Comparing Nutrient Intake by Wolf Spiders (Hogna carolinensis) Consuming Frogs (Acris blanchardi) and Crickets (Gryllodes sigillatus)

TL;DR

This study compares what wolf spiders eat when given frogs or crickets, finding that each provides different nutrients.

Contribution

The study reveals how different prey types affect nutrient intake in wolf spiders, highlighting dietary regulation in predators.

Findings

Frogs provide less lipid but more lean tissue compared to crickets.

Spiders consumed more micronutrients when eating frogs.

Both prey types offer valuable nutrients to wolf spiders.

Abstract

Herbivores and omnivores have been shown to regulate their intake of nutrients to a balance that maximizes fitness. Predators were traditionally believed to have less need for dietary regulation than herbivores, given the higher nutritional quality of animal tissue compared to plants. However, some predators, like spiders, may feed on diverse prey that could vary substantially in nutrient content and, hence, their potential quality as food items. This study compared the nutrient intake of Carolina wolf spiders (
Hogna carolinensis
) when they fed on cricket frogs (
Acris blanchardi) and crickets (
Gryllodes sigillatus
). In diet trials, spiders were fasted prior to being offered a frog or cricket for consumption. Then, prey remains and nonconsumed (control) frog and cricket samples were analyzed for lipid, lean tissue, and elemental content. Results show that frogs and crickets vary substantially in the nutrients that they provide to spiders. Frogs offer less lipids but more lean tissue compared to crickets. Additionally, spiders consumed a greater mass of micronutrients when feeding on frogs compared to crickets. While some evidence suggests that lipids may be limited for some spider species, frogs may still be beneficial to spiders' diets because they offer an abundance of lean tissue. Future research should examine how environmental and physiological factors influence the nutritional quality of prey for predators.

This study compared the nutrient intake of Carolina wolf spiders when they were fed on cricket frogs and crickets. Results show that frogs and crickets vary substantially in the nutrients that they provide to spiders. Furthermore, both prey are beneficial to the diet of the spiders.

Figures