Cuttlefish

Species	116 species
Diet	Carnivore
Length (Body)	2 to 20 inches
Weight	1.5 oz to 20 lb
Classification	Mollusca > Cephalopoda > Sepiidae
Conservation Status	Most Not Threatened
Habitat	Coastal sea and ocean waters

Cuttlefish are the ocean’s ultimate shapeshifters. Often called “chameleons of the sea,” these intelligent mollusks use specialized skin cells called chromatophores to change color, pattern, and texture instantly for camouflage or communication. Despite being colorblind, they have high-tech, W-shaped eyes that detect polarized light. They navigate using a “cuttlebone” to control buoyancy and hunt with two lightning-fast hidden tentacles. With three hearts and blue-green blood, they are biologically alien. From providing the original “sepia” ink to displaying complex problem-solving skills, cuttlefish prove that you don’t need a spine to be a genius.

Places

Coastal waters throughout Europe, Africa, Asia, and Australia

Cuttlefish can change their color and the texture of their skin in less than a second! They can go from smooth and sandy to bumpy and spiky to hide from predators.
Their pupils are shaped like the letter “W.” This strange shape helps them see in many directions at once, even in the dark, murky water.
They have three hearts that pump blue-green blood through their bodies! Their blood is blue because it uses copper to carry oxygen instead of iron like ours.
Inside their squishy bodies is a hard, chalky shell called a cuttlebone. It’s full of tiny holes that hold gas to help the cuttlefish float or sink like a little submarine.
They have eight arms, but they also have two secret tentacles tucked away in “pockets.” When they see a tasty shrimp, they shoot those tentacles out super fast to grab it!
When they get scared, they shoot out a cloud of brown ink to confuse enemies. This ink was used by artists for hundreds of years—the color is even called “Sepia” after the cuttlefish’s scientific name!

204	March 11, 2026	(North America)
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