Jellyfish
Although most jellyfish live well off the ocean floor and form part of the plankton, a few species are closely associated with the bottom for much of their lives and can be considered benthic. The upside-down jellyfish in the genus "Cassiopea" typically lie on the bottom of shallow lagoons where they sometimes pulsate gently with their umbrella top facing down. The tiny creeping jellyfish "Staurocladia" and "Eleutheria" cannot swim, and "walk" around on seaweed fronds or rocky bottoms on their tentacles. Most hydromedusae and scyphomedusae that live in coastal habitats find themselves on the bottom periodically, where they may stop swimming for a while, and certain box jellyfish species also rest on the sea bed in shallow water. Even some deep-sea species of hydromedusae and scyphomedusae are usually collected on or near the bottom. All of the stauromedusae are found attached to either seaweed or rocky or other firm material on the bottom.
Cotylorhiza tuberculata
Cotylorhiza tuberculata is a species of jellyfish, of the phylum Cnidaria, also known as the Mediterranean jelly or fried egg jellyfish. It is commonly found in the Mediterranean Sea, Aegean Sea, and Adriatic Sea. It can reach 40 cm in diameter and is usually less than 17 cm wide. It seems that this jellyfish's sting has very little or no effect on humans. The cnidarian’s smooth, elevated central dome is surrounded by a gutter-like ring. Its marginal lappets are elongated and subrectangular. Each moutharm bifurcates near its base and branches several times. In addition to some larger appendages, there are many short, club-shaped ones that bear disk-like ends.
"C. tuberculata" are the most common jellyfish of their entire order in the Mediterranean Sea. They experience an annual life cycle marked by summer population blooms, which is likely an adaptive result of the strong seasonal changes in their Mediterranean environment. Their phases of development are quite similar to that of their other jellyfish counterparts. "C. tuberculata"s four main stages of growth include the swimming larvae known as planulae, younger, sessile polyps called scyphistomae, the undeveloped young adult intermediates known as ephyrae, and the adult jellyfish forms, called medusas. In a given year, planulae are present from August to November, scyphistomae are present perennially, ephyrae can be seen from May to August, and medusa are prominent from July to November.