ASCORBIC-ACID STATUS IN THE EARLY LIFE OF WHITEFISH (COREGONUS-LAVARETUS L)

The experiment was conducted to determine the effect of dietary ascorbic acid supplementation on the accumulation of vitamin C in fish tissues. Total and dehydroascorbic acid were determined in larval and juvenile coregonids fed live Artemia salina nauplii and various commercial and laboratory-prepared compound foods. Total ascorbic acid decreased in the whole body of coregonids from approximately 122.8 μg g-1 wet weight before first feeding to 59.6 μg g-1 in 82 mg juveniles offered exclusively live food. In fish fed a diet deficient in vitamin C, the body ascorbate level decreased gradually to 12.5 μg g-1 within 1 month. In fish offered a diet containing 1483 μg ascorbate g-1 dry matter, the ascorbate level in the body decreased initially as fish weight increased up to 17 mg, but then rose again to 76 μg g-1 in fish of a mean body weight of 113 mg. It is concluded that after a few days of feeding, larval fish respond to ascorbic acid deficiency in the diet and thus the availability of ascorbate in their diet should be a matter of concern. It is suggested that the optimal dietary concentration of vitamin C is equivalent to that allowing the maintenance of "steady-state" tissue concentration in larval and juvenile fish. © 1990.