Common Cuttlefish

The common cuttlefish (Sepia officinalis) is a cephalopod of the eastern Atlantic and Mediterranean, famous for its rapid color changes and its internal shell, the cuttlebone. It has the W-shaped pupils and three hearts typical of cephalopods.

🧬 Field Guide Specimen: Open Common Cuttlefish in the CRV Science Field Guide to log the specimen, see its place among the Lophotrochozoa lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.

Millions of pigment cells (chromatophores) and reflective cells in the skin change color and pattern in a fraction of a second under nervous control. Cuttlefish are colorblind in the usual sense, but they match backgrounds in brightness and texture. Waves of color pass across the skin during hunting.

The cuttlebone is a chambered, porous structure of aragonite filled with gas and liquid. The animal adjusts the ratio to alter its buoyancy. Sepia ink was used as a pigment for centuries.

In a test similar to the marshmallow test for children, cuttlefish waited longer for a preferred food if they knew it would come, which suggests the ability to delay gratification.

• Common Octopus — another cephalopod with camouflage
• Chambered Nautilus — a cephalopod with an external chambered shell