title: Predator avoidance in extremophile fish.
abstract: Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis.
authors.affiliation: Department of Ecology & Evolution, J.W. Goethe University Frankfurt, Max-von-Laue-Straße 13, Frankfurt am Main, D-60438, Germany. david.bierbach@gmx.de.
authors.forename: David
authors.initials: D
authors.lastname: Bierbach
authors.affiliation: Institute of Biochemistry & Biology, Unit of Animal Ecology, University of Potsdam, Maulbeerallee 1, Potsdam, 14469, Germany. schnulli83@gmx.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schulte
authors.affiliation: Institute of Biochemistry & Biology, Unit of Animal Ecology, University of Potsdam, Maulbeerallee 1, Potsdam, 14469, Germany. nina-caterina@web.de.
authors.forename: Nina
authors.initials: N
authors.lastname: Herrmann
authors.affiliation: Department of Ecology & Evolution, J.W. Goethe University Frankfurt, Max-von-Laue-Straße 13, Frankfurt am Main, D-60438, Germany. cla.zim.uni@gmail.com.
authors.forename: Claudia
authors.initials: C
authors.lastname: Zimmer
authors.affiliation: División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco (UJAT), Villahermosa, Tabasco, CP 86150, Mexico.
authors.forename: Lenin
authors.initials: L
authors.lastname: Arias-Rodriguez
authors.affiliation: División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco (UJAT), Villahermosa, Tabasco, CP 86150, Mexico. jeanerimberindy@yahoo.com.
authors.forename: Jeane Rimber
authors.initials: JR
authors.lastname: Indy
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK. rwriesch.evolutionarybiology@gmail.com.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Riesch
authors.affiliation: Department of Ecology & Evolution, J.W. Goethe University Frankfurt, Max-von-Laue-Straße 13, Frankfurt am Main, D-60438, Germany. mplath@bio.uni-frankfurt.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Plath