Insights From the Evolutionary History and Biogeography of
                    <i>Discogobio</i>
                    in the Yunnan‐Guizhou Plateau

doi:10.1111/jbi.70350

DOI: 10.1111/jbi.70350 ISSN: 0305-0270

Insights From the Evolutionary History and Biogeography of Discogobio in the Yunnan‐Guizhou Plateau

JinMing Bai, JiShan Wang, Rui Min, DanTong Wang, YuanWei Zhang, Mo Wang

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ABSTRACT

Aim

The Yunnan‐Guizhou Plateau (YGP) is a key region for understanding the relationship between freshwater fish distributions and geological history. Discogobio , a karst‐dwelling benthic fish genus, represents an ideal model for testing biogeographic hypotheses, as its evolutionary history likely reflects Miocene tectonic uplift and the formation of fault basins. This study aims to reconstruct the phylogenetic relationships of Discogobio , estimate divergence times and infer ancestral ranges to clarify the origin and evolutionary history of the genus in the plateau, addressing gaps in regional biogeographic knowledge.

Location

The Yunnan‐Guizhou Plateau in China.

Taxon

Discogobio .

Methods

We obtained molecular data for 14 species of Discogobio and Discocheilus , including four newly sequenced species. A combined dataset comprising three mitochondrial sequences and four nuclear sequences was constructed, and phylogenetic relationships were inferred using Bayesian inference and maximum likelihood methods. Divergence times were estimated on the Bayesian tree using four calibration points (fossil and secondary calibrations). Finally, ancestral geographic ranges of Discogobio were inferred using RASP.

Results

Phylogenetic analyses supported the monophyly of Discogobio and Discocheilus together. Additionally, the genus Discogobio and its geographically distinct populations exhibit complex evolutionary relationships, with Discogobio sp. H22040013 regarded as a putative undescribed species of uncertain taxonomic status. Divergence time estimation and ancestral range analyses suggested that the genus originated and began diversifying in the paleo‐Nanpan River system during the Miocene (~15.57 Ma), followed by range expansion into the Pearl, Yuan (Red River) and Jinsha River systems.

Main Conclusions

Discogobio most likely inhabited the paleo river–lake system of the ancient Nanpan River Basin during the early Middle Miocene (~15.57 Ma). The first capture of the ancient Nanpan River by the proto‐Pearl River during the mid‐Miocene (~14 Ma) facilitated the initial dispersal of Discogobio (~10.09 Ma). In the late Miocene (~8 Ma), episodic uplift of the plateau combined with arid climatic conditions led to disruptions of the proto‐Pearl River, resulting in population isolation (e.g., D. tetrabarbatus , constrained by repeated marine transgressions and regressions induced by fault activities). In the Pliocene (~2.6 Ma), renewed river capture and reorganisation of lake–river connections promoted further dispersal of Discogobio into the Pearl River, Jinsha River and Yuan (Red River) basins. During the Pleistocene, additional drainage rearrangements—such as the Beipan River capture of the Xuanwei Basin and the geomorphic evolution of the Jianshui Basin—together with Quaternary climatic fluctuations, reshaped regional hydrology and facilitated the establishment of Discogobio species in increasingly isolated habitats, ultimately forming their present‐day distribution.

Outline