title: Intraspecific sexual selection on a speciation trait, male coloration, in the Lake Victoria cichlid Pundamilia nyererei.
abstract: The haplochromine cichlids of Lake Victoria constitute a classical example of explosive speciation. Extensive intra- and interspecific variation in male nuptial coloration and female mating preferences, in the absence of postzygotic isolation between species, has inspired the hypothesis that sexual selection has been a driving force in the origin of this species flock. This hypothesis rests on the premise that the phenotypic traits that underlie behavioural reproductive isolation between sister species diverged under sexual selection within a species. We test this premise in a Lake Victoria cichlid, by using laboratory experiments and field observations. We report that a male colour trait, which has previously been shown to be important for behavioural reproductive isolation between this species and a close relative, is under directional sexual selection by female mate choice within this species. This is consistent with the hypothesis that female choice has driven the divergence in male coloration between the two species. We also find that male territoriality is vital for male reproductive success and that multiple mating by females is common.
authors.affiliation: Department of Animal Ecology, Institute of Biology, University of Leiden, PO Box 9516 2300 RA Leiden, The Netherlands. maan@rulsfb.leidenuniv.nl
authors.forename: Martine E
authors.initials: ME
authors.lastname: Maan
authors.forename: Ole
authors.initials: O
authors.lastname: Seehausen
authors.forename: Linda
authors.initials: L
authors.lastname: Söderberg
authors.forename: Lisa
authors.initials: L
authors.lastname: Johnson
authors.forename: Erwin A P
authors.initials: EA
authors.lastname: Ripmeester
authors.forename: Hillary D J
authors.initials: HD
authors.lastname: Mrosso
authors.forename: Martin I
authors.initials: MI
authors.lastname: Taylor
authors.forename: Tom J M
authors.initials: TJ
authors.lastname: van Dooren
authors.forename: Jacques J M
authors.initials: JJ
authors.lastname: van Alphen
mesh_terms: D000818:Animals; D023681:Cichlids / Q000235:genetics / Q000502:physiology*; D005260:Female; D005618:Fresh Water; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D010858:Pigmentation / Q000502:physiology*; D012098:Reproduction / Q000502:physiology*; D012641:Selection, Genetic; D012737:Sex Factors; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013045:Species Specificity; D013636:Tanzania; D013731:Territoriality