DOI: 10.5061/dryad.ffbg79d2n
title: Data from: Freeze-tolerant frogs accumulate cryoprotectants using photoperiod: A potential ecological trap

description: Climate change is disrupting the reliability of photoperiod as a cue
 signaling seasonal changes in temperature. Organisms relying on autumn
 photoperiods to trigger physiological adaptations to survive winter may
 incorrectly time the onset of winter and exhibit maladaptive responses.
 Here, we demonstrate that a mid-autumn photoperiod causes a
 freeze-tolerant amphibian (Hyla versicolor) to accumulate large reserves
 of cryoprotectants (i.e. “antifreeze”) and exhibit greater cold tolerance.
 Treefrogs raised under a mid-autumn photoperiod had both higher
 concentrations of glycogen in liver tissue and larger livers compared to
 individuals from other photoperiods. This resulted in treefrogs with much
 greater total liver glycogen reserves. However, treefrogs in the
 mid-autumn photoperiod also had reduced size-specific growth rates.
 Photoperiod alone, without decreases in temperature, induced these
 physiological changes. As global warming continues to expand the growing
 season, organisms relying on photoperiod may enter an ecological trap
 where photoperiod no longer accurately signals seasonal changes in
 temperature.
description: # **Freeze-tolerant frogs accumulate cryoprotectants using photoperiod: a
 potential ecological trap**
 [https://doi.org/10.5061/dryad.ffbg79d2n](https://doi.org/10.5061/dryad.ffbg79d2n) ## Description of the data and file structure Theses datasets include data collected from an experiment where we manipulated photoperiod across gray treefrog (*Hyla versicolor*) development. We assessed a variety of traits ranging from growth to cryoprotectant accumulation. We provide data on phytoplankton and periphyton abundances during larval treefrog development in outdoor mesocosms. We also provide data on water temperature and dissolved oxygen in these mesocosms. ## List of datasets * 2023_Photo-Gray_all-hobo.xlsx * 2023_Photo-Gray_Amphibian.xlsx * n/a refers to animals that were preserved at metamorphosis and thus were not part of the thermal physiology trials/measurements. * 2023_Photo-Gray_daily-hobo.xlsx * 2023_Photo-Gray_Daylength.xlsx * 2023_Photo-Gray_DO.xlsx * n/a refers to measurements that are not relevant to the photoperiod manipulation.  * 2023_Photo-Gray_during-mani.xlsx * 2023_Photo-Gray_Glycogen.xlsx * 2023_Photo-Gray_Periphyton.xlsx * 2023_Photo-Gray_Phytoplankton.xlsx * 2023_Photo-Gray_Plasma.xlsx * 2023_Photo-Gray_Temp-Select.xlsx ## Code/Software We provide two R Markdown files for both the primary analyses presented in the main body of the manuscript and also supplementary analyses for the supplemental results. For most analyses, we fit linear mixed-effects models using the `lmer` function from the *lme4* package and obtained P-values using Likelihood-Ratio Tests with `anova`. We included `mesocosm` as a random effect in most models. Tukey HSD post hoc tests were conducted using `emmeans` from the *emmeans* package to determine significant pairwise differences between photoperiod treatments when a main effect of photoperiod was present in the Likelihood-Ratio Test. Significant interactions are included if present. `Block` was dropped from models when not significant. For the temperature selection model, we conducted a repeated measures ANOVA using `lmer` by setting the individual as a repeated measure.