Did you know that an octopus has three hearts. The main thing drives blood through the body. The others push her through the gills. There is no hemoglobin in the blood of an octopus, but it contains a large amount of copper, so the blood of these animals is blue.
The octopus is so named because it is believed to have eight legs. However, he actually has two legs, since he uses a pair of hind limbs to move along the bottom, and all the rest perform the function of hands.
An octopus can weigh up to 50 kg and a length of up to 3 m. The largest octopus was caught off the coast of the United States in 1945, weighing 180 kg and a length of 8 meters.
Scientists have repeatedly tried to determine which animals are the smartest. According to one version, the ten smartest include the following:
The octopus is the smartest invertebrate animal, although it is considered a distant relative of garden slugs and snails. Its brain has the shape of a donut, and in each tentacle there are its "branches", a kind of miniature copies. Scientists are confident that the octopus's tentacles can perform certain actions without the participation of its brain.
Octopuses are trainable, they distinguish geometric shapes - they distinguish a circle from a square, a rhombus from a triangle. They find and remember the way out of complex labyrinths, they can cooperate with other predators, agreeing on joint hunting. Octopuses have a good memory - they recognize the people who feed them and express their attitude towards them. There is a known case when one octopus living in an aquarium took a dislike to its servant and constantly doused her with water. The girl quit her job, but when she returned to work a few months later to see her colleagues, the octopus recognized her and poured water on her again.
Octopuses can use tools as well as monkeys. There are known cases of octopuses using pieces of wood to open the shells of molluscs. Others knew how to open the lids of plastic bottles and even get out of the can by unscrewing the lid from the inside.
Octopuses are very observant. They copy each other's behavior. As soon as one learns something, others immediately begin to apply his experience in practice. Octopuses are curious. They are not dangerous to humans, and it is very rare for octopuses to attack humans. However, an octopus, upon seeing a scuba diver, can wrap tentacles around his leg - just out of curiosity to feel - and then release.
The personal life of octopuses cannot be called happy. Males often fall prey to females, and females do not live long. They lay eggs only once in a lifetime, but how many - 100 thousand eggs! The female carefully looks after them - lays eggs in her tentacles, as if in a basket, protects, ventilates and cleans them without leaving her shelter. She does not eat anything at this time, and this continues for six months, or even more. And after the appearance of the babies, when after a week they begin to feed on their own, the female octopus dies of exhaustion.
On average, octopuses live for 1-2 years, and those who have lived up to 4 years are long-livers.
But how did this marine invertebrate manage to develop an intelligence comparable to that of the smartest vertebrates? Physiologist Andrew Packard believes that this happened as a result of the struggle for survival. Octopuses had to compete with fish - fighting for the same food and fleeing from the same predators - and in this competition octopuses excelled.