Blue-ringed octopus

About this species

The southern blue-ringed octopus is one of four extremely venomous species of blue-ringed octopuses. It is most commonly found in tidal rock pools along the south coast of Australia. As an adult, it can grow up to 20 centimetres (8 in) long and on average weighs 26 grams (0.9 oz). They are normally a docile species, but they are highly venomous, possessing venom capable of killing humans. Their blue rings appear with greater intensity when they become aggravated or threatened.

Text from the Wikipedia article “Southern blue-ringed octopus”, licensed CC BY-SA 4.0. Read the article

Where and when

Where it has been recorded

Worldwide

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Best months

Worldwide (open data)

January: 166 records
February: 100 records
March: 106 records
April: 97 records
May: 51 records
June: 30 records
July: 25 records
August: 21 records
September: 29 records
October: 31 records
November: 70 records
December: 67 records

Depth and water temperature

Depth

Mostly recorded at 1–4 m · Deepest record: 55 m

0–10 m: 76 records
10–20 m: 2 records
20–30 m: 1 records
30–40 m: 0 records
40–50 m: 2 records
50–60 m: 1 records

Water temperature

Recorded in surface water of 14–29 °C

12–14 °C: 1 records
14–16 °C: 127 records
16–18 °C: 58 records
18–20 °C: 19 records
20–22 °C: 1 records
22–24 °C: 3 records
24–26 °C: 3 records
26–28 °C: 13 records
28–30 °C: 4 records

Photos

(c) Mark Norman, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Miguel de Salas, some rights reserved (CC BY-SA) · CC BY-SA · iNaturalist
(c) Tim, some rights reserved (CC BY-SA) · CC BY-SA · iNaturalist
(c) Christopher Mark, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Peter Crowcroft, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Christopher Mark, some rights reserved (CC BY) · CC BY · iNaturalist

Names and classification

English: Blue-ringed octopus, Lesser blue-ringed octopus, blue-ringed octopus, lesser blue-ringed octopus, Southern blue-ringed octopus

Names in 6 more languages

German: Blaubandkrake, Blaugeringelter Krake, Kleiner Blaugeringelter Krake
Spanish: Pulpo de anillos azules sureño
French: Pieuvre aux anneaux bleus
Japanese: コマルモンダコ
Thai: หมึกสายวงน้ำเงินใต้
Simplified Chinese: 环蛸

Other scientific names: Octopus maculosus, Octopus pictus

Similar species

Blue-lined octopus
Hapalochlaena fasciata
Greater blue-ringed octopus
Hapalochlaena lunulata
Coconut Octopus
Amphioctopus marginatus
Maori octopus
Macroctopus maorum
Big blue octopus
Octopus cyanea
Pinnoctopus macropus

Sources and credits

Names and taxonomy: WoRMS (CC BY 4.0) and the GBIF Backbone (CC BY 4.0). Photos: iNaturalist observers, each under the licence shown (CC0, CC BY or CC BY-SA).

Depth, temperature, months and maps: records from OBIS and GBIF under CC0 or CC BY.
Descriptions: Wikipedia, licensed CC BY-SA, each linked to its article.
Conservation status as published by GBIF (IUCN Red List).
317 open-data records from 1879 to 2015.
Species data updated November 3, 2026.