title: Complementary effect of natural and sexual selection against immigrants maintains differentiation between locally adapted fish.
abstract: Adaptation to ecologically heterogeneous environments can drive speciation. But what mechanisms maintain reproductive isolation among locally adapted populations? Using poeciliid fishes in a system with naturally occurring toxic hydrogen sulfide, we show that (a) fish from non-sulfidic sites (Poecilia mexicana) show high mortality (95 %) after 24 h when exposed to the toxicant, while locally adapted fish from sulfidic sites (Poecilia sulphuraria) experience low mortality (13 %) when transferred to non-sulfidic water. (b) Mate choice tests revealed that P. mexicana females exhibit a preference for conspecific males in non-sulfidic water, but not in sulfidic water, whereas P. sulphuraria females never showed a preference. Increased costs of mate choice in sulfidic, hypoxic water, and the lack of selection for reinforcement due to the low survival of P. mexicana may explain the absence of a preference in P. sulphuraria females. Taken together, our study may be the first to demonstrate independent-but complementary-effects of natural and sexual selection against immigrants maintaining differentiation between locally adapted fish populations.
authors.affiliation: Department of Ecology and Evolution, J.W. Goethe University of Frankfurt, Siesmayerstrasse 70a, 60054, Frankfurt am Main, Germany. mplath@bio.uni-frankfurt.de
authors.forename: Martin
authors.initials: M
authors.lastname: Plath
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Riesch
authors.forename: Alexandra
authors.initials: A
authors.lastname: Oranth
authors.forename: Justina
authors.initials: J
authors.lastname: Dzienko
authors.forename: Nora
authors.initials: N
authors.lastname: Karau
authors.forename: Angela
authors.initials: A
authors.lastname: Schiessl
authors.forename: Stefan
authors.initials: S
authors.lastname: Stadler
authors.forename: Adriana
authors.initials: A
authors.lastname: Wigh
authors.forename: Claudia
authors.initials: C
authors.lastname: Zimmer
authors.forename: Lenin
authors.initials: L
authors.lastname: Arias-Rodriguez
authors.forename: Ingo
authors.initials: I
authors.lastname: Schlupp
authors.forename: Michael
authors.initials: M
authors.lastname: Tobler
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000818:Animals; D049628:Body Size; D002755:Choice Behavior; D017753:Ecosystem; D005260:Female; D005399:Fishes / Q000502:physiology*; D008297:Male; D052586:Mating Preference, Animal / Q000502:physiology*; D011036:Poecilia / Q000033:anatomy & histology / Q000502:physiology; D012098:Reproduction / Q000502:physiology*; D012641:Selection, Genetic / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D012934:Social Isolation