Most Fishes Can Either Live in Freshwater or Live in Saltwater

question 67

Multiple Choice

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 moves from the ocean to a freshwater environment, you would expect its urine volume to ________ and its rate of salt absorption to ________.

• A) increase; remain the same
• B) increase; increase
• C) decrease; decrease
• D) decrease; increase