EFFECTS OF A TEMPERATURE INCREASE ON OXYGEN-CONSUMPTION OF YELLOW FRESH-WATER EELS EXPOSED TO HIGH HYDROSTATIC-PRESSURE

Oxygen consumption was measured in yellow freshwater eels, Anguilla an guilla, during exposure to a hydrostatic pressure (HP) of 101 atmosphe re absolute (ATA) for 3 h, either with or without a 5 degrees C increa se in water temperature. It was found that concomitant increases in te mperature and pressure resulted in an increase in oxygen consumption t hat was lower than when pressure alone was increased. When eels were a cclimated to HP for 21 days and then submitted to a temperature increa se of 5 degrees C, this induced a significant increase in oxygen consu mption but only during the first hour. It is therefore concluded that raising the water temperature during the first hours under pressure co uld counterbalance the pressure effects on membrane fluidity in a ther modynamic manner and thus help shallow-water fish acclimate to high pr essure. In contrast, when acclimation processes are ended, the tempera ture effect disappears within 1 h.