Body size scaling relationships in flatfish as predicted by Dynamic Energy Budgets (DEB theory): implications for recruitment

In this paper, we apply the general Dynamic Energy Budget (DEB) framework to the growth and reproduction of flatfish at varying food densities with the aim to work out the various relationships between physiological and ecological variables and body size in a systematic manner. The DEB theory predicts that maximum body size is independent of temperature and only determined by 4 parameters: the environmental food conditions, the maximum surface area-specific assimilation rate, the fraction of energy spent on (somatic) maintenance and growth and the volume-specific cost of maintenance. Differences between species can be captured in differences in the environmental food conditions, the maximum surface area-specific assimilation rate and the fraction of energy spent on maintenance and growth. The DEB theory predicts that due to the latitudinal trend in environmental food conditions, maximum body size will increase with latitude, both within as well as among species. Since size at first maturation, size at hatch, larval size and size at metamorphosis directly scale with maximum body size, similar trends with latitude in these variables are expected. The DEB theory further predicts that egg and larval stage duration are related to egg volume0.25. Field data provide a strong support for the various model predictions. Implications for recruitment in flatfish are discussed.