Octopus vs Squid: What are the Differences?

Whilst octopuses and squid both belong to the class Cephalopoda, they are different creatures with many distinct characteristics that set them apart. Want to discover the key differences between octopuses and squid? Let's dive in!

Octopus vs Squid: Physical Appearance & Anatomy

Octopuses and squid may appear to have similar physical appearances from a distance, but there are many aspects of their appearances that differ. 

Octopuses have eight long, flexible arms lined with suckers, and whereas squid also have eight arms covered in either suckers or hooks (depending on species), squid have two further appendages called 'tentacles', which are longer than the rest. A further difference in this area is that octopus arms have more flexibility.

Octopuses typically have a bulbous head and a sack-like body, whilst squid have a torpedo-shaped body that's elongated and cylindrical, with a distinct head and mantle.

Squid have a stiff, internal skeleton known as a pen, which provides structural support and helps maintain their streamlined shape. Octopuses, on the other hand, have no skeleton, making their bodies soft and highly flexible.

Octopus vs Squid: Size 

Octopuses and squid both come in a wide range of sizes, from small species to much larger, however, the largest squid are much longer in size than the largest octopuses.

The biggest octopus in the world is the giant Pacific octopus, which has an average length of 16 feet, although they sometimes grow even larger.

On the other hand, the longest squid in the world is the giant squid, measuring up to an impressive 45 feet (although there are suggestions some may grow even bigger). The colossal squid is equally impressive when it comes to weight, measuring up to a staggering 1,000 pounds, or even slightly more.

Octopus vs Squid: Behavior

Social Behavior

Octopuses are solitary creatures, whereas squid may live in a group, known as a school, although they do also tend to be solitary animals.

Intelligence

Octopuses are highly intelligent and known for their problem-solving abilities, and squid, along with other cephalopods, are also believed to be very intelligent

Predator Deterrence

Predator deterrence is another area where octopuses and squid are very similar: both change color in order to avoid predators, as well as to help in catching prey, plus they both squirt ink at their predators so they can make a quick getaway.

Octopus vs Squid: Diet

A key difference between octopuses and squid is diet and how they catch their food.

Octopuses are carnivores, eating other sea-dwelling creatures, whereas squid are opportunistic omnivores (similarly to black bears, raccoons, and opossums), basically eating anything they can find.

When it comes to catching prey, octopuses grab their prey into their arms, then inject them with venom. On the other hand (or arm!), squid use their two tentacles to grab their prey.

Octopus vs Squid: Habitat & Distribution

Squids are widespread in the world's oceans, and their distribution varies depending on the species; they can be found in both shallow waters and deep underwater. Similarly, octopuses also live in all the world's oceans and while most live on the sea floor, some live closer to the sea surface. 

Octopuses and squid, despite both being members of the cephalopod family, therefore have various key differences, particularly in terms of appearance and diet. Find octopus and other sea-dwelling creature apparel in our Seas Collection.