Hammerhead sharks (Sphyrnidae) are a group of sharks that include nine species. Hammerheads are so named for the wide, flattened "hammer" shape of their head. This structure, known as a cephalofoil, projects from either side of the shark's head and may function in sensory reception, prey capture, or maneuvering. The shark's eyes and nostrils are located at the tips of the cephalofoil.
Hammerhead sharks belong to the Order Carcharhiniformes, a group commonly known as the ground sharks. Hammerheads have an anal fin and two dorsal fins without spines. They posess five gill slits and their mouth is located behind their eyes.
During the day, hammerheads often form schools of over 100 fish. At night, they take off on their own as solitary hunters. They feed on a variety of prey including lobster, fish, shrimp, squid, crabs, and snails.
- Mass: up to 230 kg
- Body Length: 0.9 - 6 m (3.0 - 20 ft)
- Diet: lobster, fish, shrimp, squid, crabs, and snails
- Reproduction: viviparous
- Kingdom: Animalia
- Phylum: Chordata
- Class: Chondrichthyes
- Subclass: Elasmobranchii
- Superorder: Selachimorpha
- Order: Carcharhiniformes
- Family: Sphyrnidae
- Genus: Sphyrna
The Genus Sphyrna contains the following species:
- Smooth Hammerhead (Sphyrna zygaena)
- Scalloped Hammerhead (Sphyrna lewini)
- Great Hammerhead (Sphyrna mokarran)
- Bonnethead or Shovelhead (Sphyrna tiburo)
- Scoophead shark (Sphyrna media)
- Scalloped Bonnethead (Sphyrna corona)
- Winghead shark (Sphyrna blochii)
- Smalleye Hammerhead (Sphyrna tudes)
- Whitefin Hammerhead (Sphyrna couardi)
Range and Habitat:
Hammerheads are found in tropical and warm temperate seas around the world. They inhabit deep open ocean habitats as well as shallow coastal waters and continental shelves.
- Burnie D, Wilson DE. 2001. Animal. London: Dorling Kindersley. 624 p.
- Taylor L. 1997. Sharks & Rays. Sydney: The Nature Company Guides. 288 p.