RTgill-W1 gill cells of the rainbow trout (Oncorhynchus mykiss) were subjected to purified goniodomins (GDs) for 24 h to create dose-response curves. The bioassays were carried out with 100 µl of total incubation volume in 96-well plates. After 24 hours, 50 µl subsamples were transferred to a new 96-well plate for the assessment of lytic activity using a lactate dehydrogenase (LDH) cytotoxicity assay kit (CyQUANT™, Thermo Fisher Scientific, C20301) following the standard protocol provided by the manufacturer. The bioassays were analysed fluorometrically using a cell-imaging multi-mode reader (Cytation™ 3 Cell Imaging Multi-Mode Reader, BioTek). All data was pre-filtered according to (1) visual inspection of the gill cell densities in the 96-well plates and if densities differed greatly data was excluded, and (2) data were grouped by each biological gill cell line replicate, each biological A. pseudogonyaulax replicate, each strain and each cell density equivalent and subjected to a Dixon outlier test. If the Dixon test was significant, data was excluded. This dataset contains three biological gill cell line replicates, each tested with three to four concentrations of GDA, GDA-sa or GDA + GDA-sa each comprised of two to three technical replicates. The bioassays were carried out between August 23 and October 7, 2023 at the Department of Food Chemistry and Toxicology (LMC), Faculty of Chemistry, University of Vienna.