Molecular taxonomy ofOsedax(Annelida: Siboglinidae) in the Southern Ocean

We report the discovery of three new species ofOsedaxin the deep Southern Ocean, expanding the diversity and geographical range of this genus of bone‐eating worms.Osedax rogersisp. n. andOsedax crouchisp. n. were found on a whale skeleton at 1444 m in the Kemp Caldera in the East Scotia Sea during the Chemosynthetic Ecosystems of the Southern Ocean (ChEsSo) project. The recently described species,Osedax antarcticus, found on whale bones implanted at a depth of 550–650 m off Smith Island in the Bransfield Strait, was also found inhabiting the whale skeleton in the Kemp Caldera.Osedax crouchias well as another new speciesOsedax nordenskjoeldisp. n. have also been found on the implanted whale bones off Smith Island. These two localities are approximately 1800 km apart demonstrating a wide distribution of species within the genus. We describe the three new species,O. rogersi, O. crouchiandO. nordenskjoeldiand report the second record ofO. antarcticus. We also present a new phylogenetic analysis forOsedax, including data examining genetic connectivity between the Scotia Arc and the Bransfield Strait.