A cnidocyte is a specialized cell found in members of the phylum Cnidaria, which includes organisms like jellyfish, corals, and sea anemones. These cells are primarily responsible for capturing prey and defense. Cnidocytes contain structures called nematocysts, which are tiny, harpoon-like organelles that can inject toxins into other organisms. When triggered, a nematocyst rapidly ejects, allowing the cnidocyte to immobilize or deter potential threats or prey. This unique mechanism is essential for the survival of Cnidaria species, enabling them to thrive in various aquatic environments.