THE EFFECTS OF SEVERE HYPOXIA ON LACTATE AND GLUCOSE-CONCENTRATIONS IN THE BLOOD OF THE CHINESE FRESH-WATER CRAB ERIOCHEIR-SINENSIS (CRUSTACEA, DECAPODA)

The effects of severe hypoxia on blood lactate and glucose levels in t he Chinese freshwater crab, Eriocheir sinensis, were investigated. An oxygen debt was observed in E. sinensis. The magnitude of the oxygen d ebt was independent of the magnitude of the oxygen deficit and the blo od lactate accumulation level. A permanent increase in blood lactate c oncentration in E. sinensis under severe hypoxia was demonstrated. The mean blood lactate production rate is 8.81 +/- 4.88 mu g/ml/min, acco unting for 35.9 +/- 20.5% of the aerobic respiration. During subsequen t recovery under normoxia, blood lactate was removed rapidly, at the r ate of 9.95 +/- 6.25 mu g/ml/min, approximately equal to the blood lac tate production rate, thus giving a symmetrical shape to the lactate-t ime curve. During initial hypoxia, the blood glucose level of E. sinen sis increased before the blood lactate increased, soon reaching a peak , then declining slowly to the original level. Recovery of blood lacta te and glucose levels happens at the same time. This pattern of blood glucose changes suggests the involvement of the crustacean hyperglycem ic hormone.