How Whale Sharks Work

Whale Shark Basics

Tourists look at a whale shark through an acrylic panoramic window at the Okinawa Churaumi Aquarium in Okinawa, Japan.
Koichi Kamoshida/Getty Images

The whale shark lives in warm ocean waters throughout the world, except for the Mediterranean Sea. In the Atlantic Ocean, its territory ranges from the northeastern coast of the United States all the way to central Brazil, across to Senegal in Africa and down to the Gulf of Guinea near Cameroon. The shark is found throughout the Indian Ocean. In the Pacific, you can find whale sharks only from Japan to Australia in the East and California to Chile in the West. Researchers believe that the whale shark migrates at various times of the year, but there isn't any solid evidence to back this up yet. While it tends to be a solo swimmer, it has been spotted schooling with its brothers and sisters when food is abundant.

If you saw a whale shark, you probably wouldn't confuse it with any other fish, simply because of its size. Aside from being the largest fish in the ocean, there are a few other physical features that might help you identify a whale shark. Its head is broad and flattened. Unlike most sharks, the whale shark's mouth is nearly at the tip of its nose instead of underneath the snout. Inside its mouth are several hundred rows of tiny, hook-shaped teeth that have been likened to a wood rasp. Although it has a mouthful of teeth, the whale shark doesn't usually use them for eating. 


Another unique trait of the whale shark is the distinctive pattern of light-colored spots and stripes on its back. Its back is bluish grey to brown with thousands of cream colored spots scattered in a pattern believed to be unique to each shark, like a human's fingerprint. Researchers aren't sure exactly why the whale shark has the spots. Some bottom dwellers have unusual markings on their backs to act as camouflage from predators swimming above them. The whale shark is neither a bottom dweller nor worried about predators. However, it's related to the carpet shark, which boasts a similar spot pattern for protection. Another theory suggests that these spots help shield the surface-loving shark from harmful ultraviolet sun rays.

Since research on these big fish is scarce, we aren't sure exactly how long whale sharks live. But sharks are notoriously long-living fish, and the whale shark's size indicates it may live up to 100 years.

Until 1995, researchers knew little about the reproductive cycle of the whale shark. Many experts thought that the large shark was oviparous, meaning that it laid eggs on the ocean floor. But in 1995, a large female whale shark was captured and observed. Scientists found that she was pregnant with 300 shark pups, ranging in size from 16 to 24 inches long (42 to 63 centimeters). This meant that the whale shark gives birth to live pups, making it ovoviviparous.

Let's find out how this big beast satisfies its appetite.