The Great Hammerhead shark, Sphyrna mokarran, is the largest among the nine recognized hammerhead species. Its distinctive head shape and specialized adaptations allow it to thrive in diverse marine environments.
Unveiling the Dimensions
The Great Hammerhead shark typically reaches an average length of 13.1 to 15 feet (4 to 4.6 meters) and can weigh around 500 pounds (230 kg). These sharks can grow considerably larger, with the longest recorded individual measuring up to 20 feet (6.1 meters). The heaviest Great Hammerhead documented was a female weighing 991 pounds (450 kg), though some sources cite a maximum recorded weight of 1,280 pounds (580 kg) for a pregnant female.
Females of this species generally grow larger than males. While males typically mature at around 12 feet (3.6 meters), adult females commonly range from 15 to 18 feet (4.6 to 5.5 meters). Measurements are usually taken as total length, from the tip of the snout to the end of the tail.
Distinguishing Features and Comparisons
The Great Hammerhead shark is easily identified by its unique cephalofoil, or hammer-shaped head, which is nearly straight across with a shallow indentation in the center. This contrasts with other hammerhead species like the scalloped hammerhead, which has a more noticeable central notch and additional indentations, giving its head a “scalloped” appearance. The smooth hammerhead has an unnotched, rounded head. Its name also refers to the pronounced and straight leading edge of its cephalofoil, making it the most distinctly hammer-shaped within its genus.
Beyond its head, the Great Hammerhead possesses a tall, sickle-shaped first dorsal fin. While impressive, it is typically smaller than the Great White shark, which can reach lengths of 18 to 26 feet. For instance, the scalloped hammerhead usually reaches a maximum length of about 14 feet and 335 pounds. The laterally expanded head also positions its eyes widely, providing enhanced binocular vision and depth perception, assisting in prey detection.
Habitat and Diet
Great Hammerhead sharks are found globally in warm temperate and tropical waters, inhabiting both coastal and offshore areas. They are often observed over continental shelves, around islands, near coral reefs, and in lagoons, though they can venture into deeper waters up to 984 feet (300 meters). These sharks are highly migratory, with some populations moving towards cooler waters during summer months.
As apex predators, Great Hammerheads have a varied diet that supports their large size. They primarily prey on seafloor inhabitants, with a particular preference for stingrays. Their diet also includes other rays, skates, bony fish such as groupers and sea catfish, crustaceans, and cephalopods like squid and octopus. They are even known to consume other sharks, including smaller hammerheads. The unique shape of their head aids in hunting; they use their broad heads to pin down stingrays on the seabed, allowing them to take bites. The cephalofoil is also equipped with electroreceptors called ampullae of Lorenzini, which help them detect the electrical signals of prey, even those buried in the sand.