Beastfile · Marine Life
Cuttlefish
Sepia officinalis
Also known as Common Cuttlefish
It puts on the best colour display in the ocean and probably cannot see colour.
Overview
A cuttlefish changes the colour, pattern and texture of its skin faster than anything else alive, running millions of pigment cells over layers of reflective ones. It uses this to vanish against sand, to send a rippling wave of dark bands down its body while hunting, and in some species to show courtship colours on one flank and female colouring on the other at the same time. The catch is that it has one visual pigment, so by the usual definition it is colour-blind. How an animal that cannot see colour matches it so precisely is unresolved; the leading idea involves reading colour from the blur its odd W-shaped pupil creates.
Origin
Coastal waters of the eastern Atlantic, North Sea, Mediterranean and Baltic, over sand and seagrass in relatively shallow water.
Habitat
OceanNotable Traits
- •Changes colour, pattern and skin texture in under a second
- •A single visual pigment, so effectively colour-blind
- •W-shaped pupil, unlike almost anything else
- •An internal cuttlebone used to control buoyancy
- •Can display courtship and female colouring on opposite flanks at once
Conservation
Near Threatened in parts of its range and heavily fished, particularly in the Mediterranean and the eastern Atlantic. Short lifespans mean populations swing hard year to year.
