Osmoregulation in Animals

Animal cells maintain a delicate balance of water and solutes in their bodies to survive, as they cannot tolerate a net gain or loss of water. This balance is maintained through two approaches.

Isotonic Regulation

Animal body fluids are kept isotonic to the external environment, even in marine saltwater environments. This means that the concentration of solutes inside the body is the same as that outside the body. As a result, these animals do not actively adjust their internal osmotic state and are known as osmoconformers.

 Osmoregulation

Some animals actively regulate their body-fluid concentrations to differ from the outside environment. They discharge excess water in hypotonic conditions (where the external environment has lower solute concentration) and excrete salts in hypertonic conditions (where the external environment has higher solute concentration). These animals are called osmoregulators.

 Different animals have distinct adaptations to regulate osmotic balance based on their environment. For example, animals in marine, freshwater, and terrestrial environments have specific mechanisms to maintain their internal osmotic state.