The effect of poly β-hydroxybutyrate on larviculture of the giant freshwater prawn Macrobrachium rosenbergii

In this study, we investigated the effect of poly β-hydroxybutyrate (PHB) on the culture performance of larvae of the giant freshwater prawn Macrobrachium rosenbergii and on the bacterial levels inside the larval gut. Instar II Artemia nauplii were cultured with or without PHB (5 g l− 1) and/or a lipid emulsion rich in highly unsaturated fatty acids (HUFA) for 24 h. The effect of feeding PHB and/or HUFA-enriched Artemia nauplii on the performance of Macrobrachium larvae was investigated. Feeding larvae of the giant freshwater prawn with PHB-containing Artemia nauplii significantly increased survival and development of the larvae. Moreover, total bacterial counts and Vibrio spp. counts were found to be significantly lower in PHB-fed larvae when compared to control larvae, indicating that the PHB addition had a growth-inhibitory effect towards these potentially pathogenic microorganisms. Finally, a combination of PHB addition and lipid enrichment resulted in the best overall culture performance since it significantly improved larval survival as well as larval development. The optimal PHB concentration and formulation for bio-encapsulation into Artemia should be investigated further to increase the economical efficiency of Macrobrachium larval production.