Exploring the relationship between environment and brain morphology in anurans: a comparative phylogenetic approach

The correlation of ecological and behavioural characteristics with morphological features of brain structures has been recurrently corroborated for different vertebrate taxa, such as mammals, birds, and fishes. Here, we asked whether such correlations can also be detected in amphibians, an animal group of great interest due to its great behavioural and ecological diversity. We analysed the shape of two brain regions, cerebellum and optic tectum, of 67 species from 32 families of the order Anura (frogs and toads), applying 2D geometric morphometrics in a phylogenetic context. We found species that share similar environments and daily patterns have a similarly shaped cerebellum and optic tectum, with diurnal and arboreal species with more varied brain shapes. We did not find a correlation between activity mode or lifestyle with shape for both brain regions; however, we found that shared ancestry had an influence in their evolution. Future studies including a higher number of species from each ecological group, and from more families, would help to better clarify whether the patterns found here are a general rule for anurans.