Difference between squid and octopus.

Squid and octopus related to shellfish are confused by many. After all, both representatives of invertebrates live in the ocean and have tentacles. But at the same time, in some ways, these creatures are unlike each other.


limbs and elongated body, belonging to the class of cephalopods.


Octopus is a mollusk, a representative of cephalopods, which has a body with eight tentacles.


Body shape

The squid, whose vital activity takes place mainly in the water column, has an elongated body. Thanks to this, it is able to “cut through” the expanses of water, making rapid forward movements with its “tail”. Well-developed fins also help squid to move (not only in water, but also above its surface).


The squid's head is separated from the body, while in the octopus these body parts are fused together. Octopuses, in their mass living on the bottom of the ocean and preferring to crawl more than swim, are rather shapeless creatures. Among them there are jellyfish-like, jelly-like individuals.


The difference between a squid and an octopus is the number of limbs. If the octopus has eight of them, then in the squid, another pair of tentacles, elongated in the process of evolution, is added to the same number. Its purpose is to capture food.

The difference can be seen in the suckers, which are dotted with the tentacles of both invertebrates. In squid, they are coarser and often have sharp, uneven edges. And in large species of this animal, the suckers are also equipped with claws that stick into the victim.

During the hunt, the squid and the octopus wield not only tentacles, but also their beak, which is much more powerful in the octopus. With this "tool" the octopus strikes the prey, and injects its poison into the resulting wound.


The fixed, well-defined shape of the squid is due to the presence in its body of a hard reduced shell, which once had an external location. Octopuses also have a shell rudiment, but it is so insignificant that it is not able to maintain a certain shape of the animal's body.

The lack of hard tissue allows the octopus to pass through narrow crevices or fit into confined spaces. And during the hunt, this creature manages to perfectly camouflage itself, as if spreading over the seabed.


Of the two animals, the octopus is able to change its color more skillfully. This is due to the fact that it is more difficult to merge with the environment at the bottom, and the need for the transition from one color to another in the animal arises quite often. Cells with various pigments, which are in the skin of the inhabitant of the depths, are responsible for the whole process.

Squid, on the other hand, in order to remain not too noticeable in the water column, it is enough to be darker in the upper part of its body and lighter in the lower one. It should also be noted that some squid exhibit bioluminescence. In other words, such animals can glow due to the functioning of special organs. Octopuses do not have such organs.


The behavior of the animals in question also has certain differences. What is the difference between squid and octopus? It lies in the fact that most squid prefer to act together and make hunting attacks in packs.

It is more common for imposing octopuses to carry out their plans alone. These predators sneak up to their prey within a throw distance or ambush their prey.


Squid Octopus
Torpedo-like body, its shape is supported by a shell rudimentThe body is soft, its shape easily changes
Developed finsFins are absent or poorly developed
The head is detachedThe head merges with the body
Reactive movementPrefers to crawl
Ten limbsEight limbs
Suction cups are coarser, can contain clawsSuction cups are softer
Less powerful beakMore powerful beak
Has less ability to change colorMore skillfully changes color
Some species have bioluminescenceDoes not have bioluminescence
Usually hunts in packsAnimal -lonely