Over the last few years, several aspects of Senegalese sole (Solea senegalensis) culture have been developed and optimised but the dietary lipid level for optimal growth has never been determined. Hence, five isonitrogenous diets (56 % dietary protein) with increasing dietary lipid levels (4,8,12, 16 and 20 % DM) were fed to satiation to triplicate groups of twenty fish (mean initial weight 10 g). Fifteen tanks were randomly assigned one of the five diets. Feed was distributed using automatic feeders, and fish were fed over a 16-week period. At the end of the experiment the fish fed on diets containing the two lowest dietary lipid levels (4 and 8 %) showed a 3-fold body-weight increase with a significantly higher daily growth index than fish fed higher lipid levels (1·2 v. 0·8). Moreover, these fish displayed a significantly lower dry feed intake (12 g/kg per d) and feed conversion ratio (1·0) compared with fish fed higher lipids levels (16-19 g/kg per d; feed conversion ratio 2·0). Low dietary lipid levels (,12 %) significantly improved nutrient retention and gain and hence growth, without major effects on whole-body composition. Despite the slight alteration in n-3 PUFA muscle content in the fish fed low-fat-diets, this fish fed low dietary lipid still remains a rich n-3 PUFA product and generally maintained its nutritional value. These results evidenced a low lipid tolerance of Senegalese sole juveniles and suggest a maximal dietary inclusion level of 8 % lipids for both optimal growth and nutrient utilisation without compromising flesh quality.Lipid nutrition: Flatfish: Dietary lipid tolerance: Protein-sparing effectThe aquaculture industry has expanded in Europe over the last decades, but few marine fish species have contributed to this growth. The successful development of Southern European aquaculture has resulted in increased production of gilthead seabream (Sparus aurata), sea bass (Dicentrarchus labrax) and turbot (Psetta maxima), leading to market saturation and reduced prices. For these reasons, great efforts have recently been devoted to find new candidate species, to improve diversity and to ensure sustainable development of the industry.Senegalese sole (Solea senegalensis) is a promising flatfish species for marine farming, especially due to its high market value. Over the last few years significant advances have been accomplished on Senegalese sole weaning techniques and larvae feeding (1 -3) . However, little is known about the nutritional needs of this flatfish species during its juvenile stage (4,5) . The protein requirement for maximum protein accretion in Senegalese sole has been estimated at 600 g/kg diet (5) , but, so far, no studies concerning the optimal dietary lipid level have been carried out.Dietary formulations in aquaculture tend to increase lipid content as a non-protein source for enhancing growth and sparing protein, and for reducing organic matter and N losses (6 -10) . Nevertheless, in flatfish species positive results on protein sparing are limited and controversial. High ...

SUMMARYIn Senegalese sole (Solea senegalensis Kaup), growth is negatively correlated to dietary lipid levels. To understand the molecular basis of this effect a molecular toolbox of 12 genes, including fgf6, fst, mstn1, myf5, mrf4, myod1, myod2, myog, myHC, mylc2, igf1r and insr, was developed. The expression profiles of these genes were investigated in white muscle and liver of fish fed with three dietary lipid levels (4%, 12% and 20%). The expression of igf-I and igf-II was also examined. MRFs and myosins were only expressed in the muscle and, except for myf5, the general trend was a decrease in expression with an increase in dietary lipids. Fgf6 was identified for the first time in liver and its expression augmented in hepatic tissues with increasing dietary lipid levels. A similar tendency was observed for mstn1 and igf-I. The opposite was observed for igf1r expression in muscle and liver. Myog, mrf4, mylc2 and igf1r were highly correlated with growth and nutrient utilisation indices. In addition to its practical implications, this work provides a valuable contribution towards our understanding of the genetic networks controlling growth in teleosts. Supplementary material available online at

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Natural products obtained from plants with biocidal activity represent an alternative and useful source in the control of biodeterioration of documentary heritage, without negative environmental and human impacts. In this work, we studied the antimicrobial activity of seven essential oils against microorganisms associated with the biodeterioration of documentary heritage. The essential oils were obtained by steam distillation. The antimicrobial activity was analyzed using the agar diffusion method against 4 strains of fungi and 6 bacterial strains isolated from repositories air and documents of the National Archive of the Republic of Cuba and the Historical Archive of the Museum of La Plata, Argentina. Anise and garlic oils showed the best antifungal activity at all concentrations studied, while oregano oil not only was effective against fungi tested but also prevented sporulation of them all. Orange sweet and laurel oils were ineffective against fungi. Clove, garlic, and oregano oils showed the highest antibacterial activity at 25% against Enterobacter agglomerans and Streptomyces sp., while only clove and oregano oils were effective against Bacillus sp. at all concentrations studied. This study has an important implication for the possible use of the natural products from plants in the control of biodeterioration of documentary heritage.