Scyphozoans are a marine class of invertebrates known as the ‘true jellyfish’. The name comes from the Greek word skyphos (σκύφος), a type of two-handled wine cup. The name evokes the cup shape of the organisms bell. Scyphozoan is both a noun and an adjective and entered the English lexicon in its current spelling in 1915 (A. E. Shipley and E. W. Macbride · Zoology · Ed. 3, 1915).
The Black Sea Nettle (Chrysaora achlyos) is a a giant jelly from this class. Although little is known about this jellyfish, it is believe to be found mostly in the deeper, calmer waters of the Pacific Ocean around Mexico and Baja California. The bell diameter can be up to 1 meter and oral arms extending to 5 or 6 meters. A carnivorous jellyfish, its long tentacles (up to 2.4 meters long when extended) catch pray such as plankton and other jellies. The Black Sea Nettle provides food and shelter for the Pacific Butterfish, which feeds on the plankton gathered by the jelly and hides inside the jelly’s bell when in danger.
You can watch the mesmerizing movements of this jellyfish here: