Advanced DHA, EPA and ArA enrichment materials for marine aquaculture using single cell heterotrophs

Abstract

Heterotrophically grown algae and fungal biomass and their residual materials from an industrial oil extraction process were used as components in marine larval and broodstock diets. Crypthecodinium sp. phospholipid extract and meal, used to enrich rotifers and Artemia nauplii, produced higher levels of DHA and higher DHA/EPA ratios in these zooplankters than Schizochytrium sp. algal whole cell preparation or fish oil-based emulsion. The improved enrichment resulted in enhanced growth of Atlantic halibut larvae, whereas several other marine larvae species (sea bream, European sea bass and striped bass) respond almost equally to all enrichment materials. In addition, a 60% replacement of menhaden oil with algal oil and meal in striped bass broodstock diets resulted in a similar growth increase to that obtained with standard commercial diets. Striped bass broodstock fish diets supplemented with an arachidonic acid (ArA)-rich oil obtained from heterotrophically grown fungi, Mortierella alpina, was shown to have significant benefits on the hatching rate of larvae. These findings demonstrate the potential of single cell heterotrophs as a partial substitute or replacement for fish-based ingredients in aquaculture diets.