DYNAMICS OF COLLAGEN INDICATING AMINO-ACIDS, IN EMBRYOS AND LARVAE OFSEA BASS (DICENTRARCHUS-LABRAX) AND GILTHEAD SEA BREAM (SPARUS-AURATA), ORIGINATED FROM BROODSTOCKS FED WITH DIFFERENT VITAMIN-C CONTENT INTHE DIET

The dynamics of hydroxyproline-proline (HYP-PRO) and hydroxylysine (HY L), as amino acids indicators of collagen, has been studied in fertili sed eggs, embryos and fasting larvae of sea bass (Dicentrarchus labrax L.) and gilthead sea bream (Sparus aurata L.). Broodstocks of the two species were fed every second day with two types of diets: one contai ning sufficient ascorbate for a normal growth and the other with an ex tra addition of a very high dose (2000 mg kg(-1) feed) of coated L-asc orbic acid (AA). The collagen hydroxylation expressed as the HYP-PRO r atio, hydroxylysine (HYL1 and HYL2) and total ascorbate (TAA) concentr ations were analysed in several embryonic and larvae developmental sta ges. TAA concentrations in the newly fertilised eggs and larvae result ed significantly higher in offspring of broodstocks fed an additional dose of 2000 mg AA/kg feed than in those fed a normal diet (P < 0.05 o r P < 0.01). The differences in HYP-PRO ratio values between the group s fed AA-supplemented and unsupplemented diets, were significant for a ll the analysed stages, being higher in the supplemented groups. The v alues of HYL were higher, although not always significantly, for all t he analysed stages, in offspring of the supplemented group, compared t o the offspring of the unsupplemented one. In conclusion, a vitamin C dose of 2000 mg kg(-1) feed, delivered every second day to sea bass an d gilthead sea bream broodstock, increases the collagen synthesis in e mbryos and fasting larvae, in comparison with a diet containing vitami n C at the recommended concentration for growth. (C) 1998 Elsevier Sci ence Inc. All rights reserved.