Octopus tetricus Click to enlarge image
Common Sydney Octopus, Octopus tetricus Image: Kevin Deacon
© Kevin Deacon

Fast Facts

  • Classification
  • Size Range
    80 cm


This is the largest octopus commonly seen in Sydney.


The undersides of the arms of the Common Sydney Octopus are rust red in colour, tapering to a tip, which may be the first thing you spot emerging from under a rock ledge.


The Common Sydney Octopus is found on intertidal rocky shores and in the ocean.


The Common Sydney Octopus is found in New South Wales.

Feeding and diet

At night the Common Sydney Octopus hunts using its sharp beak to feed on crabs and molluscs, such as snails and bivalves. It can change the colour of its skin (normally mottled brown) and shape to imitate seaweed.

Octopus tetricus
Common Sydney Octopus, Octopus tetricus Image: Kevin Deacon
© Kevin Deacon

Other behaviours and adaptations

The Common Sydney Octopus is territorial and sits in its lair during the day surrounded by rocks and rubble that it has collected to defend its home.

The octopuses' fleshy mantle can be used for jet propulsion by sucking in water and squirting it out through the siphon above. Most of the time though, they use their eight suckered arms to creep about over rock surfaces in search of food.

Octopuses are protected and cannot be taken from ocean rock platforms or Sydney Harbour.