Bacteria contribute to Artemia nutrition in algae-limited conditions: A laboratory study

We investigated the effect of the stimulation of bacterial growth on Artemia performance in combination with a standard and with a low algal feeding regime. In both regimes, organic carbon (supplied as sucrose or soluble potato starch) and N-15 labeled inorganic nitrogen (supplied as NaNO3) were used to stimulate bacterial growth in the Artemia cultures at C/N ratio 10 and 50. After a culture period of 15 days, significantly improved biomass production was obtained in all treatments with the low algae feeding regime, supplemented by carbohydrate addition. In addition, results of 15N accumulation and fatty acid analysis in Artemia indicated that Artemia utilized more bacteria in algae-limited conditions. Our study shows that bacteria can be used as a nutrient source for Artemia compensating for suboptimal algae supply. In Artemia pond cultures, carbohydrate addition may hence potentially be used to stimulate the conversion of nitrogen waste into heterotrophic bacterial biomass. This can be converted into protein-rich Artemia biomass, especially when algae are in sub-optimal supply. These findings open perspectives for alternative Artemia pond production protocols, in addition to the present management procedures that exclusively focus on phytoplankton blooms as nutrient source to sustain dense Artemia populations. (C) 2013 Elsevier B.V. All rights reserved.