Meeting Abstract
Members of the sea anemone genus Metridium, are distributed throughout the cold-temperate Pacific and Atlantic Oceans. Included within this genus is the highly variable fluffy (or plumose) sea anemone, M. senile, which has the most extensive distribution, overlapping with every species within the genus. The high variation and plasticity in morphology paired with a lack of clear, distinguishable characteristics has resulted in taxonomic confusion within the genus, particularly in regard to M. senile. As genes evolve relatively slowly within cnidaria, traditional genetic markers have been unsuccessful at resolving relationships between both geographically distant and morphologically distinct individuals. We aim to elucidate relationships within this genus using genomic data to determine whether the most widely distributed species, M. senile, is truly a single, circumboreal species, and to compare deep water, larger individuals with smaller individuals found in shallower communities in the Pacific Ocean. Additionally, as there are several records of M. senile occurring in the southern hemisphere that are assumed to be relatively recently introduced, we also aim to determine a possible origin of these populations from the northern hemisphere. For this study, we sampled 76 individuals within Metridium across the distribution, inclusive of a southern site in Chile. We use data from produced using Restriction-site Associated DNA sequencing (RADseq) to build a maximum likelihood phylogeny and a species tree. These results substantially aid us in determining the status of M. senile as a single circumboreal species and uncovers a potential explanation for the presence of M. senile in the southern hemisphere.
