A complete mitochondrial genome-based phylogeny of gooseneck barnacles confirms the sister group relationship between the eastern Pacific Pollicipes elegans and the eastern Atlantic P. pollicipes

Abstract

BackgroundGooseneck barnacles are a fascinating invertebrate group and their taxonomic classification has attracted the attention of several specialists, including Charles Darwin, who was the first to note the close relationship between two species of gooseneck barnacles found on the eastern coasts of the Pacific, Pollicipes elegans, and the Atlantic, P. pollicipes. Additionally, a third species from the eastern Pacific, P. polymerus, was believed to have diverged earlier from the group. Methods and resultsHere, we used genomic short-read sequences publicly available in GenBank to assemble the first complete mitochondrial genome of P. elegans. We conducted a phylogenetic analysis to assess the relationships among its related species and other cirripede species from the superorder Thoracicalcarea. Our phylogenetic findings based on complete mitogenomes reinforce the close relationship between P. elegans and P. pollicipes, with P. polymerus emerging as a basal branch, indicating an earlier divergence from the group. ConclusionsOur analysis provided the first robust phylogenetic assessment of P. elegans, strongly supporting its close relationship with P. pollicipes. Further efforts should aim to sequence the complete mitogenomes of other species within the order Pollicipedomorpha. This endeavor will enable a more comprehensive phylogenetic analysis of this group, whose classification remains a subject of debate.