Above: the small but deadly irukandji, or box jellyfish. Photo: Robert Hartwick.
The irukandji, sea wasp, or box jellyfish (class Cubozoa) is one of the most venomous jellyfish in the world, and are potentially fatal to human beings, though some species can be as small as your fingernail. It’s no wonder, then, how this small fish ends up dead as a Julius Caesar within seconds of being ensnared.
Watch a box jellyfish makes quick work of a helplessly curious little guppy, lured to its death by the jelly’s tentacles, which offer the deceptive, false promise of a meal: