Biology/Natural History: Diet includes sponges such as Halochondria panicea, Aplidium, Didemnum, and Corella inflata tunicates, and bivalves such as the falsejingle Pododesmus macroschisma. Ambulacral grooves may have the symbiotic polychaete worm Arctonoe pulchra, A. vittata, or Ophiodromus pugettensis.