Phylogeny and diversification of the subfamily Acheilognathinae (Cypriniformes: Cyprinidae) from China based on a...

Acheilognathinae is a subfamily of cyprinid fishes with high species diversity in East Asia, especially in China, which harbors 48 of the 87 recognized species (36 of which are endemics). To clarify its taxonomy and phylogeny, we conducted an integrative study combining morphology and multi-locus molecular data (COI, Cyt b, EGR1, EGR2B, EGR3, RH, IRBP, and RAG1) for 277 specimens representing 42 species-level lineages. Our analyses identified six candidate species and suggested revisions to several species complexes, in addition to the confirmation of distinct geographic populations within A. barbatus and A. rhombeus and established A. peihoensis as a synonym of A. barbatulus. Our phylogenetic construction resolved the subfamily into eight well‑supported, genus-level groups: Acheilognathus, Rhodeus, Tanakia, Paratanakia, Pseudorhodeus, Sinorhodeus, Unnamed Clade 1, and Unnamed Clade 2 (newly identified in this study). Divergence time estimates indicate that Acheilognathinae diversified in the Oligocene (∼28.37 Mya), with the radiation of major lineages in the Miocene. These results substantially revise the phylogenetic relationships within Acheilognathinae, highlight the prevalence of cryptic diversity, and provide a robust phylogenetic framework for future biogeographic and evolutionary studies.