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Ecological partitioning among parapatric cryptic species
Alice B Dennis1, Michael E Hellberg
1Department of Biological Sciences, 202 Life Science Building, Louisiana State University, Baton Rouge, LA 70803, USA. alicebdennis@gmail.com
Molecular Ecology
|July 13, 2010
Summary
Cryptic species of the coastal snail Melampus bidentatus exhibit different geographic ranges due to physiological tolerances. Environmental factors like precipitation and salinity, not just temperature, shape their distribution.
Area of Science:
- Ecology
- Evolutionary Biology
- Marine Biology
Background:
- Geographic ranges of species are influenced by physiological tolerances, especially in dynamic intertidal zones.
- The coastal snail Melampus bidentatus, found along the western Atlantic and Gulf of Mexico, is a model for studying range limitations.
Purpose of the Study:
- To identify cryptic species within Melampus bidentatus using molecular markers.
- To investigate the environmental factors driving the distinct geographic ranges of these cryptic species.
Main Methods:
- Utilized sequence data from mitochondrial (COI) and nuclear markers (histone H3, MCP) to delineate species.
- Modeled species distributions using marine and terrestrial environmental data to identify microhabitat differences.
Main Results:
- Identified three cryptic species of Melampus bidentatus, with two exhibiting overlapping geographic ranges.
- Temperature was a key factor, but the interaction of precipitation and salinity significantly explained range differences.
- High genetic diversity and migration within overlapping species suggest current environmental factors, not just historical limitations, define ranges.
Conclusions:
- Physiological tolerances to combined environmental factors, particularly precipitation and salinity, are critical in determining the geographic ranges of cryptic Melampus bidentatus species.
- Future climate change impacts on these snails will likely involve complex interactions of multiple environmental factors, not solely temperature shifts.
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