The effect of laboratory diet and feeding on growth parameters in juvenile zebrafish

Despite being one of the most used laboratory species in biomedical, behavioral and physiological research, the nutritional requirements of zebrafish (Danio rerio) are poorly understood, and no standardized laboratory diet exists. Diet and feeding regimen can substantially impact the welfare of the fish and, in turn, experimental reproducibility. Consequently, the establishment of a standardized diet and feeding protocol for laboratory zebrafish is imperative to enhance animal welfare, guarantee research reproducibility and advance the economic and environmental sustainability of laboratory dietary practices. Here the aim of this systematic review is to provide an overview of the parameters that need to be standardized in future nutritional studies to facilitate future meta-analyses for confirmation of an optimal juvenile diet for growth. A comprehensive search was conducted in PubMed and Scopus to identify relevant studies published up to August 2023, and the studies were selected on the basis of the predefined inclusion/exclusion criteria. The databases yielded a total of 1,065 articles, of which 14 were included in this review. We conducted data extraction and risk-of-bias analysis in the included studies. Statistical comparisons for specific growth rate, weight gain (%) and length gain (%) parameters were performed to determine the optimal feed for enhanced juvenile growth. We identified significant heterogeneity and caveats to our findings owing to a lack of standardization of experimental conditions in nutritional studies. Our findings highlight an urgent need for research on zebrafish nutrition. Therefore, the standardized parameters we have reported here represent a critical starting point for studies.