Effects of the tapeworm Hymenolepis diminuta on maternal investment in rats

摘要

The effect of Hymenolepis diminuta infection on maternal investment in rats was investigated. Litter sizes and average pup body mass did not differ between parasitized and nonparasitized mothers, either at birth or at weaning. The 2 groups of mothers also did not differ with respect to pup growth or pup mortality during lactation. Mass change during lactation was similar between parasitized and nonparasitized mothers. However, a pup-retrieval experiment showed that parasitized mothers were quickerat retrieving their pups to safety than nonparasitized mothers, and spent less time checking for potential sources of danger. These differences were particularly pronounced towards the end of the lactation period. It is concluded that H. diminuta infection increases the relative value of the current litter and current levels of maternal investment, possibly because infection reduces future reproductive success.