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Carotenoid-based colours reflect the stress response in the common lizard.

Fitze PS, Cote J, San-Jose LM, Meylan S, Isaksson C, Andersson S, Rossi JM, Clobert J - PLoS ONE (2009)

Bottom Line: While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified.This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake.Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard's PSR.

View Article: PubMed Central - PubMed

Affiliation: Museo Nacional de Ciencias Naturales CSIC, Madrid, Spain. patrick.fitze@mncn.csic.es

ABSTRACT
Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake) or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticosterone concentrations). Here, we tested whether blood corticosterone concentration affected carotenoid-based colouration, and whether a trade-off between colouration and PSR existed. Using the common lizard (Lacerta vivipara), we correlatively and experimentally showed that elevated blood corticosterone levels are associated with increased redness of the lizard's belly. In this study, the effects of corticosterone did not depend on carotenoid ingestion, indicating the absence of a trade-off between colouration and PSR for carotenoids. While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified. This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake. Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard's PSR.

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a–b. Average reflectance spectra of ventral colouration in male (a) and female (b) common lizards.The mean and SD per sex of the reflectance spectra measured at the beginning of the experiment are given.
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pone-0005111-g002: a–b. Average reflectance spectra of ventral colouration in male (a) and female (b) common lizards.The mean and SD per sex of the reflectance spectra measured at the beginning of the experiment are given.

Mentions: Since saturated carotenoid (and melanin) pigmentation removes most of the reflectance in the ultraviolet wavelengths [5] (Figure 2), we restricted the analyses to the human visible spectrum (400 nm–700 nm). Using Endler's [58] segment classification method, we derived objective estimates of hue (0–360°: 0° = red; 60° = yellow), chroma (0–100%), and brightness (0–100%), and we used the mean colouration of the three body parts measured in the analyses. The colour measurements taken three times from 218 lizards originating from the same populations were repeatable [53] (hue: F216,434 = 6.99, P<0.0001, r = 0.66; chroma: F217,437 = 7.01, P<0.0001, r = 0.67; brightness: F217,437 = 10.5, P<0.0001, r = 0.76; [59]).


Carotenoid-based colours reflect the stress response in the common lizard.

Fitze PS, Cote J, San-Jose LM, Meylan S, Isaksson C, Andersson S, Rossi JM, Clobert J - PLoS ONE (2009)

a–b. Average reflectance spectra of ventral colouration in male (a) and female (b) common lizards.The mean and SD per sex of the reflectance spectra measured at the beginning of the experiment are given.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2663031&req=5

pone-0005111-g002: a–b. Average reflectance spectra of ventral colouration in male (a) and female (b) common lizards.The mean and SD per sex of the reflectance spectra measured at the beginning of the experiment are given.
Mentions: Since saturated carotenoid (and melanin) pigmentation removes most of the reflectance in the ultraviolet wavelengths [5] (Figure 2), we restricted the analyses to the human visible spectrum (400 nm–700 nm). Using Endler's [58] segment classification method, we derived objective estimates of hue (0–360°: 0° = red; 60° = yellow), chroma (0–100%), and brightness (0–100%), and we used the mean colouration of the three body parts measured in the analyses. The colour measurements taken three times from 218 lizards originating from the same populations were repeatable [53] (hue: F216,434 = 6.99, P<0.0001, r = 0.66; chroma: F217,437 = 7.01, P<0.0001, r = 0.67; brightness: F217,437 = 10.5, P<0.0001, r = 0.76; [59]).

Bottom Line: While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified.This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake.Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard's PSR.

View Article: PubMed Central - PubMed

Affiliation: Museo Nacional de Ciencias Naturales CSIC, Madrid, Spain. patrick.fitze@mncn.csic.es

ABSTRACT
Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake) or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticosterone concentrations). Here, we tested whether blood corticosterone concentration affected carotenoid-based colouration, and whether a trade-off between colouration and PSR existed. Using the common lizard (Lacerta vivipara), we correlatively and experimentally showed that elevated blood corticosterone levels are associated with increased redness of the lizard's belly. In this study, the effects of corticosterone did not depend on carotenoid ingestion, indicating the absence of a trade-off between colouration and PSR for carotenoids. While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified. This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake. Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard's PSR.

Show MeSH
Related in: MedlinePlus