Australian Giant Cuttlefish
Ascarosepion apama
Pharaoh Cuttlefish
Acanthosepion pharaonis
About
The pharaoh cuttlefish is a master of disguise. It can shift its whole body from ghost-white to dark brown in moments, and hunts by tricking its prey into thinking it is something else entirely.
Also known as: Sepia pharaonis
How to tell it apart
Many cuttlefish species look alike and change colour the same way, so colour alone will not confirm this one. Watch its hunting display instead: if you see it curl and wrinkle one pair of arms while flapping the others in a hermit-crab-like wave, that lure display is the giveaway for the pharaoh cuttlefish.
Appearance
This cuttlefish has the typical squat, broad-finned cuttlefish body. Its skin holds thousands of tiny colour-changing cells called chromatophores, packed at up to 200 per square millimetre, sitting over a reflective layer that adds blue and green sheen. It can turn a solid pale white or solid dark brown to match a plain background, or switch to a mottled white-and-brown pattern with a darker brown circle at the centre when resting on broken ground.
Habitat
It lives on soft seabeds in the western Indian Ocean, including the Red Sea and Persian Gulf, favouring mud during the day and mud or sand at night. It settles into dens on the bottom where enough sunlight reaches, and moves up into shallower water at night to hunt. It has also spread into the Mediterranean Sea after passing through the Suez Canal.
Behaviour
By day it rests camouflaged against the seabed, switching between plain, mottled, and broken-up colour patterns to match its surroundings. When hunting, it often raises its first pair of arms into a wrinkled, curled shape while flapping its other arms at the tips, a display thought to copy the look of a hermit crab and lure prey closer. To catch prey, it holds its arms and two longer tentacles in a triangle, edges slowly in, then shoots the tentacles forward to grab its target and pull it back.
Did you know?
The pharaoh cuttlefish sometimes disguises its own arms as a hermit crab, curling and flapping them to lure in prey that would otherwise flee a predator.
Log it in Into the Blue
Describe what you saw and we name it, then keep every species you find in your Oceandex.
