Below are the names of 10 most healthy and nutritious fish and their benefits:

1. **Salmon (Salmon)**:

 - **Benefits**: Rich in omega-3 fatty acids, protein, vitamin D and B vitamins. It helps reduce the risk of heart disease and improves brain function.

2. Sardines:

 - **Benefits**: Rich in calcium, vitamin D, and omega-3 fatty acids. It is helpful for bone health and prevention of heart disease.

3. Tuna:

 - **Benefits**: Rich in protein, vitamin B12 and omega-3 fatty acids. It is good for brain and eye health and increases energy.

4. Mackerel:

 - **Benefits**: Rich in omega-3 fatty acids and vitamin B12. It is helpful in controlling cholesterol and reducing the risk of heart disease.

5. **Halibut**:

 - **Benefits**: Rich in protein, magnesium, and phosphorus. It is beneficial for muscle and bone health.

6. **Herring**:

 - **Benefits**: Rich in omega-3 fatty acids, vitamin D, and B12. It is helpful in reducing inflammation and preventing heart disease.

7. Trout:

 - **Benefits**: Rich in omega-3 fatty acids, protein, and B vitamins. It helps prevent heart disease and inflammation.

8. **Cod**:

 - **Benefits**: Rich in protein, vitamin B6, and B12. It is helpful in reducing the risk of heart disease and strengthening the immune system.

9. **Oysters**:

 - **Benefits**: Rich in zinc, iron, and vitamin B12. It helps to strengthen the immune system and prevent anemia.

10. **Rainbow Trout (Rainbow Trout)**:

 - **Benefits**: Rich in omega-3 fatty acids, protein, and potassium. It is good for the heart and nervous system and helps control blood pressure.

Regular inclusion of these fish in the diet will ensure good health and fill the deficiency of various nutrients.