Portuguese Man O’ War

I was once asked if I would rather swim in shark infested waters or Portuguese man o’ war infested waters. I definitely hesitated on my answer. The Portuguese man o’ war is highly venomous and can deliver a painful sting that can occasionally be fatal to humans. It is named after the 18th century Portuguese armed sailing ships because it was thought to resemble one when floating on the seas. Its other name is “The Floating Terror!”

We often refer to the man o’ war as a jellyfish, but it is not a fish at all. It is a siphonophore, which is a colony of specialized organisms called zooids that work together as a single unit to survive, as one. There are four specialized parts of a man o’ war and each is responsible for a specific task, such as floating, capturing prey, feeding and reproduction.

Portuguese man o’ war are characterized by a gas-filled float, or body, that can be up to six inches tall and 11 inches long, with tentacles that can grow up to 165 feet long! The float is usually blue, pink or violet, while the tentacles are dark blue or dark purple. A sting from a man o’ war can cause a variety of symptoms including immediate burning pain, redness, welts and blisters. Reactions can be severe, especially in children and small adults. Depending on the severity of the sting, other symptoms can include muscle cramps, nausea, headache, and, in rare cases, difficulty breathing and chest pain. If stung, rinse the area with sea water, apply heat and rinse with vinegar to help inactivate the venom. Do not apply ice as this can worsen the sting. You can still be stung by a man o’ war if you come in contact with it even after it has washed up on the beach for over a week.

The good news is that these creatures like to spend their time in subtropical regions of the Atlantic, Pacific and Indian Oceans. But they do show up on our shores during the warmer months when ocean temperatures rise. Strong winds and currents can also send them in our direction. So, it’s not just fins to keep your eye out for this summer!