Very colorful, this jellyfish phosphoresces when disturbed and can leave a luminous mucous behind if handled. It is called the "mauve jelly" by the British and Pellagia Noctiluca by the locals. Also known as the oceanic jelly, this species is adapted to life in the open water. It is in the class Scyphozoa, the true jellyfish. The estimated lifespan of Pelagia noctiluca is two to six months, and death is usually caused by rough waters.The habitat is primarily pelagic, or in the open ocean. However, this species can survive almost anywhere ocean currents carry it, including benthic and temperate coastal habitats.Jellyfish sometimes form shoals, or large groups. Pelagia noctiluca has appeared in shoals 45 kilometers in length, with thousands of jellyfish involved.The adults, which have separate sexes, reproduce sexually by releasing gametes from gonads located near the center of the body. The ova and sperm are released through the mouth of the jellyfish, and fertilize externally. Each fertilized egg forms a planulae, an undifferentiated mass of cells that swims with external cilia. Planula may be widely dispersed by oceanic currents. Unlike other species which have a bottom-dwelling polyp stage, Pelagia noctiluca's planulae develop directly into ephyrae, young medusae. The ephyrae quickly grows into an adult medusa, completing the life cycle.Carnivorous like other Cnidarians, this species preys mainly on zooplankton, small fish, crustaceans, other jellyfish, and eggs. Pelagia noctiluca captures its prey with tentacles armed with cnidocytes, each of which contains a nematocyst. Nematocysts have barbed filaments to trap their prey and toxins to stun them. They can even pierce the shell of a crab with their barbs. Food is digested intracellularly as well as extracellularly, in a gut cavity, enabling them to eat multicellular animals.