Paper by Garcia Jimenez et al entitled “Habitat specialisation impacts clownfish demographic resilience to pleistocene sea-level fluctuations” published in Molecular Ecology.
Study Overview:
Researchers analyzed whole-genome data from 382 individuals across 10 clownfish species to understand how host specialisation influenced demographic responses to Pleistocene sea-level fluctuations, which repeatedly fragmented coral reef habitats.
Key Findings:
- Generalist species (those associating with multiple sea anemone hosts) maintained stable population sizes and connectivity during habitat fragmentation, showing resilience to environmental instability.
- Specialist species, dependent on specific hosts, experienced severe population declines and strong genetic structuring, with little evidence of recovery after habitats reconnected.
- Geographic patterns: The Indonesian Through-Flow acted as a major dispersal corridor, while continental shelves and open ocean regions were barriers to gene flow. The Coral Triangle emerged as a critical hub of genetic diversity.
Implications:
This study highlights how ecological dependencies shape species’ vulnerability to environmental change. Incorporating host specialisation into conservation strategies is essential for predicting resilience under future habitat disruptions.
Citation:
García-Jiménez A., Talbi M., Fitzgerald L.M., et al. (2025). Habitat Specialisation Impacts Clownfish Demographic Resilience to Pleistocene Sea-Level Fluctuations. Molecular Ecology. https://doi.org/10.1111/mec.70134