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Evolutionary responses to invasion: cane toad sympatric fish show enhanced avoidance learning
1Department of Biological Sciences, Macquarie University, Sydney, Australia.
Plos One
|February 2, 2013
Summary
Native Australian fish are adapting to toxic cane toads. Studies show fish populations exposed to cane toads develop learned avoidance behaviors, protecting native biodiversity from invasive species.
Area of Science:
- Ecology
- Evolutionary Biology
- Animal Behavior
Background:
- Introduced cane toads (Bufo marinus) are toxic and threaten Australian biodiversity.
- Terrestrial vertebrates show adaptation through learned avoidance of cane toads.
- Previous lab trials confirm learned avoidance behavior after repeated exposure to Bufo marinus.
Purpose of the Study:
- Investigate aversion learning in aquatic ecosystems.
- Compare naive and sympatric populations of crimson-spotted rainbow fish (Melanotaenia duboulayi) regarding cane toad tadpoles.
- Determine if natural selection enhances avoidance learning capabilities.
Main Methods:
- Comparative study of fish populations (naive vs. sympatric) exposed to cane toad tadpoles.
- Experiments assessing learned avoidance of toxic prey.
- Evaluation of aversion learning abilities using novel distasteful prey items.
Main Results:
- Sympatric fish showed pre-existing aversion to cane toad tadpoles and reduced attacks on native tadpoles.
- Both naive and sympatric fish learned to avoid cane toad tadpoles after exposure.
- Sympatric fish demonstrated enhanced avoidance of novel distasteful prey, indicating improved learning capabilities.
Conclusions:
- Experience with toxic prey over generations can enhance avoidance learning via natural selection.
- Aquatic ecosystems show evidence of aversion learning in response to invasive species.
- Melanotaenia duboulayi populations exhibit adaptive responses to the presence of toxic cane toads.
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