The genome and mitochondrial genome characteristics of three Bathyraja species based on genome survey information

The still scarce genomic resources have limited the formulation of detailed conservation strategies for the potentially threatened ray species. Here, we performed genome survey sequencing and mitochondrial genome assembly for Bathyraja albomaculata , B. brachyurops and B. scaphiops , which differ in their currently assessed conservation status. Genome sizes were estimated at 1.70, 1.66 and 2.50 Gb, respectively, with heterozygosity ranging from 0.31% to 0.59% and repetitive sequences accounting for 33.50–49.90% of the genomes. B. scaphiops had both the largest genome and the highest repeat content. The assembled mitochondrial genomes were 16,742 − 16,787 bp long and each contained 12 protein-coding genes, 22 tRNA genes and 2 rRNA genes, with the ATP8 gene not detected during mitochondrial genome annotation. The gene organization, nucleotide composition and codon usage of three mitochondrial genomes were broadly conserved, although species-specific codon preferences were detected. All three mitochondrial genomes were strongly AT-rich, with A + T contents of 65.6–66.1%. Phylogenetic analysis showed tht B. albomaculata and B. brachyurops first clustered together, and then clustered with B. scaphiops . These datasets provide baseline genomic resources for Bathyraja species and establish a foundation for future studies of adaptive evolution and conservation genomics in deep-sea rays.