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Great Hammerhead
CarcharhiniformesAttack Relevant

Great Hammerhead

Sphyrna mokarran

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Max Length

6.1m

Overview

The largest hammerhead species, distinguished by a nearly straight cephalofoil front edge and a very tall first dorsal fin. A specialist stingray predator — its electroreception can detect rays buried under sand. Critically endangered.

Habitat

Coastal-pelagic and semi-oceanic shark occurring close inshore and well offshore. Found over the continental shelves, island terraces and in passes and lagoons of coral atolls, as well as over deep water near land. It is found near the surface and from depths of 3 ft to more than 262 ft [1 to 80 m]. It often favors continental and insular coral reefs.

Distribution

Tropical & subtropical seas worldwide

Circumtropical.

Behavior

General – A solitary, nomadic and migratory species. Some populations move poleward during the winter. Feeding – The shark feeds mostly at dusk. A shark was seen to use the underside of its hammer-shaped head to bludgeon and pin a stingray to the seabed, then the shark pivoted and bit a chunk out of the ray’s pectoral fin. Mating – Mating great hammerheads were reportedly witnessed in 70 ft [21 m] in the Bahamas. The sharks ascended, spiraling slowly around each other and copulated at the surface. While synchronous swimming as a prelude to mating has been observed with other species of sharks, copulation at the surface has not. Most species are thought to mate at or near the seafloor.

Human Safety

The species is thought to be dangerous, though relatively few incidents have been attributed to it or any other species of hammerhead sharks. The shark has approached divers without displaying aggression. However, due to its size and broad food spectrum the shark should be treated with caution.

Biology

Diet
The great hammerhead shark feeds on a wide variety of prey, but favors stingrays, groupers and sea catfishes. It also feeds on squid, crabs, tarpon, sardines, toadfishes, porgies, grunts, jacks, herring, grouper, boxfish, other sharks, skates, guitarfish, cownose and eagle rays.
Reproduction
Viviparous, with a yolk-sac placenta
Birth Size
70cm
Male Maturity
3m
Female Maturity
3m

Appearance

Great Hammerhead illustration
Dorsal
Dark olive green to brownish gray above, white below. Ventral tips of pectoral fins are not marked.

Dentition

Upper jaw
Strongly serrate.
Sources:sharksorg

Recorded incidents involving the great hammerhead

Recorded

1

Fatal

0

Fatality rate

0.0%

Years

2003–2003

Top countries

Years with most incidents

Counts are based on the species field of the Global Shark Attack File. Identifications by witnesses are often uncertain; treat figures as recorded incidents, not authoritative totals.

Frequently Asked Questions

How many shark attacks have been recorded involving the great hammerhead?
1 incidents in the Global Shark Attack File mention the great hammerhead, of which 0 were fatal (0.0%). Note that witness species identifications are often uncertain, so this is the count of recorded incidents.
Where do most great hammerhead incidents occur?
The countries with the most recorded great hammerhead incidents are United States.
Is the great hammerhead dangerous to humans?
The great hammerhead is considered relevant to human-shark incidents and has been recorded in the Global Shark Attack File. As with any large shark, encounters in the wild should be avoided.
Where does this species data come from?
Species profiles are compiled from peer-reviewed taxonomy and published references. Incident data is sourced from the Global Shark Attack File and joined to species records by name match.