Sea Cucumbers make up the Class Holothoruidea. They have elongated bodies and can range from 3 centimeters to 1 meter long. Because of their shape, they usually lay on one side. They can only move slowly, using muscle contractions of their body wall to help them along. Sea cucumbers are mainly deposit or suspension feeders. Most feed on small particles of food they trap with oral tentacles that are around their mouth. The tentacles are covered with a sticky mucus that traps small organisms and causes them to become stuck.