DNA barcoding of Lepetodrilus limpets reveals cryptic species

Lepetodrilid limpets are common inhabitants of deep-sea hydrothermal vents worldwide, but the frequent occurrence of morphologically cryptic species makes their identification very difficult. To facilitate these identifications, we provide DNA barcodes based on similar to 1,000 bp of cytochrome-c-oxidase subunit I (COI), for 20 taxa within the genus Lepetodrilus. The method was also used to identify lepetodrilids that were found living on vent decapods. A preliminary phylogenetic analysis resolved relationships among members of several cryptic species complexes; however, COI sequences alone were unable to resolve higher-level systematic relationships caused by saturation of synonymous nucleotide substitutions.