Recent genomic studies have suggested that ancient introgression may facilitate rapid diversification. The cave-dwelling group (TCG) of Triplophysa sensu lato, cave fishes endemic to the karst regions of southwestern China, exhibits high diversity and rapid evolution, representing a compelling potential example of rapid speciation during the evolution of karst landscapes. Here, we investigated the complex evolutionary history of the TCG by sampling 24 species and analysing whole-genome resequenc