design: Genomic DNA was extracted from the adductor muscle of Magallana gigas using the phenol-chloroform method. Sequencing libraries were constructed with the NEBNext Ultra II DNA Library Prep Kit. The DNA was randomly fragmented by sonication to an average size of ~350 bp. Following end repair, A-tailing and adapter ligation, the fragments were amplified by PCR. The final libraries were qualified using an Agilent 5400 instrument and subjected to paired-end sequencing (2150 bp) on a DNBSEQ-T7 platform.