The individuals displayed a variable degree of redness (exemplified in Fig. 1). Depth of capture was the most important factor explaining animal colouration, but also variation in the measured colouration increased with depth. During daytime, mean redness of individuals caught below 300 m was significantly higher than for individuals found above 200 m (Fig. 7), and mean redness of those found below 200 m was significantly higher than for those found above 100 m (Fig. 7). At night, only individuals found below 300 m had significantly higher mean redness than those caught higher in the water column (Fig. 7).