Individual assignment tests proved genetic boundaries in a species complex of Pacific abalone (genus Haliotis)

Abstract

We conducted this study to find genetic evidence to distinguish the members of Pacific abalone species complex (Haliotis discus hannai, H. discus discus, H. madaka, and H. gigantea) based on microsatellite DNA markers, illustrating the potential of microsatellites for species-assignment. First, we addressed the transferability of H. discus hannai microsatellites to the three other members of Pacific abalone and five additional species (H. diversicolor aquatilis, H. midae, H. corrugata, H. fulgens, and H. rubra). Second, using the microsatellites we applied two types of individual assignment testing (the distance-based assignment and Bayesian model-based clustering) to individuals from the Pacific abalone species. A total of 24 microsatellites were subjected to PCR trials for nine Haliotis species, and the cross-species amplification performance of these markers turned out to drop precipitously even for less divergent congeners. Within the Pacific abalone species complex, four of the 24 markers were not transferable to H. gigantea, suggesting a solid genetic boundary between H. gigantea and H. discus hannai, H. discus discus, and H. madaka. Among the three latter abalones, both assignment tests achieved approximately 90% or more success rate of assignment. The feasibility of the microsatellite markers to classify species sheds light on the genetic management of the Pacific abalone species complex.