The environmental fate, persistence, and point-source discharge of traditional molluscicidal compounds led to the development of an alternative biomolluscicide, Zequanox. Previous studies evaluated the efficacy and non-target animal safety of Zequanox in laboratory, mesocosm, and field enclosure studies. One study indicated sensitivity of salmonid species and lake sturgeon (Acipenser fulvescens Rafinesque 1817) following exposure to Zequanox, however, the exposures were not conducted in a manner consistent with the product label. This laboratory study evaluated sublethal and lethal impacts of Zequanox on lake sturgeon and lake trout (Salvelinus namaycush Walbaum in Artedi, 1792) following exposures that were conducted consistent with a Zequanox open-water label application. Fish were exposed to 50 and 100 mg Zequanox active ingredient/L for 8 h and then held for an additional 33-d for post-exposure observation. No acute mortality was observed in either species, however, significant latent mortality (46.2%) was observed in lake trout that were exposed to 100 mg of Zequanox active ingredient/L for 8 h. At the termination of the 33d holding period, biologically minimal, yet statistically significant, differences were observed in the terminal weight of surviving lake sturgeon (range 20.17 to 21.49 g) and biologically, as well as, statistically significant differences were observed in the terminal weight of surviving lake trout (range 6.19 to 9.55 g). Histological evaluation of lake trout gastrointestinal tracts suggest that a different mode of action is responsible for the Zequanox exposure-related impacts to lake trout than the mode of action that induces zebra and quagga mussel mortality. Further research is required to determine if Zequanox sensitivity is limited to lake trout or if all salmonid species are vulnerable to exposure and to determine if native fish will avoid Zequanox exposure.

The environmental fate, persistence, and point-source discharge of traditional molluscicidal compounds led to the development of an alternative biomolluscicide, Zequanox. Previous studies evaluated the efficacy and non-target animal safety of Zequanox in laboratory, mesocosm, and field enclosure studies. One study indicated sensitivity of salmonid species and lake sturgeon (Acipenser fulvescens Rafinesque 1817) following exposure to Zequanox, however, the exposures were not conducted in a manner consistent with the product label. This laboratory study evaluated sublethal and lethal impacts of Zequanox on lake sturgeon and lake trout (Salvelinus namaycush Walbaum in Artedi, 1792) following exposures that were conducted consistent with a Zequanox open-water label application. Fish were exposed to 50 and 100 mg Zequanox active ingredient/L for 8 h and then held for an additional 33-d for post-exposure observation. No acute mortality was observed in either species, however, significant latent mortality (46.2%) was observed in lake trout that were exposed to 100 mg of Zequanox active ingredient/L for 8 h. At the termination of the 33d holding period, biologically minimal, yet statistically significant, differences were observed in the terminal weight of surviving lake sturgeon (range 20.17 to 21.49 g) and biologically, as well as, statistically significant differences were observed in the terminal weight of surviving lake trout (range 6.19 to 9.55 g). Histological evaluation of lake trout gastrointestinal tracts suggest that a different mode of action is responsible for the Zequanox exposure-related impacts to lake trout than the mode of action that induces zebra and quagga mussel mortality. Further research is required to determine if Zequanox sensitivity is limited to lake trout or if all salmonid species are vulnerable to exposure and to determine if native fish will avoid Zequanox exposure.

Data associated with exposures of fathead minnows to varying concentrations of metformin and/or guanylurea. Includes three individual studies: ex vivo steroidogenesis assay, 96 h time course assay, 23 d reproduction assay. This dataset is associated with the following publication: Blackwell, B., G. Ankley, A. Biales, J. Cavallin, A. Cole, T. Collette, D. Ekman, R. Hofer, W. Huang, K. Jensen, M. Kahl, A. Kittelson, S. Romano, M. See, Q. Teng, C. Tilton, and D. Villeneuve. Effects of Metformin and its Metabolite Guanylurea on Fathead Minnow (Pimephales promelas) Reproduction (FY22 Manuscript). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 41(11): 2708-2720, (2022).

