The objective of this study was to analyze the impact of desiccation of a freshwater lake on the biomass of the submersed aquatic macrophytes M. spicatum and P. pectinatus. To this end, the biomasses in temporary and permanent lakes were compared for each submersed macrophyte. Differences in biomass of M. spicatum were significant between season (P<0.001) and lake x season interaction (P<0.05), but not significant between lake (P=0.114). On the other hand differences in biomass of P. pectinatus were significant between lake (P<0.001) and lake x season interaction (P<0.001). Significant differences were not found between season.