Which of the following fish is introduced in pond to control or eliminate
the vector responsible for the transmission of malaria and filariasis?

Options

A. Exocoetus
B. Pristis
C. Scoliodon
D. Gambusia

Explanation

To solve the question regarding which fish is introduced in ponds to control or eliminate the vectors responsible for the transmission of malaria and filariasis, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Vectors**:
- The first step is to identify the vectors responsible for malaria and filariasis.
- Malaria is caused by the Plasmodium parasite, which is transmitted by the female Anopheles mosquito.
- Filariasis is caused by Wuchereria species, which are also transmitted by female mosquitoes, particularly Culex mosquitoes.

2. **Understand the Role of Fish**:
- Next, we need to understand how certain fish can help in controlling mosquito populations.
- Some fish species feed on mosquito larvae, which can significantly reduce the number of adult mosquitoes that can transmit diseases.

3. **Evaluate the Options**:
- Now, let's evaluate the given options:
- a. Exocytous
- b. Pristis
- c. Scoliodon
- d. Gambusia
- Among these options, we need to identify which fish is known for feeding on mosquito larvae.

4. **Identify the Correct Fish**:
- Gambusia, commonly known as mosquito fish, is well-known for its ability to consume mosquito larvae.
- Therefore, introducing Gambusia into ponds can help control the populations of mosquitoes that are vectors for malaria and filariasis.

5. **Conclusion**:
- Based on the information gathered, the correct answer is **Gambusia**.

### Final Answer:
The fish introduced in ponds to control or eliminate the vector responsible for the transmission of malaria and filariasis is **Gambusia**.

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