Question

Which ecological pyramid can be inverted in aquatic ecosystems due to high turnover rate?

• A. Energy pyramid
• B. Biomass pyramid
• C. Number pyramid always
• D. Productivity pyramid

Hint:

The Pyramid of Energy is NEVER inverted because energy is lost at each transfer.
Inverted Biomass Pyramid = Aquatic Ecosystem.
Inverted Number Pyramid = Tree Ecosystem (One tree, many birds/insects).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Ecological pyramids are graphical representations of trophic levels.
An inverted pyramid means the base (producers) is smaller than the higher levels (consumers).
"Turnover rate" refers to how quickly a population replaces its biomass.

Step 2: Detailed Explanation:
In aquatic ecosystems, the primary producers are phytoplankton.
Phytoplankton are very small, have short lifespans, and reproduce extremely rapidly.
This high turnover rate means they are consumed almost as quickly as they are produced.
As a result, the "standing crop" (the biomass present at any single moment) of phytoplankton is very low.
However, their high productivity is sufficient to support a much larger biomass of zooplankton and fish.
When measured at a single point in time, the biomass of producers is less than that of consumers, creating an inverted shape.

Step 3: Final Answer:
The biomass pyramid in aquatic systems is inverted because the rapid consumption and reproduction of producers result in a low standing crop biomass.