Telomere-to-telomere genome assemblies of Coreius heterodon and Coreius guichenoti

Coreius heterodon and Coreius guichenoti are large-bodied cyprinid fishes endemic to the upper Yangtze River Basin and are recognized as protected species of conservation concern. However, the lack of high-quality reference genomes has constrained genomic studies related to their evolution and conservation. In this study, we generated near telomere-to-telomere (T2T) genome assemblies for both species using PacBio HiFi sequencing, Oxford Nanopore ultra-long reads, Hi-C scaffolding, and full-length transcriptome data. The final assemblies span 1.09 Gb for C. heterodon and 1.08 Gb for C. guichenoti. Contig N50 values reach 43.10 Mb and 42.62 Mb, respectively, and both genomes are anchored to 25 chromosomes. Repetitive elements account for 58.42% and 58.40% of the two genomes, and 25,876 and 25,778 protein-coding genes were annotated. BUSCO analyses indicate high completeness, with 99.26% and 98.93% of conserved actinopterygian genes recovered.