Making deadly jelly babies

The Irukadndji jellyfish could have sprung from the fertile imagination of a sci-fi horror writer. It looks deceptively insignificant and benign, but its entire body is a biological booby trap. In most jellyfish it’s only the tentacles that are studded with the minuscule harpoon-like, venom-loaded stinging cells known as nematocysts. But in Irukandji the bell is also armed with these toxic weapons – as many as 5000 per square centimetre. An encounter with an Irukandji can have an adult human soon fighting for their life. Like most jellyfish, the Irukandji is transparent, but it’s tiny – no more than 2.5cm wide - so you’re unlikely to see it coming and stay out of its way. And even if you did, those tentacles are extendable, reaching out to four times their relaxed length.

This jellyfish was named after the Irukandji people, traditional fishers whose Country includes the sea off the coastal regions near Cairns, Queensland. Although this was the area where the jellyfish was first recognised, its distribution is much wider. And with more people venturing into the waters where they occur, reports of stings are becoming increasingly common and scientific scrutiny of the Irukandji has been mounting.

But research on the species in the wild has had limitations. Although it’s been possible to