Why they're awesome: The largest animal on Earth is thought to be the blue whale, but these strange sea creatures can grow ...

This beautiful siphonophore, Pyrostephos vanhoeffeni, is typically encountered in Antarctic waters. Siphonophores are not an individual animal, but a colony of individuals that all serve a ...

Not only is it not a jellyfish, it's not even an "it," but a "they." The Portuguese man-of-war is a siphonophore, an animal made up of a colony of organisms working together. The man-of-war ...