Octopus

The octopus is a soft-bodied sea animal with eight arms, three hearts, blue blood and no bones, which makes it the only creature in the ocean that is more complicated on the inside than it is on the outside, and it is very complicated on the outside.^[1]

About two-thirds of an octopus's nerve cells are in its arms rather than its head. Each arm can taste, touch and make small decisions on its own, so an octopus is less an animal than a committee of eight that happens to share a lunch.

Hearts

Two of the hearts pump blood through the gills and the third pumps it round the rest of the body. The third heart stops beating while the octopus swims. For this reason octopuses prefer crawling to swimming, which marine biologists say is the most reasonable decision in the animal kingdom.^[2]

The blood is blue because it carries oxygen with copper instead of iron. Octopus blood has been tested against the Blue article and found to qualify.

Plural

The plural of octopus is octopuses. Octopi is a common mistake, since the word is Greek and not Latin, and octopodes is technically correct and used only by people who want to stop a conversation. A 1974 conference called to settle the matter was attended by eight delegates, who could not agree whether they were one delegation or eight.^[3]

See also

• Ocean – where it lives
• Blue – the colour of its blood
• Number 7 – one fewer than it needs
• Axolotl – another animal that can regrow an arm
• Mantis shrimp – another sea creature with too many of something
• Squid – an octopus with two extra limbs, technically tentacles

References

1. Tentacle, T. (2011). Eight Opinions. Inkwell Press.
2. Sucker, S. (1999). “Why Walk When You Could Swim? Hearts”. Reef Quarterly 3: 3.
3. Plural Society (1974). Proceedings of the Octopus Conference. Vols. 1–8.