Untitled

Abstract

Female sticklebacks (Gasterosteus aculeatus) use the red coloration of males as a criterion for mate choice. Redder males are more attractive. However, males often differ not only in the intensity of their coloration (from dull to bright red) but also in color quality (from yellowish to purple-red). We investigated whether the red coloration of the stickleback is actually a multiple signal made by several pigments. We kept wild caught males singly in tanks until they had built a nest and were ready to accept females. Then, we took standard photographs and measured their colors by spectrometer analyses of the slides and by descriptions of human observers. These two measurements were highly correlated. When analyzing the carotenoid content of the sticklebacks' skin we found two groups of carotenoids (astaxanthin and tunaxanthin/lutein) that were quantified for each individual. The differences in color observed in the fish are correlated to this pigment quantification. Redder fish have more astaxanthin in their skin than yellowish fish, while the color of the yellowish fish appears to be made by tunaxanthin/lutein. Our results suggest that the red coloration of sticklebacks is a multiple trait that is made of at least two different carotenoids. This opens the possibility that male sticklebacks signal more detailed information to females than a onedimensional trait would allow.

The effect of carotenoid supplementation on immune system development in juvenile male veiled chameleons (Chamaeleo calyptratus)

“…Carotenoids are a class of organic compounds that have bright red, orange, and yellow hues [11] and can produce colorful ornamental structures [12-16], but are simultaneously used for vital physiological processes [17-19]. Significantly, carotenoid molecules can play an important role in both the activation and regulation of the immune system (reviewed in [20]), though these relationships are not universal [21].…”

Dynamic resource allocation between pre- and postcopulatory episodes of sexual selection determines competitive fertilization success

“…Apparently, this resulted from a higher proportion of astaxanthin deposited in the integument of these males [56]. By contrast, male coloration in the low-quality dietary treatments (irrespective of food quantity ([þ 2] and [2 2]) was predominantly based on lutein that was ingested from the untreated chironomid larvae and differs from astaxanthin in its spectral absorbance characteristics, giving these males a rather orange 'hue' in human terms [38]. Although visual modelling suggests that sticklebacks are sensitive to variation in not only the concentration but also composition of carotenoids in a male's breeding signal [56], the role of carotenoid ratios in mate choice is less clear (but see [59]) and deserves further behavioural investigations.…”

“…), which contain moderate levels of lutein [36] and second, carotenoid-enriched red mosquito larvae, which additionally contain high levels of astaxanthin (AHA Frostfutter, Duisburg, Germany). Astaxanthin is an important component of sticklebacks' natural diet and represents one of the main carotenoids incorporated in the integument of stickleback males [37,38]. Carotenoid-enriched larvae were commercially produced by depositing them in water that contained 2 g of 10% pure astaxanthin per litre for 1 h before they were frozen.…”

Male reproductive traits of full-sibs of different age classes in three-spined sticklebacks (Gasterosteus aculeatus)

“…lutein (Czeczuga ). In the laboratory, both young and old males were fed Chironomus 1970), a major carotenoid for the development of males’ breeding coloration (Wedekind et al 1998 . Since animals cannot synthesise carotenoids de novo (Goodwin 1984), the given food supply was the only carotenoid source for the males.…”