Surf Crab

Scientific name: Ovalipes australiensis
Alternative name/s:
Sand Crab, Bait Thief, Biter
  • Updated
    30/06/26
  • Read time
    2 minutes
Ovalipes australiensis Click to enlarge image
Surf Crab (Ovalipes australiensis) is easy to identify because it is the only species of crab in Sydney with two dark red spots on its carapace. Image: Dr Isobel Bennett
© Australian Museum

Fast Facts

  • Classification
    Genus
    Ovalipes
    Species
    australiensis
    Family
    Portunidae
    Suborder
    Pleocyemata
    Infraorder
    Brachyura
    Order
    Decapoda
    Class
    Malacostraca
    Subphylum
    Crustacea
    Phylum
    Arthopoda
    Kingdom
    Animalia
  • Size Range
    10 cm

The Surf Crab is commonly found on ocean beaches between the high- and low-tide marks. The Surf Crab belongs to the family Portunidae, known as swimming crabs because of their paddle-like back legs.

Identification

The Surf Crab is easy to identify because it is the only species of crab in Sydney with two dark red spots on its carapace.

Habitat

The Surf Crab lives on intertidal beaches and in estuaries and oceans to a depth of 35 metres.

Distribution

The Surf Crab is found from Queensland, New South Wales, Victoria, South Australia, Tasmania to Perth in Western Australia.

This map shows species occurrence observations from data recorded in the Atlas of Living Australia.

Behaviours and adaptations

The Surf Crab has back legs that are modified into paddles. These paddles assist with swimming and enable the crab to dig backwards into the sand efficiently and disappear when necessary.

Local fishers refer to this crab as 'Biter' and 'Bait Thief' because it comes into shallow water and nibbles on bare feet, and removes bait from fishers' hooks.