Bar-HRM for identification of cryptic earthworm species

Accurate species identification is crucial in ecological research on sentinel species such as earthworms. Here, we developed a reliable and cost-efficient method for the rapid identification of taxa within the Allolobophora chlorotica complex of cryptic earthworm species. We combined high resolution melting (HRM) analysis with DNA barcoding (Bar-HRM) in a three-step approach: (i) selection of a mini-barcode in the 16S mitochondrial gene, (ii) test of the method on a panel of 16 reference individuals and (iii) identification at the species level of 24 unknown specimens. Thus, we proved the efficacy of Bar-HRM to discriminate between cryptic sister (or sibling) earthworm species and we provided a standardized method that can be easily adapted to other taxa.