Over the weekend, there have been sightings of “Fried Egg Jellyfish” (Phacellophora camtschatica) around Santa Ponsa, standing out due to their distinctive appearance and size, with witnesses reporting that “there were loads” in the area. This species is easily recognisable by its large, translucent bell, often reaching up to 60 cm in diameter, with a striking yellow center resembling an egg yolk—hence its nickname. Although more commonly found in cooler northern Pacific waters, these jellyfish have been increasingly observed in Mediterranean areas like Mallorca, possibly due to changing oceanic conditions.
Despite its impressive size and numerous long tentacles, the fried egg jellyfish is generally not considered dangerous to humans. Its sting is relatively mild compared to other jellyfish species, like the Lion’s mane jellyfish or the box jellyfish, and typically causes only minor skin irritation or a slight rash if contact occurs. This weak sting is part of why various small marine creatures, such as larval crabs and amphipods, are able to live on and around the jellyfish without harm. However, as with any jellyfish, it is advisable to avoid direct contact to prevent any possible allergic reactions or discomfort. Overall, the fried egg jellyfish poses little threat to swimmers or beachgoers.
Jellyfish populations (including the egg-yolk jelly) are on the rise in degraded areas as a result of increased tolerance to detrimental factors. Additionally, jellyfish play a large role in the food web and can serve as indicators of ecosystem structure and function; The larger the jellyfish population, the greater the negative impact on ecosystem services.
The fried egg jellyfish typically moves faster during the day and swims fastest during flood tides. This jellyfish undergoes vertical migrations that span the water column throughout short and long time frames. These vertical migrations allow them to enter the low depth of the hypoxia zone. This genus typically resides below the pycnocline and avoids crossing the boundary layer, but they often dive into the hypoxic layer during the day when competition is high.
By diving deep into the hypoxia zone, the fried egg jellyfish evades competition; unlike other species where hypoxia generally causes species to move away from the oxygen depleted zone, the fried egg jellyfish is able to withstand low oxygen levels for several hours at a time. And, with the belief that hypoxia regions will continue to grow, the fried egg jellyfish could thrive.