design: The clean tags were filtered to remove known non-coding RNAs (rRNA, snRNA, snoRNA, tRNA) through alignment with the GeneBank (Release 209.0) and Rfam (Release 211.0) databases. The remaining reads were then mapped to the C. gigas reference genome (GCF_000297895.1), with specific annotation of exon-mapping events. Known miRNAs were identified by aligning to MirGeneDB (https://mirgenedb.org), and novel miRNAs were predicted via hairpin structure analysis, compiling the full miRNA repertoire.