Data from: Did predation shape fish? The impact of fin spines on body form evolution across teleosts.

It is well known that predators can induce morphological changes in some fish: individuals exposed to predation cues increase both body depth and the length of spines thereby enlarging the body dimensions that gape-limited predators must overcome. If similar adaptive plastic responses to predation facilitated evolutionary change over the history of teleosts, we would expect to find that fin spines and body dimensions evolve concomitantly at the macroevolutionary scale. Using phylogenetic comparative methods, we tested the specific prediction that increases in body dimensions parallel the orientation of the fin spines across 347 teleost families, which display considerable variation in body depth and width. Consistent with our predictions, we demonstrate that lineages with fin spines on the vertical plane (dorsal and anal fins) are deeper bodied with greater variability in body depth. Lineages with spines on the horizontal plane (pectoral fins) have wider bodies but body width is more constrained in spiny lineages. Additionally, the longer the spines the deeper or wider the body. This evolutionary relationship between fin spines and body form across teleosts reveals a potential macroevolutionary signature of predation on the evolutionary dynamics of body shape. We speculate that fin spines acted as a key innovation, which worked in tandem with increases in the appropriate body dimension, allowing spiny lineages to reduce the impact of predation pressure during the Mesozoic Marine Revolution thus enabling the spiny-finned fishes and catfishes to become the diverse and dominant clades they are today.