Tissue ascorbic acid levels in European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata L.) fingerlings fed diets containing different forms of ascorbic acid

Sea bass and sea bream fingerlings of 3-4 g initial weight were fed four di ets supplemented with 250 mg/kg of ascorbic acid (AA) supplied as the fat c oated form or different phosphate ester forms. An ascorbate free diet was a lso fed. Before the start of the experiment, fish were fed an ascorbate fre e diet in order to deplete their ascorbate stores. The same diet formulatio n was used in all treatments containing fish meal LT, soybean meal and whea t flour as the main ingredients. Feeding levels were the same for all group s of fish and were close to satiation. The results obtained for fish growth and feed efficiency did not differ significantly among groups of fish for both species studied. Muscle, liver and kidney were analysed for AA content after frequent sampling of fish. Tissue ascorbate levels increased after f eeding the ascorbate containing diets, the rate of increase was although hi gher for sea bream than for sea bass. Ascorbate levels in groups fed the fa t coated diet were lower than those fed the diets containing phosphate este rs, probably due to a higher destruction of this form during feed preparati on and storage. AA levels in the tissues studied were different with muscle having the lowest and kidney the highest value. Ascorbate levels in fish f ed the ascorbate free diet decreased significantly. No growth reduction or deficiency signs were observed. (C) 1999 Elsevier Science B.V. All rights r eserved.