Poly-beta-hydroxybutyrate-enrichedArtemiasp. for giant tiger prawnPenaeus monodonlarviculture

Abstract

The beneficial effects of PHB as supplement for giant tiger prawn Penaeus monodon postlarvae using a short‐term enrichment strategy via Artemia were examined. The effects of co‐supplementing with a lipid emulsion were also evaluated to determine whether it yielded an additional benefit. Results on the average weight and larval development were not significantly different among postlarvae fed the different dietary treatments, indicating that PHB supplementation could not be used to stimulate growth in P. monodon postlarvae while such positive results have been reported in other aquaculture species. Nonetheless, significantly higher survival was obtained in postlarvae fed PHB‐enriched Artemia irrespective of lipid enrichment. In addition, PHB increased the survival of the postlarvae after exposure to a lethal dose of ammonia. Lipid supplementation nullified this effect. The cumulative mortality of postlarvae subjected to a sublethal concentration of ammonia for 24 h and subsequent exposure to pathogenic Vibrio campbelli showed that PHB but not lipids could effectively enhance the resistance of the postlarvae. Co‐supplementing lipids even significantly decreased this outcome. Our study indicates that PHB supplementation increases the quality of larval P. monodon and their chance of surviving under adverse environmental conditions. The short‐term co‐supplementation with lipid emulsion did not add to these effects.

Immunostimulatory effects of dietary poly-β-hydroxybutyrate in European sea bass postlarvae

“…The observed change in the intestinal microbial community is hypothesized to develop due to the degradation of PHB into SCFAs, causing a decrease in the GI pH, which inhibits the growth of certain pathogenic bacteria (De Schryver et al., , ; Defoirdt et al., ). Accordingly, it could be demonstrated that PHB effectively enhances the disease resistance in aquatic invertebrates (Ludevese‐Pascual et al., ; Sui et al., ) and fish. Dietary PHB protected gnotobiotic Nile tilapia larvae (Situmorang et al.…”

Artificial substratum consisting of poly-β-hydroxybutyrate-based biodegradable plastic improved the survival and overall performance of postlarval tiger shrimpPenaeus monodon

“…The overall status of the postlarvae at the start of the experimental trial and the survival and growth parameters at the end of the trial were examined according to the methods described by Ludevese‐Pascual et al, (). The number of surviving postlarvae in each tank was counted and percentage survival was computed following the formula of Thompson and Bergersen ():where X is the number of larvae present at the end of the experimental period and N is the number of larvae at stocking (day 0).…”

“…The mean weight within each replicate tank was determined by collecting all surviving postlarvae that were not used in the stress test and challenge trial. These were sacrificed by immersion in ice cold seawater and subsequently processed according to the methods described by Ludevese‐Pascual et al, (). The mean daily growth (ADG) was calculated within each replicate tank as mentioned in weight measurement and the mean ADG for each treatment was calculated following the formula of Ravuru and Mude ():…”

“…The resistance against lethal ammonium chloride of the postlarvae at the end of the experimental trial was evaluated. The computed LD 50 of 143 mg/L ammonium chloride was used (Ludevese‐Pascual et al, ) and actual ammonia stress test was carried out according to Reed and Muench () with slight modifications. Ten postlarvae were randomly collected from each tank and transferred to a container containing 2 L UV‐sterilized seawater with 143 mg/L ammonium chloride with a mean pH of 8.2.…”

“…An internal standard 20:2 (n‐6) was added before the reaction and fatty acid methyl esters (FAMEs) were extracted using hexane. Quantitative determination was done using a Chrompack CP9001 gas chromatograph equipped with an autosampler and data were expressed as mg FAMEs per gram lipid (mg/g lipid) and mg FAMEs per gram dry weight (mg/g DW) as mentioned by Ludevese‐Pascual et al, ().…”