Shanghai Universities Key Laboratory of Marine Animal Taxonomy and Evolution, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai, China; National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China.
Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, China.
Mol Phylogenet Evol. 2018 Apr;121:1-11. doi: 10.1016/j.ympev.2017.12.026. Epub 2017 Dec 27.
The Odontobutidae is a group of freshwater sleepers endemic to East and Southeast Asia. The composition of the Odontobutidae is controversial and the systematics position of some species (e.g. Philypnus chalmersi) remains unknown. Phylogenetic relationship among the odontobutids has never been really tested due to the lack of informative morphological characters, and that molecular data have not been collected in many species. Here, we sampled 41 specimens, representing all known genera of the Odontobutidae except the Laotian genus Terateleotris, in addition to a disputable odontobutid species, Philypnus chalmersi and 14 outgroups (six families). We collected sequence data of 4434 single-copy nuclear coding loci using gene capture and Illumina sequencing. A robust phylogeny of the odontobutids and outgroups was built, confirming that the Odontobutidae is monophyletic and sister to the Rhyacichthyidae. We verified that Neodontobutis, Sineleotris and Philypnus chalmersi are members of the Odontobutidae based on the resulting phylogeny as well as patterns of pectoral girdle examined by X-ray microtomography. We proposed a new genus Microdous for Philypnus chalmersi based on the new morphological and molecular evidences. The family of the Odontobutidae can be divided into two clades: Microdous (=Philypnus) sister to a group consisting of Micropercops and Sineleotris, and Odontobutis sister to a group unifying Perccottus and Neodontobutis. Divergence time among the odontobutids was estimated based on 100 most clock-like loci and three fossil calibration points using BEAST. Ancestral range of the family was reconstructed using Reconstruct Ancestral States in Phylogenies (RASP) and BioGeoBEARS. The results suggest that the common ancestor of the odontobutids originated around 30.8 Ma (20.7-42.0 Ma, 95% HPDs) in South China. Orogeny, climatic change and river capture might account for diversification and current distribution of the odontobutids.
牙鮃科是一个仅分布于东亚和东南亚的淡水睡鲨科鱼类。牙鮃科的组成存在争议，一些物种（如 Philypnus chalmersi）的系统发育位置仍然未知。由于缺乏有意义的形态特征，以及许多物种尚未收集分子数据，因此从未真正测试过牙鮃科鱼类之间的系统发育关系。在这里，我们采样了 41 个标本，代表了除老挝属 Terateleotris 以外的牙鮃科的所有已知属，以及一个有争议的牙鮃科物种 Philypnus chalmersi 和 14 个外群（6 个科）。我们使用基因捕获和 Illumina 测序收集了 4434 个单拷贝核编码基因座的序列数据。构建了牙鮃科及其外群的稳健系统发育树，证实牙鮃科是单系的，与 Rhynchichthyidae 科密切相关。根据生成的系统发育树以及 X 射线微断层扫描检查的胸带模式，我们验证了 Neodontobutis、Sineleotris 和 Philypnus chalmersi 是牙鮃科的成员。基于新的形态和分子证据，我们提出了一个新属 Microdous 来包含 Philypnus chalmersi。牙鮃科可以分为两个分支：Microdous（=Philypnus）与 Micropercops 和 Sineleotris 组成的一个组姐妹群，Odontobutis 与统一 Perccottus 和 Neodontobutis 的一个组姐妹群。使用 BEAST 根据 100 个最接近时钟的基因座和三个化石校准点估计了牙鮃科鱼类的分歧时间。使用 Reconstruct Ancestral States in Phylogenies (RASP) 和 BioGeoBEARS 重建了科的祖先范围。结果表明，牙鮃科鱼类的共同祖先起源于大约 30.8 百万年前（20.7-42.0 百万年前，95% HPDs）的华南地区。造山运动、气候变化和河流截流可能是牙鮃科鱼类多样化和当前分布的原因。
