Visualizza wikitesto di Box jellyfish

{{Disputed|date=October 2009}}
 {{Taxobox
| name = Box Jellyfish
| image = Chinorex_fleckeri.jpg
| image_width = 150px 
| image_caption = ''[[Chironex fleckeri]]''
| regnum = [[Animal]]ia
| phylum = [[Cnidaria]]
| classis = [[Cubozoa]]
| classis_authority = Werner, 1975
| subdivision_ranks = Orders
| subdivision = 
* [[Carybdeida]]
* [[Chirodropida]]
}}

'''Box jellyfish''', named for their vaguely [[cube]]-shaped [[medusa (biology)|medusae]], are a [[biological classification|class]] of [[invertebrates]] belonging to the phylum ''cnidaria'' ("box jellyfish" is a [[common name]] for the notoriously dangerous ''[[Chironex fleckeri]]''). Box jellyfish are known for the extremely potent [[venom (poison)|venom]] produced by some species. Along with ''Chironex fleckeri'', ''[[Carukia barnesi]]'' and ''[[Malo kingi]]'' are among the most venomous creatures in the world. Stings from these species are often fatal to prey animals, and extremely painful, but only occasionally fatal to humans.
==Nomenclature==

The ambiguous but commonly used terms "sea wasp," and "marine stinger" are sometimes used to refer to the more poisonous species of box jellyfish.

==Anatomy==
[[File:Haeckel Cubomedusae.jpg|thumb|150px|"Cubomedusae", from [[Ernst Haeckel]]'s ''[[Kunstformen der Natur]]'', 1904]]
Box jellyfish most visibly differ from the "true" or [[Scyphozoa]]n jellyfish in that their umbrellas are cubic, rather than domed or crown-shaped. The underside of the umbrella includes a flap, or ''velarium'', concentrating and increasing the flow of water expelled from the umbrella. As a result, box jellyfish can move more rapidly than other jellyfish, with speeds of up to six metres per minute having been recorded.<ref name=IZ>{{cite book |author= Barnes, Robert D. |year=1982 |title= Invertebrate Zoology |publisher= Holt-Saunders International |location= Philadelphia, PA|pages= 139-149|isbn= 0-03-056747-5}}</ref> 

Their nervous system is also more developed than that of many other jellyfish. Notably, they possess a nerve ring around the base of the umbrella that coordinates their pulsing movements; a feature found elsewhere only in the [[Coronatae|crown jellyfish]]. Whereas some other jellyfish do have simple pigment-cup [[ocellus|ocelli]], box jellyfish are unique in the possession of true eyes, complete with [[retinas]], corneas and [[lens_(anatomy)|lenses]]. These enable them to see specific points of light, as opposed to simply distinguishing between light and dark.

==Range==

Various types of box jellies can be found in northern [[Australia]], the [[Philippines]], [[Indonesia]], [[Hawaii]],<ref>[http://www.honolulu.gov/esd/oceansafety/boxjellymainpage.htm Jellyfish Predictions Waikiki, Hawai'i]</ref> [[Vietnam]], the [[Caribbean]], and other tropical areas.

==Defense and feeding mechanisms==
[[Image:JellyfishNetAustralia.JPG|thumb|right|250px|Jellyfish/stinger net enclosure at [[Ellis Beach, Queensland]]]]

The box jellyfish has been called "the world's most venomous creature."<ref>{{citeweb|url=http://www.telegraph.co.uk/travel/destinations/australiaandpacific/australia/7638189/Girl-survives-sting-by-worlds-deadliest-jellyfish.html|title=Girl survives sting by world's deadliest jellyfish|publisher=DailyTelegraph|accessdate=27-Apr-2010|date=27-Apr-2010}}</ref>
Each tentacle has about 500,000 [[cnidocyte]]s, harpoon-shaped needles that inject venom into the victim.<ref name="1996-Williamson">{{cite book | editor = Williamson JA, Fenner P J, Burnett JW, Rifkin J. | title = Venomous and poisonous marine animals: a medical and biological handbook | year = 1996 | publisher = Surf Life Saving Australia and University of New North Wales Press Ltd | isbn = 0-86840-279-6}}</ref> Most often, the fatal envenomations are perpetrated by the largest species of box jelly, ''[[Chironex fleckeri]]'', owing to its high concentration of [[nematocyst]]s, although at least two deaths in Australia have been attributed to the thumbnail-sized ''[[Carukia barnesi]]''.<ref name="MJA2002-fenner">{{cite journal | author = Fenner P, Hadok J | title = Fatal envenomation by jellyfish causing Irukandji syndrome | journal = Med J Aust | volume = 177 | issue = 7 | year = 2002 | url=http://mja.com.au/public/issues/177_07_071002/fen10297_fm.pdf | pmid = 12358578 | pages = (: 362–3}}</ref> Those who fall victim to ''C. barnesi'' suffer severe physical and psychological symptoms known as [[Irukandji syndrome]].<ref name="MJA1998-Little">{{cite journal | author = Little M, Mulcahy R | title = A year's experience of Irukandji envenomation in far north Queensland | journal = Med J Aust | volume = 169 | issue = 11–12 | pages = 638–41 | year = 1998 | url=https://www.mja.com.au/public/issues/xmas98/little/little.html | pmid = 9887916}}</ref>
The box jellyfish actively hunts its prey, rather than drifting as do true jellyfish. It is capable of achieving speeds of up to 4 [[knot (nautical)|knots]] (1.8 [[meters per second|m/s]]).{{Citation needed|date=October 2009}}

