Limbu Jash Hang, Rajbanshi Dipak, Hu Jiantao, Khanal Laxman, Li Chenhong
College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China; Biological Research and Conservation Center (BRCC), Damak, Jhapa, Koshi Province 56600, Nepal.
College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China; Shanghai Universities Key Laboratory of Marine Animal Taxonomy and Evolution, Shanghai Ocean University, Shanghai 201306, China.
Mol Phylogenet Evol. 2025 Sep;210:108384. doi: 10.1016/j.ympev.2025.108384. Epub 2025 Jun 1.
The Ailiidae family, endemic to South and Southeast Asia, comprises diverse freshwater catfish inhabiting major river basins across the region. Evolutionary relationships and taxonomic classification within Ailiidae family remain contentious. Here, we resolve these uncertainties using phylogenomic data from 29 specimens representing 11 species and six of the seven recognized genera, supplemented by two outgroup taxa(Pachypterus atherinoidesandP. acutirostris). Hybridization target enrichment and high-throughput sequencing yielded 4,434 single-copy nuclear coding loci. After trimming loci with more than 50 % missing taxa, 2,102 loci, totaling 505,110 bp, were used for phylogenomic analyses. The results confirm monophyly of all studied genera (Ailia, Ailiichthys, Clupisoma, Eutropiichthys, Silonia and Laides), after the reclassification of Clupisoma montanum and C. sinense into the genus Laides, based on concordant molecular, morphological and meristic evidence. Notably, Ailia coila and Ailiichthys punctata formed an early diverging clade, sister to remaining Ailiidae. Furthermore, our results corroborate that the genera EutropiichthysandSiloniarepresent distinct lineages within Ailiidae, warranting their formal retention in the family. Divergence dating estimated the most recent common ancestor of Ailiidae arose during the Pleistocene, with a median age of 2.1 million years ago (95 % HPD: 3.34-1.0 Ma). Biogeographic reconstructions identified the Ganges-Brahmaputra River basin (South Asia) as the center of origin for Ailiidae, followed by dispersal to the Irrawaddy-Salween, Pahang and Indus River basins. Pleistocene climatic fluctuations, tectonic uplift and changes in sea-level may have influenced the dispersal of Ailiidae catfishes. These geological events restructured river systems and exposed land bridges, allowing movement across previously isolated basins. Paleo-river connections between the major drainages of South and Southeast Asia likely facilitated multiple events of vicariance and dispersal, driving diversification within the Ailiidae.
艾氏鲶科鱼类特产于南亚和东南亚，包含多种淡水鲶鱼，栖息于该地区的主要流域。艾氏鲶科内部的进化关系和分类学分类仍存在争议。在此，我们利用来自29个标本的系统基因组数据解决了这些不确定性，这些标本代表了11个物种以及7个公认属中的6个属，并辅以两个外类群分类单元（薄唇深海鲇和尖吻深海鲇）。杂交靶标富集和高通量测序产生了4434个单拷贝核编码基因座。在剔除缺失分类单元超过50%的基因座后，2102个基因座，总计505,110碱基对，被用于系统基因组分析。结果证实了所有研究属（艾氏鲶属、艾氏纹胸鮡属、纹胸鮡属、真纹胸鮡属、细纹胸鮡属和莱氏纹胸鮡属）的单系性，这是基于一致的分子、形态和分节特征证据，将山地纹胸鮡和中华纹胸鮡重新分类到莱氏纹胸鮡属之后得出的。值得注意的是，短吻艾氏鲶和斑点艾氏纹胸鮡形成了一个早期分化的分支，是其余艾氏鲶科鱼类的姐妹群。此外，我们的结果证实，真纹胸鮡属和细纹胸鮡属在艾氏鲶科内代表不同的谱系，这证明它们在该科中应正式保留。分歧时间估计艾氏鲶科的最近共同祖先出现在更新世，中位年龄为210万年前（95%最高后验密度：334 - 100万年前）。生物地理重建确定恒河 - 布拉马普特拉河流域（南亚）是艾氏鲶科的起源中心，随后扩散到伊洛瓦底江 - 萨尔温江、彭亨河和印度河流域。更新世的气候波动、构造隆升和海平面变化可能影响了艾氏鲶科鲶鱼的扩散。这些地质事件重塑了河流系统并露出了陆桥，使得鱼类能够穿越先前隔离的流域。南亚和东南亚主要排水区域之间的古河流连接可能促进了多次隔离分化和扩散事件，推动了艾氏鲶科内部的多样化。
