Sea Cucumbers
Sea cucumbers (Class Holothuroidea) are cylinder-shaped invertebrate animals that live in seas worldwide. They are found in a variety of sea floor habitats, from warm tropical waters to cold deep sea trenches. These nocturnal animals have a life span of about 5 to 10 years.
Anatomy: The body of the sea cucumber is elongated, leathery and muscular; spines are contained with the skin. These echinoderms have no arms, but do have five-part symmetry. Surrounding the mouth are 8 to 30 tentacles (modified tube feet). Five double rows of tube feet (with tiny suction cups) run along the body; they are used for crawling along the sea bed or anchoring to a rock. A sea cucumber breathes by pumping sea water in and out of an internal organ called a respiratory tree. Some sea cucumbers burrow into the sea floor. Sea cucumbers have no brain. The biggest sea cucumber, the tiger's tail sea cucumber (Holothuria thomasi), is about 2 m long - most sea cucumbers are much smaller than this.
Diet: Sea cucumbers eat decaying matter that floats in the water or is in the sand.
Enemies: Sea turtles, crustaceans, many fish, and people eat sea cucumbers. Sea cucumbers can expel most of their internal organs to confuse predators - they later regrows the organs. Some sea cucumbers' bodies contain toxins that can deter attackers.
Reproduction: Eggs and sperm are broadcast (released) into the water (the sexes are separate). When an egg is fertilized and hatches, the tiny planktonic larva drifts with the ocean currents. It will eventually settle onto the sea floor and develop into an adult.
Classification: Kingdom Animalia (animals), Phylum Echinodermata (echinoderms), Subphylum Asterozoa (=Eleutherozoa - sea cucumbers, sea urchins, sand dollars, sea stars, brittle stars, and basket stars). Class Holothuroidea (sea cucumbers), about 900 species.
March 23rd, 1843 AD
The sea cucumber is an important animal to the islands of Palau. Many ecological systems depend upon it as a food resource. The sea cucumber's eggs are a primary food source for many other sea creatures. A relative of the starfish, sea cucumbers are also invertebrates with soft bodies. The Palauan people use the sea cucumber to protect their feet when walking in the reef. They squeeze the sea cucumber until it squirts out sticky threads, which they put on their feet. Even though this practice may sound harsh, the sea cucumber returns to the reef unharmed. These threads are normally used by the sea cucumber to trap its enemies.
Sea cucumbers are echinoderms. Sea cucumbers are sausage shaped, and their skin is covered with warty bumps or soft spines. When threatened, cucumbers can contract their muscles and shoot out water from their body making them shorter, thicker, and harder. Some can even shoot out their insides and then go and grow new insides.
Sea cucumbers have hundreds of tiny suction-cup tube feet that they use to crawl across the sea floor. Three common sea cucumbers are the warty sea cucumber, the California cucumber, and the white star cucumber. Warty sea cucumbers are chestnut brown with black-tipped "warts" all over their bodies. Warty sea cucumbers grow up to ten inches long. California sea cucumbers are brown to reddish-brown and are covered with pointed, cone-shaped projections. The California sea cucumber grows up to sixteen inches long. The white sea cucumber is light orange to white with long, nonretractable spines covering their bodies. White sea cucumbers grow up to four inches long.
Diet dead and decaying organic material, algae, tiny plankton
Size up to 16 inches
Color
Warty sea cucumbers - chestnut brown
California sea cucumbers - brown to reddish-brown
White sea cucumber - light orange to white
Life Cycle
Predators
Neat Facts When they are scared, some cucumbers throw out their sticky internal organs to distract any predators. Then they can grow new innards!
Types California, sweet potato, warty, white, orange, slipper
Relatives sea stars, brittle stars, sea urchins, sand dollars
1) Sea cucumbers are _________. Echinoderms
2) How long can the white sea cucumber get? 1 foot
3) How many suction cups do sea cucumbers have? hundreds
4) What do sea cucumbers eat? scallops
5) What do sea cucumbers do when frightened? play dead
