The effects of inducible defenses on population stability in <em>Paramecium aurelia</em>

What stabilizes predator-prey dynamics is often debated and not well understood. One proposed stabilizing mechanism is that the inducible defenses of prey decrease predation risk by creating a portion of the prey population that is invulnerable to predation, leading to a reduction in trophic interaction strength. We investigated the potential stabilizing effects of inducible morphological defenses in the protozoan, Paramecium aurelia, across a range of nutrient concentrations to better understand a potential stabilizing mechanism of systems under nutrient enrichment (Paradox of Enrichment).Using P. aurelia clones that differ in their ability to induce defenses, we found that the most susceptible clone that does not express any known inducible defense showed reduced survival along a gradient of increasing nutrient concentrations. Clones expressing either inducible or permanent morphological defenses (increasing body width in response to predation threat) were not significantly affected b..., To evaluate the POE in a protist-flatworm system, we used the protozoa species, *P. aurelia as the *prey and the flatworm species, *S. virginianum as the predator. Paramecium aurelia *was used as the prey species due to the ability to rapidly raise large populations and easily quantify inducible defenses.&nbsp;For use in the experiment, three clonal populations of P. aurelia were chosen to represent three different levels of an inducible defense. One clone (“FD4”) isolated from First Dam in the Logan River (41°44'31.7\"N, 111°47'24.5\"W) is “permanently induced” (i.e., expresses increased width with or without predators present), one clone (“EV2”) that does not induce (i.e., no significant increase in width with predators present), and one clone (“AUR”) shows induced changes in width in the presence of predators.&nbsp;*Stenostomum virginianim *populations, a known predator of P. aurelia (Hammill et al., 2010, 2015; Kratina et al., 2007), were grown from a single individual collected in th..., # Data from: The effects of inducible defenses on population stability in *Paramecium aurelia* Dataset DOI: [10.5061/dryad.d51c5b0fq](10.5061/dryad.d51c5b0fq) ## Description of the data and file structure This dataset includes the population patterns of the protozoan, *Paramecium aurelia*, under an increasing nutrient concentration gradient and for a predator present/absent treatment over the course of 40 days (~40-80 generations). These data also include the time to extinction for each predator-prey treatment combination. *Brief Methods Description:* To evaluate the POE in a protist-flatworm system, we used the protozoa species, *P. aurelia*, as the prey and the flatworm species, *S. virginianum* as the predator. *Paramecium aurelia* was used as the prey species due to the ability to rapidly raise large populations and easily quantify inducible defenses. In a petri dish, 30mL of media at a pre-determined nutrient concentration was added along with 100 protists and 10 flatworms. Eve...,