Seasonal variations in gastrointestinal parasites excreted by the gray mouse lemur Microcebus murinus in Madagascar

Abstract

We describe seasonal variations in gastrointestinal parasites found in feces of the gray mouse lemur Microcebus murinus. Our study was carried out in the evergreen littoral forest of Mandena, Madagascar. Fecal samples from M. murinus caught during monthly trapping sessions were screened for eggs and larvae of intestinal parasites. Gastrointestinal parasite infection of M. murinus was charac- terized by parasite species richness, the prevalence of parasites, and the intensity of infection expressed as the number of parasite eggs, larvae, and cysts per g feces. We used a modification of the McMaster flotation egg counting technique to quantify parasite egg shedding. Parasite excretions changed season- ally when analyzed on the level of individual hosts. The number of parasite species and the abundance of parasite eggs and larvae in Microcebus feces were higher during the hot season than during the cold season. Reduced parasite excretion during the cold season could be due to environmental factors or to the ability of M. murinus to enter torpor and hibernation during the cold season, which might lead to re- duced metabolism of intestinal parasites and might thus result in reduced shedding of eggs. No such variation was found when the analyses were based on samples of unknown origin.