Usually known as the blue-ringed octopus, a bite from this cephalopod can cause respiratoryparalysis (but not unconsciousness) within 30 minutes of a painless bite by the beak on the underside of this small octopus. It is normally some 8-11cm across, and a dull brown colour. However, when irritated (eg. by children playing with it) attractive blue rings appear, and a bite may occurs. Rapid (within 10 minutes) onset of progressive muscle weakness, with speech and respiratory difficulty, dysphagia and visual disturbance occur; respiratory failure mayoccur. There have been two Australian deaths. EAR can prevent death from respiratory failure.... hapalochlaena spp.
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