In their experiments on the freshwater polyp Hydra, the research team of Assistant Professor Dr. Suat Özbek and Prof.Dr. Thomas Holstein at the Centre for Organismal Studies (COS) demonstrated that cnidoin is part of the cnidarian weaponry -- the stinging capsules.
These organelles help jellyfish, corals and sea anemones capture prey and ward off enemies. When touched, a tubule is ejected within nanoseconds in a harpoon-like fashion from the interior of the highly pressurised capsule.
The discharge of the stinging thread is one of the fastest processes known in the animal kingdom. Its barbed tip injects poisons through the stinging thread that paralyse or kill the attacker or prey within seconds. "Cnidoin is a structural component of the capsule wall, which is elastically stretched prior to discharge and firing of the harpoon," explains Dr. Özbek.