Ernährungsbiologie und Nahrungsspektrum der Gerandeten Jagdspinne Dolomedes fimbriatus (Araneae: Pisauridae)

In 369 individuals of feeding Dolomedes fimbriatus (all stages/sizes) living in moorlands of Northwestern Germany, field studies were carried out, in particular concerning relations of spider size, kind/size of prey and lurking-site as well. Findings reveal extremely variable food types, depending on seasonal fluctuations of active prey species and of lurking-sites of Dolomedes. Largest prey (relative to spider size) is not captured by the big sized preadults or adults, but by juveniles of 6-9mm length. The prey spectrum comprises also syntopical spiders and opilionids. Surprisingly cannibalism among Dolomedes individuals is rahter requent in spring and autumn and may serve to maintain the population when prey is rare.