Carukia barnesi
| Carukia barnesi | ||||||||||||
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Carukia barnesi |
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| Scientific name | ||||||||||||
| Carukia barnesi | ||||||||||||
| Southcott , 1967 |
Carukia barnesi , also called Irukandji (in English Irukandji jelly fish), is a species of the class of box jellyfish (Cubozoa) within the cnidarians (Cnidaria). It occurs mainly in the Australian coastal waters, especially off Queensland and the Northern Territory . This species of jellyfish was discovered by the Australian doctor Jack Barnes in 1961 and named after him. The nettle poison of this type can cause the extremely painful Irukandji syndrome in humans.
features
Carukia barnesi has an umbrella that is typical of the box jellyfish and is almost square when viewed from above . It measures 1 to 2.5 cm in diameter, is almost transparent and has pronounced wart-like bumps on the top. The height is about 35 mm, measured from the lower edge of the screen to the apex of the screen. In contrast to other genera of the Carybdeidae family, the species does not have gastric phacellae, which are tentacle-like processes that extend into the gastric cavity. Four thin tentacles, which are also transparent, extend from the lower corners of the umbrella, from the muscle flaps (pedalia). The tentacles can reach a length of up to 100 cm. The tentacles are covered with nettle cells ; two types occur in this species: homotric, microbasic rhopaloids (type I), predominantly on the tentacles (98%), and homotric haplonemes (type II), predominantly on the screen (approx. ⅔). The stinging cells sit in a ring on the tentacles at intervals. The intervals become denser towards the point of attachment, towards the end of the tentacles the ring structures dissolve, i.e. H. the stinging cells are irregularly distributed. These ring structures, which are reminiscent of neck rings, are only known to date in Carukia barnesi . However, these structures are only prominently developed in adult medusas; young medusas have only short tentacles. Here, too, the stinging cells are roughly arranged in a ring, but not (yet) as concentrated in "neck rings" as in adult medusa. Juvenile medusa have relatively more stinging cells on the screen than adult specimens.
So far only juvenile and adult medusa stages of this type are known. The life cycle itself is still unknown, as it has not yet been possible to breed the animals in the aquarium.
Prey animals
So far little is known about the prey of Carukia barnesi in nature. Specimens of Acetes sibogae australis , a small marine shrimp species (order Decapoda, Fam. Segestidae) and larval specimens of Amphiprion sp. ( Anemonefish ) placed in a tank with adult Carukia barnesi . While not a single specimen of Acetes sibogae australis was caught during the observation period , the first specimen of Amphiprion was captured after just 5 minutes , and a second specimen from the same medusa just 4 minutes later. It is likely that adult Carukia barnesi jellyfish prefer to eat larval fish, while non-adult jellyfish tend to eat shrimp. This observation is derived from stomach contents at various stages of development.
Catching prey
The collar-like arranged nettle cells on the tentacles are of great importance for the medusa in catching prey. When the tentacles are stretched out, practically only these ring structures ("neck rings") are visible as dark spots. Jerky movements of the tentacles attract larval fish, presumably thereby imitating the prey of the fish larvae. The behavior of attracting fish rather than waiting for prey to swim by seems unique among box jellyfish; at least it has not yet been observed in any other species. Since the not yet adult medusas do not (yet) have these collar-shaped structures, they have to resort to other prey (shrimp). The change from shrimp to small fish as prey animals during ontogeny is explained by the fact that the fish have a higher nutritional value than the shrimp. It is "worthwhile" for the adult jellyfish to switch to this food with a higher energy content. The relatively higher number of nettle cells on the screen in juvenile specimens compared to adult specimens is explained by the fact that at this stage the tentacles are still short and weakly developed. It is known from other closely related species that newly metamorphosed medusas use their umbrella almost exclusively to catch prey. The nettle cells trigger on contact with the prey.
discovery
Carukia barnesi was discovered by searching specifically for her. Even before the species was discovered, Hugo Flecker named a number of different symptoms that had to be the result of a reaction of the organism to nettle poison (this was already known , for example, from contacts with the sea wasp Chironex fleckeri ) as Irukandji (later Irukandji syndrome). The name Irukandji is derived from an Aboriginal tribe that originally lived on the northeast coast of Queensland. It was suggested that the symptoms were caused by a previously unknown type of box jellyfish that is difficult to spot in open waters. In 1961 he succeeded in catching a previously unknown type of box jellyfish. In self-experiments he showed that she was responsible for Irukandji syndrome. The first scientific description was in 1967 by Ronald Vernon Southcott .
