loading page

Environmental gradients predict the ratio of environmentally acquired carotenoids to self-synthesised pteridine pigments
  • +4
  • Devi Stuart-Fox,
  • Katrina Rankin,
  • Adrian Lutz,
  • Adam Elliott,
  • Andrew Hugall,
  • Claire McLean,
  • Iliana Medina
Devi Stuart-Fox
University of Melbourne School of BioSciences
Author Profile
Katrina Rankin
The University of Melbourne
Author Profile
Adrian Lutz
The University of Melbourne
Author Profile
Adam Elliott
The University of Melbourne
Author Profile
Andrew Hugall
Museums Victoria
Author Profile
Claire McLean
Museums Victoria
Author Profile
Iliana Medina
University of Melbourne School of BioSciences
Author Profile

Abstract

Carotenoids are important pigments producing integument coloration; however, their dietary availability may be limited in some environments. Many species produce red to yellow hues using a combination of carotenoids and self-synthesised pteridine pigments. A compelling but untested hypothesis is that pteridines replace carotenoids in environments where carotenoid availability is limited. Based on a phylogenetic comparative analysis of pigment concentrations in agamid lizards, we show that environmental gradients predict the ratio of carotenoids to pteridines; carotenoid concentrations are lower and pteridine concentrations higher in arid environments with low vegetation productivity. Both carotenoid and pteridine pigments were present in all species, but only pteridine concentrations explained colour variation among species and there were no correlations between carotenoid and pteridine pigments with similar hue. These results suggest that pteridine pigments replace carotenoids in carotenoid-limited environments, irrespective of skin hue, presumably because it is metabolically cheaper to synthesise pteridines than to acquire and sequester carotenoids when carotenoids are rare.

Peer review status:IN REVISION

19 May 2021Submitted to Ecology Letters
19 May 2021Assigned to Editor
19 May 2021Submission Checks Completed
25 May 2021Reviewer(s) Assigned
16 Jun 2021Review(s) Completed, Editorial Evaluation Pending
19 Jun 2021Editorial Decision: Revise Minor