Data associated with exposures of fathead minnows to varying concentrations of metformin and/or guanylurea. Includes three individual studies: ex vivo steroidogenesis assay, 96 h time course assay, 23 d reproduction assay. This dataset is associated with the following publication: Blackwell, B., G. Ankley, A. Biales, J. Cavallin, A. Cole, T. Collette, D. Ekman, R. Hofer, W. Huang, K. Jensen, M. Kahl, A. Kittelson, S. Romano, M. See, Q. Teng, C. Tilton, and D. Villeneuve. Effects of Metformin and its Metabolite Guanylurea on Fathead Minnow (Pimephales promelas) Reproduction (FY22 Manuscript). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 41(11): 2708-2720, (2022).

The fathead minnow (Pimephales promelas) is a laboratory model organism widely used in regulatory toxicity testing and ecotoxicology research. Despite, the wealth of toxicological data for this organism, until recently genome scale information was lacking for the species, which limited the utility of the species for pathway-based toxicity testing and research. As part of a EPA Pathfinder Innovation Project, next generation sequencing was applied to generate a draft genome assembly, which was published in 2016. However, application of those genome-scale sequencing resources was still limited by the lack of available gene annotations for fathead minnow. Here we report on development of a first generation genome annotation for fathead minnow and the dissemination of that information through a web-based browser that makes it easy to search for genes of interest, extract the corresponding sequence, identify intron and exon boundaries and regulatory regions, and align the computationally predicted genes with other supporting evidence. This work greatly enhances the utility of the genome assemblies that were developed and makes it accessible to the ecotoxicology community world-wide, opening up a wide array of new research opportunities with the species. The URL associated with this data set provides access to the genome browser that was developed as well as the current gene models and evidence tracks. This dataset is associated with the following publication: Saari, T., A. Schroeder, G. Ankley, and D. Villeneuve. First generation annotations for the fathead minnow (Pimephales promelas) genome. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 36(12): 3436-3442, (2017).

This data set describes developmental and physiological effects observed in fathead minnow embryos that were exposed to sodium nitrate or conductivity-matched controls. Exposures were conducted in the laboratory from fertilization through 21 days post-fertilization (dpf). Nitrate doses were 0, 2, 5, 10, 25, or 100 milligrams per liter nitrate-nitrogen; conductivity controls were matched to the 10 and 100 milligrams per liter nitrate-nitrogen treatments. During the experiment, we assessed heart rate and percent arrhythmic heart beats at 3 dpf, timing of hatch and inflation of the posterior and anterior swim bladders, presence of pericardial edema or scoliosis, fish metrics at 21 dpf (fish length and weight; swim bladder length, width, and volume), and mortality. Water quality data during the exposure period are also presented, and include conductivity, pH, nitrate-nitrogen, total ammonia, unionized ammonia, and dissolved oxygen.

The present study describes pilot testing of a high throughput compatible transcriptomics assay with larval fathead minnows. One day post hatch fathead minnows were exposed to eleven different concentrations of three metals, three selective serotonin reuptake inhibitors, and four neonicotinoid-like compounds for 24 h and concentration response modeling was applied to whole body gene expression data. Transcriptomics-based points of departure (tPODs) were consistently lower than effect concentrations reported in apical endpoint studies in fish. However, larval fathead minnow-based tPODs were not always lower than concentrations reported to elicit apical toxicity in other aquatic organisms like crustaceans or insects. Random in silico subsampling of data from the pilot assays was used to evaluate various assay design and acceptance considerations such as transcriptome coverage, number of replicate individuals to sequence per treatment, and minimum number of differentially expressed genes to produce a reliable tPOD estimate. This dataset is associated with the following publication: Villeneuve, D., M. Le, M. Hazemi, A. Biales, D. Bencic, K. Bush, R. Flick, J. Martinson, M. Morshead, K. Santana Rodriguez, K. Vitense, and K. Flynn. Pilot testing and optimization of a larval fathead minnow high throughput transcriptomics assay. Current Research in Toxicology. Elsevier B.V., Amsterdam, NETHERLANDS, 4: 100099, (2022).