Haplotype-resolved chromosomal-level genome assembly of Chrysaora achlyos (black sea nettle)

Chrysaora achlyos is a distinctive scyphozoan species characterized by its dark pigmentation and large size. In this study, we generated a haplotype-resolved, chromosome-scale genome assembly for C.achlyos using PacBio HiFi long reads and Hi-C technology. The resulting assembly comprises two haplotypes with sizes of 246.43 Mb (contig N50 = 7.69 Mb) and 248.65 Mb (contig N50 = 7.23 Mb), Additionally, repetitive sequences were characterized, with 110.52 Mb (~44.85%) in haplotype A and 112.57 Mb (~45.27%) in haplotype B. A total of 20,471 and 20,606 protein-coding genes were predicted in haplotypes A and B, respectively. The sequencing depth, mapping coverage, contig continuity, and BUSCO assessment collectively indicated a high-quality haplotype-resolved genome assembly. This high-quality genome assembly provides a foundation for future studies in comparative evolution, toxicology, ecology, and functional genomics.