teleostei: Cypriniformes: Nemacheilidae), Zootaxa 3755 (1), pp. 33-61 : 46-49

Oxynoemacheilus chomanicus sp. nov.

( Fig. 5 )

Material: Holotype: FCFUK 176, male, 54.9 mm SL, Baneh River, (Korhe-Pazi, station 8), Baneh, Kurdistan, Iran, 36° 01' 03" N, 45° 55' 20" E, June 2009, leg. B.B. Kamangar, E. Ghaderi.

Paratypes: FCFUK 177- FCFUK 209, 12 males, 42.8–66.0 mm SL, 12 females, 40.4–67.1 mm SL, 9 juveniles, 28.4–34.9 mm SL, the same data as for the holotype; ZMMU 23086, 2 males, 49.1–60.5 mm SL, 2 females, 45.5– 50.0 mm SL, the same data as for the holotype.

Non-type specimens: FCFUK 210- FCFUK 218, 3 males, 46.6–52.3 mm SL, 6 females, 43.9–51.5 mm SL, Boein River (Boein Payepol, station 5) Baneh, Kurdistan, Iran, 35° 56' 30" N, 45° 56' 36" E, August 2009, leg. B.B. Kamangar, E. Ghaderi; FCFUK 219- FCFUK 221, 1 female, 52.2 mm SL, 2 juveniles, 27.1–30 mm SL, Choman River (Choman Tajaban, station 6) Baneh, Kurdistan, Iran, 35° 56' 53" N, 45° 41' 40" E, June 2009, leg. B.B. Kamangar, E. Ghaderi; FCFUK 222- FCFUK 225, 2 males, 41.1–42.0 mm SL, 2 juveniles, 23.0– 25.1 mm SL, Shooei River (Shooei Jemli, Station 9) Baneh, Kurdistan, Iran, 35° 58' 01" N, 45° 42' 43" E, June 2010, leg. B.B. Kamangar, E. Ghaderi.

Diagnosis: A species of Oxynoemacheilus similar to O. zagrosesis , but with body with more slender dorsalventral aspect and without a hump, transverse bands on body more regular and well-delimited, posterior processes of bony air-bladder capsule larger and directed posteriorly. The species differs from all the other representatives within the genus based on the combination of the complete lateral line, weakly emarginated caudal fin and the very large processes of bony air-bladder capsule, and the process being triangular in shape and directed posteriorly.

Description: Many external features are the same as described above for O. zagrosensis ; thus, they are not repeated here, only characters different from those in O. zagrosensis are listed. Body less deep than in O. zagrosensis , with somewhat more compressed trunk ( Figs. 5 a, 5b). Dorsal contour of body only slightly arched. Dorsal fin origin same distance from tip of snout and caudal-fin base. Distal margins of dorsal and anal fins more or less convex. Pelvic axillary lobe absent, but body wall above insertion of pelvics having skin fold lacking free posterior tip.

Mouth ( Fig. 5 c) arched, with lips rather thin but strongly furrowed; medial portions of lower lip fleshy and well-discernible from the rest of lip; upper lip complete to incised medially, lower lip broadly interrupted. Processus dentiformis moderately developed, corresponding incision weak.

Configuration of cephalic lateralis system, as in O. zagrosensis , but size of pores somewhat larger. Number of pores in cephalic canals: supraorbital 7–8 (in one paratype last pore double from one side), infraorbital 14, preoperculo-mandibular 10, supratemporal 3. Body lateral line canal complete, sometimes well-developed along whole length, sometimes obscured on caudal peduncle; however, in a few cases the lateral line is incomplete at least from one side (reaching to end of anal-fin base). Scales moderately large, slightly eccentric focal zone ( Fig. 5 d). Intestine with a single small loop not extending to stomach ( Fig. 5 e). Bony air-bladder capsule ( Fig. 5 f) with strong posterior processes directed posteriorly.

