THE EFFECTS OF ACUTE-HYPOXIA AND HYPERCAPNIA ON OXYGEN-CONSUMPTION OFTHE FRESH-WATER EUROPEAN EEL

When exposed to hypoxia, eels Anguilla anguilla were able to regulate and maintain VO2, down to a water oxygen tension (PwO(2)) of about 25 mmHg, a value far below those reported in other studies. When exposed to hypercapnia, eels showed a depression in VO2, as water carbon dioxi de tension (PwCO(2)) increased. Faced with combined hypoxia-hypercapni a, eels showed an increase in their sensitivity to hypoxia, and the cr itical oxygen tension increased to 40-45 mmHg. The possible mechanisms underlying these responses were discussed, and the implications of su ch findings for extensive culture of eels were highlighted. (C) 1997 T he Fisheries Society of the British Isles.