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]], {{dn|Batfish}}, [[Rabbitfish]], [[crabs]] ([[Portunus pelagicus|Blue Swimmer Crab]]) and various species of [[turtle]]s ([[Hawksbill turtle]], [[Flatback turtle]]). [[Sea turtle]]s, however, are apparently unaffected by the sting and eat box jellies.  

In northern Australia, the highest risk period for the box jellyfish is between October and 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.

==Taxonomy==

As of 2007, at least 36 species of box jellyfish were known, grouped into two orders and six families<ref name=Daly>{{cite journal | last = Daly | first = Marymegan | coauthors = et al. | title = The phylum Cnidaria: A review of phylogenetic patterns and diversity 300 years after Linnaeus | journal = [[Zootaxa]] | issue = 1668 | pages = 127-182 | year = 2007 | url = http://www.mapress.com/zootaxa/2007f/zt01668p182.pdf}}</ref>: 

Class '''Cubozoa'''
* Order [[Carybdeida]]
** Family [[Alatinidae]]
** Family [[Carybdeidae]]
** Family [[Tamoyidae]]
** Family [[Tripedaliidae]]
* Order [[Chirodropida]]
** Family [[Chirodropidae]]
** Family [[Chiropsalmidae]]

==Treatment of stings==
{{howto|section|date=March 2010}}
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.<ref name="MJA1989-Fenner">{{cite journal | author = Fenner P, Williamson J, Blenkin J | title = Successful use of Chironex antivenom by members of the Queensland Ambulance Transport Brigade | journal = Med J Aust | volume = 151 | issue = 11–12 | pages = 708–10 | year = 1989 | pmid = 2574410}}</ref> [[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<ref name="MJA1980-Hartwick">{{cite journal | author = Hartwick R, Callanan V, Williamson J | title = Disarming the box-jellyfish: nematocyst inhibition in Chironex fleckeri | journal = Med J Aust | volume = 1 | issue = 1 | pages = 15–20 | year = 1980 | pmid = 6102347}}</ref>; 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.

Although commonly recommended in folklore and even some papers on sting treatment,<ref>{{cite journal | author = Zoltan T, Taylor K, Achar S | title = Health issues for surfers | journal = Am Fam Physician | volume = 71 | issue = 12 | pages = 2313–7 | year = 2005 | pmid = 15999868}}</ref> there is no scientific evidence that [[urine]], [[ammonia]], [[meat tenderizer]], [[sodium bicarbonate]], [[boric acid]], [[lemon juice]], [[freshwater]], [[steroid hormone|steroid cream]], [[alcohol]], [[ice pack|cold packs]], [[papaya]], or [[hydrogen peroxide]] will disable further stinging, and these substances may even hasten the release of venom.<ref>{{cite journal | author = Fenner P | title =Marine envenomation: An update – A presentation on the current status of marine envenomation first aid and medical treatments | journal = Emerg Med Australasia | volume = 12 | issue = 4 | pages = 295–302 | year = 2000  | doi = 10.1046/j.1442-2026.2000.00151.x}}</ref> Pressure immobilization bandages, methylated spirits, or vodka should never be used for jelly stings.<ref name="MJA1980-Hartwick"/><ref name="Toxicon2002-Seymour">{{cite journal | author = Seymour J, Carrette T, Cullen P, Little M, Mulcahy R, Pereira P | title = The use of pressure immobilization bandages in the first aid management of cubozoan envenomings | journal = Toxicon | volume = 40 | issue = 10 | pages = 1503–5 | year = 2002 | pmid = 12368122 | doi = 10.1016/S0041-0101(02)00152-6}}</ref><ref>{{cite journal |author=Little M |title=Is there a role for the use of pressure immobilization bandages in the treatment of jellyfish envenomation in Australia? |journal=Emerg Med (Fremantle) |volume=14 |issue=2 |pages=171–4 |year=2002 |month=June |pmid=12164167 |doi= |url=}}</ref><ref>{{cite journal |author=Pereira PL, Carrette T, Cullen P, Mulcahy RF, Little M, Seymour J |title=Pressure immobilisation bandages in first-aid treatment of jellyfish envenomation: current recommendations reconsidered |journal=Med. J. Aust. |volume=173 |issue=11–12 |pages=650–2 |year=2000 |pmid=11379519 |doi= |url=http://www.mja.com.au/public/issues/173_11_041200/pereira/pereira.html}}</ref> Often in severe ''Chironex fleckeri'' stings, cardiac arrest occurs quickly, so [[cardiopulmonary resuscitation]] (CPR) can be life saving and takes priority over all other treatment options.

