Assessing the applicability of novel molecular tools for the taxonomic resolution of the Mytilus spp complex in Irish waters

Maddalena Tibone

The mussels of the Mytilus species complex (Mytilus edulis, Mytilus galloprovincialis and M. trossulus) are three morphologically similar species that live simpatrically in many areas of the world, hybridizing where they coexist. In Ireland, M. galloprovincialis is a Non-Indigenous Species and its presence could pose a threat to the ecology and aquaculture of the economically important Atlantic mussel M. edulis. Although an established molecular method exists to taxonomically distinguish the species, which is based on a PCR amplification of size-diagnostic amplicons, recent studies have introduced Single Nucleotide Polymorphism (SNP) markers as a novel molecular approach with higher resolution power compared to the established method.

The present study tested a recently published panel of 12 diagnostic SNPs for the Mytilus complex on a High Throughput qPCR microfluidic system (Biomark HD, Fluidigm) to verify the applicability of this approach and optimize experimental conditions. Although the genotypes obtained showed concordance between the different experimental conditions, unexpectedly they did not allow identification of the expected genotypes (two species and their hybrids). While further optimization is still needed, including a larger SNP panel, this approach has the potential to enable the investigation of occurrence and interbreeding of Mediterranean mussels with native mussels in Irish waters.