Fried Egg Jellyfish, sometimes also called Egg-Yolk Jellies, are jellyfish that sport a smooth translucent bell that has an elevated yolk-yellow bell at the center. This distinctive bell is what gives this jellyfish their name, as it looks like a cracked egg floating through the water.
This jellyfish spends a lot of time motionless, slowly pulsing the bell while drifting. The numerous short, club-like appendages extending from it contain mouth-arm openings through which the jellyfish traps prey and feeds.1 The primary prey of the Fried Egg Jellyfish is zooplankton and other jellyfish.
These appendages are usually colored a deep purple and while stingers are present, the sting has very little effect on humans. Its sting is so mild that the tentacles sometimes provide shelter to small fish in the open ocean.
Despite spending a fair amount of time motionless, the jellyfish can swim actively. The smooth rounded bell at the top can reach up to 35cm in diameter3 and pulses as it swims. The ends of this bell extend into sub-rectangular, often uneven lappets.
Cotylorhiza tuberculata is one of a couple species called Fried Egg Jellyfish and is most commonly seen in the Mediterranean Sea. Another is Phacellophora camtschatica, a larger jellyfish that can be found worldwide.
Like all jellyfish, including Moon Jellies and Sea Wasps, the populations of the Fried Egg Jellyfish ebbs and flows. This can sometimes mean massive swarms of these jellyfish in the water during the summer months, such as in July 1974 where blooms of Cotylorhiza tuberculata were reported to stretch for several kilometers along the Israeli coast.3
1. Sometimes small animals like crabs hitch a ride on top of and inside the jellyfish’s bell, tucked away from the stingers.2
2. Fried Egg Jellyfish only live for about half a year, from summer to winter.1
3. They reproduce in warm waters, asexually producing tiny medusae (aka baby jellies).
4. Primarily found in the Mediterranean, Adriatic, and Aegean Seas, but can sometimes swim out to the Atlantic Ocean.
5. Researchers think their short life cycle is an adaption to their highly seasonal environment.1
Oceana joined forces with Sailors for the Sea, an ocean conservation organization dedicated to educating and engaging the world’s boating community. Sailors for the Sea developed the KELP (Kids Environmental Lesson Plans) program to create the next generation of ocean stewards. Click here or below to download hands-on marine science activities for kids.