Sea Cucumbers Essay, Research Paper
Sea Cucumis sativuss are ocular fasinating beings. To the untrained oculus, one may inquire wheter the sea Cucumis sativus is works or animate being. They are distinguished from the other Echinoderms by the deficiency of a skeleton that is made up of calcerous home bases fixed together. Alternatively, the soft tegument is reinforced with microscopic home bases and spiculums called bonelets, giving it a coriaceous texture. All other Echinoderms are radially symetrical, while the sea Cucumis sativus posses bilateral symmetricalness. Features amoung the sea Cucumis sativuss tend to be repeated rather often, and the different features of species are minimum. The being can be found in any ocean, shoal or deep, buried in the clay or sand, hidding between stones, amoungst corals and sometimes even in sponges. They feed on microscopic beings such as Protozoa and phytoplankton. The atoms are sensed by the tentacles and so brush into the oral cavity. Many sea Cucumis sativuss injest sand or clay to absorb the organic stuffs and foods. This is the ground why the sea Cucumis sativuss are considered to be the angleworms of the sea. Sea Cucumis sativuss holding tube pess are normally in the form of a cylinder. The cylinders posses five sets of radial tube pess running from one terminal to the other. These are seperated by five interradial sets which tend to hold smaller tubing pess or are au naturel. The oral cavity is surrounded by a tussock of 10 to thirty tentacles. The form and agreement of these tentacles distinguishes the three orders of tubing footed sea Cucumis sativuss from one another. The sea Cucumis sativuss mouth has a projecting round lip. It is followed by a big throat which is surrounded by a Crown of chalky home bases. The home bases are made up of five radial parts and five to fifteen interradial parts. The snap of the calcerous home bases is because the home bases are so loosly connected. Connected to the radial home bases are five big musculuss the may go the whole length of the beings organic structure. The throat is connected to a little muscular tummy by an gorge. The tummy is so connected to a long bowel that spirals and cringles everyplace within the organic structure pit. The intestine terminals at the cloaca and anus, normally opposite the oral cavity. The bowel is attached to the organic structure pit wall by mesenteries. The Echinoderms use a H2O vascular system for respiration, elimination, motive power, and nutrient gaining control. The sea Cucumis sativuss H2O vascular system is really different from the remainder of the Echinoderms in that it is more developed, uses bodily unstable alternatively of sea H2O and is built on a pentaradial program. In add-on, unlike the others, the sea cucumber & # 8217 ; s madreporite prevarications free within the celom. The madreporite is the construction used for H2O consumption. The H2O vascular system consists of a ring canal behind the oral cavity. Five radial canals extend to the tubing pess and really little subdivisions connect to the ampullae. The ampullae control motions of the tentacles. One or more little pouch ( Polian cysts )
are attached by slender chaffs to the pealing canal. The madreporite takes in the H2O and merely exceptionally is it f
ixed to the wall. The respiratory trees are two tree-like branches that reach far within the body cavity. Sea water is pumped in and out of the trees by subtle muscular actions of the cloaca. The water then is emptied into the body cavity where it mixes with body fluid and supplements the fluid with oxygen. The respritory trees are also needed to remove carbon dioxide as well as other unwanted waste products. In additon, the respiratory trees may also take part of the excretory functions. In sea cucumbers, the sexes are seperate; some are hermaphroditic, having both sexes. They have only one gonad which is considered to be a very primitive characterisitic of the Echinoderms. Fertilization is external and the free swimming larva is called an auricularia. The reproductive organs are microscopic in size. When attacked or threatened, some species will eject certain organs such as the respiratory tree and the alimentary tract, through their anus. This clouds the water with a mucous that predators get caught or lost in. Within six weeks to two months the organs are completely grown back. This mechanism of defense shows the great regeneration powers that the sea cucumbers posses. Other organisms have symbiotic relationships with the sea cucumber. The sea cucumber is sometimes a host to the pearl fish, which slides backwards into the respiratory openings of sea cucumbers. Sometimes a pearl fish will spend it’s entrie life with one individual. Together, they form a commensal relationship, one in which no harm is done to the host. Another commensal relationship is the sea cucumber and a small fish named Carapus. This fish uses the inside of the sea cucumber as shelter. Sea cucumbers are prized in Asian markets as well as worldwide as an ingredient in cuisine. They are usually boiled, dried or made into a gelatinous soup that are gourmet luxuries amoung the Chinese, Japanese, Malayans, and other oriental peoples. It is said that when eaten, the sea cucumber has aphrodisiac qualities and could be a suppresant of musculoskeletal inflammatory diseases. The sea cucumber was once very common thoughtout the worlds oceans, but has greatly decreased due to the demands of the Asian market. While sea cucumbers in the Gal pagos have not aroused much interest in the past, scientists now fear that the rapid decline in populations of these relatively unglamorous animals may have serious affects on other species that are part of the same complex food web. Sea cucumbers are interesting organisms. They can be found in any ocean. They are unique to the Echinoderms because of their bilateral symmetry, the lack of a hard endoskeleton, and they posses a very advance water vascular system. Thyone briareus, a more advanced sea cucumber, is unique to the other sea cucumbers because of its widely distrubute calcareous plates and water vascular system with hemoglobin present. Sea cucumbers have been said to have benefical qualities when eaten and because of this they are in high demand. The demand of this organism has taken an obvious toll on the abundance of sea cucumbers the world’s oceans’ once possessed.