The great white shark is one of the largest members of the
shark subclass. Its
scientific name is
Carcharodon carcharias, and further
taxonomic information is as follows:
- Class: Chondrichthyes
- Subclass: Elasmobranchii
- Superorder: Selachimorpha (Pleurotremata)
- Order: Lamiformes
- Family: Lamnidae
It is found predominantly in
temperate waters, but can venture into
tropical zones. It is predominantly found in waters off the coasts of southern
Africa,
Australia,
New Zealand,
Japan, and sporadically in the
Atlantic and
Pacific waters near
North and
South America.
The maximum length of the animal is a subject of some debate, given that most evidence concerning size limits comes from fossilized or lost teeth rather than live specimens. However, from live captures, it is certain that adult females can reach lengths of at least 7.1 metres. They probably mature sexually at a length of 4.5 metres, or about 10-12 years of age.
Females may reproduce every two years, and have litters of between 2 and 10 pups. The total length of babies at birth is around 1.2 to 1.5 metres. Like many other shark species, the baby sharks are supported within the adult female's uterus until they are sufficiently large and mature to survive alone (this mode of reproduction is called ovoviviparity).
Contrary to popular opinion, the white shark's diet is dominated by fish, squid, molluscs, crustaceans and other elasmobranches. They do not eat marine mammals most of the time. This misconception exists due to the fact that the majority of observations of white shark feeding occur in near-shore areas, where the only available prey are pinnipeds. They also do not actively pursue human prey; the majority of attacks by great white sharks on humans are likely due to a mis-identification by the shark, as swimming humans may resemble a seal in distress, and surfers have nearly the same profile as sea turtles, a favoured prey item. One reason such attacks occur is that the eyesight of great white sharks (and sharks in general) is very poor, and they rely on their lateral line to identify suitable prey items.
There are a very large number of popular misconceptions concerning the great white. It is not an "eating machine", as is often noted in the popular press. Like almost all sharks, they have very slow metabolisms and thus may only consume large meals once every couple of weeks. The sole reason that scientists have a good idea of their dietary preferences is this slow metabolism; consumed food items may remain intact in the tractus for several days, and larger items may take weeks to be completely digested. Finally, the great white is not the largest predatory shark species. The whale shark(Rhincodon typus), which consumes zooplankton prey, can grow to a length of 12 metres. The great white is the largest shark species which preys upon larger prey items.
Great white sharks may be sufficiently scarce to merit a CITES classification of endangered, but at present they remain listed as vulnerable. They continue to be targeted by sport and trophy fishers, and are often massacred in large numbers subsequent to an attack on a human. Given their relatively late maturity, their very small litter size and infrequent spawning, this species is extremely vulnerable and may be easily extirpated if serious international efforts are not deployed immediately to save this wonderful animal.