Meeting Abstract
The order Cypriniformes consists of over 3,000 species and makes up over one-tenth of all living bony fishes. Multiple novel feeding innovations — including the loss of oral teeth, the loss of the upper pharyngeal jaw, and the loss of the stomach — shift the load of food processing entirely onto the pharyngeal teeth and lower pharyngeal jaw (LPJ) within this group. Since the LPJ plays such a singular role in food processing, quantifying the diversity of the cypriniform LPJ may help us understand how this group has diversified and adapted to novel feeding environments. Here we investigate cypriniform LPJ morphospace occupation in order to determine whether diversity in shape of the LPJ is more closely correlated with function or phylogeny. We build and analyze a geometric morphometric morphospace of over 60 genera containing altogether more than 90 species of Cypriniformes. Each specimen is characterized by 5 landmarks and 36 semilandmarks along the tooth-bearing face of the LPJ. Generalized Procrustes analysis superimposes these coordinates to a common space that isolates variance in shape. Projection from this space via principal components analysis allows us to describe major axes of shape variation. Using our own shape data in combination with trophic information and phylogenetic analyses found in the literature, we are able to quantify and interpret patterns of diversity within the cypriniform pharyngeal jaw.
