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

Despite being one of the most used laboratory species in biomedical, behavioural and physiological research, the nutritional requirements of zebrafish (Danio rerio) are poorly understood, and no standardised laboratory diet exists. Diet and feeding regimen can significantly impact the welfare of the fish and in turn experimental reproducibility. Consequently, the establishment of a standardised 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. The aim of this systematic review was to determine the optimal feed for juvenile zebrafish growth and development. A comprehensive search was conducted in PubMed, Scopus and Google Scholar to identify relevant studies published up to August 2023 and the studies were selected based on the predefined inclusion/exclusion criteria. A total of 1065 articles were identified in the databases, 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 identify an insect-based diet as optimal for juvenile growth for all three growth parameters. We also identify areas of potential heterogeneity and conclude by encouraging a standardised laboratory diet to ensure reproducible data and encourage zebrafish welfare.