Nematocysts are specialized cells found in certain animals, particularly in jellyfish, corals, and sea anemones. These tiny, stinging structures are used for capturing prey and defending against predators. When triggered, a nematocyst can rapidly eject a barbed thread that can inject toxins into its target, immobilizing it for easier consumption. These remarkable cells are a key feature of the cnidarian phylum, which includes a wide variety of marine organisms. Nematocysts come in different types, each adapted for specific functions, such as paralyzing prey or deterring threats. Their unique mechanism showcases the fascinating adaptations of life in the ocean.