Anyone who spends time on the beach will probably have encountered one or more of these punk-rock looking creatures that look like blue, purple or pink balloons, washed up with other debris on the shoreline, and with the swimming season now upon us, you may encounter them whilst swimming or boating.
I have to tell you they aren’t from Portugal at all – well maybe I should be GLAD to tell you that Portugal isn’t responsible for such a strange creature! It gets its name from the uppermost polyp, a gas-filled bladder, or pneumatophore, which sits above the water and somewhat resembles an old Portuguese warship from the 18th century at full sail, or more likely, helmets from the same period. Man o’wars are also known as bluebottles.
The Portuguese Man O’ War, (Physalia physalis) is often called a jellyfish but is actually a species of siphonophore, a group of animals that are closely related to jellyfish. A siphonophore is unusual in that it is comprised of a colony of specialized, genetically identical individuals called zooids — clones — with various forms and functions, all working together as one. Each of the four specialized parts of a Man O’ War is responsible for a specific task - floating, capturing prey, feeding, and reproduction. Found mostly in tropical and subtropical seas, they have no means of propulsion but are lazily moved by the wind and ocean currents, and for this reason, if you see one, there will probably be more lurking close by, and for this reason, the authorities involved may close the beach completely where they have been found to make it safe.
They are sneaky because beneath the balloon - which can be as much as 6 inches above the surface - hides the long stinging strands of tentacles, and to avoid threats on the surface, they can deflate this balloon at will and briefly submerge. These long, thin tendrils can extend 165 feet in length below the surface, although 30 feet is more the average. They, and the balloon part, are covered in venom-filled nematocysts used to paralyze and kill fish and other small creatures, and will sting you too if you dare to touch it!
For humans, a Man O’ War sting is excruciatingly painful, but the odds of being killed by a Portuguese Man O’ War are slim. Just because deaths are rare doesn’t mean you should touch one, as the stings can leave you with a trail of red welts on the skin, muscle cramps, elevated heart rates, and vomiting, and once a woman swimming off Sardinia was stung by one and died of what was believed to be anaphylactic shock. But beware — this stalwart Man O’ War creature may still sting you even weeks after having been washed ashore, so they aren’t to be messed with, and after drifting around for days before decomposing, even a severed tentacle can sting you.
If you are unlucky enough to get stung, first remove tentacles with a gloved hand, stick, towel, or swim fins. Rinse the area with saltwater, then apparently vinegar is next, and then soak the affected area in hot salt water for about 20 minutes. The stings may cause blisters or small, shallow sores (ulcers). The skin at the site of the stings may look dusky or bluish-purple, and healing may take many weeks, with permanent scarring possibly occurring at the site of the sting.
Given that tiny fish makeup about 70 to 90 percent of the Man O’ War’s diet (it also eats shrimp and other crustaceans), there is a fish called the Portuguese man o’ war Fish, that plays a dangerous game: It lives among the tentacles even though it’s only partially immune to its stings, somehow swimming nimbly between the stingers!
I am glad to say the Man O’ War does have a few enemies, including Loggerhead Sea Turtles and the bizarre-looking Ocean Sunfish who are thick-skinned enough to eat them. Blue Dragon Sea Slugs are rather partial to them too – they not only devour the Man O’ War but actively harvest its toxins. After storing Man O’ War stinging cells in their own skins, these slugs then use it as a predator deterrent.
If you enjoy poking along the shoreline looking for shells, etc, just be aware in the future that the bluey-purpley-coloured-slimy-looking-balloon-thing you are about to investigate might be worth giving a miss!