What do fish see?
A fish often notices movement or something that stands out from the background. A still animal matching its surroundings may be harder to see. But a predator may also smell it or detect its movements in the water.
Changing appearance
Cuttlefish and octopuses can change their colours and patterns. An octopus can also change the texture of its skin. These changes help them blend into their surroundings.
They do not really become invisible: they become harder to spot!
Tiny cells in the skin
Cuttlefish and octopuses have small pigment sacs in their skin. Muscles spread them out or let them contract, changing their appearance very quickly.
Explore the same world
