Optimal allocation of energy to growth and reproduction.

The optimal allocation of energy to growth and reproduction is considered for three different cases, i.e., a single reproduction (semelparity), reproduction through repeated discrete clutches, and continuous reproduction. The problem reduces to optimizing age and size at maturity. The best strategy is to continue growth until the change of production rate with respect to increasing body size, multiplied by life expectancy for those attaining adulthood and reproducing successfully, is greater than one. The time at which semelparous species reproduce may also be optimized; for the other modes of reproduction only physiological factors or seasonality can limit the maximum age. A brief growing season or high mortality rate are factors leading to early maturity and small adult body size.