Many confuse octopus and squid related to mollusks. This is due to the fact that both representatives of invertebrates have tentacles and live in the ocean. However, according to some, and significant, signs, they can be distinguished.
What is the difference between octopus and squid? In fact, they are largely similar, but there are differences between them, and even significant ones. Both marine inhabitants prefer to stay in the depths most of their lives, but there are known cases of their appearance on the surface. More details about how they differ will be described in the proposed article.
Definitions
Squid - a mollusk with an elongated body shape with many limbs, belonging to the class of cephalopods.
An octopus is a mollusk (a representative of the cephalopod class) with a body having eight tentacles.
Leave the terminology. After all, some of the most significant differences between squid and octopus are presented below (the photos in the article show the difference).
Color
An octopus can change the color of its body. This is due to the fact that hiding from enemies among the environment of the seabed is quite difficult, and the need for changing one color to another in this animal often arises. For a similar process, cells with different pigments in the skin of this unique representative of the depths are responsible.
In order for the squid to remain not very noticeable in the thickness of the sea, it is enough to have a darker shade of the upper body and a light shade of the lower. However, some squids may glow (have bioluminescence). This happens thanks to special organs that octopuses do not have.
Body shape comparison
Squid and octopus differ not only in color, but also in their appearance. In the first, the body has an elongated shape, so that it can "dissect" the huge underwater expanses, making sharp movements forward with the "tail". Well-developed fins also contribute to the rapid movement, both under water and on its surface.
In squid, the head is slightly isolated from the body, and in the octopus, these two parts of the body are almost merged together. In addition, octopuses, living mainly on the bottom of the sea and preferring to crawl to a greater degree, are shapeless creatures. There are even jellyfish among them, similar to jelly.
Squid and octopus rudiments
The difference is that the former has a well-defined body shape. It is caused by the reduced hard shell contained in it, which once had an external location.
And octopuses have the rudiment of a shell, but it is so insignificant that it cannot maintain the shape of the animal’s body. There is a positive point in this - the absence of hard tissues makes it possible for the octopus to move along very narrow slits or to find itself in a small limited space. In addition, during the hunt this shapeless creature is perfectly masked, flattening its body at the bottom of the sea.
Tentacle difference
The difference between squid and octopus is in the number of their limbs. The second is somewhat behind. The octopus has eight, and the squid, in addition, has two more tentacles, elongated during evolution. Their purpose is to capture food.
There is a difference in the suction cups on the tentacles of both mollusks. Coarse tentacles with uneven sharp edges are characteristic of squid. In addition, larger varieties have suction cups equipped with claws that can pierce the victim.
The difference between squid and octopus can be seen in the process of hunting for prey. They work not only with tentacles, but also with their beaks. The octopus is more powerful. The animal strikes the prey with them and injects poison into the resulting wound.
Lifestyle
Some differences have the behavior of animals. What is the difference? They consist in the fact that many squids during hunting prefer to act in packs, making hunting attacks together.
Octopuses in this regard are more imposing, and they are characterized by actions alone. They quietly sneak up on the throwing distance and attack the prey from their ambush. As you can see, the differences between the octopus and squid are noticeable in their behavior.
