The effects of altering gill water flow on gas transfer in rainbow trout

Abstract

The relationship between gill ventilation and gas transfer was studied in rainbow trout. Gill ventilation volumes were experimentally manipulated and blood gases as well as oxygen and carbon dioxide transfer across the gill were measured. At ventilation volumes below about 100 mL/min, there was an increase in blood carbon dioxide and a decrease in blood oxygen tensions. Both oxygen and carbon dioxide transfer rates in this range also declined with ventilation volume. Ventilation volumes below this level, therefore, may limit gas exchange and change blood gas tensions given constant metabolic rates. Ventilation volumes greater than 100 mL/min had little effect on blood gas tensions.