A cuttle fish is a ten-armed squid. At first sight you would think that a cuttle fish only has eight arms, but in between, two longer arms are hidden which they use to grab their prey. Mostly they live off shrimp and crabs. Cuttle fish are common in the North Sea. They can grow as big as 50 cm but are granted only a short time of life: the males will live up to three years and a female will die after only one year (after having laid her eggs).
Cuttle fish are also known as sepia. They change colours when under threat or when they are angry. Sepias bury themselves into the sand. Upon fleeing,they emit a brownlike liquid (sepia) to disturb their enemy's sight.
Cuttle fish are shellfish and do not have bones. Most shellfish live inside a shell, but the sepia's (skeletal) shell is located internally. These shells often wash ashore during summer and are known to most people as cuttle fish bone, a delicacy for many birds.