Toxicity and Hazardousness
So far it has not yet been possible to analyze the poison or the poisons of Carukia barnesi and to clarify their structure (s). The poisons of the nettle cells of the umbrella and the tentacles differ significantly, as do the poisons of different stages of development. What is certain, however, is that the poison contains a cardiotoxic component.
Despite its small size, Carukia barnesi must be classified as dangerous to humans. The sting of the jellyfish itself is hardly painful, but Irukandji syndrome occurs with a delay of about 30 to 60 minutes . Irukandji syndrome can be life-threatening in people with previous health problems without medical care. The application of vinegar, which is often recommended as an immediate measure after contact, to inactivate the nettle capsules, has meanwhile become controversial. It does not reduce the pain response. No antidote has yet been developed.
Systematics
Carukia barnesi is the type species of the genus Carukia Southcott, 1967 and was also the only species of the genus for a long time. It was not until 2005 that Lisa-Ann Gershwin described a second type of Carukia , C. shinju , which can also trigger Irukandij syndrome. The name Irukandji was initially limited to Carukia barnesi , as this species was thought to be the sole cause of Irukandji syndrome. It was only later found out that Irukandji syndrome can also be caused by other species of box jellyfish. The name Irukandji is therefore used in a broader sense in recent publications, i. e. for species that can cause Irukandji syndrome. The Irukandji species group or Irukandji species are also often referred to. However, it is not a systematic taxonomic group, since the species z. T. are not directly related to each other.
Use in film
In the episode 'Elternabend' (episode 11 of the 12th season) of the series SOKO Leipzig , the jellyfish is used for an attack.
The 4th episode of the Australian series Sea Patrol , in which three crew members come into contact with the poison of the jellyfish, is titled "Irukandji".
In the series 1000 Ways to Bite the Grass , an American student dies after swallowing an Irukandji jellyfish. This is death type # 389, which was titled Disquallified (sic!).
swell
literature
- Avril H. Underwood and Jamie E. Seymour: Venom ontogeny, diet and morphology in Carukia barnesi, a species of Australian box jellyfish that causes Irukandji syndrome. Toxicon , 49: 1073-1082, Oxford 2007 ISSN 0041-0101 doi : 10.1016 / j.toxicon.2007.01.014
- Ronald Vernon Southcott: Revision of some Carybdeidae (Scyphozoa: Cubomedusae) including a description of the jellyfish responsible for the 'Irukandji syndrome'. Australian Journal of Zoology 15 (3): 651-671 , Collingwood Victoria 1956 ISSN 0004-959X doi : 10.1071 / ZO9670651
Individual evidence
- ↑ Sharmaine Ramasamya, Geoffrey K. Isbistera, Jamie E. Seymour and Wayne C. Hodgson: The in vivo cardiovascular effects of the Irukandji jellyfish (Carukia barnesi) nematocyst venom and a tentacle extract in rats. Toxicology Letters , 155: 135-141, Amsterdam 2005 ISSN 0378-4274 doi : 10.1016 / j.toxlet.2004.09.004
- ↑ a b Types of Nematocysts at darwin.nhm.ku.edu ( memento of the original from June 24, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (English, accessed July 11, 2009)
- ^ Underwood and Seymour, pp. 1078/9
- ↑ Luca Cegolon, William C. Heymann, John H. Lange, Giuseppe Mastrangelo (2013): Jellyfish Stings and Their Management: A Review. Marine Drugs 11 (2): 523-550. doi : 10.3390 / md11020523 (open access)
- ↑ Teresa J. Carrette, Avril H. Underwood, Jamie E. Seymour (2012): Irukandji syndrome: a widely misunderstood and poorly researched tropical marine envenoming. Diving and Hyperbaric Medicine 42 (4): 214-223.
- ↑ Jamie E Seymour (2017): Are we using the correct first aid for jellyfish? Medical Journal of Australia 206 (6): 249-250. doi: 10.5694 / mja17.00053
- ↑ Lisa-Ann Gershwin: Two new species of jellyfishes (Cnidaria: Cubozoa: Carybdeida) from tropical Western Australia, presumed to cause Irukandji Syndrome. Zootaxa, 1084: 1-30, Auckland, NZ 2005 ISSN 1175-5326 PDF
