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Chironex Box Jellyfish. Image author: Guido Gautsch.

According to the U.S. National Science Foundation, 20-40 people die from box jellyfish stings in the Philippines alone each year. Box jellyfish frequent Australia’s northern oceans throughout the entire year, but are more prevalent in the wet season between November and April. Although they show many characteristics of typical jellyfish, they are actually classed as not being a true jellyfish.

True jellyfish usually just drift around, but the box jellyfish has been recorded as moving at speeds of up to six metres per minute. Since box jellyfish have 24 eyes, in four sets, they can detect and attack anything around a 360 degree zone of vision. Their eyes are defined as ‘ocelli’ meaning simple eyes that can only detect light and dark.

Small fish and invertebrates, such as prawns, are the box jellyfish’s choice of prey. Even the most venomous jellyfish in the world is not without its own predators to worry about however, as blue swimmer crabs, rabbitfish, batfish and butterfish are all a threat. Sea turtles are the box jellyfish’s most fearsome predator as they are remarkably unaffected by the stings and can quite happily munch away on a tentacle unperturbed.

Box jellyfish have very dangerous tentacles that can grow up to 3 metres in length. Most of the harm caused by these jellyfish comes from their ‘cnidocytes’ which are all over their tentacles. Cnidocytes are small ‘poison pouches’ that harbour small darts and venom. Each tentacle has over 500,000 cnidocytes. This cube or bell shaped jellyfish has four distinct sides, which gives the box jellyfish its name. A fully grown box jellyfish can grow to a respectable size of 30 cm in diameter and weigh up to 2 kg. They are usually pale blue in colour or transparent.

When tentacles wrap around their victim, they shoot their poisoned darts into the skin. The venom then enters the bloodstream. Just a small amount of box jellyfish venom is enough to stop the heart and spike blood pressure. Records show that most victims who are injected with the venom survive; however, many countries don’t require death certificates for jellyfish related deaths, so the data may be skewed.

Don’t expect the box jellyfish to be a trivial dumb blob of goo. Box jellyfish actually display complex behaviors that allow them to avoid things as well as speed up their swimming in a certain direction. Box jellyfish are in fact quite intelligent, as tests have not only shown that they have a very basic memory, but that they can also learn.

These jellyfish can be found throughout the Atlantic and east Pacific oceans, the Mediterranean, as well as North California, Japan, South Africa and New Zeeland. Box jellyfish encounters are more likely to happen 7-10 days after a full moon in Hawaii, when they come near to the shore to spawn. These spawning activities are occasionally so widespread that beaches have to be closed until it is safe to go back into the water.

A victim can immediately go into shock if stung and if they are swimming alone the pain is so severe that the swimmer will usually not be able to make it back to shore on their own. Necrosis can occur in venom infected tissue, which means that cells are destroyed causing tissue to die, often leaving permanent scars.

Unlike myth would tell you, it is not a good idea to urinate on jellyfish stings and you would certainly be doing the poor victim a favour by not considering urinating on them, as this would only further darken the tragic experience for them. Spirits and vodka should never be poured over stings either as this is also a myth, it is just a waste of time and good spirits. Natural vinegar does work however, and has saved many lives. Vinegar needs to be poured over any tentacles still attached to the victim’s body before they can be removed, as removing them before this can lead to more venom being released. If cardiac arrest occurs, CPR may keep the victim alive until help arrives. Hospitals and medical centres near areas where box jellyfish are common will usually have an antiserum called ‘antivenin’ which can relieve pain and reduce scarring.

According to Dr. Angel Yanagihara, research professor at the university of Hawaii, who was stung by box jellyfish (quoting from an article by Diana Nyad for the Huffington Post), the feeling of being stung by a box jellyfish was like her entire body was “ . . . submerged in hot, burning oil” and she yelled "Fire!, Fire!, FIRE!" Her companion who was also stung in the water was startled when his breaths per minute slowed down to just three breaths per minute. Luckily, they both miraculously survived.