The community within this ecosystem consists of seven guppies and one catfish is the true statement .
Option A is correct.
Cycling of materials is not necessary in this self-sustaining ecosystem and is incorrect. Even in a closed system like this, cycling of materials (like carbon, nitrogen, and oxygen) is crucial for long-term sustainability. The plants use nutrients and release oxygen, while the fish and snails produce waste that can be used by the plants. This circular flow is essential.
The air stone likely bubbles oxygen into the water, which is important for the fish and other organisms but the primary energy source for this ecosystem is the light bar.