Morphological traits of actinopterygian fishes do not influence their diversification rates

Species richness differences among lineages and habitats, as well as the variety of their traits, has led to the association of intrinsic and extrinsic traits of species with diversification dynamics based on the premise that these traits can influence speciation and extinction rates. In this study, we used the most extensive molecular phylogeny available for the class Actinopterygii to test the influence on diversification of three ecologically relevant and widely sampled morphological traits of ray-finned fishes: body elongation ( bel ), body lateral shape ( bls ), and maximum body size ( len ). We also included habitat type (freshwater/marine) as a trait that could interact with these morphological traits and influence diversification rates. We applied the recently developed SecSSE model of trait-dependent diversification that allows evaluating the effect of examined and concealed trait states on diversification. Our results revealed that none of the examined morphological traits nor their interaction with habitat have an effect on the diversification of the whole class. Instead, they suggest the influence of other, unmeasured trait(s) on such diversification dynamics. Still, our findings do not exclude the possibility that the examined traits can have on the diversification of particular lineages (.e.g, orders or families) within the actinopterygian radiation.