Why are fish dark on the top side and light on the bottom side?
This difference in the colouring is a form of camouflage. If you look down at a fish from the top, it is difficult to spot it as its dark top side” merges with the bottom of the lake, pond etc. If you are under the fish and look at it from there, it is again difficult to detect it because its light bottom blends with the light above the water.
