What Can the Vocal Folds of Túngara Frogs Tell us About the Complexity of their Calls?
Poster Number
33
Format
Poster Presentation
Faculty Mentor Name
Marcos Gridi-Papp
Faculty Mentor Department
Biological Sciences
Abstract/Artist Statement
The túngara frog (Engystomops pustulosus) is one of the most important models of acoustic communication among vertebrates today. More than 40 years of research have shown how female choice can drive the evolution of the male advertisement signals in this species. Males increase their attractiveness by facultatively increasing the complexity of their calls. Studies have shown that the complex calls involve a laryngeal structure called fibrous mass, which is unusually enlarged in túngara frogs, but the mechanism has not been explained. It is unclear how the facultative sound can be produced simultaneously with the normal call, and how the animals control its onset. With the goal of identifying morphological features of the larynx that could help explain the mechanisms of complex call production, we embarked on a detailed study of the entire larynx of E. pustulosus. We dissected the larynx from specimens fixated in formalin, then decalcified, dehydrated, embedded in paraffin, sectioned with microtome, mounted on slides, rehydrated, and stained the tissues. Next, we examined the sections and photographed them for measurement and 3D reconstruction. Our results show that the vocal folds have an unusually broad attachment to the arytenoid cartilage which practically divides each fold in two membranes, facilitating the addition of a secondary simultaneous vibration. The vocal folds also receive extensive attachments of the extrinsic laryngeal musculature. Such attachments seem appropriate to adjust the position of the fibrous masses in the airflow and control the onset of the complex call. Quantitative changes in common laryngeal structures rather origination of new structures seems to be the explanation for complex calling in the túngara frog.
Location
DeRosa University Center, Ballroom
Start Date
20-4-2013 1:00 PM
End Date
20-4-2013 3:00 PM
What Can the Vocal Folds of Túngara Frogs Tell us About the Complexity of their Calls?
DeRosa University Center, Ballroom
The túngara frog (Engystomops pustulosus) is one of the most important models of acoustic communication among vertebrates today. More than 40 years of research have shown how female choice can drive the evolution of the male advertisement signals in this species. Males increase their attractiveness by facultatively increasing the complexity of their calls. Studies have shown that the complex calls involve a laryngeal structure called fibrous mass, which is unusually enlarged in túngara frogs, but the mechanism has not been explained. It is unclear how the facultative sound can be produced simultaneously with the normal call, and how the animals control its onset. With the goal of identifying morphological features of the larynx that could help explain the mechanisms of complex call production, we embarked on a detailed study of the entire larynx of E. pustulosus. We dissected the larynx from specimens fixated in formalin, then decalcified, dehydrated, embedded in paraffin, sectioned with microtome, mounted on slides, rehydrated, and stained the tissues. Next, we examined the sections and photographed them for measurement and 3D reconstruction. Our results show that the vocal folds have an unusually broad attachment to the arytenoid cartilage which practically divides each fold in two membranes, facilitating the addition of a secondary simultaneous vibration. The vocal folds also receive extensive attachments of the extrinsic laryngeal musculature. Such attachments seem appropriate to adjust the position of the fibrous masses in the airflow and control the onset of the complex call. Quantitative changes in common laryngeal structures rather origination of new structures seems to be the explanation for complex calling in the túngara frog.