The ocean’s depths hold many mysteries. Among its largest predators, the great hammerhead shark stands out, recognized by its distinctive head shape. This species draws attention due to its impressive dimensions. Understanding its scale reveals insights into its life and role within ocean ecosystems.
Unpacking the Great Hammerhead’s Size
The great hammerhead (Sphyrna mokarran) is the largest species within the hammerhead family. On average, adult great hammerheads measure around 13.1 feet (4 meters) in length and weigh approximately 500 pounds (230 kg). Individual sizes can vary significantly.
Female great hammerheads grow larger than males. Males reach maturity at lengths around 7.4 feet (2.25 meters) and weights of about 113 pounds (51 kg). Females mature at approximately 6.9 feet (2.10 meters) and 90 pounds (41 kg), though some are documented at 337 centimeters (around 11 feet) in length.
The maximum recorded length for a great hammerhead is 20 feet (6.1 meters). The heaviest recorded specimen was a female caught off Sarasota, Florida, weighing 991 pounds (450 kg). Another female, caught in Florida in 2006, weighed 1,280 pounds (580 kg) at 14 feet (4.4 meters) long.
What Fuels Their Impressive Growth?
Great hammerhead sharks achieve their size through dietary habits, longevity, and widespread habitat. As apex predators, their diet provides energy and nutrients for growth. They consume a variety of prey, including fishes (tarpon, sardines, groupers), crustaceans, cephalopods (squid, octopus), and other sharks.
Stingrays are a favored prey item. Great hammerheads use their distinctive heads to pin down rays against the seafloor. Their specialized head, or cephalofoil, is also equipped with electroreceptors that help them detect electrical signals from prey hidden in the sand. This hunting strategy allows them to secure food sources across oceanic areas.
Great hammerheads have a long lifespan, living between 20 to 30 years, with the oldest known individual reaching up to 44 years. This extended lifespan provides more years for growth, contributing to their large size. They also exhibit a faster growth rate compared to some other hammerhead species, reaching maturity between 5 and 9 years of age.
Distinguishing the Great Hammerhead’s Stature
The great hammerhead has distinct physical attributes that set it apart from other species. Its “hammer” or cephalofoil is wide, with an almost straight front margin and a shallow notch in the center in adults. This shape distinguishes it from the more curved heads of other hammerhead species, such as the scalloped or smooth hammerhead. The cephalofoil’s width can be 23–27% of the shark’s body length.
Its tall, sickle-shaped (falcate) first dorsal fin is more pronounced than in other hammerhead species. This fin originates over the insertions of the pectoral fins. The body is stout, dusky brown to light gray on the dorsal surface, fading to a cream-colored underside.
When compared to other large shark species, the great hammerhead’s size is notable. While not as massive as filter-feeding giants like the whale shark or basking shark (which can exceed 40 feet), its maximum length of 20 feet places it among the largest predatory sharks. Bull sharks grow up to 11.5 feet, and tiger sharks can reach over 20 feet.