S2 E1: Squid, Cuttlefish, and Octopus

Video Transcript

Hello! I’m Doctor Brianna Hughes. Welcome to this episode of The Town Dock’s Squid Facts. Today, we’re going to talk about three similar, but different cephalopods: squid, cuttlefish, and octopus.

It’s easy to see why they’re sometimes confused. They are all undersea animals in the mollusk family. They all have tentacles attached to their head, not their body. They are all carnivores, have beaks that are sort of like a parrot, and they all will use ink to as a defense mechanism.

At first glance, you can start to tell these three apart by their general shape. Squid are longer and more cylindrical; cuttlefish are smaller and sort of spoon-shaped; octopus have very round heads and larger tentacles.

One of the biggest differences among these three species is their shell. Like we talked about in Squid Facts Episode 3, squid have a gladius or quill inside their body. This looks and feels like clear plastic. While it provides some structural support for the squid, it’s mostly an evolutionary leftover.

Cuttlefish are the most structured of the three, having an interior cuttlebone made of aragonite. Cuttlebone isn’t like human bone; while it’s stiff, it’s also brittle and porous, making it lightweight, kind of like a sturdy Styrofoam. It helps cuttlefish with their buoyancy, and is one reason cuttlefish move more slowly than squid or octopus.

Unlike the other two, octopus have no internal shell or bone. This gives them the unique ability to fit through any opening that their beak can fit through – meaning that even an octopus weighing over 500 pounds can squeeze through openings the size of a quarter. This trait, combined with their ability to open locks and latches and untie knots, makes them a difficult species to keep in captivity.

As you might have guessed, octopus are the smartest of the three species, in part because they have nine brains: a mini-brain in each of its eight arms, and the largest in its head. Squid and cuttlefish aren’t quite as illustrious, each only having one brain.

It’s also interesting to note that while octopus have eight identically-sized tentacles, both squid and cuttlefish have eight shorter arms, and two longer tentacles used to grab pray.

The final most noticeable difference among squid, cuttlefish, and octopus is how they live. Squid live in groups, usually called a shoal or school. Cuttlefish are usually solitary, but sometimes migrate in groups for extra production. And Octopus travel solo.

In terms of culinary application, all three are eaten around the world. Like the animals, their meat is similar, but not quite the same. Squid have the firmest meat, and usually we eat the body, cutting into rings, or stuffed to make appetizers. Octopus have the softest meat, and usually tentacles are what’s served on the menu. Cuttlefish meat is in-between and eaten less frequently.

Fun fact though - because cuttlefish have a larger ink sack, most of the ‘squid ink’ in food actually comes from cuttlefish.

While there are a lot more interesting details that make squid, cuttlefish, and octopus both similar to and different from each other, I hope you enjoyed this overview of these three interesting species.

Thank you for joining us for this episode of The Town Dock’s Squid Facts. For more squid facts, great recipes, and where you can purchase our calamari at a grocery store near you, go to www.towndock.com