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Review
. 2025 Apr 1;44(4):916-925.
doi: 10.1093/etojnl/vgaf036.

Critical review of chronic toxicity testing approaches with the saltwater mysid (Americamysis bahia) used in pesticide registration

Margaret Fleming  1 , Jane Staveley  2 , Alan Samel  3 , John Aufderheide  4 , T Michelle Blickley  5 , Audrey Bone  6 , Eric Bruns  6 , Tara Catron  7 , Daniel Edwards  7 , Sean Gallagher  4 , Maike Habekost  8 , Cliff Habig  9 , Kevin Henry  10 , Alan Jones  7 , Gwendolin Kraetzig  11 , Shari Long  12 , Patricia Lopez-Mancisidor  13 , Joseph Marini  14 , Amanda Milligan  4 , Adric Olson  15 , Bridget F O'Neill  5 , Eric Peterson  16 , Lee Sayers  14 , Suzanne Schneider  4 , Katie Stump  17 , Seamus Taylor  18 , Theodore Valenti  16
Affiliations
Review

Critical review of chronic toxicity testing approaches with the saltwater mysid (Americamysis bahia) used in pesticide registration

Margaret Fleming et al. Environ Toxicol Chem. .

Abstract

The United States Environmental Protection Agency (USEPA) has a conditional requirement for a chronic toxicity test with mysids (Americamysis bahia) for registration of pesticide products. Achieving performance acceptability criteria in control treatments for this study can be challenging because the current draft test guideline, which was published in 1996 under USEPA Office of Prevention, Pesticides, and Toxic Substances (OPPTS) 850.1350, Mysid Chronic Toxicity Test, provides limited information on study design and conduct. This critical review was undertaken to (1) identify areas of inconsistency in acceptability criteria between the 1996 draft OPPTS test guideline and ASTM International test guidance, (2) highlight areas that require additional clarification, (3) discuss areas that are impractical or have uncertain scientific relevance regarding the objectives of the test, and (4) provide recommendations for revision of the draft OPPTS test guideline. To achieve this, 116 final study reports from chronic mysid toxicity tests conducted over approximately the past 30 years were collected. From these reports, survival, growth, and reproduction data from negative and solvent control groups were compiled. Through investigation of trends in the data, it became apparent that no-observed-effect concentrations (NOECs) were most commonly based on reproductive endpoints, followed by adult growth endpoints and adult survival. Notably, less than 1% of studies had a NOEC based solely on a second-generation measurement endpoint. Analysis of this comprehensive data set provided clarity on the establishment of acceptability criteria for the study and elements of the testing procedure that can be streamlined without loss of critical information, which resulted in a set of recommendations to improve future versions of the chronic mysid toxicity test guideline.

Keywords: aquatic invertebrates; aquatic toxicology; marine toxicity tests; pesticide regulation.

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Conflict of interest statement

During the period this work was conducted, Margaret Fleming and Jane Staveley were employed by Exponent, a consulting firm that offers services to chemical companies, among others. Alan Samel was previously employed by FMC Corporation. John Aufderheide, Sean Gallagher, Cliff Habig, Joseph Marini, Amanda Milligan, Lee Sayers, and Suzanne Schneider are employed by contract laboratories or consulting firms, as disclosed by their affiliation, that offer services to chemical companies, among others. T. Michelle Blickley, Audrey Bone, Eric Bruns, Tara Catron, Daniel Edwards, Maike Habekost, Kevin Henry, Alan Jones, Gwendolin Kraetzig, Shari Long, Patricia Lopez-Mancisidor, Adric Olson, Bridget F. O’Neill, Eric Peterson, Seamus Taylor, and Theodore Valenti are employed by chemical companies as disclosed by their affiliation. These companies produce pesticides, among other products. Katie Stump is employed by CropLife America, who supported the present study financially via the efforts of Exponent.

Figures

Figure 1.
Figure 1.
(A) Photograph of male Americamysis bahia. (B) Photograph of gravid female Americamysis bahia.
Figure 2.
Figure 2.
The most sensitive measurement endpoints reported in the assembled mysid chronic toxicity study reports. Unless specified as an exposed offspring (generation 2; G2) of adult generation (G1) endpoint, these endpoints refer to effects on the exposed adult generation. Fourteen of the collected studies are not included because no significant impact on any measurement endpoint was observed.
Figure 3.
Figure 3.
Fraction of studies reporting each considered measurement endpoint. Includes studies that reported enough information to calculate the endpoint if not directly reported.
Figure 4.
Figure 4.
Average adult survival quartile distribution with the average value indicated with an “X.” The horizontal line indicates the ASTM International test guideline acceptability criterion for control survival (70%). Note. ASTM = American Society for Testing and Materials.
Figure 5.
Figure 5.
Average number of young produced per reproductive day quartile distribution with the average value indicated with an “X.” The horizontal line indicates the draft Office of Prevention, Pesticides, and Toxic Substances test guideline acceptability criterion for number of offspring per control female per day (3).
Figure 6.
Figure 6.
Average number of young produced per surviving female quartile distribution with the average value indicated with an “X.” The horizontal line indicates the ASTM International test guideline acceptability criterion for average number of offspring per control female (3). Note. ASTM = American Society for Testing and Materials.
Figure 7.
Figure 7.
Average day of first brood release quartile distribution with the average value indicated with an “X” and statistical outliers shown as separate points outside of the box and whisker plot.
Figure 8.
Figure 8.
Average number of brood releases quartile distribution with the average value indicated with an “X” and a statistical outlier shown as a separate point outside the box and whisker plot.
Figure 9.
Figure 9.
Average body length at test termination quartile distribution with the average value indicated with an “X.”
Figure 10.
Figure 10.
Average dry weight at test termination quartile distribution with the average value indicated with an “X” and statistical outliers shown as separate points outside the box and whisker plots.
Figure 11.
Figure 11.
Average G2 survival (%) quartile distribution with the average value indicated with an “X” and statistical outliers shown as separate points outside the box and whisker plot. Note. G2 = second generation.
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References

    1. Anderson B., Phillips B. (2016). Saltwater toxicity tests. In Blasco J., Chapman P.M., Campana O., Hampel M. (Eds.), Marine ecotoxicology (pp. 167–197). Academic Press. 10.1016/B978-0-12-803371-5.01001-8 - DOI
    1. ASTM International. (2003). ASTM International E1191-03a: Standard guide for conducting life‐cycle toxicity tests with saltwater mysids. Approved October 1, 2003. https://www.astm.org/e1191-03ar23e01.html. Last re-approved January 25, 2023.
    1. Lussier S. M., Champlin D., Kuhn A., Heltshe J. F. (1996). Mysid (Mysidopsis bahia) life-cycle test: Design comparisons and assessment. ASTM International Special Technical Publication, 1306, 257–269.
    1. Office of Chemical Safety and Pollution Prevention. (2016). Ecological Effects Test Guidelines: OCSPP 850.1300 Daphnid Chronic Toxicity Test (EPA 712-C-16-005). U.S. Environmental Protection Agency.
    1. Office of Prevention, Pesticides and Toxic Substances. (1996). Ecological Effects Test Guidelines: OPPTS 850.1350 Mysid Chronic Toxicity Test Public Draft (EPA 712-C-96-120). U.S. Environmental Protection Agency.

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