Sexual dimorphism: Males possess very fine breeding tubercles sparsely distributed on most of head and trunk but densely aggregated on basal third of pectoral-fin rays, basal quarter of pelvic-fin rays and in a band between bases of pelvic fins; at bases of dorsal-fin rays, on isthmus and on branchiostegal membranes. There are no significant differences in lengths of paired fins between males and females (Table 6), though paired fins are more broadly rounded in males.

Coloration of preserved specimens: Head and body with dark reticulated pattern overlaying a pale ground color; this pattern forms a series of more or less delimited transverse bands in the posterior 1/2 to 2/3 of trunk; sides also with mottling between bars that varying from well-developed to nearly absent; well-discernible 3-shaped black bar at base of caudal fin. All fins with dark mottling expressed and confluent to bands on dorsal and caudal fins; mottling sometimes indistinct to absent on paired fins and anal fin. Underside of head and body pale or with very fine and vague dark reticulation. Juveniles with more mottled coloration, without bars (except at caudal-fin base), but sometimes with a lateral row of large spots in posterior part of body. Peritoneum pale, sometimes with few, very sparsely distributed stellate black melanophores.

Etymology: This species is named after Choman basin; adjective.

Comparative remarks: This new species is similar to O. hamwii ( Krupp & Schneider, 1991) , but differs in the weakly emarginated caudal fin (vs. deeply forked), proportions of caudal peduncle (ratio length to depth 1.3±0.14 vs 2.47± 0.20 in O. hamwii ), proportions of body depth (maximum to least 1.4±0.17 vs 1.9± 0.07 in O. hamwii ), proportions of manubrium (width and length ratio to bony air-bladder capsule 0.19±0.01vs 0.131–0.143 and 0.21±0.03 vs 0.26± 0.04 in O. hamwii ) and several statistical differences in morphometrics ( Table 5 , Fig. 7 ).

Note: The values which followed by different letters indicate a significant difference between species in the same variable (P <0.05). The values are mean ± standard deviation. Abrevations are; ventral length (Vlbc), ventral width (Vwbc), dorsoventral depth (Ddbc), manubrium length (Mlbc) and manubrium width of bony capsule (Mwbc).

Oxynoemacheilus chomanicus can be distinguished from O. argyrogramma (Heckel, 1849) in having a weakly emarginate caudal fin (vs. deeply forked), strongly developed posterior processes of the bony air-bladder capsule (vs. weak), proportions of caudal peduncle (ratio length to depth 1.3±0.14 vs 2.08±011 in O. argyrogramma ), proportions of body depth (maximum to least 1.4±0.17 vs 1.6± 0.12 in O. argyrogramma ), shape of manubrium (almost straight vs. V-shaped), proportions of manubrium (width ratio to bony air-bladder capsule 0.19±0.01 vs 0.14± 0.04 in O. argyrogramma ) and several statistical differences in morphometrics ( Table 5 , Fig. 7 ). O. chomanicus has significantly smaller ratios of distance from snout to anterior margin of anterior nostril, distance between posterior margin of anterior nostrils and anterior margin of posterior one, horizontal eye diameter, length of dorsal fin base, pectoral-fin length, pelvic-fin length, anal fin height, length of longest rays in lower caudal lobe, dorsal head length, caudal peduncle length and larger ratios of least depth of caudal peduncle, depth at base of caudal peduncle, pelvic-anal distance, postorbital length, length of longest rays in innermost caudal lobe, maximum head width, lateral head length, width of caudal peduncle and preanal distance relative to both O. hamwii and O. argyrogramma .

The aforementioned morphometric and morphological differences between this new species and O. hamwii , O. argyrogramma and O. kurdistanicus from Irano-Anatolian region could not be due to polytypism. We examined different populations of O. hamwii from Sirvan and Karkheh basin and O. argyrogramma from two different watersheds in Sirvan basin and found consistence of the diagnostic features in all populations of each species.

