Performance of Turquoise killifish, model organism in aging, on commercial pelleted diet: a step towards husbandry standardization

Abstract

Dietary alteration is one of the most universally effective aging interventions, making its standardization a fundamental need for model organisms in aging. Here we address the current lack of standardized formulated diet for Turquoise Killifish Nothobranchius furzeri - a promising model organism. We first demonstrated that N. furzeri can be fully weaned onto a standardized commercially available pelleted diet as the sole nutrition when kept in social tanks. We then compared nine somatic and six reproductive parameters between fish fed a typical laboratory diet - frozen chironomid larvae (bloodworms) and fish fed solely on BioMar pellets. Killifish readily consumed the pellets. Although fish consumed 7.5 times less food mass in the form of pellets than bloodworms, they had comparable somatic and reproductive performance. There was no difference between diet groups in body size, specific growth rate, condition or extent of hepatocellular vacuolation. Fish fed a pelleted diet had higher juvenile body mass and more visceral fat. Pellet-fed males had lower liver mass and possessed a lipid type of hepatocellular vacuolation instead of the prevailing glycogen-like vacuolation in the bloodworm-fed group. No significant effect was found on reproductive parameters. The negligible differences between dietary groups and good acceptance of pellets indicates their suitability as a useful starting point for diet standardization (and potential manipulation) in Nothobranchius furzeri.