Oreonectes microphthalmus, Du, Li-Na, Chen, Xiao-Yong & Yang, Jun-Xing, 2008

Du, Li-Na, Chen, Xiao-Yong & Yang, Jun-Xing, 2008, A review of the Nemacheilinae genus Oreonectes Günther with descriptions of two new species (Teleostei: Balitoridae), Zootaxa 1729, pp. 23-36 : 28-29

Oreonectes microphthalmus sp. nov.

Fig. 4

Holotype: KIZ 2004009395, 39.0 mm SL, 48.2 mm TL, from Du’an County, Guangxi Zhuang Autonomous Region, China, 2004, collected by Mr. Lan Jiahu.

Paratypes: 5 ex. KIZ 2004009394, 46.9 mm SL, 57.7 mm TL; KIZ 2004009396–99, 30.8–36.1 mm SL, 37.8–44.2 mm TL. Location and data are the same as for the holotype.

Diagnosis: Body elongate; snout elongate; eyes reduced to a black pigment; body naked; cephalic lateralline system with 2+2 supratemporal, 7 supraorbital, 3+0 infraorbital and 8 preoperculomandibular pores; lateral line incomplete, with 3 pores.

Description: Body elongate; head and caudal peduncle compressed; snout elongate; snout shorter than postorbital portion of head; mouth inferior; lip surface smooth; processus dentiformis absent; lower lip with notch, completely interrupted by longitudinal groove; three pairs of undeveloped barbels, inner rostral barbel reaching vertical of anterior nostril, outer barbel reaching almost vertical of posterior nostril, maxillary barbel reaching vertical of posterior to eye; anterior and posterior nostrils separated by short distance, anterior nostril tube-like; tip of anterior nostril reaching posterior nostril; eyes reduced to black pigment.

Distal margin of dorsal fin straight; dorsal-fin origin posterior to pelvic-fin origin; predorsal length 54.7– 57.9% SL; pectoral fin reaches about 1/2 distance to pelvic fin; distal margin of pelvic fin does not reach anus; anus abuts anal-fin base; high caudal-adipose keels on upper and lower edges of caudal peduncle; caudalpeduncle length 1.6–2.1 (1.8) times longer than depth; caudal fin rounded; body naked; lateral line incomplete, with 3 pores; cephalic lateral-line system with 7 supraorbital, 3+0 infraorbital pores. The air-bladder has two chambers: posterior chamber developed, filling body cavity, and connected with anterior chamber by long, slender tube; intestine straight. Fin ray counts: P, 10; D, 10; V, 7; A, 7; C 15.

Color pattern (preserved in formalin): Body yellowish, without pigments; all fins hyaline.

Sexual dimorphism: Male has prominent stars from chin to subopercle; stars absent in female.

Distribution: Know from Du’an County, Guangxi Zhuang Autonomous Region, China.

Etymology: From Greek, micron meaning small, and phthalm meaning eye; gender masculine.

Remark: The new species is most closely related to O. furcocaudalis , as indicated by the sharing of the following characters: dorsal-fin origin anterior of pelvic-fin origin; caudal fin forked; high caudal-adipose keels on upper and lower edges of caudal-peduncle; 6–7 branched anal-fin rays; 7 branched pelvic-fin rays; and 15 branched caudal-fin rays.

It is distinguished from O. furcocaudalis by the following characters: eyes degenerate, eye diameter/ head length 3.0–6.5% (4.7) versus 7.1–9.9% (8.3); belly straight versus rounded; body depth/standard length 11.2– 14.8% (13.7) versus 19.3–22.6% (20.6); body naked versus posterior of body covered by scales; cephalic lateral-line system with 7 supraorbital, versus 9 pores; 3+0 infraorbital versus 4+8 pores; lateral line incomplete, with 3 versus 9 pores.

Figures

FIGURE 4. Oreonectes microphthalma (paratype KIZ 2004009397, 33.2 mm SL), (a) lateral and (b) dorsal views.