Dealing with Wildlife: Jellyfish

Jellyfish can turn a fine time in the ocean quickly into a catastrophe. One particular jellyfish species is even the most venomous marine animal in the world.

Jellyfish aren’t fussy. They live both at the deepest depths of the ocean and on the surface, in arctic waters and in tropical ones. Their bell-shaped head can be as small as one millimetre or as large as a car. Sometimes you’ll feel them before you’ve seen them.

These creatures are recognizable by their bell-shaped head and long, dangling tentacles. One bell can have eight groups of tentacles attached, with up to 150 tentacles in each group. Those tentacles are the worrisome aspect of their anatomy.

How jellyfish sting

Each tentacle comes loaded with microscopic barbed stingers. Each stinger has a tiny venomous tube. When the stinger activates by contact, it penetrates the skin, releasing venom. A person feels an instantaneous burning sensation. In some cases, the sting is so severe that it can cause someone to pass out or even suffer cardiac arrest.

Jellyfish aren’t deliberately hunting or attacking humans. Their venom is for protection and to kill prey. But if a human touches a tentacle, the affected area becomes irritated. Sometimes the venom enters the bloodstream. A single jellyfish can have enough venom to kill 60 adults.

Mostly, they drift with the ocean, but in the case of the box jellyfish -– the deadliest species –- they actively swim.

Box jellyfish, chironex fleckeri. Photo: Shutterstock


Box jellyfish prefer the warm waters of the Pacific and Indian Oceans. Their bell is a transparent four-sided box, making them hard to detect. Like other species, they have a cluster of six eyes, but for the box jellyfish, those clusters are on all four sides. Victims of box jellyfish stings can die within four minutes.

Recent fatalities

That’s exactly what happened to a seven-year-old girl in 2006. She’d been swimming in Australia’s tropical North Queensland when she came out of the water and collapsed in front of her parents. Resuscitation efforts failed.

A few years before, a young boy died in North Queensland after coming out of the water screaming. He had visible tentacle marks all over his body and died of cardiac arrest. His was the fourth box jellyfish fatality in three years.

Earlier in 2021, a 17-year-old Australian became the latest victim of a box jellyfish while swimming near Cape York, at the northeastern tip of Australia. The unnamed victim died in hospital a week after being stung.

One 11-year-old girl narrowly escaped death in 2010. But she was left scarred for life and needed skin grafts. The venom had burned both her legs, forearm and part of her stomach. Still, she lived to tell the tale.

A box jellyfish sting on a child’s leg. Photo: Shutterstock


“Box jellyfish, or chironex fleckeri, are known worldwide as being the most venomous marine creature and probably arguably the world’s most venomous creature full stop,” said one leading Australian expert.

Plenty of water enthusiasts coexist with jellyfish, applying caution. Note that a dead jellyfish on the beach can still sting you if you touch it.


Aside from the box jellyfish, treating jellyfish stings is the same regardless of species. First, get out of the water. Then flush the stung area with water to remove the tentacles. If tentacles are still attached, protect your hands and remove them with a dry towel. Next, immerse the stung area in hot water for 15 to 20-minute intervals. In the case of a stung torso, jump in the shower.

A vinegar station on the beach for treating jellyfish stings, Queensland, Australia. Photo: Shutterstock


When the sting comes from a box jellyfish, act fast: Remove the barbs with tweezers. Rinse the stung area with vinegar to stop the venom spreading. Contact emergency services for medical treatment. There is box jellyfish antivenom on the market which can save lives. Noe that defibrillators don’t work with box jellyfish stings: Their venom essentially locks the heart.

The best prevention however, is to stay clear of unprotected waters, especially in the Pacific and Indian Oceans between November and May. This is jellyfish season, when more float about.

The sting marks from a mane jellyfish. Photo: News Hub


One Australian stinger expert called swimming in unmarked waters Russian roulette. Although plenty of locals have swum in the such waters for generations, they are lucky that they haven’t been critically injured.

Jellyfish may be older than dinosaurs, yet remain elusive to humans. In New Zealand, for example, where jellyfish are prevalent and so is an ocean lifestyle, not one scientist specializes in them.

NASA first started sending jellyfish to space onboard the Columbia space shuttle in the 1990s. Scientists wanted to discover whether baby jellyfish developed the same sense of gravity when born in space as they do on earth. It turned out that although the jellyfish developed normally, they had difficulties discerning up from down later.

A Hawaiian beach sign. Photo: Shutterstock