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 here under:
(a) Pyramid of numbers, showing the number of organisms at each level.
(b) Pyramid of biomass, showing the total dry weight of living matter.
(c) 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.