Deadly Jellyfish
A Quick Guide to Deadly Jellyfish
The most deadly jellyfish in the oceans is the box jellyfish. They are known best for their venom, which is extremely powerful. They are among the most venomous animals in the world. A sting from a box jellyfish is very painful at the least, and deadly at the worst, even for humans. Different species of the box jellyfish are not quite as dangerous, but you don't want to stick around to see which type stung you, if you are stung.
Box jellyfish were named for their medusa, which is shaped like a box. The category that the box jellyfish belongs to includes some nineteen other species as well, most of them not as dangerous to humans. Box jellies are most common in the waters off the coasts of Australia, Vietnam, Hawaii and the Philippines.
The venom of the box jellyfish is the most deadly in all of the kingdom of animals, marine or otherwise. It has caused at least fifty-five hundred deaths since 1954. Most of those were caused by the larger box jellyfish, but some were caused by the Irukandji, which is another deadly jellyfish that frequents tropical waters. The set of symptoms suffered by people stung by this jelly is referred to as Irukandji syndrome. Unlike many jellies, the Irukandji can actively hunt, rather than simply drifting as most of its relatives do. It can move at a maximum speed of 3.5 knots.
The venom of deadly jellyfish does not affect every species in the oceans. Sea turtles will eat these jellyfish, and do not seem to be affected by their venom.
The season to be most wary of deadly jellyfish is generally from October until May, but stings can occur all over the world, and in any month. The conditions that seem to precede most human stings are an onshore breeze and calm waters, but stings have been reported in any conditions of wind and sea.
The box jellyfish are quite common in the warmer waters off the coast of northern Australia. But the swarms that can plague the beaches in summer seem to disappear in the winter, although individuals can still be occasionally spotted. Box jellies are also the only deadly jellyfish that possess a visual system. They have four sets of eyes, one set on each of its four lateral faces.
If you plan to swim at a beach where deadly jellyfish have been known to sting humans, pack a bottle of vinegar. This is useful if you are the victim of a sting, to flush the sting area and remove some of the toxin before it can spread. Vinegar won't help the pain, but it might keep you alive until medical help can arrive. Apply the vinegar also to unattached tentacles, to make sure they don't come in contact and release more venom. Remove the tentacles if you can, and summon immediate medical help.
Deadly jellyfish can be found worldwide, so if you are stung and you don't know the species – or you know it to be a deadly one – call 911 as soon as possible.