Fine-scale adaptation in a clonal sea anemone

Area of Science:

• Marine biology
• Evolutionary ecology
• Genetics

Background:

• Local adaptation is well-documented in terrestrial ecosystems but rarely explored in marine environments.
• Widespread dispersal in marine environments may lead to genetic homogenization.
• Evolutionary theory predicts local adaptation in benthic species with complex life cycles.

Purpose of the Study:

• To investigate local adaptation in the marine environment.
• To explore fine-scale spatial heterogeneity and its effect on marine taxa.
• To determine if sea anemone clones (Actinia tenebrosa) exhibit habitat-specific distributions and performance.

Main Methods:

• Genotypic mapping to identify clone distributions within headlands.
• Reciprocal transplant experiments to compare clone performance across habitats.
• Assessment of survivorship, asexual fecundity, and growth rates.

Main Results:

• Sea anemone clones (Actinia tenebrosa) showed restricted distributions to specific habitats within headlands.
• Clones exhibited significantly better performance (survivorship, fecundity, growth) in their natal habitats compared to foreign habitats.
• Evidence of site-specific selection and interclonal competition was observed.

Conclusions:

• Fine-scale environmental adaptation is important in marine taxa.
• Marine populations can exhibit local adaptation despite potential for widespread dispersal.
• The genotypic structure of populations reflects long-term interclonal competition and site-specific selection.