Alternative responses by two species of jumping spiders to unpalatability and toxicity in prey
Vickers, Michael; Heisey, Madison; Taylor, Lisa (2020), Alternative responses by two species of jumping spiders to unpalatability and toxicity in prey , Dryad, Dataset, https://doi.org/10.5061/dryad.qnk98sfdx
A key challenge for generalist predators is avoiding toxins in prey. Species-specific strategies range from total avoidance of distasteful (and potentially toxic) prey to the use of physiological mechanisms to metabolize toxins after consumption. We compare two species of jumping spiders, Habronattus trimaculatus and Phidippus regius. Based on several anecdotal observations and other aspects of their biology, we hypothesized a priori that H. trimaculatus would be (1) less willing to feed on unpalatable prey and (2) more susceptible to toxins that are consumed compared with P. regius. In Experiment 1, we presented spiders of both species with size-matched quinine-dipped crickets. Consistent with our hypothesis, all H. trimaculatus attacked and rejected them while all P. regius attacked and consumed them. In Experiments 2 and 3 we assigned spiders of both species to experimental feeding treatments with varying levels of toxicity (using toxic springtails, Folsomia candida) and assessed effects on their growth. Spiders of both species readily fed on the springtails. Collectively, results from these two experiments suggest that springtails have negative effects on both species, but that these effects are stronger in H. trimaculatus. Habronattus has a unique red retinal filter pigment (not found in Phidippus) that likely improves their ability to discriminate reds and oranges. The evolution of this unique visual system may have been driven by their heightened susceptibility to prey toxins, and thus the benefits of avoiding prey that advertise toxins with long-wavelength colors.
The attached data excel file is arranged into three experiments which are found on different labeled excel worksheets. For each experiment the data are as follows:
Experiment 1: Determining the willingness of spiders to consume distasteful prey.
In order to determine if the two species of spiders differed in their willingness to consume distasteful prey we collected the following data: stage (adult or immature), sex (male or female), and whether spiders attacked-and-consumed (yes or no) or attacked-and-rejected (yes or no) quinine dipped crickets.
Experiment 2: Determining the effects of toxins on spiders once toxic prey have been consumed.
To determine whether the two spider species were affected by the consumption of toxic prey we collected the following data metrics from three feeding treatments (control = no prey; crickets-only; springtails-only): spider ID, stage (adult or immature), sex (male or female), carapace width (mm), pre-trial weight (g), 4-week weight (g), mass change (the difference between 4-week and pre-trial in grams).
Experiment 3: Determining the extent to which spiders were feeding on toxic prey and re-examining the effects of toxic prey once consumed.
First, to assess whether spiders were feeding on springtails we conducted 15-minute visual observations and recorded whether or not (yes or no) spiders were feeding on a springtail. Second, to re-examine the effects of toxic prey once consumed by the two species we collected the following data metrics from two feeding treatments (cricket only = 1/4 of the spider's body size; cricket + springtail = one pinhead cricket, 1/4 of the spider's body size, plus 3-4 springtails): spider ID, stage (all spiders were immature), initial collection size (body length estimate, mm), carapace widths (mm), pre-trial weight (g), 4-week weight (g), mass change (the difference between 4-week and pretrial weights in grams). Finally, to examine mortality we recorded whether spiders died (yes or no), day of death, and time to death (the number of days between the start of feeding treatments and day of death).
National Science Foundation, Award: IOS-1557867