Sea Cucumbers are echinoderms from the class Holothuroidea. They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothurian species worldwide is about 1250 with the greatest number being in the Asia Pacific region.
Many of these are gathered for human consumption and some species are cultivated in aquaculture systems. The harvested product is variously referred to as trepang, bêche-de-mer or balate. Sea cucumbers serve a useful purpose in the marine ecosystem as they help recycle nutrients, breaking down detritus and other organic matter after which bacteria can continue the degradation process.
Like all echinoderms, sea cucumbers have an endoskeleton just below the skin, calcified structures that are usually reduced to isolated microscopic ossicles (or sclerietes) joined by connective tissue. In some species these can sometimes be enlarged to flattened plates, forming an armour. In pelagic species such as Pelagothuria natatrix (Order Elasipodida, family Pelagothuriidae), the skeleton and a calcareous ring are absent.
The Sea Cucumbers are named for their resemblance to the vegetable Cucumber, but are not related to the Cucumis sativus vine.
In recent years, the sea cucumber industry in Alaska has increased due to increased export of the skins and muscles to China.
In China, sea cucumbers are farmed commercially in artificial ponds. These ponds can be as large as 1,000 acres (400 ha), and satisfy much of the local demand.Wild sea cucumbers are caught by divers and these wild Alaskan sea cucumbers have higher nutritional value and are larger than farmed Chinese sea cucumbers. Larger size and higher nutritional value has allowed the Alaskan fisheries to continue to compete for market share, despite the increase in local, Chinese sea cucumber farming.
One of Australia's oldest fisheries is the collection of sea cucumber, harvested by divers from throughout the Coral Sea in far North Queensland, Torres Straits and Western Australia. In the late 1800s there were as many as 400 divers operating from Cooktown, Queensland. The main target species today are White Teat Fish, Black Fish and Sand Fish, caught by divers in waters as deep as 40 meters.