Larval dispersal in anemonefish populations

Abstract

Anemonefishes have been a model species testing and applying new methodologies that have transformed our knowledge of marine larval fish dispersal. Population genetics, otolith chemical signatures, chemical tagging, and most notably, genetic parentage analysis were all pioneered on anemonefishes and together have revealed higher levels of self-recruitment than once thought possible. Collectively, they also show that dispersal frequencies decline with distance from source, and despite a relatively short larval duration (10–12 days), some anemonefish larvae can disperse hundreds of kilometres. Studies that include 14 of the 28 known species show that the average level of self-recruitment is high (~33%) and the average dispersal distance is low (~10 km), but these estimates vary among anemonefish species, geographic locations, and years. The propensity to disperse may be greater in areas of strong hydrodynamic regimes and for species with broad geographic distributions that extend across patchy oceanic environments, and may be lowest for endemic species restricted to isolated islands. Some anemonefish populations are likely sustained by self-recruitment (e.g., Amphiprion percula), while others may require metapopulation connectivity (e.g., A. clarkii) to persist. The ability to recruit locally or disperse long distances suggests an innate resilience of anemonefish populations in the face of unpredictable disturbances. Long-term studies over multiple generations also suggest an innate plasticity and potential to adapt to local and regional environmental change.