A fish thrives better in an aquarium if green plants are growing in it. This is because

Options

A. they can eat plants for their survival
B. they like green surroundings
C. they get more oxygen
D. they inhale `CO_2` released by plants

Answer

To solve the question regarding why fish thrive better in an aquarium with green plants, we can break down the reasoning into clear steps:

### Step-by-Step Solution:

1. **Understanding the Environment**: Fish are aquatic animals that require a suitable environment to thrive. This includes not just water, but also the presence of plants.

2. **Role of Green Plants**: Green plants in an aquarium play a crucial role in maintaining the health of the aquatic environment. They contribute to the overall ecosystem within the tank.

3. **Oxygen Production**: One of the primary benefits of having green plants in an aquarium is that they undergo photosynthesis. During this process, plants take in carbon dioxide (which fish exhale) and release oxygen into the water.

4. **Oxygen for Fish**: Fish require oxygen to survive, and the oxygen produced by the plants is essential for their respiration. This is particularly important in a closed environment like an aquarium, where oxygen levels can deplete quickly.

5. **Carbon Dioxide Utilization**: While fish do not directly benefit from carbon dioxide, they produce it as a byproduct of respiration, which is then utilized by the plants for photosynthesis. This creates a symbiotic relationship between the fish and the plants.

6. **Conclusion**: Therefore, the presence of green plants in an aquarium enhances the oxygen levels in the water, which is why fish thrive better in such environments.

### Final Answer:
Fish thrive better in an aquarium with green plants because the plants produce oxygen through photosynthesis, which is essential for the fish's survival.

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