Dietary melatonin supplementation mitigates the negative effects of artificial light at night in the Pacific field cricket, Teleogryllus oceanicus
Data files
Oct 08, 2025 version files 60.04 KB
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opt.expon.mod.r
1.52 KB
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README.md
3.39 KB
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Rutkowski_et_al__2025.Rmd
8.46 KB
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Rutkowski_et_al._2025.xlsx
46.67 KB
Abstract
Artificial light at night (ALAN) is linked to negative behavioural and physiological consequences in animals. A potential mechanism for these adverse effects is ALAN’s inhibition of melatonin synthesis, a zeitgeber for cellular processes, and a powerful antioxidant. Accordingly, melatonin supplementation can ameliorate ALAN-linked pathologies. Most studies expose animals to ALAN across their whole lifespan or a single life stage, but many nocturnal species experience variable exposure across heterogeneously lit landscapes. We investigated the effects of ALAN during both early- and late-juvenile development on adult reproduction in the Pacific field cricket Teleogryllus oceanicus, and whether dietary melatonin supplementation could mitigate these effects. We found life-stage-specific developmental effects of ALAN. Life-long ALAN exposure accelerated juvenile development, yet did not affect late-juvenile, total development time or adult body mass. Moreover, we confirm the potential for melatonin supplementation to rescue male sperm viability and daily egg production by females. The degree of ‘rescue’ was sex- and potentially age-specific, which may be explained by the differential effect of ALAN on early juvenile development. Critically, this effect would have been masked had we not partitioned this early life stage, underscoring the importance of considering life-stage-specific ALAN exposure when evaluating ecological and physiological consequences.
Dataset DOI: 10.5061/dryad.tqjq2bwc4
Description of the data and file structure
Authors: Nicola-Anne J. Rutkowski, Théresa M. Jones, Kathryn B. McNamara
The dataset contains data from physiological assays (early survival, development, body weight, reproductive investment of males and females).
Files and variables
File: Rutkowski_et_al__2025.Rmd
Description: R code
The code has been broken down into chunks in order to make it more user friendly, before trying to replicate any analysis ensure the additional file (opt.expon.mod.r) is loaded otherwise the data analysis will not run.
File: Rutkowski_et_al._2025.xlsx
Description: Data from experiment, three tabs.
Variables
- Tab one ('full dataset') contains the all of the specific information for each individual.
- Cricket_ID, Sex (M/F), Light_treatment (Dark, Acute or Chronic), Original_Light (used for the egg to penultimate development analysis, where the acute individuals were still in the Dark light treatment, Dark or ALAN). Melatonin_treatment (0/50), Origin_box (the group box crickets were housed until until the pre-penultimate stage), Weight (in grams), egg_to_pen (time from egg hatch to penultimate in days), penultimate_to_adult_time (time from penultimate to adult, in days), total_development (in days), successfully mated (0/1, did mate successfully twice, females only). Eggsperday (the number of eggs laid, per day), did_produce_sperm_d1 (0/1, did a male produce a spermatophore on day 1, males only), did_produce_sperm_d2 (0/1, did a male produce a spermatophore on day 2, males only), arcsine_d1 (proportion of live sperm on day 1, arcsine transformed), arcsine_d2 (proportion of live sperm on day 2, arcsine transformed).
- Some cells in this tab are empty, here this may occur where data is specific to one sex only, or individuals failed to mate twice successfully, thus not laying eggs (females) or produce spermatophores (males).
- Tab two ('early survival') contains all the origin boxes of the crickets and their survival rates.
- Origin_box (the group box crickets were housed until until the pre-penultimate stage), date_of_setup, Light treatment (Dark or ALAN), initial_box_density (total number of individuals put in the box), Survival (number of individuals that survived to the pre-penultimate stage), proportion_survived.
- Tab three ('males') just organises the male data differently to aid with the creation of Figure 2b.
File: opt.expon.mod.r
Description: Function that establishes to which exponent (power) a variable should be raised to maximise the probability of the supplied model's residuals testing as being normally distributed using the Shapiro-Wilks test.
The function takes two arguments: the base model and the range of exponents to be tested. This range is set by default to 100 values between 0 (but not including 0) and 4.
Author: Emile van Lieshout, Date: 1/8/2013
Code/software
To set up the R code you will need to download the following packages: readxl, car, multcomp, lme4, MuMIn, smatr, tidyverse, ggplot2, dplyr, Matrix, glmmTMB, emmeans).
You will also need to load: "opt.expon.mod.r"