Australia’s marine environment is home to many interesting animals, including some harmful jellyfish collectively known as marine stingers. These marine stingers are easy to avoid but can cause discomfort if you are stung, and some of the tropical species, such as the Irukandji and the Box Jellyfish can be lethal.
The Indo-Pacific or Australian box jellyfish (Chironex Fleckeri) is claimed to be the most venomous marine animal known to mankind and its sting is often fatal.
This extremely poisonous marine stinger frequents Australia's northern oceans all year round. However, it is particularly dangerous during the wet season, from about November to April.
The Box Jellyfish (also known as a Sea Wasp) has extreme toxins present on its tentacles, which when in contact with a human, can stop cardio-respiratory functions in as little as three minutes. This jellyfish is responsible for more deaths in Australia than Snakes, Sharks and Salt Water Crocodiles.
Box jellyfish have traits that set them apart from other jellyfish. Most notably, box jellyfish can swim—at maximum speeds approaching four knots—whereas most species of jellyfish float wherever the current takes them, with little control over their direction. Box jellyfish can also see. They have clusters of eyes on each side of the box. Some of these eyes are surprisingly sophisticated, with a lens and cornea, an iris that can contract in bright light, and a retina.
Their speed and vision leads some researchers to believe that box jellyfish actively hunt their prey, mainly shrimp and small fish.
Mike Kingsford, a jellyfish expert from James Cook University, said although the creature photographed is technically a box jellyfish, it is not the type that can kill people.
He said the Mooloolaba jellyfish is what is known as a morbakka, which does not have the deadly tentacles associated with a traditional box jellyfish.
"There is a whole group of jellyfish called cubizones, which are squared, and on each corner they have a tentacle base," Professor Kingsford said. "The nasty stingers known to kill people in Australia have, on each of those corner bases, lots of other tentacles. Those tentacles can stretch for three and half metres or more, and if you get a whole tentacle on you the risk of death or injury is high."
More information on the Box Jelly fish can be found at the following links: