Lobster Shell and Hemolymph Composition Under Normal and Acidotic Conditions. ∗

Summary

The effects of increased CO₂ tension on the hemolymph and shell of fasting intermolt lobsters were examined. The citrate and calcium contents of the hemolymph were not increased. The pattern of distribution of ions observed in the dry shell of control lobsters was not altered by an increased environmental and body fluid CO₂ tension but a decrease in hemolymph pH occurred. After 100 minutes of exposure to CO₂, an increase in hemolymph inorganic phosphate was observed, and, after 140 minutes, an increase in hemolymph bicarbonate occurred. It can be concluded that, although exposure to an aqueous environment with an increased CO₂ tension results in changes in the concentration patterns of some hemolymph ions, little effect is produced on the calcified tissues of the lobster.