Examination of boldness traits in sexual and asexual mollies (Poecilia latipinna, P. formosa)
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Considering the high costs of sexual reproduction (e.g., the production of males), its maintenance and predominance throughout the Animal Kingdom remain elusive. Especially the mechanisms allowing for a stable coexistence of closely related sexual and asexual species are still subject to a lively debate. Asexuals should rapidly outnumber sexuals due to higher population growth rates, unless they face some disadvantages. Here, we investigate potential differences in feeding behavior in a system of sexual (sailfin mollies, Poecilia latipinna) and coexisting gynogenetic fishes (Amazon mollies, Poecilia formosa). In two different experiments, we tested for differences in behavioral traits associated with boldness. Bold individuals take higher risks for gains in resources, so shyer individuals should be less competitive. Our study was motivated by the recent finding that P. formosa are less likely to be preyed upon by piscine predators than P. latipinna. We asked whether this result is indicative of low boldness in P. formosa. However, no differences between the two species were detectible in our behavioral experiments measuring (a) time to emerge from shelter to explore a novel environment, (b) latency time until feeding in a novel environment, and (c) recovery time until feeding restarted after a simulated predator attack. Furthermore, different boldness measures were not correlated with each other within individuals.
KeywordsAggressive behavior Amazon molly Behavioral syndromes Competition Foraging Maintenance of sex Poeciliidae
We would like to thank Kirk Winemiller (Texas A&M University) for kindly providing laboratory facilities. We also like to thank Dylan Thompson for assistance with computer-generated images to illustrate the experimental tanks. M. Ziege kindly provided the drawings of a sailfin and an Amazon molly. Financial support came from the German Academic Exchange Service (DAAD) and the German Society for Ichthyology (to K. S.), the Hermann-Willkomm Foundation (to M. P.), as well as the Swiss National Science Foundation (to M. T.). The Texas Parks and Wildlife Department kindly issued permits for collecting fish (SPR-1008-340).
- Bell G (1982) The masterpiece of nature, the evolution and genetics of sexuality. University of California, BerkeleyGoogle Scholar
- Dawley RM (1989) An introduction to unisexual vertebrates. In: Dawley RM, Bogart JP (eds) Evolution and ecology of unisexual vertebrates. Bulletin 466. New York State Museum, New York, pp 1–18Google Scholar
- Dingemanse NJ, Van der Plas F, Wright J, Reale D, Schrama M, Roff DA, Van der Zee E, Barber I (2009) Individual experience and evolutionary history of predation affect expression of heritable variation in fish personality and morphology. Proc R Soc Lond B 276:1285–1293Google Scholar
- Fischer C, Schlupp I (2008) Predation as a potential mechanism allowing asexual mollies to invade sexual mollies. Proc Okl Acad Sci 88:1–8Google Scholar
- Maynard Smith J (1978) The evolution of sex. Cambridge University Press, CambridgeGoogle Scholar
- Sih A, Bell AM (2008) Insights for behavioral ecology from behavioral syndromes. In: Brockmann HJ, Roper T, Naguib M, Wynne-Edwards K, Barnard C, Mitani J (eds) Advances in the study of behavior, vol 38. Elsevier Academic, San Diego, pp 227–281Google Scholar
- Turner BJ (1982) The evolutionary genetics of a unisexual fish, Poecilia formosa. In: Barigozzi C (ed) Mechanisms of speciation. Alan R. Liss, New York, pp 265–305Google Scholar