Hammerhead Shark

May 10, 2009
By Damond Benningfield

The great white shark may be one of the most feared creatures in the oceans, but it’s also one of the most beautiful. Its long, streamlined body is both powerful and graceful. But the great white’s cousin, the great hammerhead shark, looks anything but graceful. Instead, it looks like something dreamed up by a mad scientist, with some sort of odd tool attached to a shark’s body.

Hammerhead shark. Credit: http://en.wikipedia.org/wiki/File:Hammerhead_shark.jpg

Hammerheads are found in warm coastal waters around the world. That includes the Atlantic and Gulf coasts of the United States. There are nine species of hammerheads. The biggest is the great hammerhead, which can grow up to 20 feet long and weigh half a ton.

Hammerheads differ from other sharks in several ways, including taller dorsal fins and smaller mouths. But the most obvious difference is the wide, flat head -- known as a “cephalofoil.” In some species it really does look like a hammer, while in others it looks more like a scoop.

The shape helps a hammerhead locate its prey. For one thing, the wide-set eyes provide a wider field of view, allowing the shark to scan a bigger area. And for another, the head is lined with sensory organs that detect small electric currents produced by their prey.

That’s especially helpful for hunting rays, which bury themselves in the sand. Some hammerheads use their snouts to pin the ray to the bottom while they begin nibbling on its wings.

So while the head may look odd, like any good hammer it’s a useful tool -- in this case, for nailing the shark’s next meal.