The effects of hypoxia on ion regulation and acid-base balance in Carcinus maenas (L.)

Abstract

1. 1. In Carcinus maenas at both 13.5%. and 30.0%. the blood pH increases during hypoxia at 40 torr, due to an elevation of scaphognathite rate (ƒ sc). However at 20 torr in both salinities the increase in blood pH is greater than at 40 torr even though the ƒ sc remains constant. 2. 2. At both salinities blood lactate levels increased with decreasing P W O 2, the changes being larger at 13.5%. than 30,0%. for a given P W O 2. 3. 3. Blood Na + does not change at any P W O 2/salinity combination, but in 13.5% blood Cl − decreases during hypoxia. 4. 4. At P W O 2 < 40 torr and in low salinity media, a greater role for ion fluxes in acid-base balance is suggested.