Moon jellyfish often live in large groups in the sea. You can easily identify them by their four moons' in the middle. These are the reproductive organs. Males have white and females have pink moons'. Moon jellyfish have short tentacles along the edge of the bell and four short arms situated around the mouth for catching food. The tentacles of the moon jellyfish are poisonous for small marine animals but people are not affected by the toxin since it does not penetrate the skin.