Meeting Abstract
Fishes use a sensational diversity of jaw mechanisms for feeding, with more than 20 mobile skeletal elements driven by numerous muscles. How can we accurately model these systems so that morphometric data can be used to assess biomechanical traits across phylogeny? Here we integrate biomechanical modeling, geometric morphometrics and phylogenetic analysis to address questions of functional diversification in coral reef fishes. New biomechanical linkage software (JawsModel2020) for analysis of cranial linkages in fishes (from muscle contraction to bite force) allows for simulation of structure-function relationships in a wide range of taxa, using the same coordinate data sets employed for geometric morphometric shape analysis. We present detailed morphometrics, modeling, and diversification of functional traits in two reef fish families, the Labridae (wrasses) and Pomacentridae (damselfishes). Phylomorphospace plots show that damselfishes have evolved largely outside of wrasse morphospace. However, frequent convergences in shape across phylogenetic groupings within families are identified, with evolutionary rates highest in recent crown group wrasses. Linkage modeling leads to several conclusions regarding the evolution of function in reef fishes: (1) Four-bar linkage structure-to-function mapping in fishes is 1-to-1; (2) Novel linkage mechanisms in reef fishes are associated with unique cranial morphospace occupation; (3) Biomechanical traits can diverge and evolve due to linkage changes, or diverge with linkages remaining static, solely due to muscle modification; (4) Multiple mechanical variables and levels of design should be considered when defining convergent or equivalent biomechanical systems. NSF DEB 1541547
