The Leopard Shark Essay, Research Paper

Leopard Shark ( Triakis semifascicata )

Family Carcharhinidae ( requiem sharks ) .

Order Chiamydoselachiformes

The Leopard Shark ( Triakis semifascicata ) is in the Family of Carcharhinidaes ( requiem sharks ) . Carcharhinidaes are the largest household of sharks in Numberss. This household consists of bull sharks, sand bar sharks, tiger sharks, great bluish sharks and more. The Leopard shark ( Triakis semifascicata ) grow to 7 pess and are to a great extent marked with black crossbars and splodges. Their dentitions are short, wide and triangular shaped. The Leopard sharks ( Triakis semifascicata ) are active, fast sharks. They are mobile, schooling sharks that roam inshore sand flats and bouldery countries. They are known to feed on colloidal suspensions, pelecypods, crustaceans, and other little underside brooding fish.

Sharks have been around for 400 million old ages and out of that 400 million old ages about 100 million old ages the sharks and their close relations have been closely unchanged in visual aspect. There are about 900 species of sharks and their close relations. There are about 400 species of sharks and more are been found and added to the list.

What makes a shark a shark? First it? s skeleton is made of gristle, which is lighter, tougher, and more flexible than bone. The most noticeable difference is its dentitions. They? rhenium jaw is lined with dentitions, moving as a conveyer belt with new dentitions replacing the old, broken and lost dentitions.

As a affair of fact their full organic structure is covered in bantam tooth-like graduated tables called cuticular denticles, which, unlike those of cadaverous fish, do non enlarge while the animate being is turning larger. Another difference is that fertilisation takes topographic point inside the female with 1 of the2 claspers inserted into her. The males use the claspers to shoot the seeds into her. The claspers are extensions of the thoracic fives. Unlike bony fishes, which normally spawn in great multitudes of bantam, immature immature, most sharks produce big, well-developed offspring enumeration, at the most, 100 to a litter. Most sharks are ovoviviparous, hatching the eggs within the female and bearing unrecorded immature. Some sharks are oviparous, nevertheless, puting their eggs externally. The eggs are frequently encased in leathery shells with tendrils that anchor them to sway or seaweed. Others species of sharks are live-bearing. Which means the yolk pouch becomes a yolk placenta in the creases of the uterine wall and gives foods to the embryo. Embryonic development takes more than six months. The immature are often born in protected closer to shore countries off from the males. Sharks normally fast for long periods during the genteelness season and live on the huge militias of lipoids stored in their livers. This helps the sharks survive because it decreases cannibalism from the female parent. The shark? s tail is asymmetrical, with the vertebral column extended into the upper lobe. The fives and dress suits of sharks are stiff. Traveling against the popular image, the dorsal fins seldom project above H2O when the fish are close to the surface. They have strong digestive enzymes and a specialised epithelial crease that spirals the length of the little bowel, enabling the fishes to absorb a great diverseness of nutrients. Sharks, to a big extent, are scavengers, eating injured fish, refuse, and other waste from ships every bit good as animate beings such as seals, polo-necks, birds, giants, pediculosis pubis, and a broad scope of fishes. The most interesting difference is called the Ampoules of Lorenzini, which detect weak electrical currents from other fish. All living things generate electrical Fieldss due to the catching of musculuss and sharks have adapted to being

able to utilize this as an advantage to happen quarry. Sharks have a really first-class sense of odor. They are able to observe little substances, such as blood in H2O and follow them to their beginning. Their sense of sigh allows the shark to catch dim motions of shadow and visible radiation in dark Waterss as it approaches its quarry. Sharks are peculiarly sensitive to sounds of low frequence and have all right directional hearing. Variety meats along their sidelong lines and on the neb enable sharks to pick up weak electrical stimulation from the musculus contractions of bony fish. Their combination of acute senses histories for the evolutionary success of sharks. The sharks besides do non obtain a swim vesica, so they seem to be in changeless gesture. If the sharks stop swimming they will easy drop to the underside. They besides have 5, 6, or even 7-gill slits alternatively of1 that bony fish have.

The universe has been tough on sharks. During a 17- month period in the 1930? s, 1,500 sharks were caught by the mesh net method along the Australian beaches to maintain swimmers safe. Up to 1,400 plus many mahimahis are caught each twelvemonth in South Africa. There is no easy manner to maintain sharks off from topographic points where people swim, breaker or scuba honkytonk. Shark cogent evidence enclosures have been built, but these can merely protect little countries because of the big coastlines. In South Africa and Australia, cyberspaces are used to pin down sharks on popular beaches. But the? man- eating sharks? aren? t the lone victim of the cyberspaces. These cyberspaces besides trap and kill many harmless sharks, mahimahis, sea polo-necks and beams. Trials are being done to see if electrical barriers can be used, that wouldn? t injury or kill the sharks and other animate beings in the procedure. An American scientist Dr. Eugenie Clark discovered that the Moses Sole from the Red Sea makes its ain shark repellant. When the Moses Sole is attacked, it secretes a milky, toxin ooze out of it? s tegument and the shark will ptyalize it out. This is another manner to forestall shark onslaughts.

Sharks play an of import ecological function in oceans, similar to that of big marauders on land. Sharks quarry on weakfish, thereby assisting a species to keep its familial strength. Because modern fishing methods have helped to consume many food-fish species, nevertheless, the industry now views sharks as rivals, to the extents that shrimp trawlers often employ electrical shields by their spiller to maintain sharks from destructing the gimmick. On the other manus, with the increasing scarceness and lifting monetary value of many nutrient fishes, particularly for United States consumers, shark meat is itself now selling at monetary values comparable to those for traditional table fishes. The meat has long been eaten, particularly in East Asiatic states, but it is now progressively being featured in United States markets and is frequently compared to swordfish. Besides the shark? s fives are made into soup.

Sharks have a bad repute as bloody-minded slayers. But merely a smattering of sharks are unsafe and onslaughts on people are rare. Shark experts are concerned that sharks are progressively threatened by over fishing. In Florida, Lemon sharks are threatened due to the devastation of Mangrove Swamps, which are of import baby’s rooms for Lemon shark whelps. Many people begin to wish and look up to sharks as they learn about them.

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Copyright day of the month 1991

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