The carotenoids of eggs of wild and farmed Atlantic salmon, and their changes during development to the start of feeding

• Published in: Journal of Fish Biology
• Main Authors: Craik, J. C. A., Harvey, S. M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1986
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1111/j.1095-8649.1986.tb04972.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.1986.tb04972.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.1986.tb04972.x

The only carotenoid detected in newly fertilized eggs of wild Atlantic salmon, Salmo salar , from western Scotland was astaxanthin at a concentration [μg carotenoid g −1 wet wt of eggs, mean ±S.D. (number of parental females)] of 6.2±1.2(7) in 1982, 6.4±1.8(20) in 1983, and 7.6 ± 13(6) in 1984. In eggs of farmed Atlantic salmon the only carotenoid detected was canthaxanthin at concentrations which varied significantly between farms depending on the level of synthetic canthaxanthin in the broodstock diet. Thus on two farms using feed with 50 μgg −1 , the levels were 11.8 ± 3.4(7) and 12.3 ± 2.9(6), while on two farms using 75μgg −1 the levels were 18.7 ± 5.0(9) and 21.2 ± 2.7(21). The levels in eggs of one‐seawinter fish (grilse) did not differ from those of two‐seawinter fish reared on the same farm and diet. During development from newly fertilized egg to fry at the end of yolk‐sac absorption, the quantity of carotenoid present per individual decreased, presumably as a result of metabolism. Despite large differences in quantity present, the quantity so metabolized was fairly constant at 2–4 μg carotenoid g −1 original egg weight for eggs from two‐seawinter farmed and wild salmon, except that in eggs from farmed grilse it was 7 μg g −1 . In fry from wild eggs, 99.14% of the remaining carotenoid was present in the integument (skin and fins) as astaxanthin, astaxanthin monoester and astaxanthin diester. In fry from farmed salmon eggs, 47 ± 8% of the carotenoid present was found in the unused yolk oil droplets and in the liver, and 37 ± 6% was found in the integument as canthaxanthin and an unidentified metabolite of canthaxanthin. These findings explain visible colour differences between fry from wild parents and fry from canthaxanthin‐fed farmed parents, particularly in the fins, liver and residual oil droplets. The canthaxanthin metabolite was also found, together with canthaxanthin, in the skin of farmed adults fed canthaxanthin. Preliminary tests showed it to be unchanged by saponification but reduced by ...