Fig. 3.

Colour change improves camouflage match in response to mismatched substrates. Changes in hue (mean ± SE) of green (n = 25) and red (n = 25) prawns when placed against seaweed of opposing coloration over 30 days to the vision of both pollack (a) and goby (b). A crossover pattern can be observed between the two colour types as hue in green prawns increases due to an increase in the relative proportion of short-wave reflectance, whereas hue for red prawns decreases due to the reduction of reflectance in this channel. Changes in JNDs (mean ± SE) over time for green and red prawns to the modelled perspectives of (c) pollack and (d) goby, demonstrating that both colour types are able to alter their coloration in response to new substrates and that this change increases the level of camouflage (lower JNDs) when perceived by ecologically relevant predators