A biomass pyramid is a graphical representation of the comparative masses of consumers and foods at different trophic levels. The name biomass pyramid comes from the fact that the information is represented in a pyramid form, with those lifeforms that have the highest energy capacity usually concentrated at the base.
Primary producers, such as plants and phytoplankton, are shown on the bottom of the pyramid, as they have the highest energy capacity; carnivores are shown at the top. This pyramid form, from primary producers to carnivores, is indicative of the poor efficiency of energy transfer from one trophic level to the next. For example, 90 percent of the energy supplied by grain is lost when raising cows for human consumption.