The major body components (bone, muscle, blubber, viscera and connective tissue) of 94 elephant seals were dissected and weighed.

Seals in growth phase 3 (more than ten weeks old) had significantly more muscle and viscera and less blubber than seals in growth phases 1 and 2 (less than ten weeks old) of similar body weight. There were no significant differences in body composition between sexes before sexual maturity, but after sexual maturity was attained males had relatively more muscle, and less bone and viscera, than females.

Prediction equations relating body component weight and body weight were derived by regression analysis. These were very highly significant, and could be used to estimate body composition from body weight.

It was demonstrated that body length could be estimated from linear measurements of some bones, which would enable an estimate of size and composition of seals to be made from bone dimensions.