Methods for Determining New Biovolumes for Copepods and Cladocerans

Abstract

Zooplankton are an important component of the food web in freshwater lake ecosystems. Despite there being an abundance of density data for zooplankton taxa in these lakes, there is very little information that exists about pelagic zooplankton biovolume or biomass in temperate lakes. Biovolume is a useful estimate of biomass energy because it determines how much space a species occupies. For this research, we developed new biovolume techniques for freshwater zooplankton based on body size and geometric shape. These techniques were applied to two groups of crustacean zooplankton, the copepods and the cladocerans. Copepod biovolume is broken into two formulas: the ellipsoid formula and the cone formula. For the cladocerans, two formulas were used: one for the Bosminidae family and one for Daphnidae family. Daphnia biovolume is composed of two formulas: the ellipsoid formula and the cylinder formula. The Bosminid family biovolume formula is the same as the ellipsoid formula. These new biovolume fomulas proved to be a useful measurement of zooplankton community structure when compared with density data.