Hapalochlaena maculosa

Blue-ringed octopus
Hapalochlaena maculosa
Hapalochlaena maculosa, Kangaroo Is, SA, Photo: Rick Stuart-Smith
Hapalochlaena maculosa
Hapalochlaena maculosa, Kangaroo Is, SA, Photo: Rick Stuart-Smith
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Hapalochlaena maculosa
Hapalochlaena maculosa


Temperate Australasia, Tropical Indo-Pacific


Characteristic neon blue rings that glow strongly when the animal is irritated, but they are quite pale when the animal is resting and therefore may not be immediately apparent. The blue-ringed octopus is one of the more infamous sea creatures because of the powerful nerve toxin that is injected with saliva if the animal is strongly provoked and bites. Despite its reputation, the species is not usually aggressive, remaining hidden among broken rock and shell during the day and venturing out from these refuges to feed at night. The female lays about 50 eggs in late autumn and carries them around under her arms for about six months. Once the eggs have hatched, the female dies. Young rapidly grow to maturity and mate in early autumn. The males then die, and the females continue on with the eggs.


Max Size: 12 cm

Sea Temperature Range: 11.6-24.6°C

Depth: 0-30m

Habitat Generalization Index: N/A

Also referred to as the SGI (Species Generalisation Index), this describes the habitat niche breadth of the species. Species with values less than 15 are found in a relatively narrow range of reef habitat types (specialists), while those over 25 may be found on most hard substrates within their range (generalists). Learn more here.

Conservation and Rarity

IUCN Status: Not Evaluated

Occurrence: Infrequent (1.8% of sites)

Occurrence describes how often the species is found on surveys within its distribution. It is calculated as the % of reef sites surveyed by RLS divers across all the ecoregions in which the species has been observed

Abundance: Solitary (1 per transect)

Abundance is calculated as the average number of individuals recorded per RLS transect, where present.

Edit by: GJ Edgar. 2008. Australian Marine Life. New Holland, Sydney