Tunicates

This small colony of tunicates (20mm) that had taken up residence on a clump of algae. Tunicates have the distinction of starting out in a free swimming stage with a “notochord” which is related to a backbone but once they settle to the bottom (under rocks and on algae for example) they become sessile filter feeders, never to move again. Photo by Jeanette Johnson, www.underwaterkwaj.com