Tiger shark - Galeocerdo cuvier
Tiger shark (Galeocerdo cuvier) is a species of requiem shark and the only extant member of the genus Galeocerdo. It is a large macropredator, capable of attaining a length over 5 m. Populations are found in many tropical and temperate waters, especially around central Pacific islands. Its name derives from the dark stripes down its body, which resemble a tiger’s pattern, but fade as the shark matures.
The tiger shark is a solitary, mostly nocturnal hunter. It is notable for having the widest food spectrum of all sharks, with a range of prey that includes crustaceans, fish, seals, birds,squid, turtles, sea snakes, dolphins, and even other smaller sharks. It also has a reputation as a “garbage eater”, consuming a variety of inedible, man-made objects that linger in its stomach. Though apex predators, tiger sharks are sometimes taken as prey by groups of killer whales. It is considered a near threatened species due to finning and fishing by humans. l
The tiger shark is second only to the great white shark in recorded fatal attacks on humans. Tiger shark teeth are unique with very sharp, pronounced serrations and an unmistakable sideways-pointing tip. Such dentition has developed to slice through flesh, bone, and other tough substances such as turtle shells.
Like most sharks, its teeth are continually replaced by rows of new teeth throughout the shark’s life. Relative to the shark’s size, tiger shark teeth are considerably shorter than those of a great white shark, but they are nearly as broad as the root as the great white’s teeth and are arguably better suited to slicing through hard-surfaced prey.
A tiger shark generally has long fins to provide lift as the shark maneuvers through water, while the long upper tail provides bursts of speed. The tiger shark normally swims using small body movements. Its high back and dorsal fin act as a pivot, allowing it to spin quickly on its axis, though the shark’s dorsal fins are distinctively close to its tail. The tiger shark is often found close to the coast, mainly in tropical and subtropical waters throughout the world. Its behavior is primarily nomadic, but is guided by warmer currents, and it stays closer to the equator throughout the colder months. It tends to stay in deep waters that line reefs, but it does move into channels to pursue prey in shallower waters. In the western Pacific Ocean, the shark has been found as far north as Japan and as far south as New Zeland. It has also been recorded in the Mediterranean, once off Spain and once off Sicily.
Tiger sharks can be seen in the Gulf of Mexico, North American beaches, and parts of South America. It is also commonly observed in the. Other locations where tiger sharks are seen include off Africa, China, India, Australia and Indonesia. Certain tiger sharks have been recorded at depths just shy of 900 m but some sources claim they move into shallow water normally thought to be too shallow for a species of its size. A recent study showed the average tiger shark would be recorded at 350 m, making tiger sharks uncommonly seen in shallow water. However, tiger sharks in Hawaii have been observed in coastal waters at depths of 6 to 12 m.
(tratto da Wikipedia)