1. Earthworms, land Planarians secrete a mucus coating to maintain a moist situation for burrowing, coiling and respiration, etc.
2. Arthropods have an external covering over the respiratory surfaces and well – developed tracheal systems.
3. In vertebrate skin, there are many cellular layers besides the well-protected respiratory surfaces that help in preventing loss of water.
4. Some animals obtain their water requirement from food as partial replacement of water lost through excretion.
5. Birds make nests and breed before the rainy season as there is availability of abundant food. But during drought birds rarely reproduce.
6. Camels are able to regulate water effectively for evaporative cooling through the-skin and respiratory system and excrete highly concentrated urine,and can also withstand dehydration up to 25% of their body weight.
