Homatula wuliangensis, Min & Yang & Chen, 2012

Min, Rui, Yang, Jun-Xing & Chen, Xiao-Yong, 2012, Homatula wuliangensis (Teleostei: Nemacheilidae), a new loach from Yunnan, China, Zootaxa 3586, pp. 313-318 : 315-316

Homatula wuliangensis sp. nov.

( Fig. 1)

Holotype. KIZ 2008008158 , 1 ex., 181.9 mm SL; Wuliang Mountain (24°17'26.6"N; 100°39'03.6"E – 24°20'37.5"N; 100°41'18.2"E, 1274–1781 m above sea level), Lancang River , at Jingdong County, Pu-Er City, China, 13 Dec. 2008.

Paratypes. KIZ 2008008156–157 (2), 159–172(14), 175–176(2), 179(1), 184(1), 197(1), 199–201(3), 203(1), 205(1), 207(1), 211(1), 214–215(2), 316–318(3), 33 ex., 64.6–191.1 mm SL, locality data as for holotype .

Diagnosis. A species of Homatula with extremely longe upper lobe of caudal fin relative to lower lobe; adipose keel developed as high and long ridge, extending anteriorly almost to posterior margin of dorsal-fin base; very closely aligned lateral bars on body, numbering more than 22 (22–26); body scaled; vertebrae 4+41(8)–42(2).

Description. Counts and proportional measurement are shown in Table 1.

Body elongate, anterior portion subcylindrical, posterior portion compressed, body depth 16.2% (15.2–18.0%) SL. Body entirely covered by small scales, with scattered scales on breast. Dorsal and ventral profiles almost straight. Anus at least one diameter to anal-fin base.

Head slightly depressed, naked, length 20.6% (18.5–22.9%) SL; snout blunt, length 44.8% (42.9–47.1%) HL; anterior nostril forming a valve, close to posterior nostril. Eye ovoid, horizontal axis longest, slightly closer to snout tip than to posterior margin of operculum. Interorbital width 28.6% (27.2–30.1%) HL. Mouth inferior, upper jaw with a median processus dentiformis (defined by Kottelat 1990); lower jaw lacking a notch. Three pairs of barbels; inner rostral barbels not reaching mouth corner; outer rostral barbels extending to mouth corner; maxillary barbels extending to middle of eye.

Lateral line complete and straight, with 114–115 pores. Cephalic lateralis system with 7 supraorbital, 4+11 infraorbital, 9 preoperculomandibular and 3 supratemporal pores.Vertebrae 4+41(8 specimens)–42(2 specimens).

Dorsal-fin margin straight, with iii, 8 1 / 2 rays. Tip of dorsal fin extending close to or reaching vertical line from anus. Pectoral fin with i, 9–10 rays. Pectoral fin extending about 1 / 3 distance from its origin to pelvic-fin origin. Pelvic fin with i, 7 rays. Origin of pelvic fin under vertical from dorsal-fin origin. Pelvic fin extending half of distance from its origin to anal-fin origin, but not reaching anus. Prepelvic length 48.8% (47.4–51.4%) SL. Pelvic axillary lobe with pointed tip. Anal fin with iii, 5 1 / 2 rays. Anal fin reaching less than 1 / 2 distance from anal-fin origin to caudal-fin base. Caudal fin without spots; fin rounded with upper lobe clearly longer than lower lobe; lower-lobe length 83.1% (78.3–88.2%) of length of upper lobe of caudal fin. Depth of caudal peduncle 86.9% (76.7–95.1%) in body depth. Ventral and dorsal adipose keels supported by rudimentary rays; dorsal keel well developed, extending forward nearly to dorsal-fin base, ventral keel extending nearly to vertical at end of anal-fin base.

In dissected specimens (KIZ 2008008165–66, 71; 131.4, 129.7 and 109.8 mm SL), intestine forming a small zigzag loop anteriorly but not reaching posterior surface of U-shaped stomach. Gas bladder osseous, anterior chamber invisible, fully enclosed in capsule; posterior chamber rudimentary.

Color in preserved specimens (fixed in 10% formalin, preserved in 75% alcohol). ( Fig. 1) Head dark brown, snout and lips grayish, nostril light, cheeks maculated. Body dark brown with 22–26 vertical bars; each bar at least twice as wide as light interspaces; anterior bars thinner; bars anterior to caudal peduncle split vertically into two or three bars. Abdomen yellow. Dorsal fin with three dark brown rows, one at base, second close to distal margin (producing a prominent light margin), and third located medially. Pectoral and pelvic fins white, dark on dorsal side. Anal fin white, dark at base. Caudal fin and adipose keels dark gray. Caudal-fin base with a blurry dark, basal bar.

Color in life. Color pattern overall similar to that in alcohol, although a little darker. Caudal and dorsal fins and adipose keel with bright red tint.

Etymology. From Latin, refering to the Wuliang Mountain.

Habitat. Homatula wuliangensis occurs in streams of mountain valleys in areas with swift current over rocky and stony substrates, interspersed with sand and gravel in higher elevation reaches (1781 m asl) and in areas with slower current in the lower reaches (1274 m asl) (Fig. 2a, b).

Distribution. Known from the Baimushan River of the Lancang River basin in Wuliang Mountains, Yunnan, China (Fig. 3).