Effects of a Spirulina platensis-based diet on zebrafish female reproductive performance and larval survival rate

International audienceThe zebrafish (Danio rerio) is a valuable laboratory animal model that is used in many research areas. However, little is known about the factors that can affect zebrafish reproduction. To determine the potential benefit of an n-6 fatty acid (FA)-rich alga on zebrafish reproduction endpoints, we investigated the effects of the cyanobacterium Spirulina platensis delivered as sole food for zebrafish broodstock. Compared with a commercial flake diet-fed group (FG), egg production of the S. platensis diet-fed group (SG) was lower. However, egg survival rate was significantly higher for SG (73%) than for FG (55%). Moreover, larvae from SG developed more quickly compared with larvae from FG, because the hatching time was significantly shorter in SG than in FG eggs. No difference in egg and/or larval weight and size was observed between treatments. Interestingly, two different maternal investment strategies were observed according to the diet type, emphasizing a tradeoff between egg quality and egg quantity. A S. platensis-based diet was well suited to meet larval dietary requirements, as evidenced by a larval survival rate of 69% at 31-days post fertilization. Therefore, based on the results of this study, a S. platensis-based diet is recommended for zebrafish larvae in the first few days of life