Octopus: a two-minute wildlife lesson

Five facts

1. An octopus has three hearts. One feeds the body, two feed the gills.
2. Even the biggest octopus can squeeze through a gap barely bigger than 2.5 cm. Its body has no skeleton.
3. An octopus has over 500 million neurons, two-thirds of them in its arms. The arms can act partly on their own.
4. In danger, an octopus can shoot out ink, camouflage itself, jet away through the water and hide.
5. The veined octopus gathers coconut shells people threw away and turns them into a shelter. That counts as tool use.

The quiz

1. How many hearts does an octopus have?

• One
• Two
• Three (correct)
• Eight

It has one main heart and two gill hearts.

2. Why can a big octopus squeeze through such a small gap?

• Its body has no skeleton (correct)
• It shrinks its arms
• It folds its shell
• It drinks less water

Its body is almost all soft tissue, with no skeleton.

3. Where are about two-thirds of an octopus's neurons?

• In its head
• In its arms (correct)
• In its gills
• In its skin

Most neurons sit in the nerve cords of the eight arms.

4. What can an octopus shoot out to escape a predator?

• Ink (correct)
• Sticky threads
• Sand
• Bubbles

Expelling ink is one of its defences.

5. What does the veined octopus collect to build a shelter?

• Coral pieces
• Coconut shells (correct)
• Sea glass
• Driftwood

It uses discarded coconut shells.

More about the Octopus

All lessons

Nature documentaries