Biology/Natural History: This species (along with C. ligatum and C. canaliculatum) were collected by Captain James Cook and were among the first mollusk species on the US Pacific Coast to be named. May climb up kelp stalk toward surface in bright weather--can climb 20-30 feet in a day. Feeds on the kelp itself, or on encrusting diatoms, bryozoans, and hydroids. Will also eat detritus and copepods, even may scavenge dead fish or other sea creatures. May attack anemones or nudibranchs. Apparently have "lips" or "jaws" which serve to cut up prey. Mucus is secreted on the shell, which may help deter predation.