Cephalofoil shape
A wide cephalofoil with an almost straight front margin distinguishes it from other hammerheads.
Photo byGerald Schömbs
Species Guide
What to know about great hammerhead sharks
A clean field guide focused on habitat, identification, behavior, and conservation context without burying the useful parts.
The great hammerhead (Sphyrna mokarran) is the largest species of hammerhead shark, reaching an average length of about 4.6 m and a maximum around 6.2 m. It occurs in tropical and warm temperate waters worldwide, typically inhabiting coastal areas and the continental shelf. Distinguishing features include a wide cephalofoil with an almost straight front margin, a tall sickle-shaped first dorsal fin, and strongly falcated pelvic fins. A solitary, strong-swimming apex predator, it feeds on a wide variety of prey—crustaceans, cephalopods, bony fish and smaller sharks—and observations suggest the cephalofoil is used to immobilize stingrays. Great hammerheads are viviparous, producing litters of up to about 50 pups roughly every two years. Although potentially dangerous, they rarely attack humans and can sometimes behave inquisitively toward divers. Heavy fishing for their large fins has driven substantial population declines.
Populations are declining substantially worldwide due to heavy fishing pressure for their large fins, prompting a Critically Endangered assessment by the IUCN in 2019.
Solitary and strong-swimming; occupies coastal areas and the continental shelf as an apex predator.
Identification
How to identify great hammerhead sharks
The visual markers divers can use underwater, plus the species most likely to cause confusion.
Key identification markers
Dorsal fin
A tall, sickle-shaped first dorsal fin.
Pelvic fins
Strongly falcated (sickle-shaped) pelvic fins.
Size
Largest hammerhead species, averaging about 4.6 m and reaching up to roughly 6.2 m.
Common lookalikes
Other hammerhead species
Other hammerhead sharks may appear similar but differ in cephalofoil shape and fin proportions.
Range and Movement
How great hammerhead sharks move through the world
The broad range, seasonal movement, or migratory behavior that shapes where divers encounter this species.
Solitary and strong-swimming; occupies coastal areas and the continental shelf as an apex predator.
Diet
What great hammerhead sharks tend to eat
Useful feeding context that often explains habitat, movement, and encounter style.
Feeds on crustaceans, cephalopods, bony fish and smaller sharks; stingrays are a favored prey and the cephalofoil appears to aid in immobilizing them.
Conservation
What is happening with Great Hammerhead Sharks
Status, pressure, and protection context grounded in cited sources rather than filler.
Populations are declining substantially worldwide due to heavy fishing pressure for their large fins, prompting a Critically Endangered assessment by the IUCN in 2019.
Main threats
Targeted and bycatch fishing for fins
Great hammerheads are heavily fished for their large fins, which are highly valued in shark fin markets.
Responsible Encounters
How to dive with great hammerhead sharks
Conservation-minded guidance for divers who want the encounter without adding pressure.
Exercise caution around great hammerheads: do not provoke or corner them, keep a respectful distance, and avoid sudden movements; note they can be inquisitive but attacks are rare.
Field Notes
Interesting things worth knowing
Useful species context that makes the encounter more meaningful once you are underwater.
Field notes
Largest hammerhead
The great hammerhead is the largest species in the hammerhead family.
Reproduction
Viviparous, with litters of up to about 50 pups roughly every two years.
Cephalofoil function
Field observations indicate the cephalofoil may be used to immobilize stingrays.
FAQ
Frequently asked questions
Clear planning and conservation answers written for search visibility and AI retrieval.
Research Sources
Great Hammerhead Shark information sources
Primary and credible references behind the field-guide and conservation claims on this page.
Sources 2Last Updated
Great hammerhead · Encyclopedia · Wikipedia
Primary wildlife guide source.
Sphyrna mokarran · Taxonomy · WoRMS
Taxonomy reference.
Related Species
More in Sharks
Related species guides in the same encounter family.
