The aquatic Coleoptera of Øvre Heimdalsvatn

The species composition, seasonal and spatial distribution, and biomass of the coleopteran Fauna of the exposed zone of Øvre Heimdalsvatn in 1972 are presented. Individual weight data are given for the 8 species present in the lake: Haliplus fulvus F., Hydroporus palustris L., Deronectes alpinus Payk., D. multilineatus , Flkstr., D. rivalis Gyll., Platambus maculatus L., Colymbetes dolabratus Payk. and Helophorus glacialis Villa. Deronectes alpinus occurred in highest densities, but P. maculatus , on account of its higher individual weight, was the major contributor to the coleopteran biomass.