Fermented feeds contribute to sustainable aquaculture by transforming waste into valuable diets for Moina macrocopa (Branchiopoda, Anomopoda) while adhering to industry standards

Abstract

Moina macrocopa is a promising zooplankton species with the potential to serve as a live food source for freshwater fish larvae. Aquaculture faces challenges in producing nutritious zooplankton to enhance larval fish growth and development. This study investigated the impact of mono and mixed enrichment on the life-table features, protein, lipid, and fatty acid content of M. macrocopa when fed various dietary supplements. It also assessed the effect of these enrichments on the growth performance, biochemical composition, digestive enzymes, and coloration of Betta splendens larvae. Results show that M. macrocopa enriched with a mix of fermented rice bran and fermented soybean meal had a significantly higher population density (30.57 ind ml−1) and survival rate (62%) compared to other treatments. This enrichment also significantly influenced life table parameters and enzyme activity. Proximate analysis revealed that larvae fed M. macrocopa enriched with this combination had the highest protein and lipid levels (22.3% and 9.03% DW, respectively). Coloration tests indicated significant differences in a * (green-red) and b * (blue-yellow) values among treatments. Specifically, fermented rice bran mixed with fermented soybean meal resulted in a red shade (a * = 2.06), while a mix with Chlorella sp. produced a more yellowish shade (b * = 1.45) (P<0.05). These findings suggest that enrichment types significantly influence the growth, coloration, and nutritional composition of cultured fish larvae, providing valuable insights for optimizing aquaculture practices. In conclusion, a waste-to-wealth fermented diet enriched to feed M. macrocopa, effectively enhanced its dietary composition and culture production, leading to improvements in the growth and survival rates of B. splendens larvae.