Sri Lanka,ශ්රී ලංකා,Ceylon,Coral Reef,Sea Cucumber,Seegurke,bêche de mer (28)

Duration 01:15 min - 21 May 2012

A sea cucumber forages the coral sands beside the Galle Fort reef. 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. There are a number of holothurian ( /ˌhɒləʊˈθjʊəriən/) species and genera, many of which are targeted for human consumption. The harvested product is variously referred to as trepang, bêche-de-mer or balate. 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.Sea cucumbers communicate with each other by sending hormone signals through the water.A remarkable feature of these animals is the catch collagen that forms their body wall. This can be loosened and tightened at will, and if the animal wants to squeeze through a small gap, it can essentially liquefy its body and pour into the space. To keep itself safe in these crevices and cracks, the sea cucumber hooks up all its collagen fibres to make its body firm again.Some species of coral-reef sea cucumbers within the order Aspidochirotida can defend themselves by expelling ...