Skip to main content


Diane L Waller

Five R Markdown files (.Rmd) were created for the study entitled: Assessments of the binary mixtures of four toxicants on Zebra Mussel (Dreissena polymorpha) mortality. R codes were used to determine toxicant mixture ratios, summarize data, and analyze dose-response relationships in single toxicant and toxicant mixture trials. Files are described in the readme file in the order in which they were used for the study. Each R Markdown file has a complimentary R Script file (.R) with the same file name. All R Markdown files were created in RStudio version 1.2.1335 with R version 3.6.1 and Tidyverse version 1.3.0. Additional packages are listed in braces, “{},” with the corresponding R Markdown description.
Freshwater mussels of the order Unionida are among the most endangered animal groups globally, but the causes of population declines are often enigmatic with little known about the role of disease. In 2018, we collected wild adult pheasantshell (Actinonaias pectorosa) and mucket (Actinonaias ligamentina) during an epidemiologic survey investigating an ongoing mussel mass mortality event in the Clinch River, USA. Histopathology and transmission electron microscopy showed a novel microsporidian parasite primarily infecting the ovary of pheasantshell. Sequencing of the small subunit rRNA gene produced a 1333 bp sequence with greatest similarity to Pseudonosema cristatellae (AF484694.1; 86.36%; e-value = 0), a microsporidium...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact