Schizothorax griseus Pellegrin, 1931

Yang, Jian, Chen, Xiaoyong & Yang, Junxing, 2009, The identity of Schizothorax griseus Pellegrin, 1931, with descriptions of three new species of schizothoracine fishes (Teleostei: Cyprinidae) from China, Zootaxa 2006, pp. 23-40 : 24-28

Schizothorax griseus Pellegrin, 1931

Figures 1–2

Schizothorax griseus Pellegrin, 1931: 146 , type locality: Koei-Tchéou (Guizhou) Province, China; Fang, 1936: 421; Nichols, 1943: 82 (in part); Lu in Wu ed. 1989: 192 (in part); Chen & Huang, 1998: 222, Fig. 156 (in part); Chen & Cao, 2000: 333, Fig. 206 (in part).

Racoma griseus, Wu & Wu, 1991: 323 , Fig. 80.

Schizothorax yunnanensis (non Norman), Tchang, 1933: 37 (in part); Zhang, 1959: 81 (in part).

Material examined. MNHN 1913–0157, 1913–0158, Syntype, 2 specimens, 240–250 mm SL; China: Koei- Tchéou (Guizhou Province). KIZ 20060156, 20060158, 20060175–178, 20060180, 7 specimens, 100.9−252.0 mm SL; China: the Zhongxi River (a tributary of upper Wu Jiang), Weixin Town, Nayong County, Bijie, Guizhou Province, 27°02΄53.0ʺN 105°12΄52.5ʺE. KIZ 20060206–209, 20060211, 5 specimens, 85.2−144.7 mm SL; China: the Sancha River (a tributary of upper Wu Jiang), Yangchang Town, Nayong County, Bijie, Guizhou Province, 25°38΄58.5ʺN 105°10΄49.9ʺE. KIZ 20060222, 20060224–225, 20060229–231, 20060288, 7 specimens, 138.7−335.0 mm SL; China: Zhiku stream (a tributary of the Sancha River), Yangchang Town, Nayong County, Bijie, Guizhou Province, 26°40΄12.1ʺN 105°10΄46.4ʺE. Uncatalogued: 4 specimens, 108.1−124.4 mm SL; China: Zhiku stream (a tributary of the Sancha River), Yangchang Town, Nayong County, Bijie, Guizhou Province, 26°40΄12.1ʺN 105°10΄46.4ʺE. KIZ 20060302–303; 2 specimens, 97.0− 144.5 mm SL; China: the Niulan Jiang (a tributary of the lower Jinsha River), Huodehong Town, Zhaotong Prefecture, Yunnan Province. KIZ 2006113001, 2006113008–010, 2006113012, 2006113020, and 2 uncatalogued specimens = 7 specimens, 97.4−171.0 mm SL; China: the Niulan Jiang, Wangzhai Village, Malu Town, Zhaotong Prefecture, Yunnan Province.

Diagnosis. Schizothorax griseus is distinguished from its congeners by a combination of the following characters: horny sheath on lower jaw absent; upper lip developed; lower lip developed, modified into three labial lobes; postlabial groove continuous, with a minute labial lobe present at middle of lower lip; scales present or embedded beneath skin on thorax in mature individuals (scalesless on thorax in juveniles); last unbranched dorsal-fin ray strong, its posterior edge with 16−24 serrae; a shallow ethmoidal groove present before nostrils; pelvic-fin origin below or anterior to vertical from dorsal-fin origin; irregular black spots scattered along lateral line on side of body; barbels much longer than eye diameter (maxillary-barbel length 1.6 times eye diameter).

Description. Morphometric data are given in Table 1 . Body elongate, laterally compressed. Snout long. Head length greater than body depth; dorsal surface of head descending sharply anterior to nostrils, forming an ethmoidal groove; head depth greater than head width. Mouth inferior, horseshoe-shaped. Lips developed, lower lip fleshy, with three labial lobes; median lobe minute, its width less than width of isthmus or eye diameter, superficially both side lobes posteriorly rugged ( Fig. 3 A). Postlabial groove continuous. Two pairs of barbels: rostral barbel equal to or shorter than maxillary barbel, reaching middle of eye; maxillary barbel extending beyond posterior border of eye. Scales minute, absent on the thorax and abdomen before pectoralfin origin in juveniles up to 144 mm SL, present or embedded beneath the skin on thorax in adults. Lateral line straight, with 95−114 (22*) scales; scales in transverse series from dorsal-fin origin to lateral line, 21−27 (23*); scales in transverse series from pelvic-fin origin to lateral line, 17−25 (14*). Two rows of enlarged scales on each side, extending from base of vent to anal fin.

