DOI: 10.5061/dryad.tqjq2bwc4
title: Dietary melatonin supplementation mitigates the negative effects of artificial light at night in the Pacific field cricket, Teleogryllus oceanicus

description: 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.
description: # Dietary melatonin supplementation mitigates the negative effects of
 artificial light at night in the Pacific field cricket, Teleogryllus
 oceanicus Dataset DOI:
 [10.5061/dryad.tqjq2bwc4](https://doi.org/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"