Vitamin C Enhances Vitamin E Status and Reduces Oxidative Stress Indicators in Sea Bass Larvae Fed High DHA Microdiets

Docosahexaenoic acid (DHA) is an essential fatty acid necessary for many biochemical, cellular and physiological functions in fish. However, high dietary levels of DHA increase free radical injury in sea bass (Dicentrarchus labrax) larvae muscle, even when vitamin E (α-tocopherol, α-TOH) is increased. Therefore, the inclusion of other nutrients with complementary antioxidant functions, such as vitamin C (ascorbic acid, vitC), could further contribute to prevent these lesions. The objective of the present study was to determine the effect of vitC inclusion (3,600 mg/kg) in high DHA (5 % DW) and α-TOH (3,000 mg/kg) microdiets (diets 5/3,000 and 5/3,000 + vitC) in comparison to a control diet (1 % DHA DW and 1,500 mg/kg of α-TOH; diet 1/1,500) on sea bass larvae growth, survival, whole body biochemical composition and thiobarbituric acid reactive substances (TBARS) content, muscle morphology, skeletal deformities and antioxidant enzymes, insulin-like growth factors (IGFs) and myosin expression (MyHC). Larvae fed diet 1/1,500 showed the best performance in terms of total length, incidence of muscular lesions and ossification degree. IGFs gene expression was elevated in 5/3,000 diet larvae, suggesting an increased muscle mitogenesis that was confirmed by the increase in the mRNA copies of MyHC. vitC effectively controlled oxidative damages in muscle, increased α-TOH larval contents and reduced TBARS content and the occurrence of skull deformities. The results of the present study showed the antioxidant synergism between vitamins E and C when high contents of DHA are included in sea bass larvae diets

Optimization of dietary vitamin C in fish and crustacean larvae: a review

HPLC techniques were adapted and standardized for quantification of ascorbic acid (AA) and its derivates in both diets and target organisms. To assess the dietary needs for AA at start of exogenous feeding, the AA content in the various live diets currently used in aquaculture (algae, rotifers, Artemia ) was analyzed. Application of techniques for boosting vitamin C using ascorbyl palmitate as the source enabled the transfer of elevated levels (up to 2,500 µg AA/g DW) of bioactive vitamin C. Larvae of fish (Clarias gariepinus, Dicentrarchus labrax, Scophthalmus maximus), white shrimp (Penaeus vannamei) and prawn (Macrobrachium rosenbergii) were enriched via the live food chain. This vitamin C enrichment procedure has proven to be a valuable technique for the evaluation of the effects of high levels of dietary vitamin C on stress resistance. However, in most of the species examined, the initial level of AA in Brachionus and Artemia impaired the determination of the AA requirements for optimal growth and survival. Formulated diets containing variable levels of stable AA-phosphate esters were used for the determination of minimal requirements for AA in the early post-weaning stage of marine fish species (D. labrax, S. maximus) and the postlarval stage of penaeid shrimp (Penaeus monodon, P. vannamei). For both fish species, results indicated that, within the concentration range tested, 20 mg AA/kg diet is sufficient for normal growth and survival. For production of postlarval shrimp, this level amounted to a minimum 20 and 130 mg AA/kg diet for P. monodon and P. vannamei, respectively, while a level of 2,000 mg AA/kg diet was needed to enhance the resistance of shrimp postlarvae to stress conditions and bacterial infections

The effect of HUFA and vitamin C-enriched rotifers on larval growth and survival of grouper (<i>Epinephelus suillus</i>)

Newly-hatched grouper larvae were reared for 24 days at a density of 15 larvae.l-1 in 250-l capacity cylindro-conical tanks filled with 200l seawater. Starting day 2, the larvae were given: Chlorella-fed rotifers (Chl-R) rotifers fed Culture Selco (INVE Aquaculture NV, Belgium) (CS-R), and rotifers fed Culture Selco and consequently enriched for 24h with 20% vitamin C (CSC-R). The rotifer density in the larval tanks was maintained at 15 rotifers.ml-1. The rotifer diet was supplemented with egg yolk until day 5. Each treatment had five replicates. Preliminary results show no significant difference in the survival rate of grouper larvae given Chl-R (4.21±2.8%), CS-R (2.56±0.9%) and CSC-R rotifers (1.89±1.5%). The total length of larvae given CS-R (9.74±1.2mm) and CSC-R rotifers (9.62±1.4mm) were significantly different (P<0.05) when compared with larvae given Chl-R rotifers (8.39±1.13mm). Likewise, the wet weight of the larvae fed CS-R (7.23±2.75mg) and CSC-R rotifers (7.29±3.02mg) was significantly different (P<0.05 from those fed Chl-R rotifers (3.26±1.66mg). The difference in growth between CS-R and CSC-R fed larvae was not significant. Additional runs will be conducted to verify the results of this experiment

Mesure du débit sanguin cérébral régional chez l'homme par le xénon 133

peer reviewe

The medical cyclotron : A new instrumentation in medicine

editorial reviewe

Enriquecimiento en ácido ascórbico del rotífero Brachionus plicatilis O.F. Müller para el cultivo de larvas de peces marinos

Actas del V Congreso Nacional de Acuicultura, Sant Carles de la Ràpita, 10-13 Mayo 1995[EN] The aim of this work was to establish a laboratory tool to permit rapid progress towards quantification of the requirement for ascorbic acid (AA) in marine fish larvae during the early feeding period. As a first step rotifers only differing in their AA levels were successfully produced. The biochemical and enzymatic composition of this organism remained stable in clear seawater for, at least, 24 hours. Therefore they were considered suitable for increasing A levels in turbot larvae. The AA level of the larvae was positively correlated with the AA content of the rotifer used. This demonstrates that AA was successfully incorporated in the larvae[ES] El objetivo de este trabajo fue desarrollar una técnica que permitiera estudiar el requerimiento de ácido ascórbico (AA) en larvas de peces marinos durante las fases iniciales de alimentación. En primer lugar, se desarrolló una técnica de enriquecimiento de rotíferos que permitió obtener distintos niveles de AA en la presa, sin observarse cambios en su composición bioquímica ni en su equipamiento enzimático 24 horas después de ser transferidos a agua limpia. Por tanto, la utilidad de la técnica utilizada se consideró satisfactoria. La utilización de estos rotíferos con larvas de rodaballo puso en evidencia una incorporación eficiente de la vitamina en las larvas, ya que el nivel de AA en estas estuvo directamente relacionado con el nivel de la vitamina en las presasEuropean Community, project no. AIR2-CT93-1449 (DG IX SSMA)N