Behavioral Ecology Advance Access originally published online on April 13, 2009
Behavioral Ecology 2009 20(3):593-600; doi:10.1093/beheco/arp036
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Behavioral dominance between female color morphs of a Lake Victoria cichlid fish
a Division of Ecology and Evolutionary Biology, Graham Kerr Building, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK b Behavioural Biology Research Group, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands c Institute of Ecology and Evolution, Division Aquatic Ecology and Evolution, University of Bern, Baltzerstr. 6, CH-3012 Bern, Switzerland d Centre of Ecology, Evolution and Biogeochemistry, Eawag Swiss Federal Institute for Aquatic Sciences, CH-6047 Kastanienbaum, Switzerland
Address correspondence to P.D. Dijkstra, who is now at Division of Environmental and Evolutionary Biology. Graham Kerr Building, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK. E-mail: p.dijkstra{at}biol.gla.ac.uk.
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Abstract |
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Species that exhibit genetic color polymorphism are suitable for studying the evolutionary forces that maintain heritable phenotypic variation in nature. Male color morphs often differ in behavioral dominance, affecting the evolution of color polymorphisms. However, behavioral dominance among female color morphs has received far less attention. We studied a polymorphic population of the cichlid fish Neochromis omnicaeruleus from Lake Victoria, in which 3 distinct female color morphs coexist, black-and-white blotched (WB), orange blotched (OB), and plain (P) color morphs. First, we investigated dominance relationships among female morphs using triadic and dyadic encounters in the laboratory. In triadic encounters, both WB and OB females dominated plain, whereas WB females dominated OB females. Dominance of WB over OB was confirmed using dyadic encounters. In a second experiment, blotched (WB or OB) and plain full-sib sisters were bred by crossing a blotched and a plain parent. In dyadic encounters, WB female morphs dominated their plain sisters, suggesting that dominance of WB females is a pleiotropic effect of color or that genes coding for color and those influencing behavioral dominance are genetically linked, explaining the association between color and behavioral dominance despite gene flow. We conclude that behavioral dominance asymmetries exist among female color morphs of the fish N. omnicaeruleus, and discuss possible mechanisms that may account for the tight association between color and behavioral dominance.
Key words: aggression, color polymorphism, dominance relationships, female–female competition, haplochromine cichlid, Lake Victoria, sexual selection.
Received 1 September 2008; revised 11 February 2009; accepted 15 February 2009.