Journal Article
Extreme habitats are not refuges: poeciliids suffer from increased aerial predation risk in sulphidic southern Mexican habitats
Riesch, R.W., Oranth, A., Dzienko, J., Karau, N., Schiel, A., Stadler, S., Wigh, A., Zimmer, C., Arias-Rodriguez L., Schlupp, I. and Plath, M.
Record Number:
4739
Year:
2010
Journal:
Biological Journal of the Linnean Society
Pages:
417-426
Volume:
101
Abstract:
Extreme environments are often considered a predation refuge for
organisms living in them. In southern Mexico several species of poeciliid
fishes are undergoing incipient speciation in a variety of extreme (i. e.
permanently dark and/or sulphidic) freshwater systems, and previous
research has demonstrated reproductive isolation between populations
from sulphidic and adjacent benign habitats. In the present study, we
investigated bird predation rates (measured as successful captures per
minute) in two sulphidic surface and several benign surface habitats, to
test the hypothesis that extreme habitats are predation refuges. We found
capture rates to be approximately 20 times higher in sulphidic
environments: probably facilitated by extremophile poeciliids spending
most of their time at the water surface, where they engage in aquatic
surface respiration as a direct response to hypoxia. Even birds that are
usually not considered major fish predators regularly engage in fish
predation in the toxic habitats of southern Mexico. Our results
demonstrate that extreme environments do not necessarily represent a
refuge from predation, and we discuss the general importance of
predation in driving incipient speciation in these systems. Finally, we
hypothesize that natural selection via avian predation may play an
important role in maintaining reproductive isolation between divergent
poeciliid populations. KW: Avian predation, divergent natural selection,
ecological speciation, Egretta thula, extremophile fish, hydrogen
sulphide, refuge hypothesis
Times Cited:
1
Relevent Species: