But the secret weapon in the Great White’s arsenal are ampullae — small pore-like markings on the snout — which provide the shark with the ability to sense the electrical fields of their prey. Each is a minute capsule filled with a gel like substance the shark excretes, sensitive to electrical discharges as low as .005 micro volts. This remarkable sensitivity is due to both the large number of ampullae, and their numerous sensory cells in each to pick up the signal which is also directly linked to the brain.
Every living creature in the sea discharges a small electrical field. Mucous membranes that coat the mouth and gills of fish also create steady current fields affected by their breathing patterns. A wounded bleeding animal produces yet another set of electrical information.
By their ability to discern these sets of information, Great Whites can detect and distinguish between prey swimming peacefully, those moving quickly in panic, and those which might be bleeding and debilitated. Recent research on interactions between great whites and various species of seals and sea lions suggests that great whites also hunt their prey visually.
These 2 sensory mechanisms make for an inescapable and formidable predator.
Food and Feeding Behavior
While young, White sharks feed on fish, rays, and other sharks, and as they begin to mature they’ll feed on marine mammals and forage for large animal carcasses. Progressing to small harbor seals, they hunt sea lions, elephant seals, and small toothed whales as they increase in size. Occasionally feeding on sea turtles and sea otters, they’ve been known to attack but not eat humans.
Camouflaging themselves near rocky bottoms, they’ll watch for unsuspecting prey near the surface. Once an animal is sighted, they accelerate quickly to the surface and ram into their kill from beneath, simultaneously stunning it and inflicting a large, potentially fatal bite. They then return to feed on the carcass.
Great Whites have one of the widest geographic ranges of any marine animal, found in all cold temperate and tropical waters from 60°N latitude to 60°S latitude. Recent satellite tracking studies reveal that they migrate long distances, sometimes crossing entire oceans.
Great White Shark Attack
The cunning Great White appears almost to be toying with this seal
prior to its ferocious attack.