The Painful Portuguese Man-of-War

An intriguing creature of tropical and subtropical waters is called the Portuguese Man-of-War (some render it Man o' War or similar), but has been found in colder waters on occasion. Is it an attempt by Portugal to rule the waves? No, it is not from there.

The Man-of-War has a floating part that remains above the water, the rest is submerged. This critter is similar to a jellyfish in some ways, especially those very long venomous tentacles that easily fire off painful stings. It's not so much an it, but more of a they.

View from above, Physalia physalis, Flickr / Bengt Nyman (CC BY 2.0)

Okay, so it's not from Portugal. What about the other part of its handle? It is thought that it has a resemblance to the sails of heavily-armed warships (probably frigates, not galleons) of yesteryear. The upper part acts like a sail, so wind and ocean currents tell it where it's going to go. Although rather small body wise, a flotilla of a thousand of these things cruising along can be alarming.

Dead ones wash up on beaches, but the tentacles can still deliver a sting. Imagine getting tangled with a live one!

The Portuguese Man-of-War is actually a colony, not a single creature. Each part is necessary for the whole. The parts have their functions, but they share a common stomach.

It is formidable, but there are predators who chow down on the Man-of-War. (That happens elsewhere in nature where a creature seems invulnerable, but a predator is immune.) To add insult to injury, the sea slug actually uses the toxins for its own predator-deterrent purposes, and the blanket octopus uses the tendrils.

There are clearly challenges for molecules-to-man-of-war evolutionists to explain. Not only how some creatures are immune to the poisons but also use them for their own purposes, but how a four-part organism would have formed by chance in the first place — and then been able to reproduce. No, the logical answer is that this is another example of the Master Engineer's work. There is also a lesson for us.

Amazingly, each man-of-war is a collection of four types of animals. These animals are called zooids, and they make up a colony. Each zooid has a different role in the life of the colony. One is the balloon that allows the whole colony to float safely near the ocean surface. Another directs the tentacles that catch food and ward off predators. A third is responsible for digestion. And finally, the fourth zooid produces the next generation of men-of-war.

To share information and food, the four zooids are connected to a hollow central stem. This stem not only connects the zooids to each other but also serves as the communal stomach for each zooid. Without this common bond, the four zooids would die.

But how did these distinct, yet connected animals ever learn to function together? What now makes them one of the most feared colonies on the seven seas . . . or at least the tropical and subtropical seas?

To read the article in its entirety or listen to the audio by my favorite reader, click on "Four for One, One for All."