Life on the edge: hydrogen sulfide and the fish communities of a Mexican cave and surrounding waters

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 H(2)S. We compared the water chemistry and fish communities of the cave and several nearby surface streams. Our st...

Full description

Saved in:
Bibliographic Details
Published in:Extremophiles : life under extreme conditions 2006-12, Vol.10 (6), p.577-585
Main Authors: Tobler, Michael, Schlupp, Ingo, Heubel, Katja U, Riesch, Rüdiger, de León, Francisco J García, Giere, Olav, Plath, Martin
Format: Article
Language:English
Subjects:
Acute toxicity
Adaptation, Physiological
Animals
Biodiversity
Caves
Chemoautotrophic Growth
Dominant species
Energy Metabolism
Fresh Water - chemistry
Habitats
Hydrogen sulfide
Hydrogen Sulfide - analysis
Hydrogen Sulfide - metabolism
Mexico
Microhabitats
Oxygen - analysis
Poecilia - metabolism
Poecilia - physiology
Poecilia mexicana
Population Density
Species diversity
Water chemistry
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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 H(2)S. We compared the water chemistry and fish communities of the cave and several nearby surface streams. Our study revealed high concentrations of H(2)S in the cave and its outflow (El Azufre). The concentrations of H(2)S reach more than 300 muM 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 H(2)S has an all-or-none effect, permitting only few species to survive in sulfidic habitats. Compared to habitats without H(2)S, P. mexicana from the cave and the outflow have a significantly lower body condition. Although there are microhabitats with varying concentrations of H(2)S within the cave, we could not find a higher fish density in areas with lower concentrations of H(2)S. 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.
ISSN:1431-0651
1433-4909
DOI:10.1007/s00792-006-0531-2