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The stinging cell of a cnidarian contains a sac that houses a coiled up tube, immersed in venomous toxins. When triggered to fire by touch, chemical stimuli, and/or nerve excitation, a hinged lid opens, the tube rapidly shoots out of the sac by eversion (turning inside out), penetrates the skin of its victim, and introduces its venom along the entire length of the tubule. When large numbers of these stinging cells deliver a sufficient amount of venom, the prey (or predator) is paralyzed and can no longer cause damage to the fragile jellyfish.
The entire evagination process only takes a millisecond or two. These stinging cells are some of the most sophisticated in the entire animal kingdom. They fire only once and then are re-adsorbed, to be eventually replaced by a brand new stinging cell. New nematocyte stinging cells (containing the nematocyst sac organelle) are created near the base of a tentacle from interstital stem cells. They migrate down the tentacle while developing the complex internal nematocyst structure, and eventually distribute themselves into a species specific pattern along the tentacle.
Wiki User
∙ 11y ago
Wiki User
∙ 11y agoA cnidocyte, cnidoblast or nematocyte, is a type of venomous cell unique to the phylum Cnidaria (corals, sea anemones, hydrae, jellyfish, etc.). It evolved in these aquatic animals as a means for them to catch prey and defend themselves from predators, despite being morphologically simple, lacking a skeleton and usually being sessile; they prey on fish and crustaceans. A cnidocyte fires a structure that contains the toxin, from a characteristic sub-cellular organelle called a cnidocyst (or cnida or nematocyst). This is, for instance, responsible for the stings delivered by jellyfish.
Each cnidocyte cell contains an organelle called a cnidocyst, which comprises a bulb-shape capsule containing a coiled hollow thread-like structure attached to it. The externally-oriented side of the cell also has a hair-like trigger called a cnidocil. When the trigger is activated, the shaft of the cnidocyst penetrates the target organism, and the hollow thread is everted into it. This discharge is one of the fastest biological processes, takes no more than a few microseconds, and reaches accelerations of about 40,000g[1]. However, it has recently been shown to occur as fast as 600 nanoseconds, thus reaching an acceleration around five million G's. After penetration, the toxic content of the nematocyst is injected into the target organism. The rapid activity of the injected neurotoxins immediately paralyzes the mobile prey, thus allowing the sessile cnidarian to devour it. For otherwise this process is used for mating rituals.
Wiki User
∙ 14y agoCnidarians use their stinging cells for capturing food and defense.
Wiki User
∙ 14y agoi think it might me a form a defence
Wiki User
∙ 11y agocnidocytes
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What is a capsule on a cnidarians tentacle called?
Nematocysts
What is one type of cell all cnidarians have?
Cnidarians all have stinging cells called nematocysts with which to catch their prey.
What do cnidarians use to defend themselves?
cnidarians have stinging cells called nematocysts located on their tantacles
What type of animal uses toxins on nematocysts to capture prey?
jellyfish and mosquitoes are two creatures that have nematocust a stinging cell used by animals hunting and stunning their prey
Where are the nematocysts of the hydra located?
The nematocysts are stinging cells of cnidarians located all along the feeding tentacles. These cells are inverted "harpoons" that react physically and chemically to stimuli at a speed of 1/1000th of a sec.
How does a starfish protect itself from other animals?
Starfish are cnidarians. They have spiny skin, some have nematocysts (stinging cells) and are generally toxic.
What two functions do nematocysts perform?
Nematocysts are the stinging cells on tentacles of a cnidarian, like a jellyfish. Since jellyfish don't have any teeth, and their body consists of gelatin, it's hard to capture prey. Nematocysts help jellyfish with feeding by stinging the prey in an attempt at trying to immobilizing the prey.
What anamiles haves pecialized stinging cells called nematocysts?
Nematocysts are specific to the phylum Cnidaria, which contains sea anemones, corals, and jellyfish, along with some less well-known animals. Nematocysts are the most common form of cnidocytes, the general term for the stinging cells all cnidarians possess.
Explain cnidocytes their nematocysts function in food capture and defense?
As to the functions: stinging nematocysts function primarily for the capture of prey, and secondarily as a defense mechanism. There are many types of nematocysts, such as those that function to inject toxins to immobilize prey, and those which serve to entangle and hold onto the intended meal by wrapping around it. Species of cnidarian jellies vary in the types of nematocysts they possess, and this can be used to some extent in classifying and identification.
How do cnidarians catch there pray?
The nematocysts allow the animal to hold the prey and venom is injected. The venom is often a neurotoxin that disables the prey and prevents too much damage to the soft bodied cnidarian. There are also chemicals injected that begin the digestion process. When the prey is ingested, more digestive chemicals are used.
What are three characteristics that all cnidarians have in common?
All cnidarians live in water, have tentacles with specialized stinging cells called nematocysts, and have an internal sac for digestion which is called the gastrovascular cavity.
What are three characteristics that all have in common?
All cnidarians live in water, have tentacles with specialized stinging cells called nematocysts, and have an internal sac for digestion which is called the gastrovascular cavity.
