Ecological pyramids are the graphical representation of the trophic structure and function at successive trophic levels. Ecological pyramids are of three general types, listed as under.$(i)$ Pyramid of number, showing the number of organisms at each level. $(ii)$ Pyramid of biomass, showing the total dry weight of living organisms. $(iii)$ Pyramid of energy, showing the rate of energy flow/productivity at successive trophic levels. Thus, fresh weight is not used for the construction of ecological pyramids.