Meeting Abstract
Angelfishes and butterflyfishes (collectively chaetodontoid fishes) are among the most economically and ecologically important, as well as charismatic, members of circumglobal tropical coral reef ecosystems. Our recent phylogenetic analyses show a strong sister-group relationship for the two families in the context of other scaly-finned “sqamipinne” fishes. By combining techniques from phylogenetics, geometric morphometrics, and computational biomechanics, we sought to quantitatively explore the biodiversity of butterflyfish and angelfish cranial and body shape features across densely sampled species phylogenies for the group. Phylomorphospace results show that size, phylogeny and diet have affected shape evolution in angelfishes and butterflyfishes, that pomacanthids and chaetodontids occupy distinct regions of phylomorphospace, and that skull shape evolution has direct functional implications. Using cranial morphometrics and computational modeling, we set out to characterize the biomechanical consequences of the intramandibular jaw joint (IMJ) that is present in many species in these two families. Modeling suggests that the IMJ is usually associated with lower bite force, but confers an increased ability to vary the vector of force application of the lower jaw. Our data reveal significant instances of both convergent and divergent evolution of morphological and biomechanical features during the radiation of chaetodontoid fishes, with morphospace groupings significantly associated with ecological traits.
