The Great White shark is also termed as the great white, white pointer, white shark or white death, is amongst a variety of large lamniform shark which can be commonly found in the coastal surface waters of major oceans.
This variety of shark can grow approximately 6.4 m (21 ft) in length in males (although some have reported about great white sharks measuring over 8 m (26 ft)and over 3,324 kg (7,328 lbs) in weight.
This shark becomes mature at around 15 years of age and was believed to have a life span of about 30 years or more than that. The actual lifespan of great white sharks is far longer than previous reports, which is estimated to be as long as 70 years or above, making it one of the longest living cartilaginous fish.
Male great white sharks usually reach sexual maturity at 26 years of age and females attain the same at 33. Great white shark possesses great speed and can accelerate to over 56 km/hr and is ranked first making the highest number of attacks on humans.
The earliest known fossils so found of the great white shark are approximately 16 million years old.
Great white sharks reside almost all coastal and offshore waters, with majority lying in Chile, South Africa, Japan and the Mediterranean, United States (as well as Northeast California).
One of the densest known populations is found around the dyer island south Africa, which have a water temperature between 12 and 24 °C (54 and 75 °F) where almost all of the shark research work is done.
Ampulla of Lorenza is an extra sense which the great white sharks like all the other sharks possess (The ampullae of Lorenzini are the special sensing organs which are a kind of electroreceptor’s, which form a network of jelly-filled pores).
These sensory organs assist the fishes to sense electric fields in the water. Each ampulla contains a jelly-filled canal opening onto the surface by a pore in the skin and ending up blindly in a group of small pockets full of a special kind of a jelly.
The ampullae are mostly gathered into groups inside the body, each group having ampulla connected to different parts of the skin, simultaneously preserving their left-right symmetry.
The canal lengths differ from animal to animal, but the pores are distributed in a specific manner to each species. The ampulla pores are slightly visible as dark spots on the skin. They provide fish with an additional sense which is capable of detecting electric and magnetic fields along with temperature gradients.
This sense helps the sharks to detect the movement of living animals. They are amongst the most sensitive underwater animals on earth and can detect variations as much as half a billionth of a volt.
Another benefit of these senses is that at close areas the sharks are able to detect the presence of animals by just the detecting there heartbeats.
- Great white shark attacks on boats – While they do not frequently attack yet on other times they even sink boats.
- In a few cases it is reported that they have attacked boats up to 10 meters in length.
- They have knocked and bumped people overboard, usually creating a lot of destruction.
Ecology and behavior –
They capsizes its back while hunting tuna bait. This shark’s social structure and behavior is not well analyzed. Exclusively in South Africa, white sharks live under a dominance hierarchy depending on the squatter’s rights, sex and size.
Females dominates the males sharks, the smaller sharks are been dominated by the larger sharks, and the residents dominate newcomers.
During the hunting phase, great whites usually tend to separate and resolve conflicts with rituals, gestures and displays. A few individuals have been found with bite marks of the white sharks.
This suggests that when a great white shark approaches closely to one another, they react through a warning bite. It is also possible that white sharks bite to prove their dominance.
They are the only few sharks known to always lift their heads above the water surface to search for their prey. This is also known as spy hopping.
These characteristics are also been observed in a minimum of one group of blacktip reef sharks, but this might be attained through constant interaction with humans (it is found that it enhances the smell abilities of the shark because smell travels a lot faster in air than through water).
White sharks are extremely curious animals display intelligence and may also exercise socializing if the situation demands.
Great white sharks being carnivorous in nature usually prey upon fish (e.g. other sharks. Rays ,tunas), cetaceans (i.e., porpoises, dolphins, , whales), pinnipeds (e.g. sea lions, fur seals, seals sea otters, sea turtles and sea birds predation upon the adult American Crocodiles Exceptional.
Stomach contents of the great white sharks also confirm that Whale sharks both adult and juvenile may also be included on the animal’s diet they seem to be highly opportunistic. These sharks prefer to prey upon someone with a high content of energy-rich fat.
The reproduction in the great white sharks has been a mystery. Some evidence shows the near-soporific effect of a large animal (such as a whale carcass) possibly inducing mating.
Great white sharks were previously expected to reach sexual maturity at around 15 years of age, but actually take a lot more years. Male great white sharks reach sexual maturity at the age of 26, while female’s sharks take 33 years to reach sexual maturity.
Life Span –
Maximum life span was expected to be more than 30 years, but a study proved it to be as much as 70 years.
Due to The shark’s low reproductive rate, sexual maturity, and late slow growth rate make it extremely vulnerable to pressures such as environmental change and overfishing.