Octopus
An octopus has nine brains. One big brain sits between the eyes. Each of the eight arms has its own smaller brain for grabbing and tasting.
On this page: nine brains, three hearts, blue blood, and the ink cloud.
Read the answer below. In Giant, kids can keep asking the octopus.
Octopus
Count nine. There is a large central brain between the eyes. There is also a bundle of nerve cells in each of the eight arms. Those arm brains can handle a lot of grabbing and tasting. They do not need to ask the center for every move. That is why an arm can keep exploring even while the main brain is busy. It is not nine little people inside. It is one animal with a very spread-out nervous system.
9
Brains (1 + 8 arms)
3
Hearts
Blue
Blood (copper protein)
Ink
Escape cloud
Three. Two gill hearts push blood through the gills. One body heart sends it through the rest of the animal. When an octopus swims hard, that body heart can even pause. That is one reason crawling is often the easier commute.
The blood uses a copper protein instead of the iron protein in your blood. Copper makes it look blue when it is carrying oxygen. It works well in cold ocean water.
If danger shows up, an octopus can squirt a dark cloud and leave. The ink is a mix of slime and pigment. It hides the getaway. It can also confuse a predator's senses. Then the octopus can jet away or squeeze into a den.
In Giant
In Giant, kids ask how many brains an octopus has, then follow the arms, hearts, and ink.
How many brains do you have?
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