Common Sydney Octopus

Octopus tetricus
Common Sydney Octopus - Marinewise © 2024 MarineWise

Quick Facts

Scientific name Octopus tetricus
Other names Gloomy Octopus
Size Up to 80 cm (31 in)
Weight Up to 9 kg (19.8 lb)


Habitat & AU Distribution Shallow coastal waters amongst rocky areas, reef and seagrass beds
Depth Range 0 - 60 m (196 ft)
Common Sydney Octopus Distribution

Interesting Info

  • The common Sydney octopus is found along the eastern and southern coasts of Australia, from southern Queensland to Tasmania and South Australia and parts of southern Western Australia.
  • They are usually a reddish-brown colour with a white underside. They have the ability to change their skin colour and texture in a matter of seconds to blend in with their surroundings, hide from predators, or communicate with other octopuses.
  • The common Sydney octopus is a predator that feeds on a variety of prey, including crabs, lobsters, and fish. They use their arms to grab their prey, and their beak-like mouth to crush and tear it apart.
  • Octopuses have three hearts and blue-green blood that is copper-based, unlike human blood which is iron-based.
  • Common Sydney octopuses are solitary creatures, and only come together to mate.
  • The common Sydney octopus typically breeds between May and August, with females laying up to 100,000 eggs in protected areas and guarding them until they hatch. Once the eggs hatch, the baby octopuses, or hatchlings, are planktonic and float freely in the water column for several weeks before settling on the ocean floor.
  • Common Sydney octopuses are able to navigate mazes and solve puzzles in laboratory settings, demonstrating their advanced cognitive abilities. They are capable of learning from experience, and are known to exhibit behaviours such as tool use and social learning.
  • Their lifespan is relatively short, being between 2-3 years in the wild, and up to 5 years in captivity.
Species Interaction

Snorkeling & Diving

Common Sydney octopus can be a fascinating species to observe while snorkeling or diving, as they are known for their intelligence, curiosity, and ability to change colour and texture to blend in with their surroundings. However, it’s important to approach these animals with caution and respect, as they are wild animals and can be dangerous if they feel threatened or cornered.

Scientific Classification

Kingdom: Animalia

Phylum: Mollusca

Class: Cephalopoda

Order: Octopoda

Family: Octopodidae

Genus: Octopus

Species: Octopus tetricus

Conservation Status

The conservation status of the common Sydney octopus in Australia is listed as “Least Concern” according to the International Union for Conservation of Nature (IUCN) Red List. This means that the species is not considered to be at risk of extinction at the global level. However, they are protected under the Fisheries Management Act 1994 and can only be taken by licensed commercial and recreational fishers.

Fish Taste Quality

Common Sydney octopus are considered a delicacy in many parts of the world. The are often used in dishes such as sushi, sashimi, and stir-fries. The taste and texture of the meat is often described as tender, mild, and slightly sweet, with a firm and chewy texture. They protected species in Australia, and it is illegal to take them without the appropriate permits and licenses.

Taste Rating: 4/5

Recreational Viewing
- Snorkeling & Scuba

Finding: Intermediate

Temperament: Curious

Location: Inner Reef, Lagoon, Seagrass Beds

Danger: None