Xu Hai-Feng, Lv Meng-Yu, Zhao Yu, Zhang Zhi-Chao, Liu Zheng, Lin Xiao-Long
Engineering Research Center of Environmental DNA and Ecological Water Health Assessment, Shanghai Ocean University, Shanghai 201306, China.
Shanghai Universities Key Laboratory of Marine Animal Taxonomy and Evolution, Shanghai Ocean University, Shanghai 201306, China.
Insects. 2025 Jun 27;16(7):675. doi: 10.3390/insects16070675.
Accurate species identification of small aquatic insects remains challenging due to their morphological similarities. This study addresses this issue by developing a DNA barcode reference library for the globally distributed (Diptera: Chironomidae). We analyzed cytochrome oxidase subunit I (COI) sequences of 241 specimens belonging to 13 species from 18 countries, including 56 newly generated and 185 publicly available COI barcodes. Our integrated approach included genetic distance analysis, haplotype network construction, and ecological niche modeling. The results revealed remarkable cryptic diversity, with sequences clustering into 30 Barcode Index Numbers and 158 unique haplotypes, most being region-specific. Notably, East Asian and North American populations showed complete genetic distinctness, suggesting long-term isolation. Environmental factors, particularly temperature and precipitation gradients, were identified as key drivers of this diversification. The study also corrected several misidentifications in existing databases. These findings significantly advance our understanding of diversity and provide a reliable molecular tool for freshwater ecosystem monitoring, with important implications for biodiversity conservation and environmental assessment.
由于小型水生昆虫形态相似，准确鉴定其物种仍然具有挑战性。本研究通过为全球分布的摇蚊科（双翅目：摇蚊科）建立DNA条形码参考库来解决这一问题。我们分析了来自18个国家的13个物种的241个标本的细胞色素氧化酶亚基I（COI）序列，包括56个新生成的和185个公开可用的COI条形码。我们的综合方法包括遗传距离分析、单倍型网络构建和生态位建模。结果显示出显著的隐存多样性，序列聚类为30个条形码索引号和158个独特单倍型，大多数是区域特异性的。值得注意的是，东亚和北美种群表现出完全的遗传差异，表明长期隔离。环境因素，特别是温度和降水梯度，被确定为这种多样化的关键驱动因素。该研究还纠正了现有数据库中的一些错误鉴定。这些发现显著推进了我们对摇蚊科多样性的理解，并为淡水生态系统监测提供了可靠的分子工具，对生物多样性保护和环境评估具有重要意义。
