Avoidance Reaction of the Eel to Water of Low Oxygen Saturation

Abstract

Experiments were carried out to examine the oxygen saturation when avoidance reaction began, and the oxygen consumption under normoxic and hypoxic conditions, by gradually decreasing the oxygen saturation at 1 hour intervals, in the Japanese eel Anguilla japonica (5g) .
The avoidance reaction began when the oxygen saturation decreased below 35%. But in the water of below 5% in oxygen saturation, the fish often went in the water of low oxygen saturation from the oxygen saturated water. The oxygen consumption decreased markedly below the oxygen saturation when the avoidance reaction began.