EFFECT OF CONCENTRATIONS OF SALT AND OXYGEN ON SYNTHESIS OF EXTRACELLULAR HEMOGLOBINS DURING DEVELOPMENT OF ARTEMIA-SALINA

The possible influences of environmental factors on the ontogenetically controlled induction of extracellular hemoglobins in Artemia salina were examined. The ontogenetical pattern obtained under our standard conditions (Heip et al., to appear for publication) was essentially unaltered by variation of salinities between 0.08 and 1.53 M. When oxygen concentrations were below 0.07-0.09 mM at a salinity of 0.51 M, a specific induction of Hb-III was demonstrated in adult animals lacking Hb-III. Under the same conditions a much less pronounced increase in the concentration of Hb-II (and also Hb-I) was observed. Upon increasing oxygen concentration to 0.17-0.21 mM, Hb-III disappeared again completely from the hemolymph, while Hb-I and Hb-II returned to approximately original concentrations and never disappeared from the hemolymph in contrast to Hb-III. These results indicate that concentrations of oxygen in the medium, rather than salinity itself, exert a significant effect on quantities of hemoglobins in the hemolymph and that Hb-III is the hemoglobin most sensitive to changes in the oxygen concentration. © 1978.