Digestive physiology and food intake in marine fish larvae with respect to diet...

• Author(s): Morais, Sofia Jacinto
• Date: 2005
• Persistent ID: http://hdl.handle.net/10400.1/768
• Origin: Sapientia - Universidade do Algarve
• Subject(s): Teses; Aquacultura; Larvas; Fisiologia digestiva; Absorção lipídica; Ingestão; Dietas larvares
• Document Type: Doctoral Thesis
• Language: English

Description

Tese dout., Aquacultura, Universidade do Algarve, 2005 A growth depressing effect of high dietary neutral lipid levels in marine fish larvae has been reported. This may be the result of a decrease in the efficiency or activity of digestive enzymes, a reduction in absorption efficiency and/or a decrease in food intake. In this thesis, work was carried out on commercially valuable species (Atlantic herring, Senegalese sole, European seabass and gilthead seabream), to investigate the effects of neutral lipid level and source (fatty acid composition) on some of these key factors influencing larval growth. The results seem to collectively indicate that lipid transport from the enterocytes into the body may be more problematic in larval stages dealing with high neutral lipid diets than lipid digestion, although both factors are likely to intervene. Food intake did not appear to be strictly regulated by total lipid content of the diet and lipid source may have an important role in controlling ingestion. Therefore, the neutral lipid level in diets for marine fish larvae has a significant impact in several factors influencing growth but clearly it cannot be dissociated of its fatty acid composition, which appears to play a central role on the nutritional and physiological effects of dietary lipid, at the ingestion, digestion and absorption levels.