Variations in Sound Production Frequency Among North American Gray Tree Frogs
Poster Number
27
Format
Poster Presentation
Faculty Mentor Name
Marcos Gridi-Papp
Faculty Mentor Department
Biological Sciences
Abstract/Artist Statement
Studies of mammalian vocal structures have demonstrated the relationship between laryngeal size and sound production frequency. This relationship is also present in anurans. Hyla chrysoscelis and Hyla versicolor, two North American gray tree frog sister species, share their physical aspect, size, ecology and behavior, but differ in chromosome numbers as H. chrysoscelis is diploid and H. versciolor is tetraploid. It has been hypothesized that H. versicolor should produce lower frequency calls than H. chrysoscelis because the former possesses greater ploidy, which results in larger cells. The evidence from field studies is, however, scarce and inconclusive. In this study, we compare the laryngeal morphology of these two species via dissection and histology. Tissues of leopard frogs (Rana pipiens) were initially employed for adjustment of the techniques, especially with relation to the decalcification of the posterior processes of the hyoid bone, which is necessary for the production of good sections of the larynx. Preliminary data from Rana pipiens indicate that our method will allows us to obtain precise measurements of the sizes and thicknesses of the laryngeal structures and of the cell sizes in epithelia and cartilages, besides the thicknesses of muscular fibers. These measurements should unveil the effects of cell size on laryngeal function, expanding the current understanding of the design and evolution of the vocal apparatus in vertebrates.
Location
Grave Covell
Start Date
21-4-2012 10:00 AM
End Date
21-4-2012 12:00 PM
Variations in Sound Production Frequency Among North American Gray Tree Frogs
Grave Covell
Studies of mammalian vocal structures have demonstrated the relationship between laryngeal size and sound production frequency. This relationship is also present in anurans. Hyla chrysoscelis and Hyla versicolor, two North American gray tree frog sister species, share their physical aspect, size, ecology and behavior, but differ in chromosome numbers as H. chrysoscelis is diploid and H. versciolor is tetraploid. It has been hypothesized that H. versicolor should produce lower frequency calls than H. chrysoscelis because the former possesses greater ploidy, which results in larger cells. The evidence from field studies is, however, scarce and inconclusive. In this study, we compare the laryngeal morphology of these two species via dissection and histology. Tissues of leopard frogs (Rana pipiens) were initially employed for adjustment of the techniques, especially with relation to the decalcification of the posterior processes of the hyoid bone, which is necessary for the production of good sections of the larynx. Preliminary data from Rana pipiens indicate that our method will allows us to obtain precise measurements of the sizes and thicknesses of the laryngeal structures and of the cell sizes in epithelia and cartilages, besides the thicknesses of muscular fibers. These measurements should unveil the effects of cell size on laryngeal function, expanding the current understanding of the design and evolution of the vocal apparatus in vertebrates.