The pharaoh cuttlefish (Sepia pharaonis ) is a large cuttlefish species, growing to 42 cm in mantle length and 5 kg in weight. It is also known as seiche pharaon.
Sepia pharaonis is likely a complex of at least three species, Sepia pharaonis I, commonly located in the Red Sea and Persian Gulf, S. pharaonis II, located from Japan to the Gulf of Thailand and northern Australia; and S. pharaonis III, located from the Indian Ocean to the Andaman Sea.
The type specimen was collected in the Gulf of Suez and is deposited at the Museum für Naturkunde in Berlin.
The pharaoh cuttlefish is native to at least the western Indian Ocean, including the Red Sea and Persian Gulf. Of all the cuttlefish species in the Persian Gulf, it is the most commonly caught. When hunting at night, it swims up to shallower parts of the sea to feast on a variety of smaller fish, crabs, and occasionally other cuttlefish. It is thought to have reached the Mediterranean Sea as a Lessepsian migrant via the Suez Canal after many of its cuttlebones were washed up on beaches in Israel in the early 2000s.
They have been observed to exhibit migratory behaviour off the south-west coast of India. They are more commonly found furthest north during August, and further south in May. They show an even distribution in October and February. Additionally, there are more juveniles present in May, and more adults present in August.
The Pharaoh cuttlefish prefer a medium to high amount of sunlight for den location during the day. Additionally, they prefer mud substrata during the day, and either sand or mud substrata during the night.
Pharaoh cuttlefish reproduce similarly to most other cuttlefish. Large males compete in combat until a victor is decided, although it is often decided without any initiation of physical combat. The males circle each other performing threatening displays of colour and tentacles until one male swims off in defeat. The victorious male then mates with females by grabbing them with their tentacles, turning the female so that the two animals are face-to-face, then using a specialized tentacle to insert sperm sacs into an opening near the female's mouth. The male then guards the female until she lays the fertilised eggs a few hours later. Females undergo a series of phases when laying their eggs, beginning with a temporary posture where their arms are held in a fist-like position. They follow this with extending their arms forward and venting onto the spawning ground and eggs via their funnels, before extending their arms to deposit the laid eggs onto the proper substrata.