Dorsal fin with three simple and 8 (32*) branched rays, last simple unbranched dorsal-fin ray strong, with 16−22 (10*) serrae along its posterior edge ( Fig. 4 A); dorsal-fin origin below or posterior to pelvic-fin origin; predorsal length greater than distance from dorsal-fin origin to caudal-peduncle base. Pectoral fin with one simple and 16 (1*), 17 (5*), 18 (6*), 19 (10*), 20 (1*) branched rays, its length more than half distance between pectoral-fin origin and pelvic-fin origin. Pelvic fin with one simple and 9 (12*), 10 (12*) branched rays. Anus located immediately anterior to anal-fin origin. Anal fin with three simple and 5 (32*) branched rays. Anal fin elongated, reaching caudal-fin base in mature females, surpassing caudal-fin base in mature males. Caudal fin forked, its lower lobe slightly longer than upper one. Pharyngeal teeth in three rows, tooth pattern 2,3,5−5,3,2, tips of teeth hooked, first tooth on inner row much small than others on same row. Outer side of first gill arch with 13−19 (20*) gill rakers, inner side with 17−26 (20*). Gas bladder with two chambers, length of posterior chamber twice that of anterior one ( Fig. 5 A). Intestine simple, with three principal bends (including ventricle) in juveniles, complicated, with five principal bends (including ventricle), in larger specimens.

Minimum Maximum Mean S.D. Pectoral-fin length/Length of pectoral-fin origin to pelvic-fin 59.2 82.9 71.0 6.5 origin

Coloration. In fresh specimens, dorsum and upper body above lateral line grey, rest of body silvery white. Pelvic, anal and caudal fins red; pectoral fin straw yellow. After fixation in 10% formalin and preservation in 75 % alcohol, upper body yellowish grey, lower body whitish; black spots scattered on upper body surface.

Distribution. The species is known from tributaries of the upper Yangtse River drainage area, including the Niulan Jiang, Yunnan, China and the Wu Jiang, Bijie, Guizhou, China ( Fig. 6 ).

Habitat and ecology. In Zhongxi River (a tributary of upper Wu Jiang), on 4 Nov. 2006, these fishes were seen in fast flowing water with a pH of 6.2 and water temperature of 16.5 °C. Here the river is 15−30 m wide, 0.5−3 m deep, and the river substrate is comprised of sand, cobblestones and boulders. The water colour is milky blue, owing to the typical karst topography of this region. Schizothorax griseus lives in the deeper layer of the river, especially in deep water close to the river bank and to large boulders and underwater caves. Other syntopic fishes include the cyprinid species Schizothorax wangchiachii , Discogobio yunnanensis (Regan) , Zacco platypus (Temminck & Schlegel) , Pseudogyrinocheilus prochilus (Sauvage & Dabry) , Acrossocheilus yunnanensis (Regan) ; the balitorid loach Schistura dabryi (Sauvage) and the sisorid catfish Glyptothorax fukiensis fukiensis (Rendahl) .

