Jellyfish (also known as jellies or sea jellies) are free-swimming members of the phylum Cnidaria. They have several different morphologies that represent several different cnidarian classes including the Scyphozoa (over 200 species), Staurozoa (about 50 species), Cubozoa (about 20 species), and Hydrozoa (about 1000-1500 species that make jellyfish and many more that do not). The jellyfish in these groups are also called, respectively, scyphomedusae, stauromedusae, cubomedusae, and hydromedusae; medusa is another word for jellyfish.
Jellyfish at Monterey Bay Aquarium.
Australian Blue Jelly
Aurelia aurita at Aquarium Finisterrae, La Coruña, Spain.
flower hat jelly (Olindias formosa)
Diningroom table jellyfish.
Jellyfish at London Zoo.
Spooky Jellyfish.Taken at the Monterey Bay Aquarium.
"Jellyfish are marine invertebrates belonging to the class Scyphozoa of the phylum Cnidaria. They can be found in every ocean in the world and in some fresh waters. The use of the term "jellyfish" is actually a misnomer since scyphozoans are not fish, which are vertebrates. Although incorrect, the term is also commonly-applied to some close relatives of true scyphozoans, such as the Hydrozoa and the Cubozoa."
Jellies at Monterey aquarium, California.
Sea Nettle. Mystic Aquarium & Institute for Exploration.
Jellyfish at the Oregon Aquarium in Newport, Oregon, US.
Cephea cephea in Mactan Cebu, Philippines.
Jelly in the Vancouver aquarium.
Jellyfish. Taken in the aquarium in Osaka.
The Stinger. Just because you don't have a brain, backbone, central nervous system, eyes or arms; doesn't mean you can't be a killer in the sea.
Jellyfish at Boston Aquarium.
The power within.