Evolutionary radiations are crucial in shaping biodiversity, characterized by rapid diversification to exploit ecological niches. Symbiosis can be a significant catalyst for such diversification, as exemplified by the mutualistic relationship between anemonefish and sea anemones. Understanding how ecological opportunities lead to adaptive morphological, behavioral, and physiological innovations and how these changes drive radiation is challenging.
We investigated anemonefish (Amphiprion) phenotypic diversification following their symbiosis with giant sea anemones. Host specificity and habitat specialization have traditionally been seen as primary drivers of anemonefish radiation. However, the functional characterization of different anemonefish species and their potential diversification into various ecological strategies remains unexplored.
We identified distinct eco-morphotypes among anemonefishes using field observations, swimming tunnel experiments, computational simulations, and morphological analyses. By examining the swimming performances of six anemonefish species from Okinawa Island, we uncovered eco-morphotypes based on morphology, physiology, and ecology, challenging the traditional generalist-specialist perspective.
Expanding our study to eight additional species across the anemonefish evolutionary tree revealed new insights into the diversification processes shaping anemonefish variety today. Our findings show that integrative phenotyping, combining in situ and laboratory observations, provides a comprehensive understanding of the drivers of adaptive radiations, enhancing our ability to unravel the complex evolutionary dynamics generating biodiversity.