A 2019 paper (Hamm et al. 2019) summarized the initial information-gathering efforts of the NTP Systematic Evaluation of the Application of Zebrafish in Toxicology (SEAZIT). Investigators in academic, government, and industry laboratories that routinely use zebrafish embryos for chemical toxicity testing were asked about their husbandry practices and standard protocols. Information was collected about protocol components including zebrafish strains, feed, system water, disease surveillance, embryo exposure conditions, and endpoints. Literature reviews assessed issues raised by the investigators. Interviews revealed substantial variability across design parameters, data collected, and analysis procedures. The presence of the chorion and renewal of exposure medium (static versus static-renewal) were identified as design parameters that could potentially influence study outcomes and are being addressed in an ongoing interlaboratory study. The information gathered in this effort provided a basis for future SEAZIT activities to promote more consistent practices among researchers using zebrafish embryos for toxicity evaluation.