Viability of brown trout embryos positively linked to melanin-based but negatively to carotenoid-based colours of their fathers.
'Good-genes' models of sexual selection predict significant additive genetic variation for fitness-correlated traits within populations to be revealed by phenotypic traits. To test this prediction, we sampled brown trout (Salmo trutta) from their natural spawning place, analysed their carotenoid-based red and melanin-based dark skin colours and tested whether these colours can be used to predict offspring viability. We produced half-sib families by in vitro fertilization, reared the resulting embryos under standardized conditions, released the hatchlings into a streamlet and identified the surviving juveniles 20 months later with microsatellite markers. Embryo viability was revealed by the sires' dark pigmentation: darker males sired more viable offspring. However, the sires' red coloration correlated negatively with embryo survival. Our study demonstrates that genetic variation for fitness-correlated traits is revealed by male colour traits in our study population, but contrary to predictions from other studies, intense red colours do not signal good genes.
Wedekind
Claus
C
Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland. claus.wedekind@unil.ch
Jacob
Alain
A
Evanno
Guillaume
G
Nusslé
Sébastien
S
Müller
Rudolf
R
D000818:Animals; D002338:Carotenoids / Q000502:physiology*; D005260:Female; D014644:Genetic Variation; D008297:Male; D008543:Melanins / Q000502:physiology*; D010858:Pigmentation / Q000502:physiology*; D018709:Statistics, Nonparametric; D014337:Trout / Q000196:embryology* / Q000235:genetics / Q000254:growth & development
D008543:Melanins; D002338:Carotenoids