Great Hammerhead Shark
Sphyrna mokarran
The great hammerhead is a large species of shark known for its unusually shaped head. An excellent hunter, it uses its senses to search for prey hidden under the sand and can use its hammer shaped head to pin down its prey. Great hammerheads develop inside their mother from eggs but are born alive! Hammerheads, like other shark species, are critically endangered due to fishing practices. We can help protect them by eating more sustainable seafood and supporting protected areas like marine protected areas!
SPECIES IN DETAIL
Great Hammerhead Shark
Sphyrna mokarran
CONSERVATION STATUS: Critically endangered
CLIMATE CHANGE: Vulnerable
Geographic Distribution
Baja California (including the Gulf of California) to Peru to Massachusetts to Uruguay to Senegal to Morocco to Mediterranean Sea (rare there) to Red Sea to Indian Ocean to Ryukyu Island to New Caledonia to Hawaii (rare there) to French Polynesia to Pitcairn Islands
Habitat
The great hammerhead is mostly found in shallow marine habitats such as the pelagic and subtidal zones, and marine oceanic areas including the epipelagic and mesopelagic zones, at depths ranging between the near-surface to 300 m.(984.24 ft.).
Physical Characteristics
The great hammerhead, like most other sharks, uses countershading as a form of camouflage. It is light gray-brown on top and white on its belly to better blend it into its environment. While the fins of the great hammerhead have no discernible markings, they can be recognized by the large notch in the center of each shark’s head and their very large size. In addition, the head of most juvenile great hammerheads is slightly curved, straightening out with age.
Size
4-6 m.(13-20 ft.), 250 kg.+(500+ lbs.); heaviest specimen approx. 450 kg.(991 lbs.)
Diet
As apex predators, the great hammerhead eats fish such as demersal fish, other elasmobranchs (especially batoids such as rays), teleosts, crustaceans, and cephalopods.
Reproduction
The great hammerhead reaches sexual maturity around 5–9 years old, with females typically maturing before males. Every two years, after a gestation period of 10–11 months, the 6–42 eggs that have developed inside the female hatch and are born alive! This amazing process classifies the great hammerhead as ovoviviparous. Breeding season timing depends on the hemisphere the sharks live in; in the northern hemisphere, they give birth in late spring or summer, while in the southern hemisphere great hammerheads give birth from October to January. Pupping (giving birth in certain animals, including sharks) seems to take place farther offshore compared to other species of sharks.
Behavior
As highly migratory, the great hammerhead is generally solitary and nomadic.
Adaptation
The great hammerhead is easily recognizable by its head shape which resembles a hammer. It uses its specialized head to pin prey, such as stingrays, to the seafloor. Another unique fact: the hammer shape of the head enables panoramic vision! These sharks can be seen swimming rolled on their sides, which generates lift, making it a more efficient way to move than swimming upright.
Longevity
20–30 years in the wild on average, with the oldest known great hammerhead shark reported to be 44 years old.
Conservation
Hammerheads occur in protected areas around the world and are subject to international management and trade controls. Hammerheads are negatively affected by overfishing for their fins and meat, as well as being caught as accidental bycatch. We can help support sharks by choosing more sustainable seafood and supporting protected areas like marine protected areas!
Special Notes
The largest species of hammerhead in the world!
SPECIES IN DETAIL | Print full entry
Great Hammerhead Shark
Sphyrna mokarran
CONSERVATION STATUS: Critically endangered
CLIMATE CHANGE: Vulnerable
Baja California (including the Gulf of California) to Peru to Massachusetts to Uruguay to Senegal to Morocco to Mediterranean Sea (rare there) to Red Sea to Indian Ocean to Ryukyu Island to New Caledonia to Hawaii (rare there) to French Polynesia to Pitcairn Islands
The great hammerhead is mostly found in shallow marine habitats such as the pelagic and subtidal zones, and marine oceanic areas including the epipelagic and mesopelagic zones, at depths ranging between the near-surface to 300 m.(984.24 ft.).
The great hammerhead, like most other sharks, uses countershading as a form of camouflage. It is light gray-brown on top and white on its belly to better blend it into its environment. While the fins of the great hammerhead have no discernible markings, they can be recognized by the large notch in the center of each shark’s head and their very large size. In addition, the head of most juvenile great hammerheads is slightly curved, straightening out with age.
4-6 m.(13-20 ft.), 250 kg.+(500+ lbs.); heaviest specimen approx. 450 kg.(991 lbs.)
As apex predators, the great hammerhead eats fish such as demersal fish, other elasmobranchs (especially batoids such as rays), teleosts, crustaceans, and cephalopods.
The great hammerhead reaches sexual maturity around 5–9 years old, with females typically maturing before males. Every two years, after a gestation period of 10–11 months, the 6–42 eggs that have developed inside the female hatch and are born alive! This amazing process classifies the great hammerhead as ovoviviparous. Breeding season timing depends on the hemisphere the sharks live in; in the northern hemisphere, they give birth in late spring or summer, while in the southern hemisphere great hammerheads give birth from October to January. Pupping (giving birth in certain animals, including sharks) seems to take place farther offshore compared to other species of sharks.
As highly migratory, the great hammerhead is generally solitary and nomadic.
The great hammerhead is easily recognizable by its head shape which resembles a hammer. It uses its specialized head to pin prey, such as stingrays, to the seafloor. Another unique fact: the hammer shape of the head enables panoramic vision! These sharks can be seen swimming rolled on their sides, which generates lift, making it a more efficient way to move than swimming upright.
20–30 years in the wild on average, with the oldest known great hammerhead shark reported to be 44 years old.
Hammerheads occur in protected areas around the world and are subject to international management and trade controls. Hammerheads are negatively affected by overfishing for their fins and meat, as well as being caught as accidental bycatch. We can help support sharks by choosing more sustainable seafood and supporting protected areas like marine protected areas!
The largest species of hammerhead in the world!