Octopods are marine animals in the family of cephalopod molluscs that lack a skeleton: neither internal nor external. Considered the smartest of all invertebrates, the common octopus is found in the tropical and temperate waters of the world's oceans. With its bulbous head, eight powerful arms with tentacles and two bulging eyes, the octopus is one of the most peculiar animals that we can find on the seabed. However, behind such a strange appearance, the octopus also hides other secrets. From him we know that he has three hearts, a brain and that on the inside of his eight arms he has powerful suction cups.
The most striking feature of the octopus is the wide range of techniques it uses to prevent or thwart attacks by its predators. To move it is veiled by a mechanism by which it expels water, which allows it to propel itself at high speed. It also has an ink tank that it uses to flee from the threats it faces in the depths of the sea. Another of its many virtues is its ability to hide in plain sight: Using a network of pigment cells and specialized muscles on its skin, the common octopus can almost instantly match the colors, patterns, and even textures of its surroundings. But if all this fails, an octopus can also lose one of its arms to escape the predator's grasp.
Source: https://www.nationalgeographic.com.es/