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Current shifts and kin aggregation explain genetic patchiness in fish recruits
Kimberly A Selkoe1, Steven D Gaines, Jennifer E Caselle
1Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California 93106, USA. selkoe@nceas.ucsb.edu
Ecology
|January 26, 2007
Summary
Marine population genetics reveals chaotic genetic patchiness due to limited larval mixing. Family structure and changing larval delivery, not lasting genetic structure, explain these patterns in kelp bass.
Area of Science:
- Marine population genetics
- Larval dispersal dynamics
- Population structure analysis
Background:
- Marine population structure is influenced by larval mixing.
- Chaotic genetic patchiness suggests limited larval mixing.
- Causes of genetic heterogeneity include migration, selection, and reproductive success.
Purpose of the Study:
- Investigate causes of genetic heterogeneity in marine populations.
- Analyze spatial and temporal genetic variation in kelp bass (Paralabrax clathratus) recruits.
- Distinguish between larval dispersal, environmental selection, and reproductive success as drivers of genetic structure.
Main Methods:
- Microsatellite markers used to analyze genetic variation.
- Recruits sampled bi-weekly over two years from five sites.
- Genetic differentiation among cohorts assessed.
Main Results:
- Significant allele frequency shifts observed sporadically in space and time.
- Genetic differentiation explained by family structure and changes in larval delivery.
- Larval dispersal patterns correlated with oceanographic current flows.
Conclusions:
- Limited larval mixing in marine populations is confirmed.
- Family structure and larval delivery changes, not lasting genetic structure, drive "chaotic genetic patchiness".
- Sweepstakes reproductive events occur at a fine scale, not creating persistent year-class structure.
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