Question

Explain the diagram:

Food chain in an aquatic ecosystem (Pond).

Answer 1

• In a aquatic ecosystem algae are eaten by insects. 
• Insects are eaten by small fish, small fish are in turn eaten by big fish. 
• And the big fish are eaten by fish eating birds. 
• In this food chain, energy flows from the algae (producer) to the insects (primary consumers) to the small fish (secondary consumers) to the big fish (tertiary consumer) and to the fish eating birds (apex consumer).