Blue-ringed octopus

This little guy - the size of a golf ball - is one of the most deadly creatures in the sea! Called the blue-ringed octopus for obvious reasons, its range is the eastern Indo-Pacific. It frequents the shallow coastal waters of Australia to the detriment of beach-goers who come into contact with it and may not even know they've been bitten, because the wound is so tiny and said to be painless. But the result is often death, because this octopus packs the same punch as the pufferfish and carries enough venom to fatally paralyze 10 large humans. Here's what happens:

"Within five to ten minutes, the victim begins to experience parasthesias and numbness, progressive muscular weakness and difficulty breathing and swallowing. Nausea and vomiting, visual disturbances and difficulty speaking may also occur. In severe cases, this is followed by flaccid paralysis and respiratory failure, leading to unconsciousness and death due to cerebral anoxia. Interestingly, the victim's heart continues to beat until extreme asphyxia sets in. Some victims report being conscious, but unable to speak or move."

The blue-ringed octopus changes its skin color and texture to camouflage itself, and only when it is threatened do the rings light up and pulsate. Because it lacks an ink sac. it has become a common addition to the marine aquarium - but toxicologists strongly disagree with this practice because of the potential danger to people who are unaware of the animal's neurotoxin - for which there is no antidote.