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Facts about Portuguese man-of-war

19 Portuguese man-of-war facts

Pacific man-of-war

Portuguese man-of-war are fascinating creatures, that are in fact a colony of individual organisms. Named after warship vessels, they resemble floating plastic bags, tinted with a bluish or pinkish hue. They are commonly found in the biggest oceans, except in the Arctic Ocean, and pose no threat to humans, but can sting painfully.

1
They belong to the genus Physalia and are its only representative.

2
They are commonly confused with jellyfish, thanks to their tentacles.

3
They are a species of marine hydrozoan, found in every ocean, except for the Arctic Ocean.

Hydrozoans are predatory marine animals, colonizing mostly warm, saline waters around the globe.

4
They are siphonophores, which means they are, in fact, living colonies of individual zooids, working as a unit.

5
Both the Portuguese man-of-war and the Pacific man-of-war are considered the same species.

Some recent research may suggest they are not the same species. The organisms present in the Pacific Ocean are smaller than the ones from the Atlantic.

6
They consist of a floating, gas-filled bladder (pneumatophore), and submerged tentacles.

7
They grow up to 31 centimeters, with 51 meters long tentacles.

8
They are translucent, but the pneumatophore has a blue, purple, or pink hue.

9
They were named after a wooden warship at full sail, that the British sailors called Man of War.

The resemblance is questionable because they rather resemble a floating plastic bag.

10
They have no individual movement method; they float with the current or the wind.

11
They are neuston organisms, which means they live on the surface of the water.

12
They are venomous.

The venom fills their thin tendrils and is used on fish and small creatures lured by the movement of their tentacles.

13
They feed on small fish, crustaceans, and shrimp.

14
They have natural predators.

The two main ones are the violet sea snail and sea slugs from the genus Glaucus. They also fell prey to loggerhead sea turtles and ocean sunfish.

15
Their sting is very painful.

It is not deadly, however, there are known cases of anaphylactic shock and cardiovascular collapse as a side effect of the sting.

16
They can sting even once the tentacle is severed, or while washed ashore.

17
The number of their population is currently unknown.

18
It is believed that each colony has a specified sex.

Little is known about their procreation, only what scientists theorize. They suggest genozoids–reproductive individuals of Hydrozoan colonies–release sperm and eggs into the ocean, and get fertilized once cross paths with the same package from other man-of-war colony.

19
They form legions of 1,000 colonies floating together.

It is most likely not an intentional strategy, but rather a result of floating with the current, as they do not have any individual movement method.

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