octopus vs squid differences and comparison 580
Difference Between Octopus and Squids

Overview: Octopus Vs Squid

Octopus and squid both belong to the Cephalopod family of aquatic animals and almost looks like. Cephalopod means ‘head footed’ referring to the animals which have their arms/legs directly attached to their heads. However, both are very different when it comes to physical traits, behavioural characteristics, habitat etc. Let’s know about these two and in end, we’ll have an animal duel based on their characteristics.

Physical traits:

Belonging to the cephalopod family both octopus and squid don’t have skeleton but very soft bodies. Octopus use its beak the only hard part of its body to eat prey. The major portion of the squid’s body comprises its conical mantle; it has two swimming fins along both side of the body. Squid can change their colour quickly as their skin is covered with chromatophores; it helps them camouflaging while they are on the hunt and also to protect themselves from predators. Octopus and squid have three hearts; two hearts pump blood to gills while another one help in blood circulation to the body. The blood of octopus and squid contains hemocyanin which is a copper-rich protein. Squids length vary depending on specie; mostly squids grow not more than 60 cm but a giant squid can reach a length of about 13m. In comparison to squids, octopus are short reaching having their length between 1m – 5m.  


Unlike other fishes, octopus and squid have different ambulation technique; they have a muscular sac in the mantle in which they suck water and expel it out quickly which gives them a force to move this is called ‘jet propulsion’. Jet propulsion provides agility to move quickly and to swim in all direction. Octopus does not have fins whereas squids have fins located on adjacent sides of their head which help them to stabilize and move slowly in water.


Octopus and squid have four pairs of sucking arms which they use to catch their prey and for movement. Apart from eight sucking arms, squids also have two tentacles through which they reach and sneeze the prey. However, both octopus and squid use venom to kill their preys. Octopus paralyzes their prey then inject salivary enzymes to make the meat of prey lose.


To breed male octopus use hectocotylus a special arm to transfer the $pёrm to the female’s mantle cavity. Female lay fertilized eggs on the ceiling of her den; it guards, cleans, and aerates eggs. The hatching period vary depending on species; it can be anywhere between 30 days –1 year. Once the hatching starts then after some time female octopus builds a rock wall to seal off then it stays there until the death.

Squid generally mate in large groups, they place their fertilized eggs on the ocean floor or seaweed. Octopus and squid die after reproduction.


Octopus and squid are masters in camouflaging and deception. They can quickly change the colour, shape and texture of the skin. It was seen when an octopus sleeps and is in its dreams they still unconsciously change colours as their reaction to the dream.


Octopus and squid lives in salt waters of tropics and temperate zones. But due to marine pollution, drastic change in their population has been seen. Cephalopods are excellent creatures in adapting to the changing environment which led to an increase in their population. Due to their rapid growth, shorter lifespan and quick adaption they are often called “Weeds of the Sea”.

Combat: Duel: Who would win??

All octopus are poisonous while some squids are poisonous. Both of these cephalopod have different forte; octopus has more muscular strength and has neurotoxin poison which can paralyze its prey whereas squids are fast having excellent evasive ability. If an octopus wants to attack squid then it has to move very fast; even if it does so it is nearly impossible for octopus to match the squids speed. The only way to attack squid is through ambush; then it can inject is venom in squid which will paralyze the squid and eventually it will die.

Octopus would win only if it was able to attack the squid otherwise squid will just swim away. Is it a draw?? Let us know what you think.

Comparison Chart: Octopus vs Squid

Comparison HeadsOctopusSquid
Sub ClassColeoideaColeoidea
ShellDo not have a hard shell or stiff bonesHas Stiff structure called a pen (flexible backbone)
Live inDens on the ocean floorLive in open waters
DietGenerally eats bottom-dwelling crustaceans as they live on the ocean floorEat shrimps and fish
Size1-5mCan grow up to 13m
BehaviourSolitary in nature, live aloneSolitary as well social, live in schools
Lifespan1-3 years9 months – 5 years

Comparison Video: Octopus vs Squid

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