Specific Growth Rates of Freshwater Algae in Relation to Cell Size and Light Intensity

Four species of freshwater green algae spanning a size range of 0.83–325.22 pg carbon per cell were grown in laboratory batch cultures under four levels of incident irradiance. There was an inverse relationship between cell size and specific growth rate at the highest light intensity tested. As light intensity was decreased, the relationship weakened. These laboratory results, in addition to some field data from arctic lakes in Canada, support recent model predictions concerning size-dependent algal growth.