ABSORPTION AND METABOLISM OF TUBE FED FATTY ACIDS AND ARTEMIA AMINO ACIDS IN RESPONSE TO DIETARY PROTEIN/LIPID RATIOS IN SENEGALESE SOLE (Solea senegalensis Kaup 1858) larvae

S. Morais, W. Koven, I. Ronnestad, M.T. Dinis, L.E.C. Conceição

The present study examined the effect of dietary protein/lipid ratio on fatty acid (FA) and amino acid (AA) absorption and metabolism on larval Senegalese sole. Additionally, different lipid-bound (triolein and phosphatidylcholine 1,2, di-oleoyl) and free ¹⁴C-FA’s (stearic acid, oleic acid and docosahexaenoic acid) were tested. Two experiments were conducted in which larvae were fed non-enriched Artemia (NEA) or Artemia enriched on soybean oil emulsion (EA) since settlement. These larvae were tube fed ¹⁴C-FA’s in the first experiment and fed AA-labeled Artemia in the second. In general, a higher growth was obtained with the NEA diet. Larvae fed EA accumulated neutral lipid within the gut epithelium and had lower absorption of the FA label due to loss through evacuation. Total AA absorption was similar, although larvae fed NEA appeared to have a faster absorption of low neutral lipid diets but an increased ingestion of a diet containing a lower lipid level may also explain the results. Finally, the tested FA’s showed intrinsic digestive and metabolic properties, independent of dietary protein/lipid ratio.

(CCMAR, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal, e-mail: smorais@ualg.pt)

home