Movement of a moon jellyfish (Aurelia aurita) by rhythmic contraction of the muscles at the edge of the umbrella, filmed at the GEOMAR Aquarium in Kiel, Germany.
<a href="//commons.wikimedia.org/wiki/User:C.Reinboth" title="User:C.Reinboth">Christian Reinboth</a>
CC BY 4.0
<span class="int-own-work" lang="en">Own work</span>