Hammerhead sharks are one of our most iconic species. There are four species of hammerhead shark in Australia’s waters: Scalloped, Great, Smooth and Winghead.
The unique ‘hammer’ shaped head helps the shark zone in on prey, such as small fish, stingrays and octopus, by detecting the direction of a scent, and enabling it to see prey both above and below at the same time.
Hammerheads live for around 20 to 30 years and can range in length from 50cm at birth to 6m adult great hammerheads – the largest of the species. Hammerheads often travel in schools, separated by sex and ranging from tens to hundreds of individuals.
Australian hammerhead shark populations are in decline. Scalloped hammerheads are estimated to have lost up to 80% of their original population in our waters and have been scientifically assessed as endangered. Hammerhead sharks are particularly vulnerable to being caught in gillnets (fishing nets) due to the unique shape of their head.
- Hammerheads swim slightly tilted on their side to conserve energy.
- Scalloped hammerheads are the only known fish to ‘hold their breath’ by closing their gills shut when they dive into deep water. This helps keep their blood warm when they’re in cold deep water where temperatures can be 5 ̊C.
Facts & Figures
COMMON NAME: Hammerhead shark
SCIENTIFIC NAME: Sphyrnidae
BODY SIZE: Max of 6m (great hammerhead), though rarely encountered over 4.5m
WEIGHT: Max of around 500kg (great hammerhead)
LIFESPAN (IN WILD): 20 to 30 years
DIET: Carnivore – stingrays, octopus and small fish
HABITAT: Temperate (smooth) and tropical (scalloped, winghead and great) waters
Great Hammerhead: Endangered (Australian Red List), Critically Endangered (Global IUCN Red List), not listed (EPBC Act 1999)
Scalloped Hammerhead: Endangered (Australian Red List), Critically Endangered (Global IUCN Red List), Conservation Dependent (EPBC Act 1999)
Smooth Hammerhead: Near Threatened (Australian Red List), Vulnerable (Global IUCN Red List); not listed (EPBC Act 1999)
Winghead: Vulnerable (Australian Red List; Global IUCN Red Coin); not listed (EPBC Act 1999)
POPULATION TREND: Decline