Sepia pharaonis

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 Zoologisches Museum 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 behavior off of 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, but during the night prefer sand or mud substrata equally. Pharaoh cuttlefish reproduce the same way as most other cuttlefish. Large males compete in combat until a victor is decided. This combat is often decided without any physical contact. The males circle each other performing threatening displays of color 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 fertilized eggs a few hours later. Pharaoh cuttlefish often show a solid color when resting on a solid color background, alternating from a pale white to all dark brown. Additionally, they can show a mottled white and brown color, with a center circle of brown. The mechanism for color is the same in the Pharaoh cuttlefish as it is in other cuttlefish. This colour-changing function is produced by groups of red, yellow, brown, and black pigmented chromatophores above a layer of reflective blue and green tinted iridophores and leucophores, with up to 200 of these specialized pigment cells per square millimeter. These sacs of color are controlled by rings of muscle around the sac. The cuttlefish expands and contracts these muscle rings in order to show different colors.