Friday, September 22, 2023

[Ichthyology • 2023] Zacco tiaoxiensis • A New Species of Genus Zacco (Cypriniformes: Cyprinidae) from Southern China


Zacco tiaoxiensis
Zhang, Zhou & Yang, 2023

苕溪鱲

Abstract
 Zacco tiaoxiensis, a new species of cyprinid fish from Tiaoxi river system in Zhejiang Province, southern China, is described. With morphological comparison, the new species is similar to Z. acanthogenys, which is widely distributed in Zhejiang Province. However, the new species could be distinguished from Z. acanthogenys by the following combination of characters: lateral- line scales comprising 41-44 (vs. 44-47), scales above lateral-line 8 (vs. 8-10), scales below lateral-line 3-4 (vs. 4-5), scales surrounding caudal peduncle 12-15 (vs. 14-17), for mature male individuals, the ventral fin reaching (vs. exceeding) the anus, etc. The morphological differences among the new species and the allopatric congener species of Z. sinensis and Z. platypus are mainly in the number of scales under the lateral line, comparable characters such as the ratio of head length to body length, and the color of the upper edge of the eyes when living. Moreover, the genetic analysis based on mitochondrial cytochrome b gene also supports that Zacco tiaoxiensis sp. nov. is a valid species.

Key words: Zacco, Tiaoxi river, new species, Cytb, genetic distance, phylogeny    

Zacco tiaoxiensis sp. nov. 
1. Holotype, preserved male specimen, SHOU2021011012, 96.9 mm standard length;
2. Paratype, preserved female specimen, SHOU2021011011, 72.5 mm standard length;
3. Alive male; 4. Alive female. 
 

ZHANG Yan, ZHOU Jiajun, YANG Jinquan. 2023. A New Species of Genus Zacco from Southern China (Cypriniformes: Cyprinidae). Journal of Shanghai Ocean University. 32(3); 544-552.

摘要:描述采自浙江省苕溪水系属(Zacco)鱼类一新种——苕溪 (Zacco tiaoxiensis sp. nov.)。经形态比较, 该新种与广泛分布于浙江各水系的棘颊(Z. acanthogenys)形态较相似, 但与之有着较明显的形态差异: 侧线鳞41~44(vs. 44~47), 侧线上鳞8(vs. 8~10), 侧线下鳞3~4(vs. 4~5), 围尾柄鳞12~15(vs. 14~17), 性成熟的雄性个体腹鳍到达(vs. 超过)肛门。新种与异域分布的中华(Z. sinensis)和宽鳍(Z. platypus)的形态区别主要在侧线下鳞数目、头长与体长的比例等可比性状以及眼睛上缘颜色等。基于线粒体细胞色素b基因的遗传分析也支持苕溪为一独立物种。
关键词:属    苕溪    新种    细胞色素b    遗传距离    系统发育