What is one adaptation aquatic organisms have for living in highly saline environments?

Aquatic organisms living in highly saline environments, such as saltwater habitats, face the challenge of osmotic pressure, where the concentration of salt outside their bodies is much higher than inside. One key adaptation to this challenge is the ability to excrete excess salt through specialized glands.

This adaptation allows these organisms to regulate their internal salt concentration, preventing dehydration and maintaining homeostasis. For instance, marine fish possess salt glands that help actively remove excess salt absorbed through their gills and food. By efficiently excreting this surplus salt, they can thrive in their saline habitats despite the risks associated with osmotic imbalance.

Other adaptations, such as reducing metabolism or changing color for camouflage, do not directly address the critical need to manage salt levels in highly saline waters. Similarly, dissolving in freshwater is not a viable adaptation for organisms in a saline environment. Hence, the ability to excrete excess salt is essential for their survival and function in these challenging ecosystems.