Sea cucumber is a type of sea animal with a long fleshy body that may look like a cucumber. It belongs to a group of spiny-skinned animals called echinoderms. Other echinoderms, including sea urchins and starfish, have sharp spines on the outside of their bodies. A sea cucumber’s spines, however, are buried deep in its skin. Hundreds of species (kinds) of sea cucumbers live throughout the oceans at all depths. Some tropical sea cucumbers grow 2 to 3 feet (60 to 90 centimeters) long. Most sea cucumbers that live in cooler regions are much smaller.
A sea cucumber’s mouth is at one end of the body and is surrounded by branching tentacles. The tentacles can lengthen and shorten, catch food, and pass food into the mouth. There are five double rows of tiny tubelike structures called tube feet on the body. The tube feet have suction disks on their ends that help the animal crawl or attach itself to objects.
A sea cucumber breathes by pumping water in and out of an organ called a respiratory tree. The animal also can throw out internal body parts to distract attackers. New body parts are later regrown. In Asia, sea cucumbers are dried and sold as food called trepang.