A cnidocyte is found in members of Phylum Cnidaria and are stinging cells. These can be found on the tentacles which are arranged in circles around their mouths. A nematocyst is coiled within a cnidocyte and contains a hooked barb. When an organism accidently brushes against the trigger of the nematocyst, the filament inside becomes uncoiled. A dart-like barb shoots into the prey and when it is discharged, a nerve toxin is released and causes the prey to become paralyzed. This helps initiate a feeding reflex in such Cnidarians as jellyfish, hydra and sea anemones.