The great white shark impresses with its size and the power of its jaws. Placed at the top of the marine food chain, this super predator is more vulnerable that it seems. Meeting with a threatened colossusextinction by human activities.
Presentation of the great white shark
The great white shark belongs to the family of lamnidae which all species have in common the capacity of thermoregulation. Higher than that of water, their internal temperature allows them to quickly warm up their muscles and to move easily in the water. cold. The animal moves its massive body easily thanks to fins Strongly developed sickle-shaped (scythe-shaped) pectoral fins and a short, almost symmetrical caudal fin, crescent-shaped. The dorsal part presents a coloration grey sometimes dark while its belly is white. The shark measures between 4 and 5 meters and weighs up to 2 tons.
The white shark: cut to hunt
Many strengths make the white shark the biggest fish predator in the world. Its conical and elongated muzzle has a jaw that can reach 90 cm wide. As for his teeth sharp like razor blades, they can be up to 75mm long. The great white shark is endowed with a hearing and a smell very sharp. The animal is able to smell a drop of blood in over 4 million liters of water and can hear prey more than 1 km away. Bulbs Lorenzini placed under its muzzle act as receptors sensitive to the fields magnetic allowing it to detect low frequency vibrations at long distances.
The great white shark, a solitary
The great white shark lives mainly in all waters temperate and tropical regions of the world, near the coasts. It is found particularly in Australia, South Africa, California, the Caribbean and is rare in mediterranean. The lamnid swims constantly to provide the body withoxygen necessary for its survival. It usually travels alone or in pairs, but never forms a colony. The animal is not territorial, it travels a lot and some specimens can travel up to 10,000 km per year.
The great white shark, a voracious
In the juvenile stage, the great white shark feeds on Pisces (swordfish, tarpons) then attacks larger prey by reaching its adult size: tuna, other species of sharks, turtles, dolphins, porpoises, elephant seals, seabirds, seals, sea lions. The animal offers itself a hearty meal every three days or so. His technique of hunt is to hide in the background water and, after spotting a target, propel like a rocket to hit it. Stunned by the collision, the prey lets itself be devoured by the powerful jaws. Contrary to popular belief, the white shark does not consider theman like an enemy. The attacks are exceptional and very often due to confusion with another prey.
Predator from birth
Males reach their maturity sexual around the age of 10. Before the breeding season – which takes place in the spring – females feed on large prey to accumulate fat in anticipation of gestation which lasts 12 to 18 months. The animal is ovoviviparous, that is, the development of the embryo occurs inside the female’s uterus. At birth, young people already measure between 1 m and 1.60 m and immediately have the instinct to predation.
The great white shark threatened with extinction
The only known predators of great white sharks are the killer whales and man. The shark is hunted for its flesh and its fins, but also for its teeth which are sold as souvenirs to tourists. His cartilages are also used in the manufacture of medicines. Note that, as with many animals, the pollution disrupts its reproductive cycles. The population of the great white shark has declined by 75% and its species is threatened with extinction. Classified vulnerable by the International Union for the Conservation of Nature (IUCN), the species has been added to Appendix II of CITES banning its fishing in many countries. A ban not always respected because of the bad reputation from which the animal suffers.