Difference Between Squid and Octopus (With Table)

There are millions if not trillions of species in the world, including us human beings. Among these are also the uncountable numbers of aquatic species that live underwater. Squids and Octopuses are two such animals, and no doubt they have quite a similar appearance.

Squid vs Octopus

The difference between Squid and octopuses is that both have different lifestyles and food spectrums. Also, the life span of an Octopus is lesser than that of a squid. Both Squids and Octopuses have 300 types of species of themselves. They have different defense techniques too.

Squids are soft-bodied animals that prefer to live on the open ocean or the coastal region. Their appearances consist of elongated bodies, smaller heads, large eyes, eight legs, and two tentacles, and most squids have a body shaped like a feather. Their eyes are on the sides of their head.

Octopus, too is a soft-bodied animal that lives on shallow water or the ocean floor. They have a bilaterally symmetrical body with two eyes, eight arms, and a mouth at the center of the tentacles. They have a very complex nervous system and are one of the most intelligent invertebrates.

Comparison Table Between Squid and Octopus

Parameter of ComparisonSquidOctopus
OrderTeuthoideaOctopoda
Arms and Tentacles108
Life Span1 to 3 years9 months to 5 years
Largest Size13 meters18 meters
Types/SpeciesO. Vulgaris, Amphioctopus marginatus, Atlantic Pygmy Octopus, etc.Sepia esculenta, common cuttlefish, Sepia Mestus, etc.

What is Squid?

Squid is a type of soft-bodied aquatic animal classified as a Cephalopoda of the Animal Kingdom and belongs to the Teuthoidea Order. Generally, squids have a feather-like structure, complex eyes on both sides of their head, and eight arms along with two tentacles which help them in hunting their prey.

They use a certain type of camouflage as their survival technique, like producing a dark ink liquid into the water and then escaping. Squids feed on the shrimps and the smaller category fishes. The two of their tentacles have rows of suckers with pointed rings.

Squids can be as small as 1.6 centimeters and as large as 20 meters (unconfirmed) in size. Squids, too, come under one of the most intelligent animals of the invertebrates. Squids mate in groups and lay their eggs on rocks or corals.

Squids are a part of cuisines in many parts of the world. In countries like Japan, Northern Atlantic, and American East Coast, they are eaten as vermicelli strips, sashimi, or tempura. The body is filled and cut into ring-shaped pieces. Even the tentacles and the ink is eaten.

What is Octopus?

Octopus too is a soft-bodied animal of the Cephalopoda class of the Animal Kingdom, and it belongs to the Octopoda order. Octopuses have a very complex nervous system and eyes and have eight arms with a beak-shaped mouth in the center. Normally, Octopuses have a round-shaped head.

All types of octopuses are venomous, although the blue-ringed octopus is the only species that is said to be dangerous to humans. Most octopuses use the camouflage technique changing their color, slipping to small cavities or shells. Some even excrete ink clouds like squids to escape.

The smallest an octopus can be is 5 centimeters which are the O. Arborescens species. In contrast, some of the largest sizes of the octopus can be 18 feet to 30 feet. As they live on the ocean floor, they use their arms to crawl. The ink produced by some species on being threatened can even paralyze the predator.

Many people love the different types of octopus as food, ranging from mostly its arms to other body parts, eaten in different regions. It is a very common dish in the Japanese, which is also a part of Sushi. Furthermore, it is also eaten as curry or with spices in many countries.

Main Differences Between Squid and Octopus

  1. Squids are active predators and live in the open ocean being swift swimmers. Octopuses are generally found on the lower grounds or the Ocean floors and even hide in the seaweeds.
  2. Squids feed on the shrimps or the smaller fish in the drifting sea, while Octopuses like to have crustaceans, like crabs, prawns, lobsters, krill, crayfish, etc., like their food.
  3. Octopus has eight arms, which helps in crawling ahead and capturing its prey. Squids, on the other hand, has eight legs along with two tentacles, with four rows of suckers.
  4. Squids generally excrete a cloud of ink in their surroundings, creating a screen that helps them escape. While octopuses form a camouflage by changing their color, or they slip into cavities or shells due to their soft body.
  5. Female octopuses guard their eggs until they are hatched. Squids lay their eggs on rocks or corals and let them hatch themselves being independent.
  6. Octopuses have a shorter lifespan of around one to three years. Squids generally have comparatively more life and can be up to 5 years.

Conclusion

Both squids and octopuses have the same ancestors, same classification in the animal kingdom, and they even look quite alike. Although many things that differentiate them if closely examined.

The legs are the easiest way to differentiate. The eight legs signify that it is an octopus unless it has two extra tentacles. Next can be the structure. Squids have a feather-like head and comparatively smaller legs. Octopus has a round head and eight long legs.

Also, an octopus will settle down in the container if you have one, while the squid will imitate its behavior and swim swiftly across it. Octopus has larger and complex eyes, like a human being, and is also quite easy to differentiate.

Octopus also tends to change colors when it feels threatened, which is not the case with a squid. Squids have a comparatively more life span than the octopus.

All these points do not need internal observation and can differentiate the animal just by an overview of it.

References

  1. https://pubmed.ncbi.nlm.nih.gov/18957229/
  2. https://link.springer.com/chapter/10.1007/978-1-4020-8278-8_35
  3. https://d1wqtxts1xzle7.cloudfront.net/44089871/Salvador___Cunha_2016_Squids__octopuses_and_lots_of_ink-with-cover-page-v2.pdf?Expires=1627388431&Signature=J3Lupe5GjX6Ynw5FQ~QN2SFM3b~N8-ImSbDJoIjXapWvu-2awZRaJQjI8dtifTGjGaNUylnQeAEC4zR9XnmhP03G3QV5ifOUJ1RB1F6l37lhEnWLd7K0Xx7jJrUqWB1SHpcLibMTmb5mM~UcMB7-l4yMvwlOr4vkO7zO-r341UUrNO1GGHGWeFXQgG-6jkdkZMayXMXxhV7g2xDqIlsnQGE5eF3X6b-9dgFs2o7gQH3IMttKJgQ4LU4UCdG6rfKpWK9qkLOKaRyKPVOcn9MkalqEYbH5vURyQFbLOE0PYv7Y0vcZKmLkgQyPjFWmsVCUfjxpaYiUEm5drnwh1pfjcQ__&Key-Pair-Id=APKAJLOHF5GGSLRBV4ZA
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