Blue ringed octopus warning (Image courtesy of Wikimedia Commons/Roy Caldwell)Although small, the blue-ringed octopus has venom powerful enough to kill humans. They live in shallow rock pools amongst algae and seaweed, hiding in crevices or the empty shells of other marine animals. They are between 4 – 6 cm long and have been seen all over Australia. It is elusive and is not aggressive, but its bite is very serious.

Normally the octopus is a mottled yellow to brown colour that camouflages perfectly with surrounding rock; the blue rings only become visible when it is aggravated.


  • Never put your hands into deep crevices or into areas you cannot see.
  • Be aware of its habitat and watch for it.

SymptomsBlue ringed octopus warning (Image courtesy of Wikimedia Commons/Roy Caldwell)

  • weakness and nausea
  • numbness and blindness
  • loss of speech, touch and the ability to swallow
  • motor paralysis
  • fixed, dilated pupils and respiratory difficulties.


  • Seek immediate medical treatment: a bite is considered a medical emergency.
  • Put a pressure immobilisation bandage over the wound.
  • Keep the patient still.
  • Commence CPR once paralysis has set in. Continue it until medical help arrives.
  • Avoid expressing panic as the patient, though paralysed, is completely conscious and alert.