Also known as: Whale Shark.
Estimated numbers left in the wild: Unknown.
The whale shark is an enormous fish, measuring 5.5 to 10 meters long, and weighing an average of 18.7 tonnes. The largest scientifically measured whale shark was 12.7 meters long and weighed no less than 21.5 tonnes. The species is likely to be 60 million years old or older, surviving from the last days of the dinosaurs. Whale sharks are deep blue with pale patterns of speckles, with pale under parts. Whale sharks have huge, wide mouths, which is one of their most notable features. These giant fish swim slowly through the warm tropical and subtropical seas.
Whale sharks, despite their name and formidable size, are extremely gentle creatures and eat only tiny organisms collected via filter feeding. Whale sharks eat large algae, krill, plankton, fish eggs, various larval forms of ocean animals, and small fish or squid. They can filter feed by opening their mouths while swimming or by actively gulping and expelling water. For this reason, whale sharks are able to target swarms of small animals or clouds of fish eggs and sperm in the spawning grounds of various species.
Humans are safe from these creatures as whale sharks are generally neutral or even slightly friendly to human beings, allowing swimmers to “ride” them for a distance. Young whale sharks sometimes play with human divers also. Though a human could theoretically be accidentally sucked into a whale shark’s mouth if they were swimming close to its lips when it decided to take a gulp of krill or fish, this is never known to have occurred.
Whale shark reproduction is largely a mystery, though one female is known to have contained over 300 small “pups” who are likely born in sequence rather than in one huge swarm. Whale sharks reach adulthood at around 30 years of age and may live for up to a century.
Location: Whale sharks are found in tropical and warm temperate oceans, including the South Atlantic, South Pacific, and Indian Ocean. Though they swim in deep waters, large groups of whale sharks gather periodically in coastal waters to feed on seasonal food sources. Up to 400 may gather where tunny spawn is occurring, for example.
Threats: Whale sharks are still commercially hunted in some areas of the world, and since their population is unknown, this hunting could potentially represent a serious threat. Taiwan and the Philippines are the main areas where whale shark hunting occurs, despite long-standing bans on fishing, importing, exporting, and selling whale sharks and their meat in Taiwan, India, and the Philippines. Oil slicks from tanker spills and oil rig disasters may present a threat to whale sharks also, though dead whale sharks have not yet been observed near these disaster areas.
Conservation efforts: Bans on fishing for whale sharks and selling or trafficking in their meat have been in place since 1998 in Taiwan and slightly later in other nations in the region. A Whale Shark Photo-Identification Library exists as an effort to catalogue and estimate the world population of these huge, fascinating fish, based on unique skin patterns of specific individuals. Such a catalogue would allow better conservation efforts since it would make population changes more measurable.
Whale Shark Videos
Oceana is the largest international organization focused only on ocean conservation, protecting marine ecosystems and endangered species such as the Whale Shark.
Wildlife Conservation Society was formed in 1895 with the aim of protecting 25 percent of the world’s biodiversity by promoting the importance of protecting wildlife and their habitats. WCS has five zoos in New York.