Strain differences in hemoglobin polymorphism, oxygen consumption, and blood oxygen equilibria in three hatchery broodstocks of arctic charr,Salvelinus alpinus.

Hemoglobin polymorphism, standard oxygen consumption, and blood oxygen equilibria were examined in three stocks of Arctic charr,Salvelinus alpinus, originating from the central Arctic (Nauyuk Lake) and Labrador (Fraser River) regions of Canada and from Norway (Storvatn) and maintained at the Rockwood Experimental Fish Hatchery in Gunton, Manitoba. Ten hemoglobin isomorphs were identified in the blood of adult charr by starch gel electrophoresis at pH 8.6. Five anodic isomorphs were found in all charr. The stocks differed, however, in the occurrence an relative concentrations of five cathodic isomorphs. Nauyuk Lake charr exhibited two hemoglobin phenotypes based on the presence of either three (3-C) or five (5-C) cathodic isomorphs whereas the Labrador charr were uniformly the 5-C phenotype and the Norwegian charr were uniformly the 3-C phenotype. Physiologically, the Labrador and Norwegian charr exhibited similar standard rates of oxygen consumption over a weight range of 0.5 to 50 g and similar blood oxygen equilibria. Charr from Nauyuk Lake exhibited higher standard oxygen consumption rates at weights above 10 g, and blood with both a higher oxygen affinity and a larger Bohr shift than the other two charr strains. All charr strains exhibited very low residual oxygen levels.