About Hammerhead Sharks

Hammerheads are some of the most striking fish in the sea. Their wide, flat heads set them apart from the rest of their chondrichthyes cousins. Nine known species of hammerhead exist, and while they’re solitary nighttime hunters, these large fish are known to form schools of up to one hundred animals during the day.

Scalloped hammerheads swim in large groups during the day, and hunt at night. Swinging their heads from side to side as they swim, they check the waters for prey. The wide positioning of the eyes gives the shark a unique vantage point. But stick something right between their eyes and they can’t see it!

The great hammerhead shark is a large, smooth-headed cousin to the scalloped hammerhead. The great hammerhead can grow to 18 feet (5.5 m) and weigh up to 1,000 lbs (454 kg).

Large schools of scalloped hammerhead females have been spotted doing a strange “dance”: They nudge each other, shake their heads, and swim around in spirals. No one knows why.

Newborn hammerheads look like little replicas of their parents. They’re born with their head projections bent back.

Hammerheads are partial to stingrays, which spend most of their time buried in the sand. The hammerhead swings its head around like a metal detector, and in this way, the ampullae of Lorenzini (aka electrosensory pores) can detect the ray’s electrical field. Then the hammerhead uses its head like a shovel, digging up the ray. Sometimes the head is used to pin down prey while the shark takes a bite. Hammerheads are immune to the venom of the rays’ tail barb.