The coastal waters of Northern Australia and the Indo-Pacific Oceans are home to a truly frightening creature - the world's most poisonous animal, the box jellyfish.
The box jellyfish actively hunts its prey, injecting a paralytic toxin into its victim, jolting it into shock and often killing it outright, so the victim never struggles to escape and damage the jellyfish's delicate tentacles. The venom of the box jellyfish contains toxins which cause cellular leakage, able to cause cardiovascular collapse and death within as little as 120 seconds. The toxin is reported to be so overwhelmingly painful that humans are likely to go into shock and drown or die of heart failure before being able to swim to shore, and survivors can expect agonizing pain for weeks, followed by lifelong, significant scarring.
But for all their deadliness, box jellyfish are strikingly beautiful, pale blue and transparent, with a cube-like bell and some four dozen 10-foot-long tentacles. Each of those tentacles, however, contains about 5,000 stinging cells.
Box jellies are among the most advanced jellyfish, capable of active movement instead of simple drifting, rocketing through the water at nearly two meters a second - roughly as fast as a human running on land. They also have clusters of six eyes on each of the four faces of their cube-shaped bells. These eyes are quite sophisticated, with a lens, retina, iris and cornea.
Interestingly, although some experts estimate as many as 100 – 200 unreported victims die annually from box jellyfish stings, sea turtles are completely unaffected by the toxin, and regularly snack upon box jellyfish.
Box jellyfish victim in the morgue