Phenotypic plasticity – the ability of an individual organism to change its phenotype in response to the environment – is the limiting factor of the acclimation ability of the organism and its importance is often highlighted in connection to global change. However, it is also crucial for species that have evolved to inhabit various environments.
The anemonefish Amphiprion clarkii is considered a generalist species, as it has a wide distribution range and is the only anemonefish that has been found to in symbiosis with all the giant sea anemones, that act as a microenvironment for the fish. Giant sea anemones have different characteristics such as toxicity or microbiome, therefore it is crucial that A. clarkii have the capacity to deal with all the different host anemones, as settlement into the different hosts is assumed to be random.
Here, we show how the pigmentation of adult A. clarkii is linked to the sea anemone they associate with, being black in Stichodactyla and orange in Heteractis. Furthermore, by using transcriptomic analysis of juveniles from both host anemones, we show that the effect of the host anemone on the fish is much deeper than just the pigmentation.