Data from: Predator life history and prey ontogeny limit natural selection on the major armour gene, Eda, in threespine stickleback
Data files
Jan 21, 2025 version files 61.04 KB
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Predator_Data.xlsx
33.26 KB
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README.md
2.27 KB
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Stickleback_Phenotypes.xlsx
25.52 KB
Abstract
Natural selection shapes the evolution of antipredator traits in prey. However, selection in the wild depends on ecological context, including features of predator and prey populations, making field studies of selection critical to understanding how predators shape selection on prey defenses. Threespine stickleback (Gasterosteus aculeatus) is a classic system to study the effects of predators on the natural selection of prey. In lakes and rivers, fish predators have been shown to impose selection against low plated adult stickleback phenotypes and genotypes. We directly measured selection by predatory salmonids on the Ectodysplasin-A (Eda) gene in estuary stickleback from California. Despite previous studies showing a positive correlation between predator presence and frequency of the Eda ‘complete’ allele in estuary populations, we found that Eda ‘low’ genotypes were not significantly more frequent in salmonid predator diets. Further, we found no evidence of changes in Eda genotype frequencies across generations that would suggest directional selection driven by predators. Prior selection studies have examined the effects of large resident trout on adult stickleback. In contrast, predators in this study were juvenile anadromous salmonids, which only ate juvenile stickleback whose plate phenotypes had not fully developed. Thus, in this case, predator life history and stickleback ontogeny may preclude strong selection on stickleback armor. Our results underscore the importance of selection studies in the wild for understanding the context-dependent nature of selection in natural populations.
README: Data from: Predator life history and prey ontogeny limit natural selection on the major armour gene, Eda, in threespine stickleback
https://doi.org/10.7291/D1MM4X
README for Dryad Submission associated with article: Predator life history and prey ontogeny limit natural selection on the major armour gene, Eda, in threespine stickleback
Description of the data and file structure
Three files are included, The R code used to analyze the data ("Software"), and two data files.
The first datafile, "Stickleback Phenotypes.xlsx", is organized with a row for each individual fish.
- Fish ID: that was associated with the preserved specimen,
- Tissue Sample Label: that was used to identify the sample tube.
- Sample: "Fall", "Spring", or "Diet" - i.e. removed from the guts of one of the predatory fish.
- Sample Date: We also record the sample date (MM/DD/YYYY)
- Fresh Length in mm is the standard length of the fish.
- Left Plate Count: the number of distinct lateral plates counted on the left side of the fish's body.
- Eda Genotype is either CC - two copies of the complete allele, CL - a heterozygote, or LL - two copies of the low allele.
- R# is reach number,
- Pred Fish # is the unique fish within that reach on that sampling date.
- Pred Fish Spp is the species Coho salmon - Oncorhynchus kisutch, or steelhead - Oncorhynchus mykiss.
- Pred FL is the fork length of the predator.
The second datafile, Predator Data.xlsx is organized with a row for each predatory salmonid that was surveyed for stomach contents.
- Fish_ID is a unique identifier within a given sampling unit.
- Date is the date of capture for which this stomach sample was taken (MM/DD/YYYY)
- Site is a location within the watershed.
- Species - Omki - Coho Salmon - Oncorhynchus kisutch, or Onmy - Steelhead - Oncorhynchus mykiss.
- FLength_mm is fork length of the predator in millimeters.
- Mass_g is the mass of the predator in grams.
- Unique ID (PIT Tag Number) is the code from the PIT tag, which can be used as a unique ID. Fish below a certain 65mm FL were not tagged.
- #TSS eaten is the number of unique stickleback that were found in the diet sample of this fish on this date
In both files, "n/a" indicates missing data.