| The subfamily Gobioninae (Actinopterygii, Teleostei, Ostariophysi, Cypriniformes, Cyprinidae) containing 30 genera and 201 species, is mainly distributed in East Asia except for partial species of the genus Gobio and all species of the genus Romanogobio distributed in Europe. Results from morphological characters were not consistent with molecular evidence on the phylogenetic position of Gobioninae. Studies using molecular evidence all strongly supported the monophyly of five families Gobioninae, Acheilognathinae, Tincinae, Leuciscinae and Oxygastrinae together. However, the phylogenetic relationships among these subfamilies have not been solved. Studies focusing on phylogenetic relationships among gudgeons genera based on morphological evidence mainly divided Gobioninae into several large groups, but have not obtained consistent conclusion. Studies based on molecular evidence strongly supported ’Hemibarbus-Squalidus’and Gobionini were monophyletic group, respectively. However, the monophyly of Sarcocheilichthyini was not well supported.Therefore, this thesis focused on two needed issues to resolve the phylogeny of Gobioninae:i) phylogenetic position of Gobioninae in Cyprinidae; ii) phylogenetic relationships among gudgeons genera. The phylogenetic relationships ofGobioninae were reconstructed based on mitochondrial genomes and nuclear multi-loci.The major results are as follows:1. Phylogenetic position of GobioninaePhylogenetic relationships among the Gobioninae, Acheilognathinae, Tincinae, Leuciscinae and Oxygastrinae were reconstructed based on twelve nuclear loci. The results show that i) the monophyly of the four subfamilies, i.e., Gobioninae, Acheilognathinae, Leuciscinae and Oxygastrinae is supported, respectively, but Tincinae is proved to be polyphyly; ii) Gobioninae represents a sister taxon of Acheilognathinae, and they together form the sister group of Tinea; iii) Leuciscinae and Tanichthysform a sister taxon, and they together represent the sister group of Gobioninae+Acheilognathinae+Tinea; iv) Gobioninae, Acheilognathinae, Tincinae and Leuciscinae together form the sister group of Oxygastrinae.2. Phylogenetic relationships among the genera of Gobioninae based on mitochondrial genomesPhylogenetic relationships among 24 generaof the subfamily Gobioninae werewell reconstructed based on mitochondrial genomes. The results show that i) the Gobioninae can be devided into three groups:’Hemibarbus-Squalidus’ group occupies a basal position, Sarcocheilichthyini and Gobionini form a sister lineage; ii) Hemibarbus-Squalidusgroup includes Hemibarbusand Squalidus; iii) within Sarcocheilichthyini,’Pseudorasbora+Pungtungia+Pseudopungtungid’ form a monophyletic group, and they together form a sister taxon of Rhinogobio; Sarcocheilichthysand Paracanthobrama form a sister taxon, and they together represent the sister group of ’Gnathopogon+Gobiocypris+Coreoleuciscus’; iv) within Gobionini, Coreiusoccupies a basal position, Ladislaviaoccupies a hypobasal position, Gobiorepresents a sister taxon of all the remaining Gobionini fishes; Gobiobotiaforms a sister taxon of Xenophysogobioand they together represent the sister group of Microphysogobio+Biwia+Rostrogobio+Huigobio Platysmacheilus+Pseudogobio+Abbottina+Saurogobio.3. Phylogenetic relationships among the genera of Gobioninae based on nuclear multilocus evidencePhylogenetic relationships among 25 generaof the subfamily Gobioninae werewell reconstructed based on fifteen nuclear loci. The results show that ⅰ)the Gobioninae can be devided into four goups:’Hemibarbus-Squalidus’ group occupies a basal position, Sarcocheilichthyini and Gobionini form a sister lineage, and they together represent a sister taxon of ’Coreius-Rhinogobio’ group; ⅱ) within the Hemibarbus-Squalidusgroup, Belligobionests in the genus Hemibarbus, and they together represent a sister group of Squalidus; ⅲ) Coreius-Rhinogobio group includes Coreiusand Rhinogobio; ⅳ) Within Sarcocheilichthyini, Gnathopogon represents a sister taxon relationship of Gobiocypris, and they together occupy a basal position of Sarcocheilichthyini; the two monophyletic group,’Pungtungia+Pseudopungtungia +Pseudorasbora’ and’ Sarcocheilichthys+Coreoleuciscus+Paracanthobrama’ form a sister taxon relationship; ⅴ) within Gobionini, Ladislavia occupies a basal position; Gobio+Romanogobioform a sister lineage and they together occupy a hypobasal position; Gobiobotiaand Xenophysogobio form a sister taxon, and they together represent the sister group of the remaining taxa; the monophyletic group, ’Microphysogobio+Rostrogobio+Biwia+Platysmacheilus’,forms a sister taxon of Huigobio;’Microphysogobio+Rostrogobio+Biwia+Platysmacheilus+ Huigobio’ represents a sister taxon of Abbottina, and they together form a sister group of Saurogobio; the genera Microphysogobio, Rostrogobio, Biwia, Platysmacheilus Jiuigobio, Abbottina and Saurogobiotogether form a sister group of Pseudogobio.In summary, this thesis based on mitochondrial genomes and nuclear multilocus evidence, i) the monophyly of Gobioninae is supported, and the sister-taxon of Gobioninae is Acheilognathinae; ii) the phylogenetic relationships among gudgeons genera have been well resolved, although partial results from mitochondrial genomes and nuclear multilocus evidence exist conflict.The findings will not only contribute to the further studies of gudgeons systematics and biogeography, but also promote the cyprinid fishes systematics. |
