Brachymystax tsinlingensis Li, 1966

Xing, Ying-Chun, Lv, Bin-Bin, Ye, En-Qi, Fan, En-Yuan, Li, Shi-Yang, Wang, Li-Xin, Zhang, Chun- Guang & Zhao, Ya-Hui, 2015, Revalidation and redescription of Brachymystax tsinlingensis Li, 1966 (Salmoniformes: Salmonidae) from China, Zootaxa 3962 (1), pp. 191-205 : 193-198

Brachymystax tsinlingensis Li, 1966 ( Fig. 2 , Table 2)

Brachymystax lenok tsinlingensis Li, 1966: 92 (type locality: Zhouzhi County, Taibai County, Shaanxi Province, China) Brachymystax lenok: Song, 1987: 14 (Minxian County, Weiyuan County, Zhangxian County, Zhangjiachuan County, Gansu Province; Zhouzhi County, Shaanxi Province, China); Qin & Wang, 1989: 52 (Upper Weihe River, Gansu Province, China)

Brachymystax tumensis: Shedko, 2001: 229

Type specimens. Lectotype: NZMC 51100 (H2057), 176.24 mm SL, Yangtze River basin: Xushuihe River, Hetaoping Village, Taibai County, Shaanxi Province, China P.R., Aug. 23, 1962.

Paratypes: NZMC 51101-51103 (H2058-H2059, H2061), NZMC 51110-51112 (H2063, H2056, H2054), 170.23-207.49 mm SL, Yangtze River basin: Xushuihe River, Hetaoping Village, Taibai County, Shaanxi Province, China P.R., Aug. 23- Sept. 5, 1962; NZMC 51104-51109 (H2064-H2066, H2073-H2075), 187.52-228.53 mm SL, Yellow River basin: Heihe River, Dudumen Village, Zhouzhi County, Shaanxi Province, China P.R., Aug. 23- Sept. 5, 1962.

Other specimens. NZMC 197877-197885 (9), 63.48-170.62 mm SL, Yangtze River basin: Xushuihe River, Dajiangou, Huangboyuan Village, Taibai County, Shaanxi Province, China P.R., Nov. 20, 2012; NZMC 197886, 82.02 mm SL, Yangtze River basin: Hongshuihe River, Hetaoping Village, Taibai County, Shaanxi Province, China P.R., Nov. 21, 2012; NZMC 197888-197892 (5), 85.20-161.62 mm SL, Yangtze River basin: Hongshuihe River, Taibai County, Shaanxi Province, China P.R., Nov. 21, 2012; NZMC 197893-99 (7), 68.53- 255.56 mm SL, Yellow River basin: Xianyihe River, Xianyiguan, Caojiawan Village, Longxian County, Shaanxi Province, China P.R., Nov. 22, 2012; NZMC 197900-197910 (11), 64.65-257.30 mm SL, Yellow River basin: Guanshangou River, Guguan Village, Longxian County, Shaanxi Province, China P.R., Nov. 22, 2012; NZMC 197913-197916 (4), 154.85-178.91 mm SL, Yellow River basin: Sujiahe River, Sujiahe Village, Longxian County, Shaanxi Province, China P.R., Nov. 22, 2012.

Diagnosis. Brachymystax tsinlingensis can be distinguished from all congeners by the following combination of characteristics: no spots on operculum; gill rakers 15-20; lateral-line scales 98-116; pyloric caeca 60-71.

Re-description. General body features are shown in Figure 2 . Morphometric and meristic characters are listed in Table 2. Body elongated, compressed. Dorsal profile rising slightly from snout tip to dorsal-fin origin, then sloping gently to adipose-fin origin, and then sloping slightly to end of caudal peduncle. Ventral profile horizontal to pelvic-fin origin, then upward clearly to caudal fin. Caudal peduncle moderately compressed. The greatest body depth at dorsal-fin origin, and least depth of caudal peduncle close to caudal-fin base.

Head blunt, top broad, flat at center. Blunt-snouted, lower jaw nearly equal to or slightly shorter than upper jaw. Teeth on the upper and lower jaws. Anterior nostril tubular and short, next to posterior nostril. Eyes large and rounded, nearer to snout lip than to trailing edge of operculum; interorbital broad. Pair of short rictal barbels, shorter than half of eye diameter. Gill opening large, reaching or extending downwards beyond pectoral-fin base. Gill rakers developed and sparse.

TABLE 2. Biometric data for species of Brachymystax .

