A tagging study attached GoPro cameras to five great hammerheads that were living out in the wild. While being monitored, the sharks spent 90 percent of their swimming time tilted to one side—usually at an angle of 50 to 75 degrees.
The bonnethead Sphyrna tiburo is a small hammerhead that frequents warm, shallow waters. It hunts crabs and shrimp—and sometimes it also ingests seagrass. One survey compared the gut contents of numerous wild bonnetheads and found that up to 62 percent of all the organic matter discovered in their stomachs was seagrass.
And in a experiment, captive bonnetheads were fed a 90 percent seagrass diet. Rather than waste away, the sharks gained weight. Either way, the bonnethead now qualifies as the only omnivorous shark known to science. If a stingray is found just above the ocean floor, a hungry great hammerhead will use its cephalofoil to pin the creature against the sand.
But the shark doesn't always escape unscathed: Great hammerheads are often found with stingray barbs on their faces. In , biologist Michelle McComb and her team captured live bonnetheads, winghead sharks, and scalloped hammerheads to test their vision. The researchers found that the binocular overlap in the hammerheads' field of vision is up to three times higher than it is in lemon and blacknose sharks—both of which have cone-shaped snouts.
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History Magazine These 3,year-old giants watched over the cemeteries of Sardinia. Magazine How one image captures 21 hours of a volcanic eruption. Great hammerhead sharks have been found at depths of feet m but typically stay in coastal waters up to feet 80 m deep. Great hammerhead sharks have been found with stingray and catfish barbs sticking out of their mouths, suggesting that they are immune to stingray and catfish venom.
Click here or below to download hands-on marine science activities for kids. Home Marine Life. Learn More. Take Action. Great hammerhead sharks live in warm temperate and tropical waters in the Atlantic, Pacific, and Indian Oceans.
They undertake seasonal migrations to cooler waters in the summer. Great hammerheads may be found in both nearshore and offshore waters, over continental shelves, near islands, and near coral reefs. Hammerheads use their cephalofoils for detection of prey using their electro-reception system.
This system allows them to detect their prey by electrical fields. Great hammerhead sharks primarily feed at dusk and eat stingrays, invertebrates, and fish , including even other great hammerheads. Their favorite prey is rays , which they pin down using their heads. They then bite at the ray's wings to immobilize them and eat the entire ray, including the tail spine. Great hammerhead sharks may mate at the surface, which is unusual behavior for a shark. During mating, the male transfers sperm to the female via his claspers.
Great hammerhead sharks are viviparous give birth to live young. The gestation period for a female shark is about 11 months, and pups are born live. The pups are about 2 feet long at birth. Hammerhead sharks are generally not dangerous to humans, but great hammerheads should be avoided due to their size.
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