Blue-ringed Octopus (Hapalochlaena maculosa)
Blue-ringed octopuses are a genus of octopus that live in tidal pools and reefs of the Pacific and Indian Oceans, from Japan to Australia. When provoked, the octopus displays bright yellow and circular blue markings, which act as a warning of its toxicity.
Despite their small size, they are recognised as one of the most venomous marine animals and can be dangerous to humans. Their venom consists of a cocktail of poisons, including tetrodotoxin, histamine, tryptamine, octopamine, taurine, acetylcholine, and dopamine. It is produced by bacteria in the octopus’s salivary glands and is injected with a bite.
The venom can cause respiratory arrest, heart failure, severe or total paralysis and blindness. Death can occur in a few minutes and is usually due to insufficient oxygen reaching the brain. The victim may remain conscious, but unable to breathe.
There is no antivenom available, increasing its danger. Treatment usually involves artificial respiration, such as using a ventilator, until the toxin is metabolised and removed by the body.
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