''Octopus kaurna'', also known as the southern sand octopus, is an

octopus An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttle ...

native to the waters around the Great Australian Bight and

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

. It has an arm span of up to with long, unusually thin

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s joined at the base by webbing and studded with small suckers. The species was first identified by Timothy Nathaniel Stranks. Kaurna is the name of an Australian Aboriginal clan which lived in the Adelaide region of South Australia.

Behaviour

Unlike most octopuses, ''O. kaurna'' lacks color-changing chromatophors. However, it is able to hide from predators by burrowing itself in sand. The process begins with the octopus using its

siphon A siphon (from grc, σίφων, síphōn, "pipe, tube", also spelled nonetymologically syphon) is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in a ...

to inject water into the sand, creating

quicksand Quicksand is a colloid A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a ...

-like conditions which enable burrowing. Then, it uses its arms to burrow into the sand. Two arms will be extended to the surface, creating a ventilation shaft. At the same time, ''O. kaurna'' will use mucus to stabilize the shape of the burrow. Finally, the octopus will retract its two arms and push out loose sand with its siphon, creating a mucus-lined, ventilated burrow to rest in. While many octopuses bury themselves in a shallow layer of sediment for camouflage, ''O. kaurna'' is the only known species to exhibit sub-surface burrowing.

References

Octopodidae Molluscs of the Pacific Ocean Cephalopods of Australia Molluscs described in 1990 {{Octopus-stub