Feeding

This phylum is known for its diversity in its feeding. Echinoderms are carnivores, herbivores, filter feeders, and detritus feeders. All echinoderms are heterotrophs (including active, omnivorous, scavenging, selective predators and mud swallowing). Many carnivorous echinoderms, like the sea star, use their tube feet to force open shells, particularly mussels, clams and scallops. Once the shell has been pried open, the echinoderm expels its stomach out of the mouth, releasing enzymes into the preys open cavity. The enzymes then liquefy the meat, and the prey is digested in its own shell. The herbivorous sea urchin scrapes algae from rocks with their five-part jaw arranged in a structure known as "Aristotle's lantern." Many echinoderm filter feeders, such as sea lilies and basket stars feed on small suspended organisms that are floating in the water or the bottom of the ocean floor. The sea cucumber, a detritus feeder slowly moves across the ocean floor ingesting a combination of detritus and sand, and digest the organic material leaving the sand grains behind.