Chromosome-level genome assembly and annotation of Chinese herring (Ilisha elongata)

The Chinese herring (Ilisha elongata) is a commercially and scientifically significant fish species. In this study, we conducted high-precision whole-genome sequencing using two high-throughput platforms: second-generation MGI and third-generation PacBio. Hi-C technology assisted in assembling the contig sequences onto 24 chromosomes, resulting in a high-quality chromosome-level genome map with excellent continuity and coverage. The completed genome size was approximately 815 Mb, with a contig N50 of 4.82 Mb, scaffold N50 of 32.61 Mb, and a chromosome mounting rate of 95.32%. SNP and InDel purity rates were 0.003% and 0.012%, respectively, and the genome assembly completeness was 96.68%, assessed by BUSCO. Repetitive sequences were annotated via ab initio and homology predictions, identifying 295.7 Mb of repetitive sequences, constituting 35.08% of the genome. A total of 26,381 protein-coding genes were predicted, with 24,596 functionally annotated.