Great White Sharks Facts, Photos, Video

Posted on August 24th, 2013 by Mike

The Great White Shark (Carcharodon carcharias), also known as White Pointer, White Shark or Amaletz, is an exceptionally big lamniform shark found in coastal surface waters in all major oceans. Reaching lengths of about 6 meters (20 feet) and weighing over 2000 kilograms (4,000 pounds), the Great White is the world’s largest predatory fish. They are the only known surviving species of their genus, Carcharodon.

Distribution
White sharks live in almost all the cold or temperate waters of the planet, with greater concentrations in the southern coasts of Australia, in South Africa, California, and to a degree in the Central Mediterranean and the Adriatic Sea. The densest known population is found around Dyer Island, South Africa where up to 31 different white sharks have been documented by Michael Scholl of White Shark Trust in a single day. It can be also found in tropical waters like those of the Caribbean and has been recorded off Mauritius. It is also a pelagic fish, but recorded or observed mostly in coastal waters in the presence of rich game like otariids, cetaceans, other sharks and large bony fish species.

Capabilities
Great Whites have a sixth sense given by the Ampullae of Lorenzini, which permits them to detect the electromagnetic field emitted by the movement of living animals. It has been recently discovered that the Great White’s primary and most refined sense is sight. Individuals who lose their sense of sight–partially or totally–can scarcely survive.

White shark’s reputation as ferocious predators is well-earned, yet they are not (as once was believed) indiscriminate “eating machines”. They hunt using an “ambush” technique, taking their prey by surprise from the bottom. It is the one shark that lifts its head above the sea surface to gaze at other objects such as prey. This is known as ‘spy-hopping’. It is theorized that the shark may also be able to smell better this way, since smells travel through air faster than through water.

Great White sharks primarily eat fish, smaller sharks, turtles, dolphins, and pinnipeds such as seals and sea lions. They are apex predators; the only animals known to attack them are other Great Whites, sperm whales and orcas.

Great Whites, like many other sharks, have rows of teeth behind the main ones, allowing any that break off to be rapidly replaced. Their teeth are unattached to the jaw and are retractable, like a cat’s claws, moving into place when the jaw is opened. Their teeth also rotate on their own axis (outward when the jaw is opened, inward when closed). The teeth are linked to pressure and tensor-sensing nerve cells. This arrangement seems to give their teeth high tactile sensitivity.

Breeding, behavior, and lifespan
There is still a great deal that is unknown about Great White behavior, such as mating habits. Birth has never been observed, but several pregnant females have been examined. Great Whites are ovoviviparous, the eggs developing in the female’s uterus, hatching there and continuing to develop until they are born, at which point they are perfectly capable predators. The embryos can feed off unfecundated eggs. The delivery takes place in the period transitioning Spring and Summer.

The young, which number 8-9 (with a maximum of perhaps 14) for a single delivery, are about 1.5 m (5 ft) long when born. Their teeth are provided with small side cusps. They grow rapidly, reaching 2 meters of length in the first year of life. Almost nothing, however, is known about how and where the Great White mates. It should be noted that there is some evidence that points to the near-soporific effect as the result of a large kill (such as a large whale) possibly inducing mating.

A White Shark can reproduce when a male’s length is around 3.8 meters and a female’s length is around 4.5 to 5 meters. Their lifespan has not been definitively established, though many sources estimate 30 – 40 years. It would not be unreasonable to expect such a large marine animal to live longer however.

Captivity
The Great White has yet to be successfully kept in captivity and all attempts to keep one in captivity prior to August 1981 lasted 11 days or less. However, a Great White broke that record by lasting 16 days in captivity at SeaWorld San Diego. [1]

In 1984, the Monterey Bay Aquarium in Monterey, California housed its first Great White. [2] However, in July 2003, Monterey researchers captured a small female and kept it in a large, netted pen off Malibu for five days, where they had the rare success of getting the shark to feed in captivity before it was released. [3] It was not until September 2004 that the aquarium made history by becoming the first aquarium in the world to place a Great White on long-term exhibit. The young female, who was caught off the coast of Orange County, was kept in the aquarium’s massive 1 million-gallon Outer Bay exhibit for 198 days before her successful release back to the wild in March 2005. [4]

Probably the most famous Great White to be kept in captivity was “Sandy” and in August 1980 she became the first and only Great White to be housed at the Steinhart Aquarium in San Francisco, California. She was returned to the wild when she would not eat anything given to her and would constantly bump against the walls.

Conservation status
It is unclear how much a consummate increase in fishing for Great Whites had to do with the decline of Great White population from the 1970s to the present. No accurate numbers on population are available, but populations have clearly declined to a point at which the Great White is now considered endangered. Their reproduction is slow, with sexual maturity occurring at about nine years of age, such that population can take a long time to rise.

In 2005, a tagged Great White named Nicole was recorded swimming from South Africa to Australia and back, 22,000 kilometers round trip. Researchers believe it may have undertaken this journey to mate, and hope studies such as this will produce more effective conservation measures. [6]

The Convention on International Trade in Endangered Species (Cites) has put the Great White shark on its ‘Appendix II’ list of endangered species. The shark is targeted by fishermen for its jaws, teeth, and fins, and as a game fish. White shark, however, is rarely an object of commercial fishing, although its flesh is considered valuable. If casually captured (it happens for example in some tonnare in the Mediterranean), it is sold as Smooth-hound shark.

Size
While the average length of a Great White is 4 to 5 m (females generally being larger than males), the question of the maximum size of Great White sharks has been subject to much debate, conjecture, and misinformation. Richard Ellis and John E. McCosker, both academic shark experts, devote a full chapter in their book The Great White Shark (1991) to analysis of various accounts of extreme size.

Today, most experts contend that the Great White’s “normal” maximum size is about 6 m (20 ft), with a maximum weight of about 1900 kg (4200 lb). Any claims much beyond these limits are generally regarded as doubtful, and are closely scrutinized.

For some decades, many standard ichthyology reference books listed an 11 m (36 feet) Great White captured in south Australian waters near Port Fairy in the 1870s as the largest individual. While this was the commonly accepted maximum size, reports of 7.5 to 10 m (25 to 30 ft) Great Whites were common and often deemed credible.

Some researchers questioned the reliability of the Port Fairy shark, noting it was much larger than any other accurately reported Great White. The question was settled in the 1970s, when J.E. Reynolds examined the Port Fairy shark’s jaws and “found that the Port Fairy shark was of the order of 5 m (17 feet) in length”.[7]

Ellis and McCosker write that “the largest White Sharks accurately measured range between 19 and 21 ft (about 6 m), and there are some questionable 7 m (23 feet) in the popular