Thursday, April 30, 2020

The Leopard Shark Essays - Carcharhinidae, Shark, Leopard Shark

The Leopard Shark 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 family of sharks in numbers. This family consists of bull sharks, sandbar sharks, tiger sharks, great blue sharks and more. The Leopard shark (Triakis semifascicata) grow to 7 feet and are heavily marked with black crossbars and blotches. Their teeth are short, broad and triangular shaped. The Leopard sharks (Triakis semifascicata) are active, fast sharks. They are nomadic, schooling sharks that roam inshore sand flats and rocky areas. They are known to feed on soles, bivalves, crustaceans, and other small bottom dwelling fish. Sharks have been around for 400 million years and out of that 400 million years about 100 million years the sharks and their close relatives have been closely unchanged in appearance. There are about 900 species of sharks and their close relatives. 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 cartilage, which is lighter, tougher, and more flexible than bone. The most noticeable difference is its teeth. They're jaw is lined with teeth, acting as a conveyor belt with new teeth replacing the old, broken and lost teeth. As a matter of fact their entire body is covered in tiny tooth-like scales called dermal denticles, which, unlike those of bony fish, do not enlarge while the animal is growing larger. Another difference is that fertilization takes place inside the female with 1 of the2 claspers inserted into her. The males use the claspers to inject the semen into her. The claspers are extensions of the pectoral fins. Unlike bony fishes, which usually spawn in great masses of tiny, immature young, most sharks produce large, well-developed offspring numbering, at the most, 100 to a litter. Most sharks are ovoviviparous, hatching the eggs within the female and bearing live young. Some sharks are oviparous, however, laying their eggs externally. The eggs are often encased in leathery shells with tendrils that anchor them to rocks or seaweed. Others species of sharks are viviparous. Which means the yolk sac becomes a yolk placenta in the folds of the uterine wall and gives nutrients to the embryo. Embry onic development takes more than six months. The young are frequently born in protected closer to shore areas away from the males. Sharks commonly fast for long periods during the breeding season and live on the vast reserves of lipids stored in their livers. This helps the sharks survive because it decreases cannibalism from the mother. The shark's tail is asymmetrical, with the vertebral column extended into the upper lobe. The fins and tails of sharks are rigid. Going against the popular image, the dorsal fins rarely project above water when the fish are close to the surface. They have strong digestive enzymes and a specialized epithelial fold that spirals the length of the small intestine, enabling the fishes to absorb a great diversity of foods. Sharks, to a large extent, are scavengers, eating injured fish, garbage, and other waste from ships as well as animals such as seals, turtles, birds, whales, crabs, and a wide range of fishes. The most interesting difference is called t he Ampoules of Lorenzini, which detect faint electrical currents from other fish. All living things generate electrical fields due to the contracting of muscles and sharks have adapted to being able to use this as an advantage to find prey. Sharks have a very excellent sense of smell. They are able to detect small substances, such as blood in water and trace them to their source. Their sense of sigh allows the shark to catch dim movements of shadow and light in dark waters as it approaches its prey. Sharks are particularly sensitive to sounds of low frequency and have fine directional hearing. Organs along their lateral lines and on the snout enable sharks to pick up weak electrical stimuli from the muscle contractions of bony fish. Their combination of keen senses accounts for the evolutionary success of sharks. The sharks also do not obtain a swim bladder, so they seem to be in constant motion.

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