The Butterflies of the Sea

This photo is taken on January 2013 in Barcelona's Aquarium.During their life cycle many jellyfish have two different life forms, just as butterflies and caterpillars are two different forms, so we could call them butterflies of the sea. One life form is fixed to the seabed, the polyp, and the other, the jellyfish, lives freely in the open sea where it moves on the marine current. Adult jellyfish reproduce sexually and create larvae, the planulas, which attach themselves to the sea bed to form polyps. These polyps reproduce asexually through a germination process and under certain environmental conditions will generate the small ephyras that eventually become jellyfish.