The shark can circulate water at a rate up to 1.7 L/s (3.5 US pint/s). Whale sharks have been observed 'coughing' and it is presumed that this is a method of clearing a build up of food particles in the gill rakers. Any material caught in the filter between the gill bars is swallowed. This fine sieve-like apparatus, which is a unique modification of the gill rakers, prevents the passage of anything but fluid out through the gills (anything above 2 to 3 mm in diameter is trapped). During the slight delay between closing the mouth and opening the gill flaps, plankton is trapped against the dermal denticles which line its gill plates and pharynx. The many rows of teeth play no role in feeding - instead the shark sucks in a mouthful of water, closes its mouth and expels the water through its gills. It feeds on phytoplankton, macro- algae, plankton, krill and small nektonic life, such as small squid or vertebrates. The whale shark is a filter feeder - one of only three known filter feeding shark species (along with the basking shark and the megamouth shark). No reliable documentation exists of those claims and they remain little more than 'fish-stories'.

In 1934 a ship named the 'Maurguani' came across a whale shark in the Southern Pacific ocean, rammed it, and the shark consequently became stuck on the prow of the ship, supposedly with 4.6 m (15 ft) on one side and 12.2 m (40 ft) on the other. There have even been claims of whale sharks of up to 23 m (75 ft). The shark was too heavy to pull ashore, but Smith estimated that the shark was at least 17 m (55.7 ft) and weighed approximately 37 tonnes (81,500 lb), which have been exaggerated to an accurate measurement of 17.98 m and weight 43 tonnes in recent years. Smith describes a huge whale shark caught in a bamboo fish trap in Thailand in 1919. Perceval Wright spent time in the Seychelles, during which he managed to obtain several small whale shark specimens, but claimed to have observed specimens in excess of 15 m (49 ft), and tells of reports of specimens surpassing 21 m (69 ft). Stories exist of vastly larger specimens - Quoted lengths of 18 m (59 ft) are not uncommon in the popular shark literature - but no scientific records exist to support their existence. The largest specimen regarded as accurately recorded was caught on November 11, 1947, near the island of Baba, not far from Karachi, Pakistan. The whale shark is not an efficient swimmer since the entire body is used for swimming, which is unusual for sharks and contributes to an average speed of only around 5 km/h. Whale shark in main tank at Osaka Aquarium. Males range over longer distances than females (which appear to favour specific locations). The whale shark is solitary and rarely seen in groups unless feeding at locations with an abundance of food. Its range is restricted to about ☓0 ° latitude. While thought to be primarily pelagic, seasonal feeding aggregations of the sharks occur at several coastal sites such as Ningaloo Reef in Western Australia Útila in Honduras Donsol in the Philippines and Pemba and Zanzibar off the coast of Tanzania. The whale shark inhabits the world's tropical and warm-temperate oceans. The name 'whale shark' comes from the fish's large size and eating habits that is, a shark as large as a whale that shares a similar filter feeder eating mode. He proceeded to publish a more detailed description of the species in 1849. It was described the following year by Andrew Smith, a military doctor associated with British troops stationed in Cape Town.

The species was first identified in April 1828 following the harpooning of a 4.6 m (15 ft) specimen in Table Bay, South Africa. The species is believed to have originated about 60 million years ago. The shark is found in tropical and warm oceans and lives in the open sea. This distinctively-marked shark is the only member of its genus Rhincodon and its family, Rhincodontidae (called Rhinodontes before 1984), which is grouped into the subclass Elasmobranchii in the class Chondrichthyes. The whale shark, Rhincodon typus, is a gentle and slow filter feeding shark that is the largest living fish species.

Whale shark size