Complete mitochondrial genome of the worm snail <i>Thylacodes adamsii</i> (Littorinimorpha: Vermetidae) from South Korea

The worm snail <i>Thylacodes adamsii</i> (Mörch, 1859) (Littorinimorpha: Vermetidae) is a sessile gastropod that mainly inhabits rocky shores along the warm temperate to tropical ocean. Herein, the complete mitochondrial genome (mitogenome) of <i>T. adamsii</i> from South Korea was characterized. The genome is 14,913 bp in length and contains 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes. The genome organization and base composition of <i>T. adamsii</i> are similar to those of other vermetids. A phylogenetic tree was reconstructed using maximum likelihood based on the nucleotide sequences of the 13 PCGs; this tree supported the monophyly of Vermetidae. The complete mitogenome of <i>T. adamsii</i> can assist with molecular species identification and vermetid phylogenetic research in the future.