The common octopus has a highly developed brain and has a rudimentary cortex.
Why are octopuses unique
Octopuses are considered the most developed among all invertebrates.
It easily distinguishes geometric shapes and people.
Octopuses are trainable and have good memory (both short and long-term).
In octopuses, only 30% of neurons are in the head, and the rest are in the tentacles.
In other words, each tentacle can independently make decisions and perform tasks.
Why does an octopus need 9 brains
No other way. An octopus has eight arms.
Each of them has its own brain and one, the central one, controls the entire nervous system.
Therefore, you get nine brains.
Octopuses can dream
Zoologists have suspected that cephalopods can see nightmares.
After observing a captive octopus named Costello, researchers found four cases in which it suddenly changed color during sleep, moved its body and limbs erratically, and even released ink.
Perhaps the sleeping mollusk had dreams with the participation of predators - and tried to protect itself from them or escape.
How long does an octopus sleep
REM sleep in octopuses repeated every half hour or hour and lasted only a short time, about 40 seconds; then the octopus turned pale again and calmed down.
Very short REM sleep is characteristic of birds and reptiles, so in this sense it is more correct to compare octopuses with them rather than with animals.
Previously, we talked about the evolution of bears.
