Meeting Abstract

36.3  Friday, Jan. 4  The Relationship between Jaw Morphology and Prey Capture Behavior in Anurans HENG, A.R.*; LAPPIN, A.K.; NISHIKAWA, K.C.; California State Polytechnic Univ.; California State Polytechnic Univ.; Northern Arizona Univ. hengaikroy@yahoo.com

During ballistic prey capture in toads, tongue projection is powered by the transfer of momentum from the lower jaw to the tongue. This extremely rapid movement depends upon the storage and recovery of elastic strain energy in the depressor mandibulae muscles and in-series connective tissues. The energy storage phase requires a mechanism to resist mouth opening prior to the ballistic movement, while the depressor mandibulae muscles generate force and store energy. To test the hypothesis that toads possess morphological specializations that serve to resist mouth opening, we compared the jaw morphology of several anuran taxa, including species that do not exhibit ballistic tongue projection. The mandible of all anurans examined lies along the lingual aspect of the maxillae. Toads, however, have exaggerated maxillary grooves in which the mandible is seated when the mouth is closed. This arrangement secures the mandible within the upper jaw margin, thus providing a locking mechanism based on wet adhesion. In addition, toads are unusual in that they completely lack teeth. We propose that this reflects the importance of an intimate association between the maxillae and mandible in resisting mouth opening during the energy storage phase of ballistic prey capture.