The limitations of ecological pyramids are

Concept:

• An ecological pyramid is a pictorial representation of the relationship between different organisms in an ecosystem.
• It is of three types: Pyramid of the number, Pyramid of biomass, and Pyramid of energy.
• The base of each pyramid represents the producers or the first trophic level while the apex represents the tertiary or top-level consumer.

Explanation:

The Limitations of an ecological pyramid are:

• It does not take into account the same species belonging to two or more trophic levels.
• It assumes a simple food chain, something that almost never exists in nature; it does not accommodate a food web.
• The saprophytes are not given any place in ecological pyramids even though they play a vital role in the ecosystem.
• Thereby, the correct option is ''all of them''

Important Points

• The pyramid of biomass in the sea or pond is generally inverted because the biomass of fishes far exceeds that of phytoplankton.  

• The pyramid of energy is always upright, can never be inverted, because when energy flows from a particular trophic level to the next trophic level, some energy is always lost as heat at each step.