Medusa (installation) - 2007 Murano glass Format variable Exhibition view: Medusa, Secession, Vienna, 2007. The pink jellyfish Pelagia noctiluca is currently forming rapidly growing overpopulations. For lack of natural enemies such as turtles and tuna fish, whose populations have seriously decreased due to over-fishing and water pollution, as well as rising water temperatures which are ascribed to the climate change, it finds optimal reproduction conditions in European waters. Its function for the marine biology has been explored by natural history museums for a fairly long time by means of preparing exemplars in alcohol. Thanks to its aesthetic properties, glass reproductions of this species can be found in souvenir shops in many popular seaside resorts.