Southern Keeled Octopus
Hammer Octopus – Octopus australis
The Southern Keeled Octopus is common in shallow coastal waters of south-eastern Australia, although it is often confused with the morphologically similar Octopus australis. It is often caught incidentally during scallop and mussel dredging.
Identification
Octopus berrima is typically cream to light brown with a skin-keel around the mantle edge. It has large papilla over each eye.
Habitat
This species is most common in sand habitats and seagrass beds in shallow waters, although it has been captured at depths greater than 250m.
Distribution
Octopus berrima is endemic to more temperate seas off southern New South Wales and southern Australia, as opposed to the similar O.australis which is endemic to subtropical waters of Southern Queensland and central New South Wales.
Feeding and diet
Feeds primarily on crabs and other crustaceans.
Other behaviours and adaptations
When agitated, Octopus berrima will flares its webs and darken chromatophores present around the eyes. Like its relative, the Hammer Octopus, the Southern Keeled Octopus hides in the sand during the day or uses rocks and human rubbish as shelter.
Breeding behaviours
The female lays large eggs and attaches them singly to hard rocky surfaces. The hatchlings are well-developed and immediately settle in the seafloor and start foraging.
Economic impacts
Forms the basis of small-scale octopus pot fisheries in South Australia and Victoria.
References
- Norman, M., (2000) Cephalopods- A World Guide, ConchBooks, Germany (Hackenheim)
- Norman, M & A. Reid., (2000) A Guide to Squid, Cuttlefish and Octopuses of Australasia, CSIRO Publishing, Victoria (Collingwood)
- Stranks, T.N., & M.D.Norman (1992) Review of the Octopus australis complex from Australia and New Zealand, with description of a new species (Mollusca: Cephalopoda), Memoirs of the Museum of Victoria 53(2): 345-373.
