DOI: 10.5061/dryad.2547d7x39
title: Data from: Non-parallel impacts of predators on the evolution of colouration plasticity in Trinidadian killifish

description: Animal colouration is a key trait affecting survival and reproduction, yet
 the evolutionary drivers of colouration plasticity remain poorly
 understood. Here, we examine how predation shapes both baseline
 colouration and physiological colouration plasticity in the Trinidadian
 killifish (Anablepsoides hartii). This species inhabits streams that vary
 in fish predator presence, creating a replicated natural experiment across
 three rivers. We hypothesised that fish from high-predation sites would
 exhibit lighter baseline colouration due to associations with open canopy
 and increased light, and that predation would select for stronger
 plasticity in background-induced colour change. We assessed colouration
 before and after exposure to black or white backgrounds and analysed
 variation by predation regime, river, and sex. Our results show that
 baseline colouration differed significantly by predation regime, river
 identity, and sex, with high-predation fish generally lighter. A. hartii
 also displayed strong plasticity, darkening on black backgrounds and
 lightening on white. However, the effect of predation on plasticity was
 inconsistent across rivers, suggesting that local ecological factors
 mediate these responses. Our study provides rare empirical evidence for
 both baseline and plastic variation in colouration driven by ecological
 context, offering new insight into how phenotypic plasticity evolves in
 response to environmental pressures like predation.
description: # Dryad dataset Dataset DOI:
 [10.5061/dryad.2547d7x39](10.5061/dryad.2547d7x39) ## Description of the
 data and file structure Data and code supporting the article 'Local
 adaptation in colouration plasticity of Trinidadian killifish'. This
 primarily consists of 3 .csv files containing collected data regarding the
 focal individuals and surrounding ecological measurements. More
 specifically, all_killifish_colourmap_calib.csv contains the calibrated
 colour values for each fish, Ecological_variables.csv contains ecological
 measurement data and Killifish_sex_length.csv contains both the sex and
 length data for each individual. This dataset also contains the Shape
 files of Trinidad used to create Figure 1, which was downloaded from
 [https://hub.arcgis.com/datasets/uwi::coastline-trinidad-and-tobago/about](https://hub.arcgis.com/datasets/uwi::coastline-trinidad-and-tobago/about). ### Files and variables #### File: Ecological_variables.csv **Description:** Ecological measurements of the focal sites ##### Variables * Date: date measurement was taken (day, month, year) * River: Which river was measured (AM = Arima, AP = Aripo & EC = El Cedro) * Predation: Which regime was measured (HP = High Predation, KO = Killifish-only) * sample: The sample taken, to distinguish within site variation * water_temp: Water temperature in °C * conductivity: Conductivity in µS * oxygen_saturation: Oxygen saturation in % * lux: light measured in Lux * width_m: widest point of stream in m at that section * depth_m: deepest point of stream in m at that section * canopy_cover: estimated canopy cover in % * time: time of day observed * weather: approximate weather conditions at time of sample * pH: pH values as measured in the stream #### File: Killifish_sex_length.csv **Description:** Supplementary file to add the covariates of sex and length ##### Variables * File: Name of photo file for an individual fish * Sex: The sex of the fish contained within (F = Female, M = Male, J = juvenile and not possible to sex) * Length: The length of the fish in mm #### File: all_killifish_colormap_calib.csv **Description:** Primary data file for analysis ##### Variables * : Column with file path to the associated photo. This is a redundant column * specimen.factors: detailed file name for each individual photo, which is used in the code to provide identity and independent variables. * r_interior1: the extracted colour value for the red colour channel at position interior 1 * g_interior1: the extracted colour value for the green colour channel at position interior 1 * b_interior1: the extracted colour value for the blue colour channel at position interior 1 * r_interior2: the extracted colour value for the red colour channel at position interior 2 * ... * these columns continue for every position and produce too many columns to describe each one, but they all follow the same basic structure. #### File: Shape_files.zip **Description:** Zip file containing the shapefiles necessary to recreate 'Figure 1' in the associated manuscript (Elevation map of Trinidad with sampling sites identified). Shapefiles are vector-based geographic information system (GIS) data. They can be opened and used in any GIS software and in R or Python. A shapefile consists of multiple file types beyond the .shp (specifically, .cpg, .dbf, .prj, and .shx). The user only interacts directly with the .shp file but the other files need to be in the same directory. Specifically in this case the shapefiles refer to the coastline of Trinidad and Tobago. #### File: 2025_08_29_Analysis_script.R **Description:** Code to reproduce the analyses and each figure ## Code/software The code was created using R (R Core Team (2024). \_R: A Language and Environment for Statistical Computing. R Foundation for 'statistical Computing, Vienna, Austria. [https://www.R-project.org/](https://www.R-project.org/). The packages used with are: 'Car' 'ggplot2' 'tidyr' 'dplyr' 'MANOVA.RM' 'adegenet' 'emmeans' 'patchwork' 'cowplot' 'sf' 'terra' 'elevatr' 'grid' 'viridis' 'ggrepel' ## Access information Other publicly accessible locations of the data: * NA Data was derived from the following sources: * The shapefiles were derived from [https://hub.arcgis.com/datasets/uwi::coastline-trinidad-and-tobago/about](https://hub.arcgis.com/datasets/uwi::coastline-trinidad-and-tobago/about)