Obiettivo The aim of the project is to study biotic factors influencing growth and survival rates in newly hatched larvae of Scophthalmus maximus (the significance of protein quality in food organisms commonly used in rearing of turbot larvae will be identified). In order to modify the protein level and/or composition of the rotifers (Brachionus plicatilis) 3 different kinds of microdiets were produced. These microdiets were compared with commercial boosters: Protein-selco (PS), DHA-selco (DHA) and Culture selco (CS). No differences were observed in terms of successful production of rotifers by using these diets. Different treatments tested to modify the total protein level of the rotifers showed no significant differences, but total lipid and total carbohydrate levels responded to the treatments. The copepods were kept on the same algae species as the rotifers (Isochrysis galbana). These copepods used for larval rearing showed the highest protein level of all the tested feeds. The turbot larvae fed on copepods and/or rotifers enriched with a mixture of DHA and PS with a mixture of DHA and the protein enrichment made by the project, Nylon-Protein (NP), showed a marked increase in protein content with age. Larvae fed with DHA enriched rotifers only showed a low increase protein content with age. Growth performance was also the best in those larvae fed on copepods or DHA/PS or DHA/NP enriched rotifers. No differences were found amongst the differently treated groups of larvae concerning lipid and/or carbohydrate content. The composition of the digestive enzymes of the rotifers and of the turbot larvae were different, and might be complementary. In rotifers different feeding regimes produced different enzyme activity patterns. Esterase activity level did not change under different treatments but proteolytic and amylolytic activity level showed differences in the enrichment experiments. The effect of different parental origin on larval performances was tested. For larval protease content no significant differences were found between 47 batches coming from different females. High and variable mortality rates were encountered during the experiments. A new endoparasite was discovered as a possible candidate for causing these mortalities.The research work will be focussed on the physiology and biochemistry of growth and digestion in young larvae. After commencement of feeding, the quantitative and qualitative aspects of amino acid metabolism and how these promote or influence growth and survival will be examined. Furthermore, the efficiency of the enrichment process for Artemia will be investigated. It is expected to determine the optimum levels of protein enrichment. The factors to be studied will be: protein content; ribonucleic acid (RNA) to deoxyribonucleic acid (DNA) ratio; proteolytic enzyme activity; and amino acid composition. These analytical studies on the effect of feed enrichment will be linked with oxygen consumption measurements to quantify total metabolic activity. Campo scientifico natural sciencesbiological sciencesgeneticsDNAnatural sciencesbiological sciencesbiochemistrybiomoleculeslipidsnatural sciencesbiological sciencesbiochemistrybiomoleculescarbohydratesnatural scienceschemical sciencesorganic chemistryaminesnatural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes Programma(i) FP2-FAR - Community research and coordination programmes (EEC) in the fisheries sector, 1988-1992 Argomento(i) Data not available Invito a presentare proposte Data not available Meccanismo di finanziamento Data not available Coordinatore Christian-Albrechts-Universität Kiel Contributo UE Nessun dato Indirizzo Düsternbrooker Weg 20 24105 Kiel Germania Mostra sulla mappa Costo totale Nessun dato Partecipanti (2) Classifica in ordine alfabetico Classifica per Contributo UE Espandi tutto Riduci tutto CSIC-INST INVESTIGACIONES MARINAS Spagna Contributo UE Nessun dato Indirizzo Vigo Mostra sulla mappa Costo totale Nessun dato UNIV KOEBENHAVN-LAB MARINEBIOLOGI Danimarca Contributo UE Nessun dato Indirizzo Helsingoer Mostra sulla mappa Costo totale Nessun dato
