ANAEROBIC METABOLISM DURING ANOXIA IN THE BURROWING SHRIMP CALOCARIS-MACANDREAE BELL (CRUSTACEA, THALASSINIDEA)

The thalassinidean shrimp Calocaris macandreae inhabits complex burrows in marine muddy sediments which are subject to severe hypoxia. In the laboratory, C. macandreae was highly tolerant of anoxia (LT(50) = 43 hr) and accumulated L-lactate as the major end-product of anaerobic metabolism. Metabolic recovery of C. macandreae from anoxia was slow; haemolymph lactate concentrations returned to normal levels after approximately 40 hr. Anaerobic metabolism appeared to be initiated only during exposure to severe hypoxia (PO2 < 7 Torr).