NL·0711Herbarium of the Nature Library
- Name
- Sphyrna mokarran
- Family
- Sphyrnidae
- Native to
- Tropical and warm temperate coastal waters worldwide
- Habitat
- Coastal waters, Coral reef, Continental shelf
Great hammerhead
Sphyrna mokarran
Also calledCornuda gigante (Spanish) · Hirashumokuzame (Japanese) · Grand requin-marteau (French) · Mano (Hawaiian, shark)
The largest hammerhead, with a tall sickle dorsal fin and a near-straight 'hammer' packed with electroreceptors. It specialises in stingrays, pinning them to the seabed with its head.
The great hammerhead is the largest species of hammerhead shark, belonging to the family Sphyrnidae, attaining an average length of 4.6 m (15 ft) and reaching a maximum length of 6.2 m (20 ft). It is found around the globe in all the warmer parts of the oceans. The great hammerhead can be distinguished from other hammerheads by the shape of its "hammer", which is wide with an almost straight front margin, its tall, sickle-shaped first dorsal fin, and its strongly falcated pelvic fins. A solitary, strong-swimming apex predator, the great hammerhead feeds on a wide variety of prey ranging from crustaceans and cephalopods, to bony fish, to smaller sharks. Observations of this species in the wild suggest that the cephalofoil functions to immobilize stingrays, a favored prey. This species has a viviparous mode of reproduction, bearing litters of up to 2-49 pups every two years. Wikipedia
What it can do
- iThe cephalofoil spreads ampullae of Lorenzini wide, helping detect buried prey's electric fields
- iiUses the head to pin stingrays to the seabed while biting
- iiiSwims rolled on its side, using its tall dorsal fin as a 'wing' to cut drag by about 10%
- ivSeemingly immune to stingray barbs; individuals have been found with dozens embedded in the mouth
In the field
Field marks
- aBroad hammer-shaped head with a nearly straight front edge and a central notch in adults
- bVery tall, sickle-shaped first dorsal fin
- cTall pelvic fins with a curved rear margin
- dGrey-brown above, white below
- Not to be confused with
- Scalloped hammerhead (S. lewini) has a curved front edge with a strong central notch and a lower dorsal fin; smooth hammerhead (S. zygaena) lacks the central notch.
- Where to see it
- Bimini, Bahamas (Dec–Mar); Jupiter, Florida; Rangiroa, French Polynesia
- When
- Bimini Dec–Mar; Rangiroa Dec–Mar
Life & habits
- Diet
- Stingrays, other rays, groupers, catfish, smaller sharks
- Habitat
- Coastal reefs, lagoons and continental shelves to 80 m
- Size
- Commonly 3.5 m; up to ~6 m
- Lifespan
- Up to about 44 years
Mostly solitary nomad that makes seasonal migrations along coasts; extremely vulnerable to capture stress and often dies on lines.
Where it lives
Recorded sightings
—
geo-referenced records in GBIF, from museums, herbaria and field observers.
Native range
Tropical and warm temperate coastal waters worldwide
Drag the globe to turn it. Dots are where records exist, not a range map; darker means more records.
In the old herbals & bestiaries
No plate in the Source Library names this exact species, so these show its closest relatives as the old naturalists drew them: same genus, or the same kind of animal. Click a plate to read the page it came from, with translation.
Books on Marine Fishes
Relative · Guillaume Rondelet · 1554 · p.410
History of Animals, Book II: On Oviparous Quadrupeds
Relative · Conrad Gessner · 1586 · p.518
Recherche curieuse d'antiquités, venuës d'Italie, de la Grece, d'Egypte, & trouvées à Nimegue, a Sant...
Relative · Chevalier, Nicolas · 1714 · p.54
History of Animals, Book II: On Oviparous Quadrupeds
Relative · Conrad Gessner · 1586 · p.518
In the stacks
Searching the stacks…
Every page naming Sphyrna mokarran in the Biodiversity Heritage Library →
Marginalia
Its fins are highly prized in the shark-fin trade; hammerheads were listed on CITES Appendix II in 2013.
Curiosity
A pregnant female can carry up to about 55 pups, which are born with their hammers bent back to ease birth.
Kinship
Photographs: iNaturalist contributors under the licences shown. Records: GBIF.org. Historical plates: Source Library (CC BY-SA 4.0; originals public domain). Summary text: Nature Library editors and Wikipedia (CC BY-SA). Medicinal and edibility notes are historical and educational, not advice. iNaturalist taxon 56766.