SERUM AND COLOSTRUM IMMUNOGLOBULIN LEVELS IN THE NORTHERN FUR-SEAL CALLORHINUS-URSINUS

IgG, IgM, and IgA were measured in the serum and colostrum of adult and immature Northern Fur Seals (Callorhinus ursinus). Levels of these immunoglobulin classes in adults were comparable to those in terrestrial mammals. However, maternal transfer of immunoglobulin to neonatal pups either transplacentally or via the colostrum was low. The rate of appearance of IgG and IgA in the serum of pups from 3 days to 4 months was less than in most terrestrial mammals. IgM was present at 19% of the adult average in full term pups and rapidly rose to 70% of the adult value by 5 weeks of age. The significance of these results in regard to rookery mortality of fur seal pups is discussed. © 1979 Pergamon Press Ltd. All rights reserved.