Why the energy pyramid is pypamidal-shaped?
It is shaped that was as a nmemonic to help you to remember in the natural order of things, as you move up the levels of the pyramid, fewer and fewer plants or animals exist at that level. Yet many prey animals that are not predatory in their nature, such as mice, eat a lot of grain or vegetative matter and provide food for raccoons, which are prey for wolves. In the ocean, there are more steps because microbes get eaten multicellular animals, which in turn get fed on by small fish, which get fed on by larger wish which get fed upon by tuna, cod, small sharks, which get fed upon by killer whales, and larger sharks. A given area can only support a certain number of those animals at each level.
