Common cuttlefish (Sepia officinalis), Arrábida National Park, Portugal. The common cuttlefish is one of the largest and best-known cuttlefish species. They are a migratory species that spend the summer and spring inshore for spawning and then move to depths of 100 to 200m during autumn and winter. They only have a lifespan of 1–2 years and have many predators including sharks, dolphins, seals, fish, and cephalopods which includes other cuttlefish. During the day, most cuttlefish can be found buried below the substrate and fairly inactive. At night however, they are actively searching for prey and can ambush them from under the substrate. Cuttlefish are carnivorous and eat a variety of organisms including crustaceans (crabs and shrimp), small fish, molluscs (clams and snails), and sometimes other cuttlefish.