Schizopygopsis chengi chengi ( Fang, 1936 )

Tian, Fei, Liu, Sijia, Chen, Shengxue & Zhao, Kai, 2025, Revision of Schizopygopsis chengi Fang 1936 (Cypriniformes: Cyprinidae), with a description of a new subspecies, Zootaxa 5590 (4), pp. 481-506 : 494-496

Schizopygopsis chengi chengi ( Fang, 1936) ( Figure 6 , Tables 3 and 8)

Chuanchia chengi (Fang Bingwen), 1936 , Sinensin, 7(4): 454 (Western Sichuan Province)

Schizopygopsis malacanthus chengi : Cao Wenxuan, Deng Zhonglin, 1962, Acta Hyfrobiogica Sinica 2: 45 (The Dadu River); Cao Wenxuan, 1964, edited by Wu Xianwen et al., The Cyprinid Fishes of China I: 189 (The Dadu River).

Materials examined

NWIPB2107001–19 (19 specimens), 67–253 mm SL, collected in Western China: Qinghai Province: Kepei Village: Marke River , one of the headstreams of the Dadu River ; 100.92 E, 32.66 N; collected by S. Liu and K. Zhao, July 2021 .

NWIPB2107019–28 (10), collected in Western China: Qinghai Province: Jiangritang Village: Keke River , one of the headstreams of the Dadu River ; 101.12E, 32.24 N; collected by S. Liu and K. Zhao, July 2021 .

Diagnosis

Schizopygopsis chengi chengi is distinguished from Schizopygopsis chengi baoxingensis by having a greater number of gill rakers in the first gill arch. The numbers of outside and inside gill rakers ranged from 15–20 and 25–37, respectively, in S. c. chengi and from 10–15 and 16–23, respectively, in S. c. baoxingensis. It differed from S. c. duokeheensis by having anal scaly sneath terminating at the base of the ventral fin.

Description

D. iv, 8; P. i, 19–21; V. i, 9; A. iii, 5; vertebrae 4 + 42–46.

The morphometric measurements are shown in Table 7.

Body elongate, slightly flat. Snout obtuse and round. No barbels. Mouth inferior, oral fissure nearly straightly transverse, inner side of the lower jaw sharp with a strong horny layer. Head large and convex. Dorsal profile convex and sloping. Ventral profile flat. Nostrils 2 on each side, close together, near eye edge relative to tip of snout. Gill rakers of the first gill arch long and dense. Pharyngeal teeth in 2 rows, 4.3/3.4; slightly hooked and pointed at the tip and with a concave grinding surface. Last unbranched dorsal fin ray weak with small and few serratures at the posterior edge. Body naked with a group of minute scales bordering the scapular region. The lateral line is complete and straight along the middle of the body and tail. The origin of the dorsal fin closer to the tip of the snout than to the base of the caudal fin. Commencement of the ventral fin under the 4–5 th dorsal branched ray. The anterior and posterior angles of dorsal fin squarish. Anal opening proximity to the origin of the anal fin. The tip of the anal fin reaches the base of the caudal fin. Caudal forked. Anal sneath consisting of enlarged scales on each side, extending anteriorly and terminating at the base of the ventral region.

Color pattern

Alcohol-preserved specimens black-gray, abdomen yellowish, whole body with black spots. The dorsal and caudal fins yellow to pale brown, and the ventral and anal fins yellow.

Distribution and habitats

Schizopygopsis chengi chengi is distributed in the headstreams of the Dadu River, the Marke River and the Keke River in Bama County, Qinghai Province, China ( Fig. 7 ). The coexisting fishes included Gymnocypris potanini , Schizothorax davida , Schizothorax prenanti , Triplophysa markehenensis , Triplophysa stenure , Triplophysa leptosome , Triplophysa orientalis and Triplophysa microps .

Schizopygopsis chengi chengi dwells in cold highland streams with a substrate of sand, pebbles and gravels at altitudes of 3000–4000 m above sea level. It feeds on plant fragments and algae on pebbles and gravels as well as insects such as Gammaridea sp. (gammarid) and Chironomus sp. (chironomid).

Etymology

The subspecies Schizopygopsis chengi chengi was named after W. C. Cheng (Ệ万ṱ), an assistant botanist at the Herbarium of the Biological Laboratory of Science Society of China, who identified and presented the specimen. The Chinese name for this species is suggested as 大ăẹṳaeḛẽ名亚ª.

Figures

FIGURE 6. Holotype of S. c. chengi. a. The lateral view of holotype S. c. chengi. b. The dorsal view of holotype S. c. chengi. c. The ventral view of holotype S. c. chengi. d. The morphology of anal fin in holotype S. c. chengi. e. The inner side of gill arch from left side of S. c. chengi. f. The outer side of gill arch from left side of S. c. chengi.

FIGURE 7. The habit of S. c. chengi in the Marker River.