commented on "11 July 2013 ..."
IRUKANDJI jellyfish have been again spotted at Ningaloo Reef off the West Australian coast following a spate of stings earlier this year.
These jellyfish are transparent which makes them virtually invisible in the water and they are tiny - they can be as small as 1cm. A sting from this jellyfish can be fatal. Here is a link to the Queensland Ambulance Service Irukandji jellyfish fact sheet.