Portuguese Man-of-War: a two-minute wildlife lesson

Ocean Oddities · day 3 of 7

Five facts

1. It looks like one animal, but a Portuguese man-of-war is a colony of genetically identical zooids, each with a job like hunting or digesting.
2. Its tentacles can reach 30 m long and are armed with venomous stinging cells.
3. Its float, the pneumatophore, can hold as much as 13 % carbon monoxide, a gas the animal produces itself.
4. Colonies are either left-handed or right-handed, steering about 45° off the wind direction.
5. Pushed along by the sails on their floats, they sometimes drift in groups of more than 1,000.

The quiz

1. What is a Portuguese man-of-war really?

• A colony of zooids (correct)
• A single large jellyfish
• A kind of sea snail
• A floating seaweed

It is a colony of genetically identical zooids, each with its own job.

2. How long can its tentacles be?

• Up to 3 m
• Up to 30 m (correct)
• Up to 1 m
• Up to 300 m

Its tentacles can reach 30 m long.

3. Which gas can the float hold, a gas the animal produces itself?

• Helium
• Methane
• Carbon monoxide (correct)
• Hydrogen

The float can hold as much as 13 % carbon monoxide.

4. About how far off the wind direction do colonies steer?

• About 5°
• About 90°
• About 180°
• About 45° (correct)

Colonies steer about 45° off the wind direction.

5. How many can drift together in one group?

• Over 1,000 (correct)
• About 10
• About 50
• Over 100,000

They sometimes drift in groups of more than 1,000.

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