"claimed to be the most venomous marine animal known," according to the Australian Institute of Marine Science. They state that it causes excruciating pain to humans, often followed by death, sometimes within two or three minutes, and that the chance of survival if stung while swimming alone is "virtually zero."
The body of Chironex is the size of a basketball.
Luckily, here in Hawaii, we have the Carybdea alata and Carybdea rastonii species. They're not so big (less than 6") and not so bad (only cause anaphylactic shock in the lucky individuals allergic to their venom) as their relatives in Australia. One of the ladies in my department, Angel Yanagihara studies their venom and goes on regular collection trips in the middle of the special "8th night".
I would also like to comment about the figure the author of the Wikipedia article chose for the box jellyfish. It is a drawing by Ernst Haeckel, my new favorite scientific rebel who apparently made up some data to support his pet hypotheses. A case of artistic license, maybe? Some of his famous "fakes" were included in the embryo drawings, shown here in Romanes's 1892 version where the background has been changed to white from black:
He later admited that 6-8% of the images may have been "falsified" (translated).
Tomorrow, we plan on going to the North shore to snorkel Shark's Cove. The jellyfish are not so prevalent up there, so we should be fine. I am more worried about riding up there on the back of Megan's motorcycle. An hour and a half on a cruiser. I can't wait...