sea wasp

This article's factual accuracy is disputed. Please see the relevant discussion on the talk page. (October 2009)

Box Jellyfish
"Cubomedusae", from Ernst Haeckel's Kunstformen der Natur, 1904
Scientific classification
Kingdom:	Animalia
Phylum:	Cnidaria
Class:	Cubozoa Werner, 1975
Order:	Cubomedusae Haeckel 1877
Families
Alatinidae Carybdeidae Chirodropidae Tamoyidae

Jellyfish/stinger net enclosure at Ellis Beach, Queensland

Box jellyfish, named for their cube-shaped medusae, are a class of invertebrates belonging to the class Cubozoa, as well as being the preferred common name for notoriously dangerous Chironex fleckeri.

Nomenclature

The Cubozoa class contains at least 19 different species, with some being only slightly less lethal than C. fleckeri.

The ambiguous but commonly used terms sea wasp and marine stinger have in places been applied to some species of Cubozoans, but these names vastly understate the danger posed by Chironex fleckeri and Carybdea alata, and their inappropriate use may cause carelessness that could result in death.

In at least one context where C. fleckeri occurs, the term box jellyfish is understood to only refer to this species, rather than the entire order. This is likely because of the considerable importance of wariness of C. fleckeri, compared to the relative unimportance of non-threatening species of box jellyfish to those inhabitants.^{[citation needed]}

Cubozoans are categorized separately from other types of jellyfish and are considered more complex than Scyphozoans.

Range

Various types of box jellies, ranging in toxicity, can be found in Australia, the Philippines, Indonesian Coast, Hawaii^[1], Vietnam, the Caribbean and other tropical areas. Box jellyfish are extremely venomous and can kill humans; some marine species (such as turtles) are immune to the venom, and are known to feed on the jellyfish.

Box jellyfish are best known for the extremely powerful venom possessed by some of their species. The species Chironex fleckeri, Carukia barnesi, and Malo kingi are amongst the most venomous creatures in the world. Stings from such species are excruciatingly painful, either initially or as an after-effect, and are often fatal to their prey and sometimes even for humans. However, not all species of Box Jellyfish are this dangerous to humans.

Defense and feeding mechanisms

Box jellyfish venom is the most deadly in the animal kingdom^{[citation needed]} and has caused at least 5,568 recorded deaths since 1954^{[citation needed]}. Each tentacle has about 500,000 cnidocytes which are harpoon-shaped needles that inject venom into the victim.^[2] Most often, these fatal envenomations are perpetrated by the largest species of box jelly, Chironex fleckeri, owing to its high concentration of nematocysts, though at least two deaths in Australia have been attributed to the thumbnail-sized Carukia barnesi.^[3] Those who fall victim to C. barnesi suffer severe physical and psychological symptoms known as Irukandji syndrome.^[4] The box jellyfish actively hunts its prey, rather than drifting as do true jellyfish. It is capable of achieving speeds of up to 4 knots (1.8 m/s).^{[citation needed]}

Box Jellyfish are known as the "Suckerpunch" of the sea not only because their sting is rarely detected until the venom is injected, but also because they are almost transparent.

The venom of cubozoans is very distinct from that of scyphozoans, and is used to catch prey (fish and small invertebrates which includes shrimp and bait fish) and for defense from predators, which include the Butterfish, Batfish ^{[disambiguation needed]}, Rabbitfish, crabs (Blue Swimmer Crab) and various species of turtles (Hawksbill turtle, Flatback turtle). Sea turtles, however, are apparently unaffected by the sting and eat box jellies.

The highest risk period for the box jellyfish is between October to May, but stings and specimens have been reported all months of the year. Similarly, the highest risk conditions are those with calm water and a light, onshore breeze; however, stings and specimens have been reported in all conditions.

Box jellyfish are abundant in the warm waters of northern Australia and Indo-Pacific. However, the swarms generally disappear during the Australian winter (though occasional individuals are found throughout the year). American researchers using ultrasonic ^{[disambiguation needed]} tagging reported that these creatures sleep on the ocean floor between 3 pm and dawn; it was believed that they sleep to conserve energy and to avoid predators. However, this 'sleep' hypothesis was challenged by many other researchers, and analysis of sting patterns demonstrated that a reasonably high proportion of stings occur within this time period. Furthermore, the small sample size in the "sleep experiment" (i.e., 1 of 3 total tested actually 'slept'), combined with the unusual feature of a large, metal sensor potentially weighting down the animals, led researchers to discount the hypothesis of sleep.

If swimming at a beach where box jellyfish are known to be present, a bottle of vinegar is an extremely useful addition to the first aid kit. Once a tentacle of the box jellyfish adheres to skin, it pumps nematocysts with venom into the skin, causing the sting and agonizing pain. Following a sting, vinegar should be applied for a minimum of 30 seconds, resulting in the removal of any unfired nematocysts. A box jellyfish sting can kill a human.^[5] Acetic acid, found in vinegar, disables the box jelly's nematocysts that have not yet discharged into the bloodstream (though it will not alleviate the pain). Vinegar may also be applied to adherent tentacles, which should then be removed immediately; this should be done with the use of a towel or glove to avoid bringing the tentacles into further contact with the skin. These tentacles will still sting if separated from the bell, or if the creature is dead. Removing the tentacles without first applying vinegar may cause unfired nematocysts to come into contact with the skin and fire, resulting in a greater degree of envenomation. If no vinegar is available, a heat pack has been proven for moderate pain relief.^[6] However, careful removal of the tentacles by hand is recommended.^[7] Vinegar has helped save dozens of lives on Australian beaches.

Although commonly recommended in folklore and even some papers on sting treatment,^[8] there is no scientific evidence that urine, ammonia, meat tenderizer, sodium bicarbonate, boric acid, lemon juice, freshwater, steroid cream, alcohol, cold packs, papaya, or hydrogen peroxide will disable further stinging, and these substances may even hasten the release of venom.^[9] Pressure immobilization bandages, methylated spirits, or vodka should never be used for jelly stings.^[7][10][11]

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