Abstract
Scanning electron-microscopic studies on the structural characteristics and the functional morphology of the mouthparts provide information on the presumed food and the feeding behaviour of Hyperia galba. The structure of the mouthparts and analyses of the gut contents indicate that this species mainly feeds on animal food. Morphologically, the mouthparts — particularly the mandibles — have not yet undergone severe reductions typical for many parasitic species. Hyperia galba has relatively recently evolved into parasitism which due to anamorphic development is obligatory but temporary.
