The fascinating shape of Fried Egg Sea Jellies hides an intriguing biology. They have many short appendages, usually coloured deep purple, with mouth openings to capture prey. Their bells are made up of three layers: the epidermis, which houses a basic nervous system; the mesoglea, a jelly-like layer that gives structure; and the gastrodermis, the innermost layer that helps nutrient exchange.

Fried Egg Sea Jellies host specialised algae called zooxanthellae in their tissues. In this unique partnership, also known as mutualism, the algae produce food through photosynthesis and share the nutrients with the sea jellies, while the sea jellies provide a safe place for the algae to live in. They also catch a variety of plankton using their distinctive appendages.

Populations rise and fall naturally with changing ocean conditions—but human activities may be driving unusually large blooms. Since this species reproduces in warm waters, rising ocean temperatures could make blooms more frequent. Runoff from coastal activities, like farming, adds nutrients that may also fuel rapid growth.