Data for: Validation of a nutria (Myocastor coypus) environmental DNA assay highlights considerations for sampling methodology

Nutria (Myocastor coypus) is a semi-aquatic rodent species that is invasive across multiple regions within the United States. Here we evaluated a qPCR assay previously described for use in Japan for application across invasive populations in the United States. We also compared two environmental DNA sampling methodologies for this assay: field filtration of large volumes of water passed through filters versus direct sampling of small volumes of water. We validated assay specificity, generality, and sensitivity, compared assay performance between two independent laboratories, and successfully tested the assay in situ on a known wild population. The filtration method required fewer samples for environmental DNA detection than direct sampling, but the choice of methods should be assessed based on specific field conditions and time and budget considerations. Our extensive assay validation and comparison across laboratories suggests that the assay is ready to be applied in environmental DNA m..., We evaluated assay specificity in vitro by testing DNA extracted from tissue, blood, or scat samples from one individual of each of six related nontarget sequences, including guinea pig, long-tailed chinchilla, North American porcupine , muskrat, mountain beaver, and North American beaver. Tissue samples were sourced from collections at the National Genomics Center for Wildlife and Fish Conservation (NGC; Missoula, MT). These samples were originally collected by state and federal partners from wildlife mortalities in accordance with appropriate sampling permits and wildlife handling approvals. Scat samples from guinea pig and long-tailed chinchilla were collected from animal pens at a local pet store and did not require any animal handling. DNA from all samples was extracted via DNeasy Blood and Tissue Kits (QIAGEN) and diluted to 0.1 ng/µL, as determined using a Qubit 2.0 fluorometer (Thermo Fisher Scientific) prior to quantitative polymerase chain reaction (qPCR). Each qPCR reaction w..., Microsoft Excel and R or RStudio are required to open the data files included with this submission.