Remarks. The type locality of S. griseus is Koei-Tchéou (Guizhou Province), China. The species was earlier thought to be widely distributed, having been reported from the Yangtse, the Pearl, the Lancang Jiang (upper Mekong) and the Irrawaddy drainages ( Fang, 1936; Cao, 1964; Huang, 1989; Mo in Chu & Chen, 1989; Wu & Wu, 1991; Chen & Cao, 2000). In this study, we examined specimens from Guizhou Province, which are clearly different from those described by Pellegrin (1931) and Fang (1936) in that scales are present on the thorax in adults. Pellegrin (1931) indicated no scales on thorax of S. griseus , but Fang (1936) examined two syntypes and stated that one of these had scales on the thorax. In the material of S. griseus deposited in KIZ, scales were obviously present or embedded beneath thoracic skin in adults. Furthermore, an examination of photographs of the syntypes of S. griseus shows scales apparently present on the thorax in the bigger specimen (MNHN 1913-0158) ( Fig. 1 ). Material of S. griseus examined by Pellegrin (1931), Fang (1936) and this study share the following characters: mouth in mature specimens inferior, lower lip developed with three labial lobes in mature individuals, postlabial groove continuous with a small median lobe, last unbranched dorsal-fin ray strong, its posterior edge with numerous serrae, and barbels much longer than eye diameter. Fang (1936) illustrated the intestine of a specimen of 90 mm SL. This drawing is consistent with the four specimens we examined, the longest of which is 260 mm SL. Fang (1936) noticed the variation between specimens of S. griseus of different ages; we too, detected variations of snout length and lower-lip structure as noted by Fang (1936). Additionally, our 230 mm SL specimen had an intestine with 5 principal bends (including the ventricle) according to the notation of Fang (1936). Although some variation is apparent between their results and ours, we feel all the material represent same species, S. griseus .

Figures

FIGURE 1. Lateral view of Schizothorax griseus, syntype, MNHN 1913 - 0158, 250 mm SL; China: Koei-Tchéou (Guizhou Province).

FIGURE 2. Lateral view of Schizothorax griseus, KIZ 20060175, 202.0 mm SL; China: the Zhongxi River, Weixin Town, Nayong County, Bijie, Guizhou Province.

FIGURE 3. Ventral view of head of: (A) Schizothorax griseus, KIZ 20060175; (B) S. nudiventris, KIZ 20050507224; (C) S. heterophysallidos, KIZ 20060038; and (D) S. beipanensis, KIZ 20060065. Scale bar = 10 mm.

FIGURE 4. Lateral view of the last unbranched dorsal-fin ray of: (A) Schizothorax griseus, KIZ 20060206, 141.7 mm SL, China: the Sancha River, Yangchang Town, Nayong County, Bijie, Guizhou Province; (B) S. nudiventris, KIZ 20050507224, 148.0 mm SL; China: the Lancang Jiang, Wulonglong village, Badi Town, Weixi County, Yunnan Province; (C) S. heterophysallidos, KIZ 775854, 143.8 mm SL; China: Luoping, Yunnan Province; and (D) S. beipanensis, KIZ 20060064, 157.0 mm SL; China: the Suoqiao River, Shanbanqiao Town, Pu’an County, GuiZhou Province.

FIGURE 5. Gas bladder of (A) Schizothorax griseus, KIZ 20060156, 252.0 mm SL; (B) S. nudiventris, KIZ 20050510270, 145.9 mm SL; and (C) S. heterophysallidos, KIZ 20060037, 163.0 mm SL. Scale bar = 20 mm.

FIGURE 6. Map showing distributions of Schizothorax griseus, S. nudiventris, S. heterophysallidos and S. beipanensis.

Tables

TABLE 1. Morphometric data for Schizothorax griseus (n = 32).

SL (mm)	85.2	335	144.6 57.9
HL	23.6	86.3	37.2 13.6
% SL
Body depth	19.2	24.3	22.0 1.2
Head depth	13.4	17.6	16.1 0.88
Head length	22.7	27.6	26.0 1.1
Snout length	7.5	10.6	8.6 0.7
Longest branched dorsal-fin ray	15.4	22.6	18.9 2.0
Predorsal length	51.9	58.3	54.8 1.4
Caudal peduncle length	15.7	18.8	17.2 1.0
Caudal peduncle depth	6.6	10.6	9.5 0.7
% HL
Body depth	73.3	95.0	84.8 5.5
Head depth	58.0	66.9	61.8 2.2
Head width	49.3	58.6	54.1 5.5
Snout length	28.9	41.1	33.1 3.0
Eye diameter	15.1	24.4	20.9 2.5
Interorbital width	36.4	51.1	43.1 3.7
Rostral barbel length	21.1	42.4	29.0 4.9
Maxillary barbel length	23.8	45.2	34.5 4.8
Eye diameter/Rostral barbel length	35.6	109.4	74.5 16.2
Eye diameter/Maxillary barbel length	33.4	93.7	62.3 13.1
Caudal peduncle depth/Caudal peduncle length	40.9	65.5	55.5 4.2
Predorsal length/Prepelvic length	99.6	108.3	103.9 2.1