Predictive length-dry mass regressions for freshwater invertebrates in a pre-alpine lake littoral

To date, no regressions for invertebrates from lentic environments are available to facilitate biomass estimation. Predictive length-dry mass regressions for 20 freshwater invertebrate taxa from a pre-alpine lake littoral in Central Europe are presented here. Regressions were calculated by fitting a power function to body-length parameters. For Gammarus roeseli, the head height, an easily measurable length parameter, was used. Differences between regressions of different taxa were confirmed by analyses of covariance. Equations for invertebrates grouped at a higher taxonomic level had lower coefficients of determination; therefore, the use of regression equations at the lowest possible taxonomic level is indicated. A comparison of regressions with those published for related taxa in streams revealed significant differences, supporting the opinion that equations should be applied carefully and their use restricted to waterbodies with similar abiotic conditions.