In this article we will discuss about the structure of Cuttle-Fish (Sepia) with the help of a diagram.
1. It is a marine mollusc commonly called cuttle-fish and is commonly used as food.
2. Body bilaterally symmetrical, somewhat ovoid and dorsoventrally flattened.
3. Body is distinguished into head, neck (collar) and trunk (body).
4. Head is round and bears two large and bulging eyes, 4 pairs of small straight and forwardly directed arms and a pair of long, curved and clubbed tentacles.
5. Each arm, along its inner concave surface, bears four rows of large and distinct suckers.
6. The tentacles bear suckers along their free clubbed end.
7. Collar is reduced and is hidden beneath the trunk.
8. Trunk bears a thick and broad lateral fin, all along its length.
9. External shell absent but a greatly reduced and calcareous. Internal shell is present below the dorsal skin.
10. In male the left tentacle is hectocotelyzed and is used for copulation.
11. The arms and tentacles are modifications of foot.
12. An ink gland is present which ejects ink-like fluid as a device to escape from the enemy.