Allometric Growth

Allometric growth is the pattern where body parts grow at rates that differ from overall body size, so proportions change as a fish ages. It is described by the power relationship W = a L^b: when the exponent b equals 3 growth is isometric, while b above or below 3 marks positive or negative allometry. Most fish run b between 2.5 and 3.5. Stock assessment uses the length-weight relationship to convert measured lengths into biomass, to derive condition factor, and to feed yield-per-recruit and length-based models. A misfit a or b biases every weight-at-length estimate downstream.