View of a reef from above

What is the Most Deadly Australian Jellyfish?

The deadliest Australian jellyfish are the Irukandji jellyfish and the Box jellyfish.

jellyfish in an equarium

The Great Barrier Reef is home to some amazing marine life, which makes it a magnet for ocean enthusiasts!

But like most environments in Australia, we should all be aware of potentially dangerous wildlife out there. And in the Great Barrier Reef’s case, it’s the jellyfish.

The box jellyfish and the Irukandji jellyfish are two different jellyfish that are different in their size – but they are still both venomous.

Box Jellyfish

The box jellyfish is characterised by…

  • A cube-shaped body
  • Found in shallower waters
  • Tentacles on box jellyfish are long, translucent and almost ribbon-shaped

Irukandji Jellyfish

The Irukandji Jellyfish is known as Australia’s most lethal sting. The Irukandji jellyfish is characterised by…

  • Small jellyfish, that are only 1-3.5cm in diameter
  • A cube-shaped bell
  • 1.2-meter-long tentacles

What’s the difference?

Both jellyfish are very venomous, but they are different in appearance. The Irukandji are smaller, and their tentacles are more translucent.

Box jellyfish’s tentacles tend to be a bit thicker. The tentacles can even reach about 20cm long each side of the ‘box.’

Stinger safety

But don’t be put off by jellyfish when you visit the Great Barrier Reef – there are lots of measures in place to make sure that you aren’t stung, and ways to stay safe in stinger season! 

If you spot any beaches with yellow signs with a symbol of a jellyfish, be more aware when you’re swimming.

The simplest and most effective way to avoid a sting is obviously to avoid going in the ocean in the first place.

But if you are going in the ocean, then you can…

  • Swim only in the stinger nets
  • Wear a stinger suit
  • Tell people where you are swimming
  • Swim only on patrolled beaches
Cameron Ward

Managing Director at Sightseeing Tours Australia

Cameron Ward turned his travel passion into a thriving Australian tourism business. Before he co-founded his own business, Sightseeing Tours Australia, he was enjoying being a Melbourne tour guide. Even now, Cameron delights in helping visitors from all around the world get the most out of their incredible Australian trip. You’ll see Cameron leading tours or writing about his favourite Australian places where he shares his local insights.

Google Reviews Trustpilot Reviews