Mastigias papua is one of the numerous marine animals living in symbiosis with zooxanthellae, a photosynthetic alga.

Spotted jellies also acquire much of their nutrition via an endosymbiotic relationship with photosynthetic zooxathellae, such as those of the genus Cladocopium.

[5][7][8] Spotted jellies range throughout the Indo-Pacific, from the Fijian Islands to the western Indian Ocean, and from Japan to Australia.

[9] Some populations of spotted jellies in Palau have been found to occur in huge groups (called "smacks"), which have become tourist attractions.

[10][8] Spotted jellies are predated upon by the sea anemone Entacmaea medusivora, which capture the jellyfish in their tentacles.