IMMUNOGLOBULIN-M SERUM LEVELS IN FEMALES AND PUPS OF SOUTHERN ELEPHANT SEAL (MIROUNGA-LEONINA) DURING THE SUCKLING PERIOD

This paper reports Immunoglobulin M (IgM) levels in serum samples from eight female-pup Fairs of southern elephant seals (Mirounga leonina), at King George Island, Antarctica. IgM levels were determined on sera obtained from sequential sampling throughout the suckling period (app roximately 23 days). The IgM concentration in southern elephant seal s erum was measured by single radial immunodiffusion on agarose plates. Female IgM levels (123.5-613.0 mg/dL, n = 8) were significantly higher than pup levels (5.9-123.6 mg/dL, n = 8). Both groups showed an incre asing trend throughout the entire suckling period, with significant di fferences in relation to stages of lactation. Pup IgM levels on the fi rst day of life (mean +/- SD, 7.6 +/- 2.9 mg/dL, n = 3) suggest that e ndogenous synthesis takes place before birth. (C) 1998 Elsevier Scienc e Inc.