Why cannot land animals live in water? ?

Land animals have evolved to live in terrestrial environments and have adaptations that allow them to survive on land. These adaptations include lungs for breathing air, limbs for walking or running, and skin that is not adapted for constant immersion in water. Additionally, land animals may not have the ability to regulate their body temperature in water, as they are adapted to the temperature fluctuations of terrestrial environments. Overall, the physiological differences between land and water environments make it difficult for land animals to survive in water for extended periods of time.