Why are whales not considered to be fishes?

Explanation

**Step-by-Step Solution:**

1. **Classification of Whales and Fishes**: Whales are classified as mammals, while fishes belong to a different category in the animal kingdom. This classification is based on various physiological and anatomical characteristics.

2. **Body Temperature Regulation**: Whales are warm-blooded (endothermic), meaning they can maintain a constant body temperature regardless of the environment. In contrast, fishes are cold-blooded (ectothermic), which means their body temperature fluctuates with the surrounding water temperature.

3. **Respiration**: Whales breathe air using lungs, allowing them to exchange gases directly with the atmosphere. Fishes, on the other hand, do not have lungs; they breathe underwater through gills, which extract oxygen from water.

...