testine (diamond). (B) with Hoechst 33342. The mCherry IL-17 web fluorescence labels the kidney (arrowheads) as well as the intestine red fluorescence throughout Snapshot of a gata1:DsRed larva (5 dpf) in lateral position. Hematopoietic cells are marked by (diamond). (B) Snapshot of a gata1:DsRed larva (5 Ventral gfp/brightfield overlay image on the marked by red heart (five dpf), exhibiting green MDM2 custom synthesis fluoresthe entire body. (C)dpf) in lateral position. Hematopoietic cells arelarval myl7:GFPfluorescence throughout the whole body. (C) Ventral gfp/brightfield overlay image of the larval myl7:GFP heart (five dpf), exhibiting green fluorescence in myocardial cence in myocardial cells about the heart chambers (atrium and ventricle) and in the atrioventricular canal. cells around the heart chambers (atrium and ventricle) and inside the atrioventricular canal.four.2. Reproducibility and Standardization 4.2. Reproducibility and Standardization Existing toxicity testing in zebrafish is impeded by the lack of experimental protocol Present toxicity testing in zebrafish is impeded by the lack of experimental aquatic standardization and by the resulting lack of reproducibility. One particular instance is theprotocol standardization and by the organic lack of reproducibility. needs a well-defined extoxicity analysis of ionizableresultingchemicals (IOCs), whichOne instance may be the aquatic toxicity analysis pH and buffer situations [216]. These crucial experimental concerns in perimental setup,of ionizable organic chemicals (IOCs), which requires a well-defined experimental setup, pH and buffer situations [216]. These important experimental concerns in zebrafish experimentation are increasingly recognized and discussed by the toxicological zebrafish experimentation are increasingly recognized and discussed by the toxicological neighborhood [66,67]. One particular essential aspect of this discussion could be the current heterogeneity neighborhood [66,67]. One crucial aspect of this discussion is the current varying culture of distinctive breeding conditions in zebrafish study, which includes the use ofheterogeneity of distinct breeding circumstances in zebrafish analysis, which includes the medium) [74,217], differmedia for embryos (e.g., E3 embryo medium vs. 0.3Danieau use of varying culture media for embryos (e.g., for incubation [75,164] 0.3Danieau s medium) [74,217], distinctive ent well-plate formatsE3 embryo medium vs. and numerous temperature conditions or illuwell-platestatus of for incubation [75,164] and variousand detailed circumstances of breeding mination formats incubators [54]. Standardization temperature reporting or illumination status of embryos and larvae is critical for information comparison, reproducibility and reliconditions of incubators [54]. Standardization and detailed reporting of breeding conditions of embryos and larvae is important for data comparison, reproducibility and reliability. Adult potential. Adult fish also need certain upkeep conditions (e.g., water high-quality, fish also need particular maintenance circumstances (e.g., water top quality, light/dark cycle, tank size, enrichment, and density) and nutrition (e.g., feeding plan, timing, food composition) for their wellbeing and the generation of viable fry for toxicological experiments, which really should be included in reported protocols related to other vertebrate species (for detailed info see Arrive recommendations: arriveguidelines.org/; accessed 9 December 2021). For Europe FELASA (Federation of European Laboratory Animal Science Associations) recommendations h