DOI: 10.5281/zenodo.14938799
title: Data and R code for: Meuthen D., and Mutingwende, N. (2025). Chilled but potent: validating the ability of frozen alarm cues to induce antipredator defences in a freshwater gastropod.

description: Data and R code of the article: Meuthen D., and Mutingwende, N. (2025). Chilled but potent: validating the ability of frozen alarm cues to induce antipredator defences in a freshwater gastropod.

This data originates from two laboratory experiments on the freshwater gastropod Physella acuta aiming to validate the efficacy of frozen alarm cues. In the first experiment, we examine crawl-out behaviour following a one-time exposure of 46 days old individuals to either fresh and previously frozen alarm cues as well as to fresh and previously frozen water controls. In the second experiment, we assess morphological plasticity by using a split-clutch approach and raising full siblings under the same treatments before measuring shell thickness in 33 day old individuals. Detailed information on how the data was obtained is contained in the corresponding manuscript.  Description of the data, file structure and column names

tariel-et-al-only-CCX-data.csv - Dataset obtained from Tariel et al. (2020) to derive priors for the analysis of escape behavior. Here, the full dataset was reduced to the individuals whose parental and developmental environments were in the absence of simulated predation risk.Variables in this dataset are described in https://doi.org/10.5281/zenodo.4243834

Tariel J, Plénet S, Luquet E, 2020. How do developmental and parental exposures to predation affect personality and immediate behavioural plasticity in the snail Physa acuta? Proc Roy Soc B 1941, 20201761. doi: https://doi.org/10.1098/rspb.2020.1761

crawl-out-behaviour.csv - Dataset containing the crawl-out behaviour data as derived from the first (behavioural) experiment.

date - the date at which this individual was sampled.ID - the ID of the individual snail.family - the family (i.e., maternal identity) of the individual snail.clutch - the clutch that the individual snail was derived from.tank - the ID of the tank that the individual snail was raised in.treatment - the combined treatment (FRE-W: fresh water, FRO-W: previously frozen water, FRE-AC: fresh alarm cues, FRO-AC: previously frozen alarm cues).treatment_fig - variable names used to match treatment identity with names used to generate figures (so as to allow re-ordering of columns in a non-alphabetical way).weight_g - the body mass of an individual snail. Assessed with a digital scale.preservation.state - the method of post-preparation downstream storage of cues prior to the experiment (FRO = frozen, FRE = fresh).cue.type - the type of the cue used during in the experiment (W = water, AC = alarm cues).avg_thickness - the average shell thickness. Calculated as the average from the top, middle and bottom of the aperture.perservation.state.num - the method of post-preparation downstream storage of alarm cues prior to the experiment, expressed as numbers (FRE = 0, FRO = 1).cue.type.num - the cue type, expressed as numbers (W = 0, AC = 1).mortality - indicates whether this individual has experienced natural mortality of conspecifics within its home tank.crawlout_time_s - the time the snail required to leave the water (in seconds).crawlout_censored - indicates whether the snail left the water within the experimental time (0=no, 1=yes).

behavioural-experiment-cue-donors.csv - Dataset containing information on the individuals used as alarm cue donors in the first (behavioural) experiment.

morphological-experiment-cue-donors.csv - Dataset containing information on the individuals used as alarm cue donors in the second (morphological) experiment.

production.date - the date that donors were sacrificed to produce alarm cues.use.date - the date that these alarm cues were used in the experiment.ID - the ID of the donor snail.preservation.state - the method of post-preparation downstream storage of cues prior to the experiment (FRO = frozen, FRE = fresh) shell_height_mm - the distance between the shell apex and the bottom of the aperture. Assessed with a digital caliper.shell_width_mm - the distance at the widest part of the shell. Assessed with a digital caliper.weight_g - the body mass of an individual snail. Assessed with a digital scale.mass_in_pool_g - the cumulative body mass of the snails pooled for alarm cue production.matched_with - the ID of the donor that this alarm cue was matched with during the experiment to ensure matching body mass.

parental-individuals.csv - Dataset containing information on the individuals used as parents to generate individuals for the present study.

date.set.up - the date that parental snails were set up for breeding.ID - the ID of the parental snail.shell_height_mm - the distance between the shell apex and the bottom of the aperture. Assessed with a digital caliper.shell_width_mm - the distance at the widest part of the shell. Assessed with a digital caliper.weight_g - the body mass of an individual snail. Assessed with a digital scale.experiment - whether the parental snail was used to generate individuals for the first (behavioral) or the second (morphological) experiment.

shell-thickness.csv - Dataset containing the shell thickness data as derived from the second (morphological) experiment.

thickness_top - shell thickness at the top of the aperture. Assessed with a digital caliper.thickness_mid - shell thickness at the middle of the aperture. Assessed with a digital caliper.thickness_bot - shell thickness at the bottom of the aperture. Assessed with a digital caliper.

snail-mortality.csv - Dataset containing data on individual mortality across both experiments.

alive - number of snails alive in the tank at the date of sampling.dead - number of snails found dead in the tank until the date of sampling. Difference between 6 (the initial number of snails added to each tank) and the number of alive snails.proportion_dead - proportion of snails found dead in the tank until the date of sampling. Calculated by dividing the number of dead snails by 6 (the initial number of snails added to each tank)experiment - whether this tank contained individuals for the first (behavioral) or the second (morphological) experiment.

escape-behaviour.csv - Dataset containing the escape behaviour data as derived from the first (behavioural) experiment.

escape_time_s - the time each snail needed to reach the water surface (in seconds).

brmsescgauss_final.rds - Bayesian mixed-effect model aiming to analyze escape behavior with a gaussian distribution. Included for reproducibility.

brmsescstudent_final.rds - Bayesian mixed-effect model aiming to analyze escape behavior with a student's t distribution. Included for reproducibility.

brmsescskewnormal_final.rds - Bayesian mixed-effect model aiming to analyze escape behavior with a skew normal distribution. Included for reproducibility.

report-skewnormal.Rds - Report on the contents of the best fitting (skew normal) Bayesian mixed-effect model using the report R package. Included for reproducibility.

skewnormal-posterior-draws.Rds - Posterior draws from the best fitting (skew normal) Bayesian mixed-effect model for plotting Fig. S1b in the supplementary material. Included for reproducibility.

Commented analysis code is contained in the following files

2025-02-26-R-Code-OSF.html

2025-02-26-R-Code-OSF.Rmd

Software versions used

## R '4.4.2'

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