Cuttlefish are marine animals of the order Sepiida belonging to the Cephalopoda class (which also includes squid, octopuses, and nautiluses). Despite their common name, cuttlefish are not fish but molluscs. Recent studies indicate that cuttlefish are among the most intelligent invertebrate species. [1] Cuttlefish have an internal shell (cuttlebone), large W shaped eyes, and eight arms and two tentacles furnished with denticulated suckers, with which they secure their prey. Cuttlefish eat small molluscs, crabs, shrimp, fish and other cuttlefish. Their predators include dolphins, sharks, fish, seals and other cuttlefish. They live about 1 to 2 years.