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12 Educational Facts About Cuttlefish

Last Reviewed and Updated on August 2, 2022

Cuttlefish is an interesting creature that can be found only in saltwater. They’re masters at camouflage, and they are intelligent creatures. Read through some of the most fascinating facts about cuttlefish, and it may just become one of your favorite animals.

1. Cuttlefish have a unique “bone” called the cuttlebone

A cuttlebone is a hard but brittle internal structure. It’s not really a bone but an internal shell. Bones are mostly made of collagen calcium, and a cuttlebone is made of calcium carbonate, much like the shells of snails and seashells.

2. They have a W shaped pupils

Cuttlefish have sophisticated eyes. Their most distinctive feature is the shape of the pupil, which resembles the letter W.

3. They may be able to see before they are born

What has to be one of the most interesting facts about cuttlefish is the fact their eyes are fully developed before they are born. It is thought they start observing their surroundings even before they hatch from their eggs. Additionally, this is thought to have an effect on what kind of prey they hunt, showing a preference for the prey they saw before they hatched. Pretty cool, right?

4. They are not fish

The cuttlefish name is misleading (just like starfish and jellyfish) as these animals are not fish. They are marine mollusks, just like squid, octopus, and nautilus.

5. They have one of the largest brain-to-body size ratios in invertebrates

Invertebrates are cold-blooded animals without a backbone. When it comes to this group of animals, cuttlefish have one of the largest brain-to-body size rations, possibly even topping the octopus. This ratio alone doesn’t determine the intelligence of a species but is a contributing factor, and cuttlefish are thought to be very intelligent creatures.

6. Cuttlefish have eight arms and two tentacles

These animals have eight arms and two tentacles, all lined with suckers. The arms are specialized for grasping prey, while the two tentacles are used for capturing prey.

7. They have a green-blue blood

Most animals on earth have iron-based blood, which is red. Cuttlefish, on the other hand, have copper-based blood, which makes the blood green-blue colored. The copper-based blood functions better in carrying blood through their bodies in habitats with colder temperatures and lower oxygen concentrations.

8. A cuttlefish has 3 hearts

Just like the squid and the octopus, a cuttlefish has 3 hearts. The main heart supplies the whole body while the two other hearts pump blood to the gills.

9. All cuttlefish have ink

All species of cuttlefish have ink stores which they use to deter or distract their predators. If threatened, a cuttlefish will release ink, creating a smokescreen or a decoy to distract and confuse its predators while the cuttlefish escapes.

10. Flamboyant cuttlefish are venomous

The flamboyant cuttlefish has a highly toxic venom that is on par with that of a blue-ringed octopus.

11. They can change color

These sea animals can change both the color and the texture of their skin. What’s more they can do it super fast.

12. There are over 120 species of cuttlefish

There are many of them, and there is much variation between species.

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