Alex Mustard / Bue ring octopus (Hapalochlaena lunulata) walking across the sea bed. Dauin, Dauin Marine Protected Area, Dumaguete, Negros, Philippines. Bohol Sea, tropical west Pacific Ocean.

Alex Mustard / Blue ring octopus (Hapalochlaena lunulata) walks across the sea bed. Dauin, Dauin Marine Protected Area, Dumaguete, Negros, Philippines. Bohol Sea, tropical west Pacific Ocean.

Alex Mustard / Large blue ring octopus (Hapalochlaena lunulata) swimming just above the sea bed. Dauin, Dauin Marine Protected Area, Dumaguete, Negros, Philippines. Bohol Sea, tropical west Pacific Ocean.

David Hall / Poison ocellate octopus (Amphioctopus mototi) with blue ring which appears when disturbed. Pantar, Alor Archipelago, Indonesia.

David Hall / Poison ocellate octopus (Amphioctopus mototi), warning colouration with blue ring and stripes. Pantar, Alor Archipelago, Indonesia.

Alex Mustard / Poison ocellate octopus (Amphioctopus siamensis) moves across the sand. When disturbed, this species advertises its poisonous nature by flashing Blue ring on the dark patch beneath the eye. Lembeh Str...

Alex Mustard / Tropical blue ring octopus (Hapalochlaena lunulata) is small but has one of the most venomous creatures in the ocean, its bite injects a neurotoxin that paralyses its victim. It flashes its blue rings...

Alex Mustard / A blue ring octopus (Hapalochlaena lunulata) flashes its blue rings as it crawls over a coral reef. Kapalai Island, Sulu Sea, Sabah, Borneo, Malaysia..

Alex Mustard / An undescribed species of blue ring octopus (Hapalochlaena sp.) swimming at night. Java Sea, Puri Jati, Bali, Indonesia. South East Asia.

Alex Mustard / Southern / pacific blue-ringed octopus (Hapalochlaena maculosa) swims across the seabed. Port Philip Bay, Blairgowrie, Melbourne, Victoria, Australia.

Jeff Rotman / Scientist holding a poisonous Pacific blue-ringed octopus (Hapalochlaena maculosa) in his hand. The octopus can emmit a fatal neurotoxin through it's saliva when provoked, and there is no known anti-v...

Jeff Rotman / Blue-Ring Octopus (Hapalochlaena maculosa) swimming at night, Eastern Australia, Pacific Ocean.

Brent Hedges / Blue-ringed Octopus (Hapalochlaena maculosa) South Australia, Australia

GEORGETTE DOUWMA / Pacific blue ring octopus {Hapalochlaena maculosa} Sulawesi, Indonesia

Jeff Rotman / Poisonous Blue-ringed octopus {Hapalochlaena maculosa} jets away at night, Australia

Jeff Rotman / Poisonous Blue-ringed octopus {Hapalochlaena maculosa} jets away at night, Australia

Jeff Rotman / Pacific Blue Ring Octopus at night in defence posture. Sydney Australia Hapalochlaena maculosa

Jeff Rotman / Pacific Blue ring octopus {Hapalochlaena maculosa} Eastern Australia, Pacific Ocean

Juergen Freund / Pacific blue ring octopus {Hapalochlaena maculosa} Indo Pacific

Jeff Rotman / Pacific blue ring octopus at night (Hapalochlaena maculosa) Australia

Constantinos Petrinos / Pacific blue ring octopus {Octopus maculosa / lunulata} note enlarged blue rings of agitated animal; toxic species. Lembeh, Sulawesi, Indonesia. Colour change Sequence.

Constantinos Petrinos / Pacific blue ring octopus {Octopus maculosa / lunulata} has blue rings that enlarge when agitated; toxic species. Sulawesi, Indonesia. Colour change Sequence.

Juergen Freund / Pacific blue ringed octopus {Hapalochlaena maculosa} Sulu-sulawesi seas, Indo-Pacific

David Fleetham / Pacific blue ring octopus (Hapalochlaena maculosa) on orange sponge, South Australia.

Nature Production / Pacific Blue-ringed Octopus {Hapalochlaena fasciata} Izu Osezaki, Shizuoka, Japan, January

Carine Schrurs / Pacific blue ring octopus swimming {Hapalochlaena maculosa} Sulawesi Indonesia

Carine Schrurs / Pacific blue ring octopus on coral {Hapalochlaena maculosa} Lembeh strait Sulawesi

Fred Bavendam / Southern blue-ringed octopus (Hapalochlaena maculosa) female, carrying eggs, Edithburgh, South Australia, Great Australian Bight.

Fred Bavendam / Southern blue-ringed octopus (Hapalochlaena maculosa) female carrying eggs, resting on seabed, Edithburgh, South Australia, Great Australian Bight.

Fred Bavendam / Southern blue-ringed octopus (Hapalochlaena maculosa) female carrying eggs, Edithburgh, South Australia, Great Australian Bight.

Fred Bavendam / Southern blue-ringed octopus (Hapalochlaena maculosa) female carrying eggs, drifitng in open ocean, Edithburgh, South Australia, Great Australian Bight.

Fred Bavendam / Southern blue-ringed octopus (Hapalochlaena maculosa) investigating several bivalve shells on seabed, Edithburgh, South Australia, Great Australian Bight.

Fred Bavendam / Southern blue-ringed octopus (Hapalochlaena maculosa) female carrying eggs, resting on seabed, Edithburgh, South Australia, Great Australian Bight.

Fred Bavendam / Southern blue-ringed octopus (Hapalochlaena maculosa) female carrying eggs, resting on seabed, Edithburgh, South Australia, Great Australian Bight.

Fred Bavendam / Southern blue-ringed octopus (Hapalochlaena maculosa) female carrying eggs, resting on seabed, Edithburgh, South Australia, Great Australian Bight.

Alex Mustard / Blue ring octopus (Hapalochlaena lunulata) patrols the seabed. Anilao, Batangas marine protected area, Luzon, Philippines. Verde Island Passages, Tropical West Pacific Ocean.