Zheng Ling-Ling, Yu Dan, Sun Ning, Wang Cheng, Chen Wen-Jun, Ding Zu-Fa, He Shun-Ping, Yang Lian-Dong
State Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology, Chinese Academy of Sciences Wuhan China.
School of Ecology and Environment Anhui Normal University Wuhu Anhui China.
Ecol Evol. 2024 Oct 3;14(10):e70352. doi: 10.1002/ece3.70352. eCollection 2024 Oct.
The Ili River Valley, located in the northwest of China, serves as a vital repository for fish genetic resources. Its extensive water network and diverse climate have given rise to a unique fish composition and endemic species. In this study, we collected the cytochrome c oxidase subunit I (COI) sequences from 660 fish specimens in the Ili River Valley. The effectiveness of DNA barcoding in identifying fish species in the area was assessed by examining genetic distances, constructing phylogenetic trees, and performing ABGD (Automatic Barcode Gap Discovery) analyses, among other methods. In total, 20 species were identified, including one unidentified species ( sp.). Except for and (only one sample), the maximum intraspecific genetic distance among the remaining species was smaller than the minimum interspecific distance, which proves that the species exhibit obvious barcode gaps. In the Neighbor-Joining trees, 20 species formed separate monophyletic branches. According to ABGD analysis, 660 sequences were categorized into 19 Operational Taxonomic Units, with sp. and grouped into a single OTU. The in this study exhibits shared haplotypes and significant genetic divergence, suggesting the potential presence of cryptic species. Furthermore, the nucleotide diversity across all species fell below the threshold level, indicating that the local fish population is gradually declining. In conclusion, this study has demonstrated the effectiveness of DNA barcoding in identifying fish species in the Ili River Valley, providing valuable data to support the conservation of local fish resources.
伊犁河谷位于中国西北部，是鱼类遗传资源的重要储存库。其广泛的水网和多样的气候造就了独特的鱼类组成和特有物种。在本研究中，我们从伊犁河谷的660个鱼类标本中收集了细胞色素c氧化酶亚基I（COI）序列。通过检查遗传距离、构建系统发育树以及进行ABGD（自动条形码间隙发现）分析等方法，评估了DNA条形码在识别该地区鱼类物种方面的有效性。总共鉴定出20个物种，包括一个未鉴定物种（sp.）。除了[两个物种名称未给出]（仅一个样本）外，其余物种的种内最大遗传距离小于种间最小距离，这证明这些物种表现出明显的条形码间隙。在邻接树上，20个物种形成了单独的单系分支。根据ABGD分析，660个序列被分类为19个操作分类单元，[未鉴定物种名称]和[另一个未鉴定物种名称]被归为一个单一的OTU。本研究中的[未鉴定物种名称]表现出共享单倍型和显著的遗传分化，表明可能存在隐存物种。此外，所有物种的核苷酸多样性均低于阈值水平，表明当地鱼类种群正在逐渐减少。总之，本研究证明了DNA条形码在识别伊犁河谷鱼类物种方面的有效性，为支持当地鱼类资源保护提供了有价值的数据。
