Physalia physalis also known as the Portuguese Man O' War is commonly mistaken for a jellyfish. "The Portuguese man-of-war is a siphonophore, an animal that is made up of a colony of organisms working together. The name comes from the uppermost polyp, a gas filled bladder, or pneumatophore, which sits above the water and somewhat looks like an old warship at full sail. They are also, known as bluebottles for the purple-blue color of their pneumatophores" (A Portuguese man of war). The tentacles can extend to 165 feet, although, the average length is 30 feet (Portuguese Man-of War Physalia physalis).