Thursday, 17 January 2013

Tiger Shark Images

Source (google.com.pk)
Tiger Shark Images Biography

The tiger shark, Galeocerdo cuvier, is the fourth largest shark, after the whale shark, basking shark and great white shark, averaging 14 feet long and up to 2000 pounds. It lives in most of the worlds’ tropical and sub-tropical oceans, and is found in large numbers around Pacific islands, where it lives close to the coasts in the deep waters just off of reefs.  Tiger sharks prefer warmer waters, though they have been found in temperate waters, and tend to stay closer to the equator during cold months. They will swim swiftly in quite shallow water when pursuing prey, and have been observed in harbors and estuaries.

Tiger sharks hunt mostly at night, alone, and reach from the surface waters down to over 1000 feet, and swim at around two miles per hour, with occasional sprints when needed. It is not a commercially fished species, but is fished by “game” fisherman, and slaughtered for its fins, and the liver which is a source of vitamin A used in vitamin oils.

Biology
Renowned for its voracious appetite and indiscriminate feeding habits, the tiger shark has been known to consume an incredible array of items, from standard prey such as fish, turtles and marine mammals, to human rubbish, including burlap sacks and car license plates (4) (5). Such behaviour enables this species to overcome the problem of food shortages, which can affect sharks that feed more selectively (2).
Unfortunately, the tiger shark’s curiosity and tendency to sample such a wide variety of objects has meant that on occasion it has been responsible for attacks on humans. As a result of its large size, tiger shark attacks can be fatal, but in spite of a great deal of media hype, they are extremely rare (4) (6). A solitary species, the tiger shark usually feeds at night, moving to inshore locations where it engages in active hunting of prey, as well as scavenging, before returning to deeper waters where it spends the day (4). Home ranges appear to be very large, with electronically tagged tiger sharks released in Hawaii swimming over 16 kilometres within a day of being released, and taking between two weeks and nine months to revisit the release area (2).

Tiger sharks are ovoviviparous, which means that after fertilisation, the embryos develop within the female’s uterus, receiving nourishment from a yolk sac. Once the yolk sac nutrients are exhausted the embryos are thought to gain further nourishment from secretions produced by the uterus until birth takes place. The gestation period—from egg fertilisation to birth— takes between 14 and 16 months, with births taking place in the Northern Hemisphere between April and June, and in the Southern Hemisphere from November to January (4). Litter sizes vary between 10 and 82 pups, with the newborns measuring between 0.5 and 1.05 metres (2).

Tiger Shark Images
Tiger Shark Images

Tiger Shark Images

Tiger Shark Images

Tiger Shark Images

Tiger Shark Images

Tiger Shark Images
Tiger Shark Images

Tiger Shark Images

Tiger Shark Images

Tiger Shark Images

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