Scyphozoa

See also: Jellyfish

The scyphozoaires (of the Scyphozoa ) are a Taxon animals Cnidaire S. They are generally called jellyfishes , although this term indicates also a particular stage in the reproductive life of the cnidaires. The jellyfishes are transparent and gelatinous organizations which can contain up to water 95%.

The majority of the scyphozoaires pass by the two stages polyp and jellyfish, with prevalence of the stage jellyfish.

There exist jellyfishes mortals like the Cuboméduse (Guêpe of the seas) or the Physalia ground cherry (Galère Portuguese) which can kill a man in a few minutes: a serum is now available. It is in the form of jellyfishes without veil contrary to the hydrozoaires.

Reproduction and Life cycle

The gonades of Scyphozoaires are of origin endodermal. The majority of the jellyfishes pass by two different forms during their life cycle:

  • first is planktonique, the free form jellyfish,
  • second is Benthique, the form Polype which is fixed.

The fixed stage is represented by a polyp called Scyphistome, generally recluse. This last product of young jellyfishes (éphyrule S) by Strobilation: the animal buds while outputting itself by section at the upper part of the body. The scyphistome is not sexué, but a kind of Larve persistent, while the Scyphoméduse grows while changing to allow the reproduction.

Jellyfishes of the French coasts

Close to the island of Oléron, one particularly distinguishes two types of jellyfishes. It is first of all about the common jellyfish ( Rhizostoma pulmo ). This one can reach 90 centimetres and its death does not prevent its many tentacles from causing violent burns. This animal is of white color. The other type is the blue Jellyfish ( Aurelia aurita ). This one is much smaller since it measures 25 centimetres on average. It is strewn with blue features, from where its name. It is quite as poisonous as the preceding one. For the punctures of the most current jellyfishes such as those which currently infest water of the Mediterranean, the simplest way of constraster the effect of toxins, is to expose the zone reached to the heat (warm water, roller heated by the sun) which destroys the molecules responsible for cutaneous irritation. However, there exist also very effective ammonia sticks to blur the pain.

Classification

According to ITIS:
  • order Coronatae
    • family Atollidae
    • family Atorellidae
    • family Collaspididae Haeckel, 1880
    • family Linuchidae
    • family Nausithoidae
    • family Paraphyllinidae
    • family Periphyllidae
  • subclass Discomedusae

According to ADW:

  • order Coronatae
    • family Atollidae
    • family Atorellidae
    • family Collaspididae
    • family Linuchidae
    • family Nausithoidae
    • family Paraphyllinidae
    • family Periphyllidae
    • family Tetraplatidae
  • order Rhizostomatida
    • family Archirhizidae
  • order Rhizostomeae
  • order Semaeostomeae
  • order Stauromedusae
    • family Cleistocarpidae
    • family Eleutherocarpidae
    • family Kyopodidae
    • family Tesseranthidae

External bonds

  • See a detailed diagram of the Jellyfish
  • vital Cycle of a jellyfish
  • Hydraires with the Meeting and in the Indian Ocean

Simple: Jellyfish

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