Whale Sharks

March 23, 2008
By Damond Benningfield
Episode:

The great white may be the bad boy of the shark world, but when it comes to size, weight, and sheer toothiness, another species puts it to shame. The whale shark is by far the largest fish on Earth. It can grow to 40 feet or longer and weigh more than 20 tons. An adult whale shark’s mouth is wide enough to swallow a person, and it has thousands of teeth.

Whale Shark. Credit: Georgia Aquarium

But the whale shark is the gentle giant of its kind. It glides serenely through warm waters, feeding on small organisms and occasionally playing with divers.

Whale sharks get their name both from their great size and from their eating habits, which are like those of some whales -- instead of chomping into prey with their many teeth, they use their gills to filter microscopic plants and small animals out of the water. They’re especially fond of fish eggs, and will follow schools of snapper for hours, waiting for them to spawn.

Much about the whale shark is poorly understood. Scientists know that the young are born live, that they may reach maturity around 25 or 30 years, and they may live for a century. But what happens between birth and maturity isn’t well known.

One thing that we do know is that individuals are easy to identify. The tops of their bodies feature patterns of white markings that are as unique to an individual shark as fingerprints are to a person.

We also know that the whale shark population worldwide is dwindling. Their fins are a delicacy in some regions, so overfishing is taking its toll on this gentle giant.