Spider body size and longevity after exposure to lead-polluted soil
Data files
Dec 10, 2024 version files 14.15 KB
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README.md
1.91 KB
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Spiderling_data.csv
12.24 KB
Abstract
Heavy metal pollution is pervasive in urban soils, and it can negatively impact the fitness of arthropods. Arthropod populations can evolve to become more tolerant or resistant to metals, but the mechanisms of these processes are understudied. Here, we tested the hypotheses of fixed adaptation and facultative adaptation in a lead (Pb)-exposure experiment using the progeny of field-collected Pardosa milvina spiders from urban (elevated soil Pb) and rural (background soil Pb) habitats. We predicted that spiders from both populations that were reared in the elevated Pb treatment would exhibit decreased body size in comparison to individuals reared in background Pb soil due to a facultative shift in metabolic investment from growth to Pb resistance, or, alternatively, that urban spiders would exhibit no change in body size across treatments, supporting fixed adaptation as a consequence of a legacy effect of urban Pb pollution. We found no evidence that exposure to elevated Pb soil had an effect on P. milvina’s adult body size or survival, regardless of population origin. Our results indicate that the amount of Pb accumulated by the spiders was not sufficient to induce a measurable change in body size, or that there was a fitness cost that was not measured in the experiment, such as changes in fecundity or body condition. Overall, these findings do not provide support for fixed or facultative adaptation to Pb pollution in P. milvina; as such, future studies should investigate other possible tradeoffs, including changes in egg size, body weight, and foraging effort.
README: Spider body size and longevity after exposure to lead-polluted soil
https://doi.org/10.5061/dryad.vdncjsz4w
Description of the data and file structure
Offspring from field-collected spiders (Pardosa milvina) were reared on soil substrates with three concentration ranges of Pb. The spiders came from two populations (rural and urban) for a total of six experimental treatments. Spiderlings were reared on a diet of springtails and crickets until they matured and eventually died. We recorded the survival time of adult spiders (n = 41-61) and measured the carapace width of a subset of specimens in each group upon death (n= 7-15). Measurements were made with an ocular micrometer (eye piece units) and converted to millimeters.
Pb_concentrations_of_treatment_soils.docx: Pb concentrations of treatment soils. Values were obtained by performing nitric acid microwave digestion (EPA Method 3051) followed by Inductively Coupled Plasma analysis on five subsamples from each treatment.
Files and variables
File: Spiderling_data.csv
Description:
Variables
- Popul: Location where spiderling's mother was collected (rural = Wooster, OH, USA; urban = Cleveland OH, USA)
- Treatment: Concentration of soil lead (high, low*, or background; see supplemental table for Pb ranges in mg/kg).
- *"Low" was revised to "elevated" in the published manuscript; this is reflected in the supplemental table.
- Longevity: Days that the spider lived (day 0 being when a spiderling was placed in its treatment soil). Missing values indicated by "NA".
- Sex: Male or Female. Missing values indicated by "NA".
- Age: Adult, penultimate, or immature. Missing values indicated by "NA" or blank cells.
- Body_Size: Carapace width in millimeters (converted from eyepiece units). Missing values indicated by "NA".
Code/software
No software is needed.
Methods
Offspring from field-collected spiders (Pardosa milvina) were reared on soil substrates with three concentration ranges of Pb. The spiders came from two populations (rural and urban) for a total of six experimental treatments. The spiderlings were reared on a diet of springtails and crickets until they matured and eventually died. We recorded the survival time of adult spiders (n = 41-61) and measured the carapace width of a subset of specimens in each group upon death (n= 7-15). Measurements were made with an ocular micrometer (eye piece units) and converted to milimeters.