DNA barcoding using cytochrome oxidase I (COI) of pulmonate gastropods from Batan Island, Batanes, Philippines

DNA barcoding has emerged as a powerful tool for species identification, with the cytochrome c oxidase subunit I gene (COI) gene as the marker of choice for animals. In the Philippines, barcoding has focused primarily on fish, birds and plants, with less emphasis on snails. This study reports, for the first time, the COI sequences of pulmonates collected from Batan Is., Batanes. Five species belonging to five different families were sequenced for the 655 bp partial coding region of the COI gene. These are Eulota mighelsiana (Family Bradybaenidae), Ryssota sagittifera batanica (Family Helicarionidae), Satsuma batanica (Family Camaenidae), Trochornorpha troilus (Family Trochomorphidae) and Sarasinula plebeia (Family Veronicellidae). All available COI sequences of species under the identified families were obtained from GenBank. A total of 377 sequences, with 589 bp length, were analyzed from 136 species. Of the five species from Batan Is., only S. batanica had a conspecific match (99.7% similarity) from GenBank. The other four are novel. Base frequencies and GC contents are relatively similar for all families. An apparent bias against C was observed and most variations occurred at the 3rd codon position.