The common cuttlefish is a large species and can attain a maximum mantle length of 490 mm and body weight of 2 kg in temperate waters, and 300 mm and 2 kg in subtropical regions (Reid et al. 2005). It inhabits sandy or muddy substrates and can tolerate brackish waters; younger individuals tolerate lower salinities and more environmental instability than adults (Reid et al. 2005). Both adults and young bury in the sand during the day (Reid et al. 2005). It ambushes prey from its hiding place in the sand, feeding on a wide variety of prey including crustaceans, molluscs, polychaetes, small demersal fish as well as other cuttlefish (cannibalism is common when other prey abundances are low) (Reid et al. 2005). They are preyed upon by sharks, demersal fishes and other cephalopods (Reid et al. 2005). Growth rates are rapid leading to a life span of one to two years (Reid et al. 2005). During autumn and winter individuals migrate to deeper water (approximately 100m); returning to shallow water in spring and summer (Reid et al. 2005). In the Mediterranean large males return to shallow waters ahead of females with females and smaller individuals joining them throughout the spring and summer (Reid et al. 2005). Males demonstrate courtship behaviour and will guard females from rival males (Reid et al. 2005). Spawning occurs in shallow, inshore waters in April to July in the western Mediterranean and January to April off Senegal (Reid et al. 2005). Males have on average 1,400 spermatophores, and females can have between 150 and 4,000 eggs (8 to 10mm in diameter) depending on their body size (Reid et al. 2005). The eggs are attached to a range of substrates, including seaweed and shells, and are darkened with ink (Reid et al. 2005). The duration of embryonic development is temperature dependent and ranges from 30 to 90 days (Reid et al. 2005). Those young that hatch in spring usually spawn in the autumn of the following year; those that hatch in autumn usually spawn in the spring of their second year (Reid et al. 2005). Young are restricted to shallow water until their cuttlebones are fully formed (Reid et al. 2005). Due to post spawning mortality in females there is sometimes a bias in adult males (Reid et al. 2005). This species has been raised successfully in aquaculture (Reid et al. 2005).