Shore Buddies Wisdom Wednesday
Photo by Chelle Blais
It’s not a jellyfish! The Portuguese Man o’ War may look like a bloated jellyfish, but it’s actually a siphonophore—a bizarre group of animals that consist of colonies made up of dozens, hundreds, or even thousands of genetically-identical individual creatures. These colonies spend a lot of time floating at the water’s surface, and when the gas bladder is expanded, it looks—and acts—a bit like a sailboat, hence the “Man O’ War.” Man O’War tentacles can be up to 165 feet long! At least, that’s the maximum length for the dactylozooids—which are normally around 30 feet long and use venom-spewing cells to deliver painful, neurotoxic stings. When a tentacle is detached from the rest of the colony, it might wash ashore somewhere or drift around for days on end until it decomposes. Be warned: Even a severed tentacle can sting you. Some fish live in them! Given that tiny fish make up about 70 to 90 percent of the Man O’ War’s diet (it also eats shrimp and other crustaceans), the Portuguese Man O'War Fish is playing a dangerous game: It lives among the siphonophore's tentacles even though it's not immune to its stings, swimming nimbly between the stingers. Young fish eat planktons which wander under their hosts and, as they get older, will sometimes steal the Man O’ War’s prey—or nibble on its tentacles.