A Mastigias papua is reflected on the surface of the "Jellyfish lake" on the island of Eli Malk in Palau (Micronesia). This lake and very particular: it is inhabited only by two types of jellyfish, some fish and some anemone (Entacmea medusivora). Having no enemies from which to protect the jellyfish have lost their stinging power. The lake is literally flooded with thousands and thousands of these Scifozoi. It is not possible to dive in this lake: more than 15 meters deep in fact, for chemical reasons, the water contains fatal percentages of hydrogen sulfide.