The venom is very painful to humans, and can result in skin welts or even an allergy-like response. If you see a Portuguese Man O’War, admire from afar and do NOT touch!

Jellyfish don’t go after humans, but someone who swims up against or touches one — or even steps on a dead one — can be stung all the same. But stings from some types of jellyfish — such as the box jellyfish (also called sea wasp) — are very dangerous, and can even be deadly.

box jellyfish

Does peeing on the sting help? Quite simply, no. There is no truth to the myth that peeing on a jellyfish sting can make it feel better. Numerous studies have found that this simply doesn’t work.

When a man o’ war stings, its long tentacles release thousands of microscopic venom-injecting capsules called nematocysts. On contact with skin, the nematocysts deliver a toxic chemical cocktail into its victim. In more severe cases, a sting can trigger chest pain, difficulty breathing, and even death.

Resembling an 18th-century Portuguese warship under full sail, the man o’ war is recognized by its balloon-like float, which may be blue, violet, or pink and rises up to six inches above the waterline.

Box Jellyfish

Lifespan & Reproduction Depending on water temperature and conditions, it’s estimated that the average Portuguese Man-o-War lives for at least one year. Individual Man-of-War colonies consist of either all-female polyps or all-male polyps.

It has toxins that can cause cardiac problems and is also harmful to the eyes, so handle it with care. For the rare individual who is allergic to it, they should also not eat it.

Its bell can be 2.5 metres across, and its tentacles can stretch over 30 metres – about the same length as a blue whale. This is 10 metres longer than the tentacles of the famous Portuguese man-of-war – which in any case is not a true jellyfish but a hydrozoan.

Box jellyfish stings can be fatal because of the creature’s barbed tentacles containing venom. If you encounter these tentacles, the jellyfish can poison you with immediate effects. Not all stings will cause death. However, all of those stung experienced serious symptoms within a few minutes.

A ten-year-old girl has become the first person ever to have survived an attack from a lethal box jellyfish, the world’s most venomous creature. Rachael Shardlow was stung by the creature while swimming in the Calliope River, near Gladstone, in Queensland, Australia.