The extinction of many species of Cichlid fish in Lake victoria is mainly attributed to

Options

A. Habital loss
B. Co-extinction
C. Over-exploitation
D. Alien-species invasion

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the main reason for the extinction of many species of Cichlid fish in Lake Victoria.

2. **Identifying the Options**: The options provided are:
- A) Habitat loss
- B) Co-extinction
- C) Over-exploitation
- D) Alien species invasion

3. **Analyzing Lake Victoria**: Lake Victoria is known to be the natural habitat of Cichlid fish. It is important to consider what changes have occurred in this ecosystem.

4. **Historical Context**: In the 1950s, a new species, the Nile perch, was introduced into Lake Victoria. This introduction is a key event to consider.

5. **Impact of Nile Perch**: The Nile perch is a predatory fish that significantly affected the population of Cichlid fish. The introduction of this alien species led to increased competition for resources and predation on Cichlid fish.

6. **Evaluating the Options**:
- **Habitat Loss**: There is no evidence of habitat loss for Cichlid fish in Lake Victoria, as they still inhabit the lake.
- **Co-extinction**: While some species may face co-extinction, it is not the primary reason for the decline of Cichlid fish.
- **Over-exploitation**: There is no significant evidence to suggest that over-exploitation is the main cause of extinction for Cichlid fish in this context.
- **Alien Species Invasion**: The introduction of the Nile perch is a clear example of alien species invasion, which has led to the decline of native Cichlid populations.

7. **Conclusion**: The main reason for the extinction of many species of Cichlid fish in Lake Victoria is primarily due to alien species invasion, specifically the introduction of the Nile perch.

**Final Answer**: Alien species invasion.

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