The whale shark is NOT a whale but is the biggest shark and the biggest fish. It has an enormous mouth, which can be up to 4ft (1.4m) wide. Unlike most sharks whose mouth is on the underside of the head, its mouth is at the very front of its head. The whale shark has a wide, flat head, a rounded snout, small eyes, 5 very large gill slits, 2 dorsal fins and 2 pectoral fins. Just behind the shark’s eye is the spiracle which is a vestigial first gill slit used for breathing when the shark is resting on the sea floor. Its tail has a top fin much bigger than the lower fin.

The whale shark has unique light-yellow markings on its very thick dark gray skin. Its skin is up to 4 in (10 cm) thick. There are three outstanding ridges running along each side of the shark’s body.

The whale shark is well over 40 ft long, weighing up to 15 tons. The average size is 25 ft (7.6 m) long. Like most sharks, females are larger than males.

World Range & Habitat
Whale sharks reside in warm water both along the coast and in the open seas. The spend most of their time near the surface.

Feeding Behavior
It is a filter feeder and sifts large amounts of plankton through its gills as it swims. After closing its mouth, the shark uses gills rakers that clean the captured prey from its gills. Gill rakers are bristly structures. Anything that doesn’t pass through the gills is eaten. The shark’s prey includes plankton, krill, small fish and squid. The shark can sieve over 1500 gallons of water an hour. The Whale shark’s 3,000 very tiny teeth are of almost no use.

Reproduction
The Whale shark was long thought to be oviparous (an egg 14 inches (36cm) long was found in the Gulf of Mexico in 1953; being the largest egg in the world) and was thought to be a Whale shark egg. Lately, pregnant females have been found containing hundreds of pups, so Whale sharks are viviparous, giving birth to live young. Newborns are over 2ft (60 cm) long.

Warnings & Comments
Whale sharks are solitary creatures and have been rarely seen in groups of whale sharks.

They are very slow swimmers at speeds of now more than 3 mph (5 kph). Unlike most sharks they swim by moving their entire bodies from side to side.

Whale sharks are harmless to people and typically indifferent to divers.

It has been estimated for Whale sharks to live for up to 100-150 years.