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.
Sea cucumbers are generally scavengers, feeding on debris in the benthic layer. Their diet consist of plankton and other organic matter found in the sea. One way they might get a supply of food is to position themselves in a current where they can catch food that flow by with their tentacles when they open. Another way is to sift through the bottom sediments using their tentacles. They can be found in great numbers beneath fish farms.
They have the peculiar adaptation of expelling first sticky threads, perhaps to incapacitate predators, and then their internal organs when startled by a potential predator. These organs can then be regrown.
Sea cucumbers reproduce by releasing sperm and ova into the ocean water. Depending on conditions, one organism can produce thousands of gametes.
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.
Sea cucumber is one of the most unique foodstuffs in Chinese community cuisine. It is highly valued for its supposed medicinal properties. The flesh of the animal is "cleaned" in a process that takes several days. Trepang is often purchased dried, and rehydrated before use. The product is used in Chinese stews and braised dishes due to its gelatinous texture but is unappetising on its own. In Japanese cuisine, Konowata is made of cured sea cucumber entrails from which they extract, salt, and cure. It is considered a major delicacy. However as kosher observant this food is out of our food list as it is not kosher although it may seem good.
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