Effects of dietary vitamin C on tissue ascorbate and collagen status in sturgeon hybrids (Acipenser ruthenus L. x Acipenser baeri Brandt)

The aim of this study was to determine the vitamin C status of various tiss ues, and collagen concentration in cartilage, of a sterlet (Acipenser ruthe nus L.) x Siberian sturgeon (Acipenser baerii Brandt) hybrid fed different dietary vitamin C rations. Growth, vitamin C status and collagen concentrat ion were measured in groups fed diets supplemented with 150, 300, 600 mg.kg (-1) ascorbate-2-polyphosphate (APP); 100, 200, 400 mg.kg(-1) ascorbate-2-m onophosphate (AMP), 1000 mg.kg(-1) L-ascorbic acid (AA) and with an almost ascorbate free diet (Total AA > 5 mg.kg(-1)), as a control. No significant differences in growth were observed, and no external symptom s of scurvy developed in the vitamin C-free group. No reduction in total vi tamin C concentration was revealed in the tissues examined, as compared wit h initial concentrations. Ascorbate-2-phosphate esters were only found in k idney or hepatopancreas of fish fed with these vitamin C derivatives. Signi ficantly (p<0.05) lower contents of collagen were observed in the control g roup after 8 weeks feeding. No significant differences were found among the groups after 16 weeks although the collagen concentration in the cartilage was slightly lower in the control group without vitamin C supplementation.