the countercurrent exchange respiratory system of fish, which of the following would not be expected? the countercurrent exchange

he countercurrent exchange respiratory system of fish, which of the following would not be expected? Blood flows through the gills from anterior to posterior. Water travels over the gills from anterior to posterior. In the back (posterior) portion of the gill, the amount of carbon dioxide in the gills is higher than the water. In the front (anterior) portion of the gill, the amount of oxygen in the gills is lower than the water.