Ontogenetical studies on extracellular hemoglobins of Artemia salina

Abstract

Ontogeny of the three extracellular hemoglobins of zygogenetic races of Artemia salina was studied. Hb-II was the first hemoglobin to appear in the swimming nauplius at about 2 hr posthatching, followed by Hb-III at about 8 hr posthatching. Hb-I was detectable by benzidine-H 2O 2 staining of cellulose acetate electrophoregrams only after the seventh to ninth day posthatching, when the functional gills were formed. Hb-III was always lower in quantity than Hb-II and disappeared completely from the hemolymph between the thirtieth and fourtieth day posthatching. This disappearance of Hb-III was earlier in the female than in the male. Both Hb-I and Hb-II were found to remain for most of the life period in the hemolymph of both the male and female, but Hb-II decreased gradually or sometimes disappeared in the old female, whereas this hemoglobin was continuously the major species in the old male. The general ontogetical pattern described in the present study appears to agree with the observations using different races of Artemia salina including several parthenogenetic ones. We conclude that ontogenesis is the factor most responsible for the observed hemoglobin polymorphism in Artemia salina.