This beautiful yet deadly animal is native to Northern Australia and is also some times referred to as the 'marine stinger' or 'sea wasp'. It is believed to be one of the, if not the most venomous creature around. This jellyfish has tentacles which are covered in high amounts of nematocysts as well as venom.
The Chironex is one of the largest jellyfish in these waters and it's bell can grow to the size of a soccer ball. Each corner of the bell has 15 tentacles.The sting from a Chironex can be fatal and is extremely painful, often associated with severe effects on the victims nervous system and heart. These jellyfish are known for their ability to kill a victim within 4 minutes, faster than any snake. If stung one should apply vinegar to the sting as to prevent nematocysts which have not yet been let off. CPR may also be required shortly after the sting has taken place. It is important if stung to immediately seek medical attention. An anti-venom for the Chironex does not exist, making the importance of experienced help a necessary.
So if you head to Northern Australia for some diving, be sure that you look out for warnings signs on beaches about these creatures and never take the threat of them lightly.