Oxynoemacheilus chomanicus differs from O. zagrosensis sp. n. in its body proportions (see discussion below; Tables 3, 7, 8 and Figs. 4 a and 5a), especially in its much less deep and non-humped body. The ratio of maximum body depth to least depth of caudal peduncle is 1.42±0.17 vs 1.56± 0.15 in O. zagrosensis . The caudal fin is much longer in O. chomanicus than O. zagrosensis . The color pattern of the adult specimens is also different: transverse bands or lateral row of transversely extended spots in O. chomanicus are more regular and better delimited than in O. zagrosensis , though the juveniles are hardly distinct in this character. The shape of the bony air-bladder capsule is sharply different in the compared species (see Figs. 4 f and 5f); the posterior processes are much smaller and directed laterally in O. zagrosensis instead of the large processes directed posteriorly in O. chomanicus , the manubrium width and the dorsoventral depth of bony capsule of O. chomanicus are larger than in O. zagrosensis .

Recent molecular analysis using cytochrome b indicates species-level differences between O. chomanicus and O. zagrosensis ( Ghaderi, 2012) .

Figures

FIGURE 4. Oxynoemacheilus zagrosensis sp. n.: a) holotype, SL 55.5 mm; b) juvenile, SL 25.7 mm; c) mouth structure; d) scale; e) gastrointestinal duct; f) bony air-bladder capsule, ventral view.

FIGURE 5. Oxynoemacheilus chomanicus sp. n.: a) holotype, SL 54.9 mm; b) juvenile, SL 29.4 mm; c) mouth structure; d) scale; e) gastrointestinal duct; f) bony air-bladder capsule, ventral view.

FIGURE 7. Comparison of some morphometric ratios between O. hamwii, O. argyrogramma, O. kurdistanicus and O. chomanicus. Values are mean ± 95 % confidence interval. The morphometric ratios are: a) width of caudal peduncle (wcp), horizontal eye diameter (oo), distance between posterior margin of anterior nostrils and anterior margin of posterior one (An to pn), length of pelvic fin base (LPelFB); b) maximum head width (wc), length of dorsal fin base (lD), length of longest rays in innermost caudal lobe (lC / m), depth at base of caudal peduncle (dbcp); c) lateral head length (lc), pectoral-pelvic distance (PV), length of longest rays in lower caudal lobe (lc / l), pectoral-fin length (lP); d), least depth of caudal peduncle (h), postorbital length (po), width of bony interorbital space (io), distance from snout to anterior margin of anterior nostril (dsn); e) dorsal head length (dlc), caudal peduncle length (lcp), pelvic-anal distance (VA), anal fin height (hA); f) preanal distance (aA), the ratio of the caudal peduncle length to the least depth of caudal peduncle (lcp / h).

Tables

TABLE 5. The morphometric ratios of the bony air-bladder capsule in studied loaches species.

Species	size sample SL ± sd (mm)	Vlbc ± sd (mm)	Vwbc / Vlbc ± sd
O. chomanicus	4 44.0 ± 7.66	5.23 ± 0.93	0.48 ± 0.04c
O. zagrosensis	6 55.3 ± 5.36	6.38 ± 0.24	0.46± 0.04bc
O. kurdistanicus	7 49.75 ± 6.86	5.03 ± 0.45	0.42±0.03ab
O. hamwii	4 46.15 ±10.77	5.08 ± 1.12	0.43±0.03abc
O. argyrogramma	3 46.93 ± 6.92	4.97 ± 0.59	0.43±0.01abc
T. kosswigi	4 36.4 ±1.99	3.08 ± 0.13	0.46±0.04bc
continued.
Species	size sample Ddbc / Vlbc ±sd	Mlbc / Vlbc ± sd	Mwbc / Vlbc ±sd
O. chomanicus	4 0.39±.08b	0.21±0.03a	0.19±0.01c
O. zagrosensis	6 0.31±0.02a	0.22±0.02ab	0.15±0.03ab
O. kurdistanicus	7 0.32±0.02a	0.24±0.03abc	0.15±0.02abc
O. hamwii	4 0.32±0.03a	0.26±0.04bc	0.13±0.03a
O. argyrogramma	3 0.32±0.01a	0.24±0.02abc	0.14±0.04ab
T. kosswigi	4 0.33±0.03ab	0.27±0.01c	0.15±0.03abc