Confusing words explained
“octopus” vs “squid” — What’s the Difference?
Octopuses have 8 arms and no fins; squids have 10 tentacles and visible fins.
Key takeaway
Quick Difference: octopus vs squid
Octopuses have 8 arms and no fins; squids have 10 tentacles and visible fins.
octopus vs squid Side-by-Side Comparison
Meaning of octopus
A sea creature with eight long arms and a soft body that can change color.
A soft sea animal with eight arms and no bones, able to change its color.
Use 'octopuses' for the plural, not 'octopi', even though many people say it.
- The octopus is in the water.
- Octopuses are very intelligent creatures that can solve problems.
Meaning of squid
A soft-bodied ocean creature with ten arms covered in suckers and an ink sac for defense.
A sea animal with a soft body, eight arms and two tentacles, that can change color and release ink.
Use squid for both singular and plural. Plural is usually squid not squids.
- The squid has ten arms.
- Squid use ink to escape from predators.
Usage Notes & Nuance
octopus: Octopuses, not octopi, is the correct modern English plural. Octopi is a common mistake.
squid: Squid is a common food in Mediterranean and Asian cuisines.
How to Remember the Difference
Octopus = 8 arms only, lives on the bottom. Squid = 8 arms + 2 longer tentacles, swims in open water.
Common Mistakes with octopus and squid
Mistake with octopus
Wrong: The octopi were swimming in the tank.
Correct: The octopuses were swimming in the tank.
Octopuses is the correct modern plural, not octopi.
Mistake with octopus
Wrong: The octopus change their color.
Correct: The octopus changes its color.
Singular octopus needs singular verb and 'its' pronoun.
Mistake with squid
Correct: An octopus has eight arms; a squid has ten.
Mistake with squid
Correct: I caught three squid.
Practice Quiz: octopus or squid?
Choose the word that best completes each real example sentence.
Question 1
The _____ is in the water.
Question 2
The giant _____ can weigh up to 600 pounds and live deep in the ocean.
Question 3
The _____ has ten arms.
Pick at least one answer, then press Check answers to see how you did.
You scored 0 out of 3
Frequently Asked Questions About octopus vs squid
What’s the difference between “octopus” and “squid”?
Octopuses have 8 arms and no fins; squids have 10 tentacles and visible fins.
When should I use “octopus”?
Use 'octopuses' for the plural, not 'octopi', even though many people say it.
When should I use “squid”?
Use squid for both singular and plural. Plural is usually squid not squids.
How can I remember octopus vs squid?
Octopus = 8 arms only, lives on the bottom. Squid = 8 arms + 2 longer tentacles, swims in open water.
Is it “octopus” or “squid” in example sentences?
Use the quiz above to test the pair with real example sentences from the available word data.