Water flow across the gills of fish that maximizes the efficiency of gas exchange is known as _____.

A) capillary movement
B) countercurrent exchange
C) deoxygenation
D) pharyngeal movement
E) osmosis

Question

Water flow across the gills of fish that maximizes the efficiency of gas exchange is known as _____.
 
A) capillary movement
B) countercurrent exchange
C) deoxygenation
D) pharyngeal movement
E) osmosis

Quizplus · Accepted Answer

Countercurrent exchange is the mechanism by which water flows across the gills of fish in the opposite direction to the flow of blood in the gill capillaries. This maximizes the efficiency of gas exchange by maintaining a gradient for oxygen uptake along the entire length of the gill.

Water Flow Across the Gills of Fish That Maximizes the Efficiency