==References==
{{reflist|2}}

==Bibliography==
* {{cite journal | last = Daly | first = Marymegan | coauthors = et al. | title = The phylum Cnidaria: A review of phylogenetic patterns and diversity 300 years after Linnaeus | journal = [[Zootaxa]] | issue = 1668 | pages = 127–182 | year = 2007 | url = http://www.mapress.com/zootaxa/2007f/zt01668p182.pdf}}

* Gershwin, L. 2005a. Taxonomy and phylogeny of Australian Cubozoa. PhD, School of Marine Biology and Aquaculture, James Cook University, Townsville, Queensland.

* Gershwin, L. 2005b. Two new species of jellyfishes (Cnidaria: Cubozoa: Carybdeida) from tropical Western Australia, presumed to cause Irukandji Syndrome. Zootaxa 1084: 1–30.

* Gershwin, L. 2005c. ''Carybdea alata'' auct. and ''Manokia stiasnyi'', reclassification to a new family with description of a new genus and two new species. Memoirs of the Queensland Museum 51(2): 501–523.

* Gershwin, L. 2006a. Comments on ''Chiropsalmus'' (Cnidaria: Cubozoa: Chirodropida):  a preliminary revision of the Chiropsalmidae, with descriptions of two new species. Zootaxa 1231: 1–42.

* Gershwin, L. 2006b. Nematocysts of the Cubozoa. Zootaxa 1232: 1–57.

* Gershwin, L. 2007. ''Malo kingi'': A new species of Irukandji jellyfish (Cnidaria: Cubozoa: Carybdeida), possibly lethal to humans. Zootaxa 1659: 55–68.

* Gershwin, L. & Alderslade, P. 2006. ''Chiropsella bart'', n. sp., a new box jellyfish (Cnidaria: Cubozoa: Chirodropida) from the Northern Territory, Australia. The Beagle 22: 15–21.

==External links==
*[http://www.ucmp.berkeley.edu/cnidaria/cubozoasy.html Cubozoa classification]
*[http://library.thinkquest.org/C007974/2_1box.htm ThinkQuest: Box jellyfish, Boxfish, Deadly sea wasp]
*[http://www.jellyfishfacts.net/box-jellyfish.html Box Jellyfish – Jellyfish Facts]
*[http://www.barrierreefaustralia.com/the-great-barrier-reef/jellyfish.htm Box Jelly Fish, dangers on the great barrier reef]
*[http://pharyngula.org/index/weblog/comments/jellyfish_eyes/ Jellyfish eyes]
*[http://www.honolulu.gov/esd/oceansafety/boxjellymainpage.htm Jellyfish Predictions Waikiki, Hawai'i]
*[http://lifeinthefastlane.com/2008/12/box-jellyfish-chironex-fleckeri/ Box Jellyfish by an Australian toxicologist]



{{Animalia}}

{{DEFAULTSORT:Box Jellyfish}}
[[Category:Cubozoa| ]]
[[Category:Venomous animals]]

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[[ca:Cubomedusa]]
[[cs:Čtyřhranky]]
[[da:Havhveps]]
[[de:Würfelquallen]]
[[es:Cubozoa]]
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[[lt:Kubomedūzos]]
[[nl:Dooskwallen]]
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[[pl:Kostkowce]]
[[pt:Cubozoa]]
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[[uk:Кубомедузи]]
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