cancun mark:There is however something even more dangerous than the box jelly, it is called irukanji, and has the same (australia indo pacific) range. the difference is that it is much smaller, ten times worse, but is not restricted to turbid coastal waters like the box jelly.
This comment piqued minor taxonomic outrage (i.e. WHAT THE ^*#* IS THIS?!), so I looked it up. "Irukanji" is in fact Carukia barnesi, and it is most definitely a box jelly within the Class Cubozoa. Box jellies are NOT restricted to turbid coastal waters, but "merely" subtropical and tropical water throughout the world's oceans. The dang things can pop up near anywhere in this zone, but people are on the coasts, so that's where they're most commonly reported. The terms "box jelly" and "sea wasp" are used to denote all members within this group, not individual species.
Here's a link I cross-checked with, and it's got an outstanding view of two of the four eyes. Check out those wicked googlies! :icon10:
http://www.ucmp.berkeley.edu/cnidaria/C_barnesi.html