By Lambe Lamis 
The ocean existence encloses quite a few hidden wonders which are in the variety of dynamic plants and awesome animals. A single can’t very easily imagine what kinds of animals are dwelling under the ocean water. The animals vary in size from that observed by microscope to the substantial whales. One such marine creature which seems to be very peculiar is the brittle star. The brittle star belongs to the kingdom Animalia and phylum Echinodermata. The buy to which brittle stars belong is the Ophiuroidea so they are also known as as ophiuorids. They are carefully relevant to the sea stars. They have really flexible prolonged arms with the help of which they crawl over the substratum of the sea ground. They have pretty extended arms which may perhaps arrive at up to 60 cm in size and are five in number. They are also identified as serpent stars.
They are not simply identified by individuals and stay unnoticed but they share a various group. About 1,500 species of brittle stars are regarded these days and are found normally at the depth of 500 m downwards. It is considered that the ophiuroids have advanced in the early Ordovician about 500 million years in the past. They have tailored to large array of maritime habitats from the tropics to the poles. They are also identified attached to the coral reefs and some species are also regarded to tolerate the brackish drinking water their exoskeleton is produced up of ossicles. There are about 1900 extant species and 230 genera of brittle stars divided into three orders which incorporate the Oegophiurida, Phrynophiurida, and Ophiurida. Stenurida is an buy of the Paleozoic period and is extinct.
Like all the echinoderms ophiuroids have robust inclination in direction of the pentaradial symmetry. The entire body outline of the brittle stars is identical to that of the starfish in acquiring all the 5 arms are connected to the central disc with a slight distinction that all the arms are not completely connected to the central disc. This central disc is made up of all the entire body organs and the various organs do not enter the arms as it is found in the starfishes. The underside of the central disc encloses mouth surrounded by five jaws designed up of skeletal plates. Madreporite is current in concerning any of the jaw plates and current on the lower aspect but in starfish it is current on the higher facet.
H2o vascular process is very properly marked in the brittle stars as it is the attribute feature of echinoderms. Water vascular system offers strength for locomotion. Tube toes are the terminations of the water vascular method. Ordinarily one madreporite is existing in the drinking water vascular program but species deficiency madreporite also. Suckers and ampullae are absent in the tube feet of brittle stars. The nervous technique is pretty basic and is made up of a major nerve ring that sends fine nerves all together the arms. The actual locale of the nerve ring is in the central disc. The feeling organs are not well developed. They lack eyes also. The nerve endings of the nerve ring carry out the get the job done of contact, flavor etc.
The mouth of the brittle star is encircled by five jaws which carry the perform of anus as well as mouth serving for each egestion and ingestion of food items. Just guiding the jaws is the oesophagus and a blind abdomen. The digestion progresses in the pouches of the belly and the wall of the abdomen is made up of hepatic cells. Ophiuroids are in essence thought of to be scavengers or detritivores and modest particles of food stuff are carried towards the mouth with the enable of tube feet. Sometimes they also feed of crustaceans and small worms. The bases of the arms have cilia lined sacs termed bursae which are used for trade of the gases. The cilia present on the bursae are the chief supply for going the drinking water currents loaded in oxygen which is rotated by the water vascular method. The bursae are also organs of excretion as they include the phagocytic cells taking part in the elimination of wastes from the body. The exoskeleton of ophiuroids is produced up of calcium carbonate like all echinoderms which is existing in the form of calcite. The calcite ossicles fuse alongside one another to form plates which are later on on protected by the epidermis having the kind of syncytium. The sexes are frequently independent but number of species are hermaphroditic as well. The gametes are stored in the pouches located on the arms and are unveiled by means of the bursae. Fertilization is exterior and the gametes are shed in the surrounding water. Couple of species are viviparous also and display parental care by establishing their immature larvae in the bursae. Couple women of some species have a dwarf male attached completely to its mouth.
The brittle stars attain maturity in two yrs and develop into total grown in about 3-fours. Their regular lifestyle span is of five yrs only but couple of species may possibly even stay lengthier than this. They have fantastic powers of regeneration also called as autotomy. Autotomy is the method of defence in which the ophiuroids break-off a single of their arms when attacked by the predator and operate absent. This misplaced arm is generated later on on by regeneration process. They shift with the aid of their arms which absence suckers. They are also attacked by parasites which consist of the protozoans, nematodes, algae and many others. They are even though non-poisonous but are not used as foods by individuals. They are used by the fish-keepers as a section of aquarium.
The brittle stars are extremely excellent as they are typically un-recognized by the predators.