HEMOCYANIN SYNTHESIS DURING HYPO-OSMOTIC STRESS IN THE SHORE CRAB CARCINUS-MAENAS (L)

1. 1. Adaptation of crabs to 50% seawater resulted in a singificant increase in hemocyanin content when compared to levels in seawater-adapted crabs. 2. 2. Copper content in the hemolymph of crabs adapted to low salinity was twice the concentration found in seawater-adapted animals. The copper-hemocyanin ratio was 0.18 in both low salinity and seawater-adapted crabs, and total body copper remained constant under low salinity and seawater conditions. 3. 3. Incorporation of radiocarbon derived from [U-14C]leucine and [U-14C]aspartate into hemocyanin was enhanced during the first 30 hr after transfer of crabs into 50% seawater. The level of incorporation was greater for radiocarbon derived from leucine than aspartate. 4. 4. The total amino-acid content of hemocyanin in crabs adapted to dilute seawater for 14 days was greater than the total in hemocyanin from seawater-adapted animals. There were no statistically significant variations between individual amino acids in hemocyanin from crabs adapted to the different salinities. 5. 5. A possible osmoregulatory function for hemocyanin is suggested in terms of information obtained in the present study and current findings relative to amino-acid metabolism during hypo-osmotic stress. © 1979.