The cuttlefish is found in some medieval encyclopedias. It is a fish that lives in the ocean near Mauretania, where so many fly out of the water that they can sink ships. Sepia is one of the two cuttlefish species mentioned by Pliny the Elder. The cuttlefish (as sepia) has its name because it is easily caught in enclosures (sepes). It conceives through the mouth, and produces very strong black ink.

Cuttlefish (sepia) ink was the source of a reddish-brown (sepia color) ink used for writing in ancient Greece and Rome (some sources say the ink is black). When the ink is placed in a lamp with the light removed, it makes makes people appear to be Ethiopian (i.e. black).