The algae octopus uses an elaborate camouflage scheme to stay safe. It can change the color and shape of structures on its body and arms to make it look like an algae-covered shell.
When that doesn’t work, though, it has another defense mechanism: Run! It can hoist its body on two of its eight arms and skedaddle, running as fast as it can swim. In fact, it’s one of only two species of octopus that’s known to run on two “legs.”
They’re tiny and they’re brainless, but the box jellyfish of Australia, known to science as Carukia barnesi, packs a deadly punch — and its victims aren’t random. Researchers already knew this extremely venomous predator was one of a half dozen jellyfish that cause Irukandji syndrome, named for an aboriginal tribe that lived in the area where most of the stings occur. Symptoms in humans include lower back pain, severe muscle cramps, vomiting, anxiety and occasional cardiac problems that can lead to death.
