Original paper

The impact of microparasites on the vertical distribution of Daphnia magna

Fels, Daniel; Lee, Valentino A.; Ebert, Dieter


Microparasites are common in Daphnia magna populations. We studied to what extent the infection with microparasites alters the habitat selection of the waterflea D. magna. In particular, we investigated whether the microsporidian microparasites Glugoides intestinalis, Flabelliforma magnivora, Ordospora colligata and Micro1 and the bacterium Pasteuria ramosa influence depth selection of Daphnia magna. All of them changed the spatial position during the day as compared to uninfected waterfleas. 24-h video sequences of hosts infected with Micro1, Glugoides intestinalis or Pasteuria ramosa showed that night positions were not affected by parasitism. The results suggest that microparasites contribute to variation in depth selection of D. magna.


infectionparasitismhabitat selectionglugoides intestinalisflabelliforma magnivoraordospora colligatapasteuria ramosa