@article{RieschSchluppTobleretal.2006,
  author    = {Riesch, R{\"u}diger and Schlupp, Ingo and Tobler, Michael and Plath, Martin},
  title     = {Reduction of the association preference for conspecifics in cave-dwelling Atlantic mollies, Poecilia mexicana},
  series = {Behavioral ecology and sociobiology},
  volume    = {60},
  journal   = {Behavioral ecology and sociobiology},
  publisher = {Springer},
  address   = {New York},
  issn      = {0340-5443},
  doi       = {10.1007/s00265-006-0223-z},
  pages     = {794 -- 802},
  year      = {2006},
  abstract  = {Cave animals are widely recognised as model organisms to study regressive evolutionary processes like the reduction of eyes. In this paper, we report on the regressive evolution of species discrimination in the cave molly, Poecilia mexicana, which, unlike other cave fishes, still has functional eyes. This allowed us to examine the response to both visual and non-visual cues involved in species discrimination. When surface-dwelling females were given a chance to associate with either a conspecific or a swordtail (Xiphophorus hellerii) female, they strongly preferred the conspecific female both when multiple cues and when solely visual cues were available to the female. No association preference was observed when only non-visual cues were provided. In contrast, cave-dwelling females showed no preference under all testing conditions, suggesting that species recognition mechanisms have been reduced. We discuss the role of species discrimination in relation to habitat differences.},
  language  = {en}
}
@article{ToblerSchluppHeubeletal.2006,
  author    = {Tobler, Michael and Schlupp, Ingo and Heubel, Katja U. and Riesch, Rudiger and Garcia de Leon, Francisco J. and Giere, Olav and Plath, Martin},
  title     = {Life on the edge: hydrogen sulfide and the fish communities of a Mexican cave and surrounding waters},
  series = {Extremophiles : life under extreme conditions},
  volume    = {10},
  journal   = {Extremophiles : life under extreme conditions},
  publisher = {Springer},
  address   = {Tokyo},
  issn      = {1431-0651},
  doi       = {10.1007/s00792-006-0531-2},
  pages     = {577 -- 585},
  year      = {2006},
  abstract  = {Most eucaryotic organisms classified as living in an extreme habitat are invertebrates. Here we report of a fish living in a Mexican cave (Cueva del Azufre) that is rich in highly toxic H2S. We compared the water chemistry and fish communities of the cave and several nearby surface streams. Our study revealed high concentrations of H2S in the cave and its outflow (El Azufre). The concentrations of H2S reach more than 300 mu M inside the cave, which are acutely toxic for most fishes. In both sulfidic habitats, the diversity of fishes was heavily reduced, and Poecilia mexicana was the dominant species indicating that the presence of H2S has an all-or-none effect, permitting only few species to survive in sulfidic habitats. Compared to habitats without H2S, P. mexicana from the cave and the outflow have a significantly lower body condition. Although there are microhabitats with varying concentrations of H2S within the cave, we could not find a higher fish density in areas with lower concentrations of H2S. We discuss that P. mexicana is one of the few extremophile vertebrates. Our study supports the idea that extreme habitats lead to an impoverished species diversity.},
  language  = {en}
}