Brachymystax tsinlingensis (n=50) Brachymystax lenok (n=84) Brachymystax tumensis (n=14)

Number of branched rays

Dorsal fin 10-11 9-10 9-10 Anal fin 9 8-10 8-10 Pectoral fin 15-16 14-17 15-16 Pelvic fin 9 8-9 9

Number of countable characters

rakers 15-20 17-29 23-25 Lateral-line scales 98-116 111-158 111-124 Pyloric caeca 60-71 70-111 55-65 Circumpedunclar scales 34-40 34-40 32-48

Mean± Mean±

Range(mm) Range (mm) Range(mm) Mean±SD (mm±SD)

SD (mm±SD) SD (mm±SD)

Standard length 63.48-257.3 147.22±53.81 76.21-340.36 202.73±63.61 112.86-133.45 123.29±6.87 % standard length

Body depth 10.87-31.05 21.66±3.02 12.04-38.97 22.81±2.40 20.64-25.55 22.72±1.39 Predorsal length 38.53-59.28 47.78±2.83 36.65-62.71 48.80±3.06 45.02-50.77 47.90±1.72 Head to dorsal 15.34-37.72 29.48±3.32 25.89-44.88 31.72±2.77 27.32-33.57 29.89±1.96 Dorsal-fin base length 12.02-19.64 15.21±1.37 8.97-22.42 13.11±1.95 11.60-15.07 13.52±0.98 Dorsal-fin length 16.56-24.79 21.06±1.66 14.30-29.66 19.1±2.30 14.30-21.12 18.76±1.60 Preanal length 61.18-85.22 77.62±3.77 68.34-91.41 79.67±4.18 73.86-78.88 76.51±1.25 Anal-fin base length 8.90-13.07 10.71±0.86 7.01-12.95 9.53±0.96 8.90-10.78 9.99±0.59 Anal-fin length 14.37-20.10 16.87±1.16 12.38-23.01 15.38±1.57 13.36-15.55 14.63±0.64 Prepectoral length 21.69-33.80 26.10±2.98 17.33-30.56 23.83±1.88 22.17-27.84 24.77±1.68

…Continue on the next page Dorsal-fin origin in front of vertical line of pelvic-fin origin, nearer to snout tip than to caudal-fin base; distance between snout tip and dorsal-fin origin nearly equal to distance from posterior end of dorsal-fin base to adipose-fin origin. Dorsal fin short, posterior end of base opposite to pelvic-fin origin. Pectoral fin insertion in vertical through posterior margin of operculum, pectoral fin short, not reaching to upright position of dorsal-fin origin. Pelvic-fin insertion nearer to anal-fin base than to pectoral-fin origin, opposite to third or fourth branched ray of dorsal fin, end not reaching to anus. Anal fin short, insertion nearly at midway between pelvic-fin origin and caudal-fin base, origin nearly opposite to adipose-fin origin. Adipose-fin origin nearer to caudal-fin base than to dorsal-fin base. Caudal-fin bifurcate, upper lobe equal to lower one.

Lateral line complete, almost straight. Body covered by small scales. Lateral-line scales 98-116, rows of scales above lateral line 20-28, below lateral line 20-28. Predorsal scales 47-70, regularly arranged. Circumpeduncular scales 34-40. Gill rakers 15-20. Pyloric caeca 60-71. Air bladder with one chamber, larger than eye diameter, with thin membrane and slim vessel connecting to intestine.

Coloration. Live individual ( Fig. 3 ): body generally brownish, back dark brownish, light yellowish on sides and whitish on belly. A number of black oval spots with light pinkish edges scattered on back and sides except on operculum; 7-8 dark spots on the bases of dorsal fin and adipose fin. Around 10 light blackish bars on side of body. Orange on the edges of pectoral fin, pelvic fin, anal fin and caudal fin.

Preserved specimens ( Fig. 2 ): lectotype specimen had been fixed and preserved in formalin since 1962, and then transferred to alcohol in 2005. Body dark brownish, back darker and belly lighter. Spots on back and sides; bars on sides. All fins light grayish.

Distribution. This species is only found in parts of the Taibai Mountains segment of the Qinling Mountians, including Heihe, Xushuihe and Qianhe, which are located in the Yangtze and Yellow River basins in China ( Fig. 4 ). Although reported in South Korea, the identification of this population needs to be confirmed.

Habitat. Brachymystax tsinlingens inhabits mountainous rivers of 900-2300 m above sea level and seldom is found in the rivers on the plain. Substrates are composed of gravel and larger stones. This species lives mainly in two environments, shallow areas of streams (0.3-0.5 m) and deep pools (> 15 m) which alternate with one another in rivers. During the breeding season, B. tsinlingensis spawns at shallows. Stream water is typically clear, has high transparency and is slightly alkaline, with a velocity 0.2-0.5 m /s. Shore vegetation is prolific. This species is typically found syntopically with Phoxinus lagowskii , P. oxycephalus , Paracobitis variegatus , Pseudorasbora parva , Triplophysa sellaefer , T. shaanxiensis , T. robusta and T. dalaica , based on our investigations from 2012- 2013.

Etymology. The name of this species, tsinlingensis , is derived from the name of the area in the Qingling Mountains where the species was collected.

Figures

FIGURE 2. Brachymystax tsinlingensis, NZMC 51100 (H 2057), lectotype, 176.24 mm SL. [HALF COLUMN]

FIGURE 3. Live Brachymystax tsinlingensis, collected from the type locality. [HALF COLUMN]

FIGURE 4. Distribution of Brachymystax in China and neighbor areas, above: Distribution; below: Collect locality of B. tsinlingens. (Dot, B. tsinlingens; triangle, B. lenok; diamond, B. savinovi; cross, B. tumensis; square, Brachymystax sp.). [HALF COLUMN]