Data are given for the oxygen consumption, heart rate and relative blood ion concentration in the shore crab, Carcinus maenas, during periods of reduced oxygen pressure and anoxic conditions in its environment. Down to values of about 20 mm Hg pO2, Carcinus regulates oxygen uptake. The oxygen uptake is more strongly influenced by temperature than heart rate. Anoxic conditions can be survived during about two days. During anoxia apparently internal changes occur, causing the animals to loose locomotory control. Ion regulatory capabilities are, however, unaffected. Up to a certain time these internal changes are reversible; then a slow recovery takes place when the normal environmental oxygen concentration is restored. |
