The alien species introduced into lake Victoria that was responsible for the extinction of cichlid fishes is.

Options

A. African catfish
B. Water hyacinth
C. Carrot grass
D. Nile perch

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the alien species introduced into Lake Victoria that caused the extinction of cichlid fishes.

2. **List the Options**: The options provided are:
- A) African catfish
- B) Water hyacinth
- C) Carrot grass
- D) Nile Perch

3. **Understand the Context**: Alien species are non-native organisms that, when introduced to a new environment, can disrupt local ecosystems. In this case, we are focusing on Lake Victoria, which is known for its rich biodiversity, particularly cichlid fishes.

4. **Analyze the Options**:
- **African Catfish**: While it is an alien species, it is not primarily known for causing the extinction of cichlid fishes.
- **Water Hyacinth**: This is an invasive plant that can affect water bodies but does not directly feed on fish.
- **Carrot Grass**: This is also an invasive plant and does not impact fish populations directly.
- **Nile Perch**: This is a large predatory fish introduced in the 1950s, which feeds on the native cichlid fishes.

5. **Conclusion**: The Nile Perch is known for its significant impact on the cichlid population in Lake Victoria, leading to their decline and extinction.

6. **Final Answer**: The alien species responsible for the extinction of cichlid fishes in Lake Victoria is the **Nile Perch** (Option D).

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