* They live in water: Their entire environment is water. They are surrounded by it and constantly in contact with it.
* They absorb water through their skin: Most ocean animals have permeable skin, meaning water can easily pass through it. They absorb water directly from their surroundings.
* They drink seawater: Some animals, like marine mammals, do drink seawater. However, their bodies have special adaptations to deal with the salt, allowing them to extract the fresh water they need.
* They get water from their food: The fish and other animals they eat contain water.
Exceptions:
* Marine mammals: While they can absorb water through their skin and get it from their food, they still need to drink fresh water. They do this by drinking seawater and filtering out the salt using special glands.
* Marine reptiles: Some marine reptiles like sea turtles can also drink seawater, but they have mechanisms to remove the excess salt.
In short, ocean animals are very well adapted to their watery environment and don't face the same challenges in getting water as land animals do.