Question

Marine water fish drink more water than freshwater fish. Do you agree? Justify.

Answer 1

• In freshwater fish, the surrounding water has less salt concentration when compared to the inside environment (inside the fish). Water moves into the fish by osmosis passively through the gills, skin, and stomach. Freshwater fish eliminates excess water in dilute urine.
• In marine water fish, the surrounding water has more salt concentration when compared to the inside environment (inside the fish). The fishes lose water passively. So, marine water fish have to drink more water than marine water fish. The excess salt is eliminated primarily in highly concentrated urine.

Hence, marine water fishes drink more water than freshwater fishes.