Data from: Habitat complexity alters the strength of sexual selection on female brain size in a livebearing fish
Data files
Nov 19, 2025 version files 168.35 KB
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Habitat_complexity_script.R
79.62 KB
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Matings.xlsx
54.20 KB
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Pairwise.xlsx
31.77 KB
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README.md
2.76 KB
Abstract
Animals often reproduce in complex environments, which should generate selection for both enhanced detectability in signaling traits and improved cognitive processing abilities. However, the extent to which signaling and cognitive traits have evolved to overcome the challenges of interacting in complex habitats remains understudied. We examined whether habitat complexity influences sexual selection in the pygmy halfbeak, Dermogenys collettei, a small livebearing freshwater fish. Using free-swimming arenas, we created low- and high-complexity environments and observed mating behaviors in mixed-sex groups. While the opportunity for sexual selection did not differ significantly between environments for either sex, we observed positive selection gradients for female brain size in open arenas, but not in complex habitats. Selection on morphological traits associated with visual signaling was also primarily detected in open environments, particularly in females. These results suggest that habitat complexity may reduce selection pressures on both cognitive traits, such as brain size, and signaling traits relevant to mate choice. Together, our findings highlight the importance of integrating cognitive traits into sexual selection theory and considering sex-specific selection across ecologically relevant contexts.
Dataset DOI: 10.5061/dryad.kh18932mr
Description of the data and file structure
R script, and data used to run the analysis and plots presented in: Daupagne, L., Devigili, A., McNeil, R., Wheatcroft, D., Kolm, N., & J. Habitat complexity alters the strength of sexual selection on female brain size in a livebearing fish. Evolution.
Files and variables
File: Habitat_complexity_script.R
Description: The only file that you need to open. Loads datasets and formats data for running the analysis and plotting figures. All of the files must be within your working directory for the analysis to work.
File: Matings.xlsx
Description: file containing data on individual ID
Variables
- day=day of the experiment.
- arena=arena ID.
- sex=M/F.
- individual_ID_in_video=ID used when recording.
- arena_type=no_barriers(open)/barriers(complex).
- beak_L=beak length (from the tip of the lower jaw to the anterior part of the eye) (mm).
- standard_L=body length (from the anterior part of the eye to the caudal peduncle) (mm).
- Gravid_spot=gravid spot area (mm2)
- brain_area= total dorsal brain area (mm2)
- anal_R=area of red coloration on anal fin (mm2)
- caudal_R=area of red coloration on caudal fin (mm2)
- dorsal_R=area of red coloration on dorsal fin (mm2)
- beak_R=area of red coloration on the beak (mm2)
- total_R=total area of red coloration mm2)
- anal_Y=area of yellow coloration on anal fin (mm2)
- cadual_Y=area of yellow coloration on caudal fin (mm2)
- dorsal_Y=area of yellow coloration on dorsal fin (mm2)
- beak_Y=area of yellow coloration on the beak (mm2)
- total_Y=total area of yellow coloration (mm2)
- No_matings=total number of matings
Cells filled with NA represent values that are not applicable (e.g., males do not have gravid spots)
File: Pairwise.xlsx
Description: file containing data on pairwise interactions
Variables
- arena_ID
- day=day of the experiment.
- arena=arena ID.
- person=person who recorded the behaviors.
- arena_ID_in_video=arena ID when recording was done
- arena_type=no_barriers(open)/barriers(complex).
- female_arena_ID=female ID when recording
- male_arena_ID=male ID when recording
- number_matings=total number of matings
Cells filled with NA represent values that are not applicable (the second observer did not provide an arena ID when recording was done)
Code/software
We provide the raw data files ("Matings.xlsx", "Pairwise.xlsx") and script file ("Habitat_complexity_script.R") to process the raw data, make plots, and run the statistics in R.