Each cnidae is located within a specialized cell that houses it, this cell is a capsule with an attached hollow thread. Nematocyst is the more familiar term applied to specialized cnidae that are characteristic of scyphozoan and other types of jellies, and other cnidarians. As to the functions: stinging nematocysts function primarily for the capture of prey, and secondarily as a defense mechanism. There are many types of nematocysts, such as those that function to inject toxins to immobilize prey, and those which serve to entangle and hold onto the intended meal by wrapping around it.