Sea Cucumbers

Sea cucumbers are sluggish, often brightly colored creatures with cylindrical or sausageshaped bodies. Yet, despite their unusual looks, they have many remarkable qualities.

Sea cucumbers belong to the large group of animals known as echinoderms (spiny-skinned animals) that includes the starfish and the sea urchins. Sea cucumbers are closely related to sea urchins. The sea urchins have a rigid outer skin, called a test, but the outer skin of sea cucumbers is not rigid. Instead, it is made up of chalky plates loosely set in a flexible body wall. The body wall has muscles that allow it to change shape. Three rows of tube feet run along the underside of the body and two run along the top. Tube feet are

narrow, flexible,water-filled organs that enable echinoderms to move about.

The anus is set at one end of the sea cucumber’s body. The mouth is located at the other end of the animal, and is surrounded by a crown of oral tentacles. These are used when feeding, but they can be withdrawn by powerful muscles if danger threatens. Some sea cucumbers can protect themselves by ejecting sticky white threads from their bodies to tangle up predators. Sea cucumbers are highly prized as food in parts of Asia. Some are also used in medicine.

Clean Sweepers

Sea Cucumbers feed either by sieving food particles from sea water or by sweeping up particles which have settled on the seabed. Different species are adapted to eat particles of different sizes, so they can live side by side without serious competition.