Did you know: saltwater fish drink water. Freshwater fish do not?
saltwater fish drink seawater to replace the water they lose through osmosis, where water moves out of their bodies across their gills and skin, and they excrete excess salt through specialized cells in their gills and kidneys. Here's a more detailed explanation: Osmosis and Water Loss: Saltwater fish live in an environment where the surrounding water is much saltier than their body fluids. This difference in salt concentration causes water to move from the fish's body (where it's less salty) to the surrounding seawater (where it's saltier) through a process called osmosis.
Drinking Seawater: To counteract this water loss, saltwater fish constantly drink seawater. Salt Excretion: The high salt content in seawater poses a challenge for saltwater fish, as they need to get rid of the excess salt they ingest. They do this through specialized cells in their gills that pump out salt and through their kidneys, which produce a small amount of highly concentrated urine to excrete excess salt. Contrast with Freshwater Fish: Freshwater fish, on the other hand, live in an environment where the surrounding water is less salty than their body fluids. This means water moves into their bodies through osmosis, and they need to constantly eliminate excess water by producing large amounts of dilute urine.
