The Great Hammerhead Shark
Great hammerhead sharks are the largest of all species of hammerheads. They are not afraid of humans but they are also not particularly interested in humans. However, they are considered a potentially dangerous shark, unlike many of the other species, and they have been known to attack humans. Below are more great hammerhead shark facts for kids and adults. Click on image to enlarge.
The average size of this shark is about 18 feet in length and 500 pounds in weight. The largest reported length is 20 feet and the largest reported weight is 991 pounds.
The eyes are located on the sides of their hammer-shaped heads. It is believed that the head is shaped this way because it allows them to scan (like a metal detector) a large area when hunting prey. Sensory organs in the head help them detect their prey, even those buried in the ocean bottom. Their good sense of smell also helps them locate their prey.
These sharks can be found living in shallow coastal waters and in much deeper waters offshore in oceans throughout the world.
Stingrays are a favorite food for great hammerhead sharks and apparently the ray’s sharp, venomous defensive spines do not affect these sharks. The hammerhead will use its "hammer" to pin the stingray down while it eats it. Other prey includes squid, octopus, crabs, lobsters, fish, and other sharks. They are also known to be cannibalistic, meaning they will eat their own species.
Hammerheads are viviparous, meaning the eggs hatch inside the body and the babies are fed through a placenta. Just as with humans, the placenta transfers oxygen and nutrients to the baby from the female’s bloodstream and it transfers waste products from the baby to the female for elimination. The gestation period lasts about 11 months. Each litter can produce 13 to 42 pups. The pups will be roughly 2 feet in length at birth.
The following are more great hammerhead shark facts for kids and adults:
• The scientific name for the giant hammerhead shark is Sphyrna mokarran.
• Although these sharks are not targeted directly by commercial fisherman, they are a bycatch (accidentally caught in the nets). The hide of the shark is used as leather, the meat is consumed by humans, the fins are used to make soup, the liver’s oil is for vitamins, and the carcass is made into fishmeal.
• Adult giant hammerheads have no major predators. However, large sharks will prey on the young.
• The life span of these sharks are approximately 20 to 30 years.
Marine Bio: Sphyrna mokarran, Great Hammerhead Shark – https://marinebio.org/species.asp?id=87
Florida Museum of Natural History: Great Hammerhead – https://www.flmnh.ufl.edu/fish/gallery/descript/greathammerhead/ghammerhead.html
Image courtesy of https://www.flickr.com/photos/12734746@N00/343117155/