The retaining of additional astaxanthin (presumably mono-esters) in epithelial tissue (Fig. 2) may underlie the ability of prawns to resist the negative effects of exposure to white substrates. Based on the results from the uncooked animals, the negative effects of exposure to white substrates might be a larger contributor to overall prawn colour score than the positive effect of exposure to black substrates, although this response may be affected by the initial colour of the animals.Overall, these data clearly demonstrate that diet and substrate colour work in combination to improve prawn pigmentation. The absolute RGB values recorded in this study were likely to have been greatly impacted by the red colour of the tanks used for the 6-
week trial. This can also influence the ability of animals to respond to exposure to black or white substrates. The increase in RGB values in most groups over time may indicate that, regardless of the treatment, the animals continued to adapt to their background over time. Tanks
of another colour, such as mid-grey, may provide a better intermediate colourin future work. Nonetheless,the effects of this study remain clear.