The Effects of Reduced Gill Area and Hyperoxia on the Oxygen Consumption and Swimming Speed of Rainbow Trout

Abstract

Rainbow trout with a cautery-induced 30 % reduction in functional gill area showed significant proportional reductions in maximum oxygen consumption in comparison to controls, but oxygen consumption at rest and at subcritical swimming speeds was not affected. This corroborates suggestions that total gill area is utilized for oxygen uptake only under conditions of maximum aerobic demand. During swimming trials, hyperoxia (, 300mmHg) neither increased of control fish nor compensated for the reduced apparent in fish with reduced gill area. Therefore a direct limitation on oxygen uptake at the gills is implied.