Portuguese Man-of-War 

Anyone unfamiliar with the biology of the venomous Portuguese man-of-war would likely mistake it for a jellyfish. 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 comprises four separate polyps. It gets its name from the uppermost polyp, a gas-filled bladder, or pneumatophore, which sits above the water and somewhat resembles an old warship at full sail. Man-of-wars are also known as bluebottles for the purple-blue color of their pneumatophores.

A Portuguese man-of-war is actually a colony of individual organisms called polyps.

The tentacles are the man-of-war's second organism. These long, thin tendrils can extend 165 feet in length below the surface, although 30 feet is more the average. They are covered in venom-filled nematocysts used to paralyze and kill fish and other small creatures. For humans, a man-of-war sting is excruciatingly painful, but rarely deadly. But beware-even dead man-of-wars washed up on shore can deliver a sting.

The tentacles of the Portuguese man-of-war are painfully venomous.

Man-of-wars are found, sometimes in groups of 1,000 or more, floating in warm waters throughout the world's oceans. They have no independent means of propulsion and either drift on the currents or catch the wind with their pneumatophores. To avoid threats on the surface, they can deflate their air bags and briefly submerge.

A Portuguese man-of-war's tentacles can be up to 165 feet long.

Each of the four specialized parts of a man o' war is responsible for a specific task, such as floating, capturing prey, feeding, and reproduction. Found mostly in tropical and subtropical seas, men o' war are propelled by winds and ocean currents alone, and sometimes float in legions of 1,000 or more!