Ophyrotrocha is easy to keep in the laboratory and has therefore been used in several studies of evolution and speciation. The phylogenetic relationships within the group are, however, still not clear and morphological and molecular data are contradictory. Here we attempt to shed light on the phylogeny by adding an additional gene (cytochrome c oxidase subunit I) to the previous analyses of the group. However, the results are still incongruent with the results from the morphological data. We also include a species of the genus Iphitime, and conclude that this species falls within the Ophryotrocha clade. The implications are discussed.
