Fish do not derive energy from the side, as "side" is not a source of energy. However, if you are referring to the diet of a fish, it can vary depending on the species. Some fish are herbivores and primarily feed on plant matter, while others are carnivores and feed on other animals. Still, some fish are omnivores, consuming both plant and animal matter. It is difficult to determine an exact percentage for the energy obtained from each source without specifying a particular species of fish.
