Tiger sharks are named for the dark, vertical stripes found mainly on juveniles. As these sharks mature, the lines begin to fade and almost disappear. These large, blunt-nosed predators have a duly earned reputation as man-eaters. They are second only to great whites in attacking people. But because they have a near completely undiscerning palate, they are not likely to swim away after biting a human, as great whites frequently do.
They are consummate scavengers, with excellent senses of sight and smell and a nearly limitless menu of diet items. They have sharp, highly serrated teeth and powerful jaws that allow them to crack the shells of sea turtles and clams. The stomach contents of captured tiger sharks have included stingrays, sea snakes, seals, birds, squids, and even license plates and old tires.
Tiger sharks are common in tropical and sub-tropical waters throughout the world. Large specimens can grow to as much as 20 to 25 feet (6 to 7.5 meters) in length and weigh more than 1,900 pounds (900 kilograms). They are heavily harvested for their fins, skin, and flesh, and their livers contain high levels of vitamin A, which is processed into vitamin oil. They have extremely low repopulation rates, and therefore may be highly susceptible to fishing pressure. They are listed as near threatened throughout their range.
The tiger shark is a solitary, mostly nocturnal hunter, and is notable for having the widest food spectrum of all sharks, consuming a variety of prey ranging from crustaceans, fish, seals, birds, squid, turtles, and sea snakes to dolphins and even other smaller sharks. The tiger shark has been known to eat inedible, man-made objects that linger in its stomach, and it has a reputation as a "garbage eater". While the tiger shark sits atop the food chain as an apex predator, killer whales have been known on occasion to prey on them.
Swimming Efficiency and Stealth[]
All tiger sharks generally swim slowly, which, combined with cryptic coloration, may make them difficult for prey to detect them in some habitats. They are especially well camouflaged against dark backgrounds. Despite their sluggish appearance, tiger sharks are one of the strongest swimmers of the carcharhinid sharks. Once the shark has come close, a speed burst allows it to reach the intended prey before it can escape.
Reproduction[]
Males reach sexual maturity at 2.3 to 2.9 m (7.5 to 9.5 ft) and females at 2.5 to 3.5 m (8.2 to 11.5 ft). Females mate once every three years. They breed by internal fertilization. The male inserts one of his claspers into the female's genital opening (cloaca), acting as a guide for the sperm. The male uses his teeth to hold the female still during the procedure, often causing the female considerable discomfort. Mating in the Northern Hemisphere generally takes place between March and May, with birth between April and June the following year. In the Southern Hemisphere, mating takes place in November, December, or early January. The tiger shark is the only species in its family that is ovoviviparous; its eggs hatch internally and the young are born live when fully developed.
The young develop inside the mother's body up to 16 months. Litters range from 10 to 80 pups. A newborn is generally 51 to 76 cm (20 to 30 in) long. How long tiger sharks live is unknown, but they can live longer than 12 years.
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