What is difference in the colour of fish when viewed from top and bottom?

When viewed from the top, many fish species exhibit a darker coloration. This serves as a form of camouflage, helping them blend in with the darker depths of the water and the substrate below. By matching their dorsal coloration with the surrounding environment, fish can avoid detection from above, such as from aerial predators like birds.

In contrast, when viewed from the bottom, many fish species display lighter shades or even reflective coloration. This adaptation helps them camouflage against the brighter, sunlit surface waters. By matching their ventral coloration with the lighter environment below, fish can minimize their visibility to predators lurking beneath them.

This variation in coloration is particularly important in open water environments, where fish are more exposed and vulnerable to predators from both above and below. By adapting their camouflage strategies to their surroundings, fish can increase their chances of survival and successfully evade predators.