Biomass is the living or organic matter of living organism, in terms of weight, present at any given time in the environment. In a food chain, it can be depicted by pyramid of biomass, which is upright in terrestrial ecosystem and inverted in aquatic ecosystem. Pyramid of energy gives the amount of energy trapped per unit time and area in different trophic levels of a food chain with producers forming the base and top carnivores at the tip. Energy content is expressed as kcal/m2/yr or kJ/m2/yr. This pyramid is always Upright. Pyramid of number shows the number of individuals per unit area of various trophic levels in a food chain, with producers, kept at the base and top carnivores at the tip. It is upright in terrestrial and pond ecosystem and inverted in parasitic food chain.