10 Amazing Facts About Cuttlefish

Spectacular lavender cuttlefish

With green blood, three hearts, and able to change colour in a flash, it sounds like a ‘weird aliens’ movie creature ~ Paula Weston

The amazing cuttlefish belongs to the class “cephalopoda”, the same family which octopus and squid belong to.

Cuttlefish at Georgia Aquarium

Not only does the cuttlefish have the characteristics described above but it is also considered to have the highest intelligence of any invertebrate, as well as the ability to see backwards, use jet propulsion and keep buoyancy in the same way that submarines do. Oh, it shoots jets of ink as well!

Pfeffers Flamboyant Cuttlefish

10. Cuttlefish bone is filled with gas!

Cuttle-bone (the things you see in bird cages) has small chambers and like a submarine, filling or releasing the gas in them controls the cuttlefish’s buoyancy.


Image: Firefly5

Close-up of cuttlefish head

9. The flesh of the Flamboyant Cuttlefish is poisonous

This is the only species of cuttlefish known to have any poisons and it carries a unique toxin in its muscles. This species is also short and stubby, unlike the long graceful bodies of most others.


Sepia latimanus (reef cuttlefish) with dark coloration, seconds before turning white.

8. The cuttlefish eye is shaped like a W.

The unique shape of the pupils plays a part in the most highly developed eyes of any animal. They allow the cuttlefish to perceive light polarization and completely reshape their eyes to focus. They also really do have the proverbial eyes in the back of the head, with a second spot on the fovea which allows them to see backwards.

Sepia latimanus (reef cuttlefish) with white coloration. Seconds prior, this individual was dark in coloration.

7. Cuttlefish can change color in mere seconds

The beautiful pink reef cuttlefish seen here and in the previous image is actually the same fish. The two pictures were taken just seconds apart, cuttlefish change color using a series of special skin cells, chromatophores, iridophores and leucophores, which reflect light in all sorts of colors.


Image: Raoul654


Infant Cuttlefish Shows Camouflage

6. Cuttle fish can make themselves completely invisible

Not only do they reflect colors, they are able to merge almost completely with the seafloor.

Image: opencage

Common cuttlefish Sepia esculenta

5.Cuttlefish shoot jets of ink

Cuttlefish ink was the original sepia which was once used by artists – nowadays replaced mostly with synthetic sepia. The ink is used as a defense to confuse predators and allow the cuttlefish time to escape.


Image: Ogergo


4. Cuttlefish don’t have a tail

They have a fin all the way around their body instead of tail fins, like squid, and they use this fin to control movement.

Image: ifish

Pharaoh Cuttlefish using its rocket propulsion, Moyo Island

3. Cuttlefish have jet propulsion

Cuttlefish can escape from enemies by using rocket propulsion. Water is squeezed down their body (mantle) into a special tubular muscle (siphon) that controls the direction as they are propelled backwards for a short distance


Large cuttlefish Sepia apama from Komodo National Park

2. Cuttlefish have green blood

Their blood is green because it uses the protein hemocyanin which has copper in it rather than hemoglobin.

Cuttlefish, Great Barrier Reef, Cairns, Australia

1. Cuttlefish have 3 hearts

They have three separate hearts, one for each gill and and one for the rest of the body. One reason is that their blood flows more rapidly as hemocyanin contains much less oxygen than hemoglobin.

These amazing animals (cephalopods) are so unique and beautiful. Even submarines have made use of their buoyancy methods and they have physical characteristics that no other animal has, yet most of us only know them by the piece of cuttle-bone in a bird cage. Hopefully these facts have led you to admire them as much as I do.

Sources: 1, 2, 3