Irukandji – Box Jellyfish

Tiny – silent – deadly

How can anything so small be so incredibly dangerous? This little killer beauty is a Box Jellyfish, and it goes by the name of Irukandji, from the name of the Australian tribe where it was discovered. According to their tales, there is a silent terror in the water that makes people die in unimaginable agony.
Irukandji is very small jellyfish, the “head” or bell section is about 5 to 25mm in diameter, and the tentacles may be anywhere from one inch to … 3 feet. Those tentacles are full of stingers that inject venom into the skin (there are also stingers on the bell). Since the jellyfish is so small, normal net enclosures do little or nothing to stop it.

There are a few discovered species and we’ll make every effort to provide pictures of each.

  • Carukia barnesi
  • Maolo kinki
  • Alatina alata
  • Alatina Mordens
  • Malo maximus
  • Carybdea alata

Geographical Location

For a long time it was believed that it was confined to Australia’s northern coast, however Irukandji has been sighted in Japan, the British Isles and even the coasts of Florida.

Modus Operandi

It’s dangerous because it’s tiny and very venomous. It doesn’t actively pursue a human being, nor does it want you for breakfast. It does, however, possess a very strong defense mechanism. It’s lifecycle is still unknown.

When Stung

It induces what is commonly called Irukandji Syndrome due to venomization. The Irukandji Syndrome is nothing less than utter agony, during which patients have been known to actually beg to be killed. The pain is absolutely unbearable even when a patient is given a maximum dose of Morphine.
The venom it injects is largely unknown, and what the venom does in the body is also unknown, but here are most of the symptoms


  • headache
  • backache
  • muscle pains
  • chest, abdominal pain
  • nausea, vomiting
  • sweating
  • anxiety
  • hypertension
  • tachycardia
  • pulmonary edema
  • feeling of impending doom

The symptoms can last from hours to weeks.


The sting is rarely fatal, although people have been known to die from a sting due to cardiac arrest.

First Aid

The symptoms will present themselves in roughly 30 minutes and are characterized by ever increasing pain. Don’t touch the affected area, since the stingers are still in the skin and will likely end up in your hand.


Since there is no known antidote at the time this article was written, treatment is supportive only. The victim is usually given antihistamines and anti-hypersensitive drugs, morphine, etc. Magnesium sulfate has been known to reduce the pain and hypertension in Irukandji Syndrome.
What to do:
Seek medical care immediately

What not to do:
Do not flush the area with vinegar. It was once thought to neutralize the stinging aparatus of the jellyfish, but it has been proven to amplify the effects.