One of the 26 sharks on WAnimals
Cartilaginous fish · Carcharhiniformes · Sphyrnidae
Scalloped Hammerhead
Sphyrna lewini
It faces an extremely high risk of imminent extinction in the wild. See full glossary
It is famous for gathering in large schools of hundreds around seamounts, a social behaviour uncommon in sharks that scientists still do not fully understand.
Weight
100 kg – 152 kg
Size
3.7 m – 4.3 m
Lifespan
30 years
Diet
Carnivore
Feeds mainly on other animals.
Activity
Irregular activity
Active at irregular times, by day or night depending on circumstances.
Social structure
School
Gathers in coordinated schools, typical of fish.
Sighting difficulty
Very hard
Fun facts
- It forms large schools of hundreds around seamounts.
- While mating, the pair sink slowly through the water.
- Stingray spines have been found lodged in its own stomach.
Life cycle & biology
- Skeleton type
- Vertebrate - cartilaginous skeleton (chondrichthyan fish)
- Habitat & environment
- Warm temperate and tropical coastal waters worldwide, over continental and island shelves near deep water
- Birth weight
- 42 - 55 cm long at birth
- Size at birth
- 42 - 55 cm long at birth
- Sexual maturity
- Male: 6-10 years (~140-165 cm) | Female: 15-17 years (~212 cm)
- Gestation / incubation
- 8-12 months
- Litter / clutch size
- 12 to 41 young per litter
Sources consulted: Shark Research Institute; California State University Long Beach fact sheet; FishBase; Animal Diversity Web; Shark Angels; Springer Environmental Biology of Fishes (reproductive biology study); PubMed (Brazilian coast age growth study)
Where to find it
See its range on the interactive mapBest time: From June to October at the seamounts of the tropical eastern Pacific — Cocos, Malpelo, Galápagos — when it forms large schools.
Where to watch it
Parques y spots de buceo donde se ha documentado esta especie — se muestran 20 de 35 documentados.
Related species
Other species in the catalogue with the most in common with Scalloped Hammerhead — same habitat, park, country, tags or family.
Critically EndangeredGreat Hammerhead
Sphyrna mokarran
VulnerableGreat White Shark
Carcharodon carcharias
Shortfin Mako
Isurus oxyrinchus
VulnerableGrayfish
Alopias vulpinus
Near ThreatenedBull Shark
Carcharhinus leucas
How to help
The scalloped hammerhead is classified as critically endangered. Organizations such as UICN, WWF y Wildlife Conservation Society work specifically on its conservation and that of its habitat; looking into their programs is a good starting point if you want to get involved.
It's documented in 15 real protected areas — part of why protecting these places matters for its conservation.
Keep exploring
Based on what we already know about scalloped hammerhead.
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