DOI: 10.5061/dryad.gtht76hx9
title: Data from: Inbreeding and competitor’s genetic relatedness affect dynamic male color-ornament expression in a cichlid fish

description: We examined the dynamic color-expression in male groups of the cichlid
 Pelvicachromis taeniatus during competition over breeding sites. Groups
 (trios) were either inbred or outbred and consisted each of 2 unfamiliar
 brothers and an unfamiliar, unrelated male. Males of P. taeniatus are
 territorial and develop a carotenoid-based yellow coloration at the
 ventral body region and the caudal fin. Intense body coloration signals
 dominance. Our study showed i) that outbred males generally developed more
 intense yellow coloration (chromaticity) during the experiment compared to
 inbred males and ii) that related males were more intensively colored at
 the caudal fin after the trials than the unrelated males. In conclusion,
 our study indicates environment-dependent inbreeding depression in a male
 ornament as well as positive kin-selected effects on ornamentexpression.
 Our study describes understudied sources of phenotypic variation in
 ornamental traits in animals.
description: <strong>Experimental animals/
 procedure</strong> The study animals were adult
 male Pelvicachromis taeniatus. In- and outbred P. taeniatus from the third
 generation of laboratory-bred fish were used. Inbred lines resulted from
 full-sibling breeding. Outbred fish originated from mating between
 unrelated individuals. All individuals were bred at the Institute of
 Evolutionary Biology and Ecology of the University of Bonn. In the
 experiment, 24 inbred and 24 outbred adult male P. taeniatus originating
 from 11 inbred and from 7 outbred families were used. 
 Five outdoor tanks were used during this experiment, which
 allowed us to simultaneously conduct five trials. Three adult male P.
 taeniatus (i.e., two unfamiliar, related individuals, and one
 unfamiliar unrelated individual) were separately transferred to each
 experimental. In one experimental tank, only one trio was introduced. In
 total, 8 inbred trios and 8 outbred trios were tested. In inbred trios,
 the unrelated fish originated from a different inbred line. We used only
 unfamiliar males to exclude dominance effects caused by
 previous interactions between males. All three fish were simultaneously
 released at the center of the tank. The fish were kept together in the
 tanks for three days without disturbance to give them the opportunity to
 build territories in the prepared ceramic caves. Before and after each
 trial, standard lengths (SL) of the males were measured (snout to the base
 of the caudal fin) and fish were weighted.To quantify the intensity of
 body coloration, photographs were taken using a standardized set-up
 including a photo box before and after each experiment.
 <strong>Data analysis</strong> To
 analyze the intensity of coloration, the program Adobe Photoshop CS4
 Extended (Version 11.0.2) was used. The coloration was measured in form of
 Lab-values by applying the CIELab color space, which is commonly used to
 study fish coloration. CIELab values separate contrast (L*) from color
 (a*, b*). Ten points at the caudal fin and ten points at the ventral body
 area were determined to quantify the yellow coloration. The
 Lab-chromaticity value was calculated by applying the formula:
 𝑐ℎ𝑟𝑜𝑚𝑎𝑡𝑖𝑐𝑖𝑡𝑦 = √𝑎² + 𝑏² <strong>Statistical
 analysis</strong> Data were analyzed using the
 software R 4.0.3. Color variables (chromaticity caudal fin coloration and
 chromaticity ventral coloration) were analyzed by conducting LMEs using
 the lme4-package. The effects of inbreeding and brother presence on the
 yellow color intensity (after the experiment) at the ventral body area and
 the caudal fin were investigated by LMEs. All predictor variables were
 binary. The initial color intensity was added as co-variate to control for
 significant differences in coloration among the fish before the
 experiment. We furthermore tested an interaction between the effects of
 inbreeding and the presence of a brother. As random factors, the family
 and the male group ID were included into the LMEs to control for multiple
 uses of families and group effects. Non-significant variables were removed
 stepwise from the LMEs in the order of their statistical relevance using
 the backward elimination procedure of the step function in the lmerTest
 package. To investigate the effects of inbreeding and kinship on the
 dominance behavior, we conducted a LME using inbreeding and brother
 present as explanatory variables and cave occupation as response variable.
 Again, we also tested the interaction between the effects of inbreeding
 and kinship. The same random effects were used. 
description: # Inbreeding and competitor’s genetic relatedness affect dynamic male
 color-ornament expression in a cichlid fish
 [https://doi.org/10.5061/dryad.gtht76hx9](https://doi.org/10.5061/dryad.gtht76hx9) **Summary of the study** We examined the dynamic color-expression in male groups of the cichlid *Pelvicachromis taeniatus* during competition over breeding sites. Groups (trios) were either inbred or outbred and consisted each of 2 unfamiliar brothers and an unfamiliar, unrelated male. Males of *P. taeniatus* are territorial and develop a carotenoid-based yellow coloration at the ventral body region and the caudal fin. Intense body coloration signals dominance. Our study showed i) that outbred males generally developed more intense yellow coloration (chromaticity) during the experiment compared to inbred males and ii) that related males were more intensively colored at the caudal fin after the trials than the unrelated males. In conclusion, our study indicates environment-dependent inbreeding depression in a male ornament as well as positive kin-selected effects on ornament expression. Our study describes understudied sources of phenotypic variation in ornamental traits in animals. Data collection: LG, SV Code: LG ## Description of the data and file structure ### Files and variables #### File: Data\_GussoneColour\_dynamics\_inbreedingR1.csv ##### Variables * Tank: Number of experimental tank * Fish ID: Number to identify each fish: GroupID_tank number_related/nonrelated * Family_tank_number: Identification number to determine the breeding line and breeding tank number * Family: Breeding family identification number * GroupID: Number of experimental trial to identify each trio * Kin_Nonkin: Related or unrelated to other experimental fish in same tank/trial * Inbreeding_Outbreeding: Inbred or outbred individual; I=Inbreeding, O=Outbreeding * Weight1: weight [g] on start date of experiment * Standard_length1: length [cm] on start date of experiment (snout to the base of the caudal fin) * absolut_size1: length [cm] on start date of experiment (snout to the end of caudal fin; total size) * BCI: body condition index * LAB_tailfin: LAB values of the tailfin on start date (chromaticity (LC)= √(a^2+b²)) * LAB_ventral: LAB values of the belly/ ventral side on start date (chromaticity (LC)= √(a^2+b²)) * LAB_tailfin2: LAB values of the tailfin on end date (chromaticity (LC)= √(a^2+b²)) * LAB_ventral2: LAB values of the belly/ ventral side on end date (chromaticity (LC)= √(a^2+b²)) * Cave_occupied: Did individual occupy cave during the experiment? Yes=1, No =0 ## Code/software **File: Inbreeding_P.taeniatus_clean.Rmd** ([https://zenodo.org/records/14796616](https://zenodo.org/records/14796616)[)](https://doi.org/10.5281/zenodo.14680057) Code to conduct linear mixed models and produce graphs. All statistical analyses was conducted in R 4.0.3. Packages: lme4, Version 1.1.35.5 lmerTest, Version 3.1.3 sjPlot, Version 2.8.17 ggplot, Version 3.5.1 dplyr, Version 1.1.4 gridExtra, Version 2.3 stringr, Version 1.5.1 ## Version changes **14-Feb-2024:** R code was updated. We included visualizations of the predicted model outputs.