Activity 12.3 Let us read (Page 194) Researchers conducted a study to see how fish in ponds Class 8
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Activity 12.3 Let us read (Page 194) Class 8
Activity 12.3 Let us read (Page 194) Class 8
Researchers conducted a study to see how fish in ponds affect seed production in the plants nearby. They observed two ponds with fish and a large number of flowering plants around them; B without fish and fewer flowering plants around it (see Fig. in your textbook). Think of a reason for these observations.
1. Compare the number of dragon flies, bees, and butterflies in both ponds.
Answer:
Observations:
| Insect type | P and A (with fish) | P and B (without fish) |
| Dragonflies | Fewer | More |
| Bees | More | Fewer |
| Butterflies | More | Fewer |
Think of a reason for these observations.
Answer:
- Fish eat dragonfly larvae, reducing the adult dragonfly population in Pond A. With fewer dragonflies (which prey on bees and butterflies), the number of pollinators (bees, butterflies) increases in Pond A.
- In Pond B, the absence of fish allows dragonfly larvae to thrive, leading to more dragonflies that reduce bee and butterfly populations.
2. What does this study show? How does the population of fish in a pond affect seed production in nearby plants?
Answer:
- This shows an indirect effect when fish influence plant seed production through the food web. Fish reduce dragonfly larvae, which
- Higher fish population in a pond decreases dragonfly numbers, indirectly boosting pollinators which enhances pollination and seed production in nearby plants.