Mediterranean Fried Egg Jellyfish

About

The Mediterranean fried egg jellyfish (Cotylorhiza tuberculata) is one of those animals that stops people in their tracks the moment they see it. The bell is pale yellow to cream with a raised, yolk-like dome at the center, ringed by a flattened margin and fringed with short, club-tipped oral arms and small trailing tentacles in purple and yellow hues. The resemblance to a sunny-side-up egg is genuinely uncanny. In the wild this species drifts through the open waters of the Mediterranean and Adriatic Seas, typically in late summer and autumn when blooms can be large enough to clog fishing nets. In captivity, it is exclusively a kreisel-tank animal. The gentle circular current of a kreisel keeps the bell suspended and prevents it from being damaged against walls or equipment. It absolutely cannot be housed with fish, which will nip at its delicate tissues. Feeding requires live or appropriately sized prepared foods delivered into the water column. The entire lifespan runs roughly a year, so what you are keeping is essentially a living annual. This is firmly expert-level territory: water quality must be pristine, flow carefully calibrated, and husbandry consistent. For those willing to invest in proper setup, though, few animals are more striking to watch.