Staying alive: The post‐consumption fate of parasite spores and its implications for disease dynamics

Abstract

Studies on the effects of selective predation by fish on disease dynamics in Daphnia generally assume that consumption by fish means the death of the parasite. I use a combination of feeding trials and infection assays to test this assumption using the host Daphnia dentifera and its common, virulent yeast parasite, Metschnikowia bicuspidata. Approximately 50% of Metschnikowia spores consumed by bluegill sunfish were released in fecal pellets. These spores remained infective to D. dentifera. Therefore, consumption of infected hosts by fish is not necessarily a dead end for the parasite, and in some cases, fish predation may actually help fuel epidemics in natural populations.