Portuguese Man of War (Physalia physalis) - stock photo

Over/under view of a Man of War, also known as Portuguese Man of War, Physalia physalis. The Man of War is a jelly-like marine invertebrate of the family Physaliidae. The name "man-of-war" is borrowed from the man-of-war, an 16th century English armed sailing ship, more than likely due to the bladder which acts as a sail for the marine organism. View shows both the air bladder keeping the organism afloat and the stinging tentacles. Winds, seas and currents drive the movement of this organism. It is not a true jellyfish, but a colonial organism, made up of many minute animals called zooids.