Most fishes can either live in freshwater or live in saltwater habitats, but not in both. If you move a marine fish from the ocean to a lake, it will quickly die, and vice versa. However, a small number of fish species are capable of moving between the two environments. Salmon are osmoregulators that hatch in rivers, spend most of their lives in the ocean, and return to the river where they were born in order to breed.
-When a salmon leaves the river and moves out to sea, you would expect ________ to leave its body by osmosis and that excess ________ would need to be pumped out.

Question

Quizplus · Accepted Answer

When a salmon moves from a freshwater environment to the ocean (a saltwater environment), water would tend to leave its body by osmosis due to the higher salinity outside its body. To maintain its internal salt balance, the salmon would need to actively pump out excess salt that it accumulates.

Most Fishes Can Either Live in Freshwater or Live in Saltwater