Sealife guideThe scalloped hammerheadSphyrna lewini

Last updated on 03/29/2025 at 12:35 AM
Taxonomy
  • Common name: Scalloped hammerhead
  • French name: Requin marteau halicorne
  • Spanish name: Tiburón martillo,cornuda común
  • Scientific name: Sphyrna lewini (Griffith & Smith, 1834)
  • Family name: Sphyrnidae
  • Order name: Carcharhiniformes
  • Class name: Elasmobranchii
Description
The scalloped hammerhead shark is a medium-sized shark species, typically measuring 6.5 to 10 feet in length, with the largest specimens reaching up to 13 feet. Its body color ranges from gray to brownish on the back and whitish on the belly. The first dorsal fin is large and triangular, while the second one is very small. As the shark ages, the tips of its pectoral fins darken, along with the tip of the lower lobe of the tail.
The scalloped hammerhead (Sphyrna lewini)
The scalloped hammerhead (Sphyrna lewini) ©  | Dreamstime.com
The scalloped hammerhead shark's head has a distinctive T-shape, which gives it its name of hammerhead shark, but with a front edge that is slightly more curved than the great hammerhead shark and a well-defined notch in the center.
Geographic range
The scalloped hammerhead shark is a coastal shark that inhabits warm, temperate, and tropical waters of the Atlantic, Pacific, and Indian oceans.
The scalloped hammerhead shark is found along the eastern Pacific coast from California to Peru, along the western Atlantic coast from New Jersey to Brazil, including the Gulf of Mexico and the Caribbean Sea. It also inhabits waters from Japan to Tahiti, nearly the entire African coastline, from the Mediterranean to Namibia on the west coast, and from the Red Sea to South Africa on the east coast
Habitat
The scalloped hammerhead shark is found above continental and insular shelves, around seamounts, and near coral reefs, at depths of up to 900 feet. This species is highly gregarious, often forming large schools of over 100 individuals, though smaller groups of 10 to 50 sharks are also common. Occasionally, the scalloped hammerhead can also be observed solitary.
Juvenile scalloped hammerhead sharks typically inhabit shallow coastal waters, while adults prefer deeper offshore waters.
The scalloped hammerhead shark regularly makes deep nocturnal dives, reaching depths recorded by scientists of over 2,950 feet, with a record of 4,070 feet for a female tracked in Hawaii.
Diet
The scalloped hammerhead shark has a varied diet, feeding on fish, cephalopods such as squids and octopuses, which it hunts at great depths, as well as, to a lesser extent, crustaceans like crabs and shrimp.
They can also feed on other sharks, including members of their own species, and show a particular preference for stingrays, being apparently immune to their venomous spines.
Reproduction
The scalloped hammerhead shark is a viviparous species, with females giving birth after a gestation period ranging from 8 to 12 months. They give birth to litters of 15 to 40 pups, measuring between 14 and 22 inches at birth.
The nursery areas are typically located in very shallow waters, providing a protected environment for the growth of the juveniles. Males reach sexual maturity at around 8 to 10 years, while females become mature between 12 and 15 years.
Females show site fidelity to certain coastlines and breeding areas, and do not engage in oceanic migrations.
Did you know ?
The longevity of the scalloped hammerhead shark can reach up to 30 years.
The scalloped hammerhead is listed as many other marine species within The IUCN Red List of threatened species. The scalloped hammerhead appears in the IUCN Red List since 2019 within the category Critically Endangered !
Within the same genus
Bonnethead shark (Sphyrna tiburo)
Bonnethead shark
(Sphyrna tiburo)
Great hammerhead shark (Sphyrna mokarran)
Great hammerhead shark
(Sphyrna mokarran)
Within the same family
Hammerhead shark (9 espèces)
Hammerhead shark
(9 espèces)
Discover also
Broadnose sevengill shark (Notorynchus cepedianus)
Broadnose sevengill shark
(Notorynchus cepedianus)
Caribbean reef shark (Carcharhinus perezi)
Caribbean reef shark
(Carcharhinus perezi)
Dusky shark (Carcharhinus obscurus)
Dusky shark
(Carcharhinus obscurus)
Frilled shark (Chlamydoselachus anguineus)
Frilled shark
(Chlamydoselachus anguineus)
Grey reef shark (Carcharhinus amblyrhynchos)
Grey reef shark
(Carcharhinus amblyrhynchos)
Pelagic thresher shark (Alopias pelagicus)
Pelagic thresher shark
(Alopias pelagicus)
Sand tiger shark (Carcharias taurus)
Sand tiger shark
(Carcharias taurus)
Tawny nurse shark (Nebrius ferrugineus)
Tawny nurse shark
(Nebrius ferrugineus)
The marine species
Bicolor angelfish (Centropyge bicolor)
Bicolor angelfish
(Centropyge bicolor)
Cylinder anemone (Cerianthus membranaceus)
Cylinder anemone
(Cerianthus membranaceus)
Eastern clown anemonefish (Amphiprion percula)
Eastern clown anemonefish
(Amphiprion percula)
King penguin (Aptenodytes patagonicus)
King penguin
(Aptenodytes patagonicus)
Thornback cowfish (Lactoria fornasini)
Thornback cowfish
(Lactoria fornasini)
Umbrella weed (Acetabularia acetabulum)
Umbrella weed
(Acetabularia acetabulum)
Yellow-spotted triggerfish (Pseudobalistes fuscus)
Yellow-spotted triggerfish
(Pseudobalistes fuscus)
Yellowmouth barracuda (Sphyraena viridensis)
Yellowmouth barracuda
(Sphyraena viridensis)

Our latestUpdates

Tenerife island
Wednesday, November 19th 2025
Tenerife island
Tenerife, the largest of the Canary islands, is a volcanic gem in the Atlantic ocean. It boasts an incredible variety of landscapes, from golden or black sand beaches to the subtropical forests of the Anaga mountains and the majestic Teide volcano, Spain's highest peak. With its picturesque villages, rich local culture and countless outdoor activities, Tenerife is a perfect destination for every type of traveler.
Batz island
Saturday, November 15th 2025
Batz island
Located in the English Channel off the northern coast of Brittany, just a few kilometers from the town of Roscoff, Batz island is a true little haven of peace where you can enjoy its wild landscapes, unspoiled beaches and historical heritage.
The common sea fan
Friday, November 7th 2025
The common sea fan
The common sea fan, is a type of soft coral found in the warm, shallow waters of the Caribbean and the western Atlantic ocean. It grows in wide, fan-shaped forms that sway gently with the ocean currents, helping it catch tiny food particles drifting by. Its beautiful purple branches are covered by a thin living tissue that hosts tiny algae, which provide much of the coral's energy through sunlight.
Photo of the Day
Mérou géant (Epinephelus itajara)
Mérou géant
(Epinephelus itajara)