Visual signals. Biological Science 3 2011. What is vision?. Light signals are detected by photoreceptors in the eye (in mammals, located on the retina at the back of the eye) Electrical signals are transmitted to the brain via nerves The brain processes these signals to form a ‘picture’.
Biological Science 3
Few animals have good colour vision. Most animals either see no colours, or only see the world as shades of blue and yellows.
Many fish have different colourings on their dorsal and ventral (top & bottom) sides, so that they are camouflaged when seen from below or above, as do penguins
Some organisms make themselves appear larger & more threatening. Many mammals erect their hairs to appear larger and more dangerous. e.g. Frill necked lizards display their frill to intimidate predators (it also helps with temperature regulation)
with changes in colour/swelling
Some fish which live in deep water with very little light have light-producing organs on the sides of their bodies. The light is used to attract prey or scare away predators.