Chironex fleckeri Click to enlarge image
Box jellyfish Image: Gavin Dally
© Gavin Dally

Fast Facts

  • Classification
  • Size Range
    up to 30 cm bell, up to 3 m tentacles


The infamous sea jelly is large and transparent with a box-shaped bell and up to 60 tentacles in four clumps along the base of the bell.


This species occupies the tropical Australian coastal waters from Western Australia through the Northern Territory to Queensland.

Feeding and diet

Found most often in summer in inshore waters as they feed on bay-dwelling prawns, coastal mangroves, creeks and rivers. They can swim toward movement and may go into the shallows on hot, cloudy, still days in search of prey which, in the summer wet season, can lead to stings in murky coastal river waters.

Danger to humans

  1. If stung call emergency services: Mobile phone: 112 Landline: 000
  2. Be prepared to give CPR (Cardiopulmonary resuscitation) if needed.
  3. Calm the patient and stop them from rubbing the stung area.
  4. Flood the stung area with vinegar for at least 30 seconds.
  5. Apply pressure-immobilisation bandage:
  • Wind the bandage around the bitten arm or leg, starting from the bite.
  • The bandage should not be so tight that it restricts blood flow.
  • Wrap the entire limb, then apply a splint to prevent movement.
  • Keep the victim as still as possible.
  • Do not remove the bandage.

Seek medical attention as soon as possible.

First aid guidelines were correct at time of publication however these guidelines change over time. For up to date first aid information consult medical professionals such as St John's Ambulance.