Effect of culture system and diet in early larval stages over skeletal deformities development in gilthead sea bream

[ES] Main deformities such as lordosis, opercular deformities and upper/lower jaws shortening are considered as quality descriptors in commercial marine fish fry production and seem to be related with larval culture conditions in early larval stages. The aim of this work was to obtain information about the contribution of the diet and rearing system to the apparition of these abnormalities in gilthead sea bream (Sparus aurata) larvae in semi-industrial scale facilities. For that purpose, two different larval rearing systems semi-intensive and intensive were compared; besides, two different rotifer enrichments, DHA Protein Selco, (Inve Aquaculture, Dendermonde, Belgium) (R1) and Red Pepper Paste, (Bernaqua bvba, Turnhout, Belgium) were tested in the intensive system. Biochemical composition of larvae, preys and commercial products was analysed. At 50 days post hatching six hundred fish per treatment were individually studied under stereoscope and deformity frequency recorded. Besides at 95 days post hatching fry were soft X ray monitored. Both rotifer enrichment and rearing system affected survival, growth and deformity frequency. Rearing system did not affect total larvae fatty acid content except at 20 dah, where DHA were significantly higher and EPA significantly lower in Semi-intensive system. A significantly lower percentage of deformity rates together with better survival and growth were obtained in the semi-intensive system. In dietary treatment, rotifer enrichment significantly affected larval survival. R1 rotifers enrichment significantly (P<0.05) improved survival when compared to fed R2 larvae. The content of DPA was significantly (P<0.05) higher in R2 fed larvae reflecting the R2 rotifers content of this fatty acid. The level of this FA tended to decrease in concordance with the rotifers replacement by artemia in the diet. The effects n-3-HUFA and DPA (22:5n-6) over larval survival and skeletal deformities development is discussed.

The Azores Current System and the Canary Current from CTD and ADCP data

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Human skeletal muscle and erythrocyte proteins involved in acid-base homeostasis: adaptations to chronic hypoxia

[EN] Chronic hypoxia is accompanied by changes in blood and skeletal muscle acid-base control. We hypothesized that the underlying mechanisms include altered protein expression of transport systems and the enzymes involved in lactate, HCO3- and H+ fluxes in skeletal muscle and erythrocytes. Immunoblotting was used to quantify densities of the transport systems and enzymes. Muscle and erythrocyte samples were obtained from eight Danish lowlanders at sea level and after 2 and 8 weeks at 4100 m (Bolivia). For comparison, samples were obtained from eight Bolivian natives. In muscle membranes there were no changes in fibre-type distribution, lactate dehydrogenase isoforms, Na+,K+-pump subunits or in the lactate-H+ co-transporters MCT1 and MCT4. The Na+-H+ exchanger protein NHE1 was elevated by 39 % in natives compared to lowlanders. The Na+-HCO3- co-transporter density in muscle was elevated by 47-69 % after 2 and 8 weeks at altitude. The membrane-bound carbonic anhydrase (CA) IV in muscle increased in the lowlanders by 39 %, whereas CA XIV decreased by 23-47 %. Levels of cytosolic CA II and III in muscle and CA I and II in erythrocytes were unchanged. The erythrocyte lactate-H+ co-transporter MCT1 increased by 230-405 % in lowlanders and was 324 % higher in natives. The erythrocyte inorganic anion exchanger (Cl--HCO3- exchanger AE1) was increased by 149-228 %. In conclusion, chronic hypoxia induces dramatic changes in erythrocyte proteins, but only moderate changes in muscle proteins involved in acid-base control. Together, these changes suggest a hypoxia-induced increase in the capacity for lactate, HCO3- and H+ fluxes from muscle to blood and from blood to erythrocytes.

Extraction system and determination of PAH in seawater and it implementation in submarine vehicles

[EN]Policyclyc aromatic hydrocarbons (PAHs) are a potential risk for human health and marine biota in general that make necessary the monitorization of them. A miniaturized extraction system capable to extract PAHs from seawater was developed and optimized with the objective of implement it in an oceanographic buoy in the future. An analytical method was optimized by high performance liquid chromatography for the determination of extracted PAHs by the extraction system. The analytical method was validated and applicated to real samples of differents points of Gran Canaria. The method has enough sensitivity to detect and quantify concentrations below the concentrations established in the legislation. In some places where samples were taken some compounds exceed the legislation while other compounds follow it