Increased water fertility may be characterized by high prey densities and longer wavelength, low light conditions. Normally, a larger test is formed at higher feeding rates, shown most distinctly in Globigerinella siphonifera. The effect of increased food availability on test size of Orbulina universa is larger at lower temperatures, a condition that prevails during upwelling events. For logistical reasons, the mean final size of Globigerinoides sacculifer does not show a consistent tendency with feeding rate. Globigerinoides ruber does not tolerate high levels of brine shrimp and was thus not cultured at higher feeding levels. Globigerinella siphonifera and O. universa reach smaller shell sizes under light conditions that characterize fertile regions (yellow-green) relative to typical open ocean light conditions (blue). G. ruber attains smaller shell sizes under blue light relative to yellow-green light. Again, G. sacculifer does not show a clear trend with respect to final test size under normal and upwelling light. -from Authors