How does the hydra use the nematocysts?

Hydra use nematocysts, specialized stinging cells, primarily for capturing prey and defense. When a potential prey, such as small aquatic animals, comes into contact with the tentacles of the hydra, the nematocysts release a coiled thread that can inject toxins and immobilize the prey. This allows the hydra to secure its food and facilitate digestion. Additionally, nematocysts serve as a deterrent against predators, helping to protect the hydra from being eaten.