nematocyst

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nem·a·to·cyst

(nem'ă-tō-sist),
A stinging cell of coelenterates consisting of a poison sac and a coiled barbed sting capable of being ejected and penetrating the skin of an animal on contact; of considerable consequence in large jellyfish and in the Portuguese man-of-war which possess large numbers of these stinging cells that can cause great pain and even death.
Synonym(s): cnida, cnidocyst
[nemato- + G. kystis, bladder]

nematocyst

(nĕm′ə-tə-sĭst′, nĭ-măt′ə-)
n.
A capsule within specialized cells in the tentacles of cnidarians, such as jellyfish and corals, containing a barbed, threadlike tube that delivers a toxic sting to predators and prey.

nem′a·to·cys′tic adj.

nem·a·to·cyst

(nem'ă-tō-sist)
A stinging cell of coelenterates consisting of a poison sac and a coiled barbed sting capable of being ejected and penetrating the skin of an animal on contact; of considerable consequence in large jellyfish and in the Portuguese man-of-war whose large numbers of these stinging cells can cause great pain and even death.
[nemato- + G. kystis, bladder]

nematocyst

A coiled, tube-like stinging organ of various coelenterates, such as jellyfish. The nematocyst injects a chemical paralyzant.
Nematocystclick for a larger image
Fig. 227 Nematocyst . Nematocysts of Hydra. (a) Discharged. (b) Undischarged.

nematocyst

a structure formed of a hollow thread within a bladder in the CNIDOBLAST or thread cell of COELENTERATES. On stimulation, for example by prey, the thread is everted. Several types exist, such as stinging cells that inject poisonous substances into the prey through the thread, and sticky cells which exude a sticky substance which causes the prey to adhere to the coelenterate tentacle. Enormous numbers are present on the tentacles of some forms and nematocysts are responsible for the jellyfish ‘sting’. Such cells can be utilized by other organisms, for example flatworms preying on coelenterates. The nematocysts migrate to the surface layer of a flatworm which has fed on the coelenterate and are used by the flatworms in exactly the same way as coelenterates use them.
References in periodicals archive ?
In seawater alone and in the absence of vibrations, test probes touched to tentacles had a mean ([+ or -]SEM) number of discharged nematocysts of 18 [+ or -]2 per field of view (controls) (Fig.
An analysis of the nematocysts of the beadlet anemone Actinia equina and the green sea anemone Actinia prasina.
like flushing with sea water, using tweezers or scraping off with a card, should be done carefully as it carries the risk of further discharge of nematocysts. [20] The application of vinegar and an ice pack to the local area to reduce pain is recommended.
Keywords: Envenomation, Jellyfish, Nematocyst, Treatment, Turkey
Venom was extracted from freeze-dried nematocysts using the technique described by Seymour et al.
Despite popular belief, chemicals such as alcohol, meat tenderiser, ammonia or baking soda should not be applied, as they only encourage more discharge by the nematocysts.
It is armed only by absorbing nematocysts, which are stinging cells borrowed from the hydra, and emigrating them to its ectoderm.
Sketch the Portuguese Cnidaria slide man of war tentacle, Portuguese man of war labeling the nematocysts. slide 2.
Each is tipped with stinging nematocysts. "These capsules contain darts and are filled with toxins and can be very nasty," says Rodriguez.
Remember, a lot of the stinging nematocysts have been "knocked out" by the vinegar.