Effect of carotenoids and background colour on the skin pigmentation of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)

Three 2-factor experiments were conducted to determine the effects of background colour and synthetic carotenoids on the skin colour of Australian snapper Pagrus auratus. Initially, we evaluated the effects on skin colour of supplementing diets for 50 days with 60 mg kg −1 of either astaxanthin (LP;...

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Bibliographic Details
Main Authors: B Doolan, G Allan, M Booth, Paul Jones
Format: Other Non-Article Part of Journal/Newspaper
Language:unknown
Published: 2008
Subjects:
Online Access:http://hdl.handle.net/10536/DRO/DU:30017880
https://figshare.com/articles/journal_contribution/Effect_of_carotenoids_and_background_colour_on_the_skin_pigmentation_of_Australian_snapper_Pagrus_auratus_Bloch_Schneider_1801_/21054532
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Summary:Three 2-factor experiments were conducted to determine the effects of background colour and synthetic carotenoids on the skin colour of Australian snapper Pagrus auratus. Initially, we evaluated the effects on skin colour of supplementing diets for 50 days with 60 mg kg −1 of either astaxanthin (LP; Lucantin ® Pink), canthaxanthin (LR; Lucantin ® Red), apocarotenoic acid ethyl ester (LY; Lucantin ® Yellow), selected combinations of the above or no carotenoids and holding snapper (mean weight=88 g) in either white or black cages. In a second experiment, all snapper (mean weight=142 g) from Experiment 1 were transferred from black to white, or white to white cages to measure the short-term effects of cage colour on skin L* , a* and b* colour values. Skin colour was measured after 7 and 14 days, and total carotenoid concentrations were determined after 14 days. Cage colour was the dominant factor affecting the skin lightness of snapper with fish from white cages much lighter than fish from black cages. Diets containing astaxanthin conferred greatest skin pigmentation and there were no differences in redness ( a* ) and yellowness ( b* ) values between snapper fed 30 or 60 mg astaxanthin kg −1 . Snapper fed astaxanthin in white cages displayed greater skin yellowness than those in black cages. Transferring snapper from black to white cages increased skin lightness but was not as effective as growing snapper in white cages for the entire duration. Snapper fed astaxanthin diets and transferred from black to white cages were less yellow than those transferred from white to white cages despite the improvement in skin lightness ( L* ), and the total carotenoid concentration of the skin of fish fed astaxanthin diets was lower in white cages. Diets containing canthaxanthin led to a low level of deposition in the skin while apocarotenoic acid ethyl ester did not alter total skin carotenoid content or skin colour values in snapper. In a third experiment, we examined the effects of dietary astaxanthin (diets had 60 mg ...