Whale sharks are familiar, and yet mysterious. In many locations, boats take tourists out to view and swim with these giants. And yet experts are still baffled by things like exactly how they feed. Never fear, though. Scientists and researchers are on the case!

Here are some things scientists have learned:

1) Seawater is forced into the throat. Using photos, they measure the size of a whale shark’s wide open mouth. They calculate the amount of water that enters as the shark swims or as it sucks at the surface of the ocean.

2) Filter pads catch food. By experimenting with screening devices, people figure out what size plankton and tiny sea creatures will be captured on the ten pads that act like kitchen strainers lining the whale shark’s throat.

3) Food is probably pushed down toward the shark’s stomach as it piles up on the filter pads. Scientists often use their knowledge of other filter feeding sharks and whales to make educated guesses like this.

4) After passing through the (A) filter pads, water goes through (B) vents that direct the seawater over (C) gill membranes, which extract oxygen, and finally out of (D) gill slots on each side of the shark. Biologists can examine these organs carefully by dissecting a dead animal.

5) Several times an hour while feeding, whale sharks clear their clogged filter pads. People aboard small research boats can actually watch as sharks cough out clouds of food debris.

Want to Know:

Marine biologists ask: Do whale sharks really spend up to seven hours a day feeding and yet thrive on the amount of food energy in just a large McDonalds meal?

Fun to Know:

Baby sharks are called pups. And whale sharks are slow to grow up. They don’t start having pups until they are about 25 years old.