title: Dietary carotenoid availability, sexual signalling and functional fertility in sticklebacks.
abstract: In species where males express carotenoid-based sexual signals, more intensely coloured males may be signalling their enhanced ability to combat oxidative stress. This may include mitigating deleterious oxidative damage to their sperm, and so be directly related to their functional fertility. Using a split-clutch in vitro fertilization technique and dietary carotenoid manipulation, we demonstrate that in non-competitive fertilization assays, male three-spined sticklebacks (Gasterosteus aculeatus) that are fed higher (but biologically relevant) levels of carotenoids had a significantly increased fertilization success, irrespective of maternal carotenoid intake. Furthermore, within diet groups, a male's fertilization success was positively related to the expression of his carotenoid-based nuptial coloration, with more intensely coloured males having higher functional fertility. These data provide, to our knowledge, the first demonstration that dietary access to carotenoids influences fertilization success, and suggest that females could use a male's nuptial coloration as an indicator of his functional fertility.
authors.affiliation: Division of Ecology and Evolutionary Biology, Faculty of Biomedical and Life Sciences, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, UK. t.pike@exeter.ac.uk
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Pike
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Blount
authors.forename: Jan
authors.initials: J
authors.lastname: Lindström
authors.forename: Neil B
authors.initials: NB
authors.lastname: Metcalfe
mesh_terms: D000819:Animal Communication; D000818:Animals; D001824:Body Constitution; D002338:Carotenoids / Q000494:pharmacology*; D004032:Diet; D005260:Female; D005298:Fertility / Q000187:drug effects / Q000502:physiology*; D005307:Fertilization in Vitro; D016014:Linear Models; D008297:Male; D010858:Pigmentation / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D023701:Smegmamorpha / Q000502:physiology*
chemical_list: D002338:Carotenoids