Hypotoxin a poisonous fluid for prey that kill th prey so it is called as poisonous fluid.

The poisonous fluid of Hydra's nematocyst is called hypnotoxin. Let us understand this in detail:

Hydra and Nematocysts:
Hydra is a freshwater invertebrate belonging to the phylum Cnidaria. It has tentacles around its mouth that are used to capture prey. The tentacles contain stinging cells called nematocysts. Nematocysts are unique to cnidarians and are used for defense, capturing prey, and movement.

Composition of Nematocysts:
Nematocysts are composed of a capsule and a coiled thread. The thread is covered with tiny barbs and lined with toxic fluid. When the nematocyst is triggered, the capsule explodes, and the thread is propelled outwards, injecting the toxin into the target.

Hypnotoxin:
Hypnotoxin is the toxic fluid present in the coiled thread of the nematocyst. It is a type of neurotoxin that affects the nervous system of the prey. The toxin binds to specific receptors on the prey's nerve cells, disrupting the normal functioning of the nervous system. This leads to paralysis and ultimately death of the prey.

Difference between Toxin and Venom:
Toxin and venom are often used interchangeably, but they have different meanings. Toxins are substances produced by living organisms that are harmful to other organisms. Venom, on the other hand, is a type of toxin that is injected into another organism through a bite or sting.

Hydra's Nematocysts and Hypnotoxin:
Hydra's nematocysts contain hypnotoxin, which is a type of venom. When the tentacles of the Hydra come into contact with the prey, the nematocysts are triggered, and the hypnotoxin is injected into the prey. This paralyzes the prey, making it easier for the Hydra to capture and consume it.

Conclusion:
In conclusion, the poisonous fluid of Hydra's nematocyst is called hypnotoxin, which is a type of neurotoxin that affects the nervous system of the prey. It is a type of venom that is injected into the prey through the nematocysts.