In size, jellyfish can range from one millimeter to 16 inches. Portuguese man o’ war’s feeding tentacles can measure up to 160 feet (50 meters) in length.
In terms of color, jellyfish can come in a wide range of hues from yellow to deep blue to vivid purple to pale lilac to bright orange to deep red. The blue, violet, or pink float of the man o’ war resembles a Portuguese naval ship under full sail from the 18th century, hence the name.
Having a smooth body with small tentacles, jellyfish can sting other organisms. They lack bones, brains, hearts, and eyes. The Portuguese man o’ war is a siphonophore, a group of specialized animals called zooids that act together.