Trade-off between hunting ability and starvation tolerance in the wolf spider, Pardosa pseudoannulata (Araneae: Lycosidae)

Abstract

Experiments were conducted to investigate whether there is a trade-off between hunting ability and starvation tolerance in spiderlings of a wandering spider, Pardosa pseudoannulata Boes. et Str. The width of the carapace (the cover over the cephalothorax) was used as an index of hunting ability, as a larger carapace was confirmed as being advantageous for capturing prey. Abdomen width was used as an index of starvation tolerance because individuals with larger abdomens survived longer under fasting condition. Effects of carapace width and abdomen width on starvation tolerance were examined using multiple regression analysis. The carapace width was found to have a negative effect but the abdomen width had a positive effect on starvation tolerance. Moreover, the ratio of abdomen width to carapace width was significantly different among clutches. These results suggested that there is a trade-off between carapace width and abdomen width, that is, between hunting ability and starvation tolerance, and also suggested that the trade-off might be an allocation strategy specific to each clutch.