This is one of the most transparent tunicates found on the Pacific Coast from Alaska to Southern California. Water enters the top of the tunicate at the incurrent siphon where it is filtered by the gill slits of the pharynx. The food is then taken into the mouth and stomach. The waste material is then expelled through rectum and anus in the atrium and passes out the excurrent siphon. It is this waste material in the rectum that is most easily seen within the tunicate.
Corella inflata is often confused with the similar species Corella willmeriana. C. inflata has a shorter rectum as well as a larger “inflated” atrial chamber in comparison to C. willmeriana (Cathy Carolsfeld and Henry Choong, personal communication, Nov. 7, 2017).
Lamb, Andrew, and Bernard P. Hanby. Marine Life of the Pacific Northwest: a Photographic Encyclopedia of Invertebrates, Seaweeds and Selected Fishes. Madeira Park, BC, Harbour Publ., 2009.