Male coloration signals direct benefits in the European bitterling (Rhodeus amarus)
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Female mating preferences are frequently associated with exaggerated male sexual traits. In the European bitterling, Rhodeus amarus, a fish with a resource-based mating system, male coloration is not associated with indirect genetic benefits of female mate choice, and does not reliably signal spawning site quality. We tested a link between the extent of male carotenoid-based coloration and testis size and number of spermatozoa stripped from the testes. Male body size predicted spermatozoa number, but less reliably than the extent of male coloration. Male color was a highly significant predictor of spermatozoa number, with approximately 26 % of variance in the number of spermatozoa stripped from males predicted from male color after controlling for male body size. Body size, but not coloration, predicted teste size. Female bitterling often risk sperm limitation, especially during pair spawnings, and male nuptial coloration may be under direct selection through female mate choice as a signal of male fertilization efficiency.
KeywordsOviposition Mate choice Mating system Nuptial coloration Sexual selection Spermatozoa
We are grateful for constructive comments by Rowena Spence and two anonymous reviewers. Financial support came from Czech Science Foundation grant 206/09/1163. Experimental procedures conformed to Czech and British legal requirements and the study was overseen by the University of St Andrews Animal Welfare and Ethics Committee.
- Agbali M (2011) Female mating decisions in the rose bitterling (Rhodeus ocellatus). PhD thesis, University of St Andrews, UKGoogle Scholar
- Agbali M, Spence R, Reichard M, Smith C (2012) Direct fitness benefits are preferred when the strength of direct and indirect sexual selection are equivalent. Isr J Ecol Evol 58:279–288Google Scholar
- Andersson M (1994) Sexual selection. Princeton University PressGoogle Scholar
- Casalini M (2012) Male mating tactics in the rose bitterling (Rhodeus ocellatus) and European bitterling (Rhodeus amarus). PhD thesis, University of St Andrews, UKGoogle Scholar
- Eberhard WG (1996) Female control: Sexual selection by cryptic female choice. Princeton University PressGoogle Scholar
- Levitan DR (1998) Sperm limitation, gamete competition, and sexual selection in external fertilisers. In: Birkhead TR, Møller AP (eds) Sperm competition and sexual selection. Academic, LondonGoogle Scholar
- Mjelstad H (1991) Displaying intensity and sperm quality in the capercaillie Tetrao urogallus. Fauna Norv Ser C Cinc 14:93–94Google Scholar
- Reichard M, Liu H, Smith C (2007b) The co-evolutionary relationship between bitterling fishes and freshwater mussels: insights from interspecific comparisons. Evol Ecol Res 9:1–21Google Scholar
- Spence R, Reichard M, Smith C (2013) Strategic sperm allocation and a Coolidge effect in an externally fertilizing species. Behav Ecol 24:82–88Google Scholar