Biology/Natural History: This species is hermaphroditic. Fertilization is external, during the summer. The tunic is thin but tough, with 12.4% organic content. Just over half the organic matter in the tunic is tunicin (a carbohydrate); the rest is protein. Vanadium content of the body is low (but higher in the tunic?) Predators include the seastar Orthasterias koehleri. The copepod Pygodelphys aquilonarius may live symbiotically in the branchial chamber and many invertebrates may live around the base.