The feather star (Florometra serratissima) is the only swimming species in the Pacific Northwest, and it lives in water shallow enough to be accessible by scuba divers.  While resting on the bottom, their large feeding arms extend outward gleaning small particles of food from the passing current.  Feather stars can crawl on the bottom, or use their many arms for swimming.  Feather stars are echinoderms related to sea stars, sea cucumbers, and sea urchins, and all have radial symmetry.