Ontogeny of middle ear tuning in male and female túngara frogs (Engystomops pustulosus)
Poster Number
27
Format
Poster Presentation
Faculty Mentor Name
Marcos Gridi-Papp
Faculty Mentor Department
Biological Sciences
Abstract/Artist Statement
Frequency tuning in amphibian auditory systems is influenced by many possible factors such as body size, morphology of the eardrum and ossicles, and sex. The significance of size on auditory tuning in frogs has already been characterized in larger bullfrogs: the larger the body size, the lower the tuning frequency. This pattern remained consistent in the considerably smaller túngara frogs (Engystomops pustulosus; snout to vent length: 22-33 mm). The study therefore delved into an additional variable - ontogeny. As frogs undergo puberty, their auditory structures might specialize in each sex and result in distinct frequency tuning. This hypothesis was tested by measuring the frequencies to which the eardrums and body walls of túngara frogs were tuned throughout live in both sexes. The goals of this study were: to quantify the relationship between body size and the tuning of eardrums and body wall along the ontogeny of a small amphibian; and determine if sex causes a difference in the tuning of the eardrums and body wall when the data are corrected for body size. Individuals were bathed in anesthetic in order to place microscopic retroreflective bead precisely on the center of the eardrum and body wall for data collection. The frog was then placed 50 cm away from a calibrated loudspeaker which played pure tones at the same intensity over a range of frequencies. The vibrations were recording by a laser Doppler vibrometer focused on the bead’s reflective surface while sound was played. Juveniles were tuned to higher frequencies (4kHz) than adults (2-3kHz), and females were tuned to lower frequencies (2-2.5kHz) than males (3kHz). The observed differences in tuning between stages of life and sex indicate that ontogeny does affect auditory tuning. We are currently analysing the data to characterize the allometric relationships and determine the effect of sex.
Location
DeRosa University Center, Ballroom
Start Date
25-4-2015 10:00 AM
End Date
25-4-2015 12:00 PM
Ontogeny of middle ear tuning in male and female túngara frogs (Engystomops pustulosus)
DeRosa University Center, Ballroom
Frequency tuning in amphibian auditory systems is influenced by many possible factors such as body size, morphology of the eardrum and ossicles, and sex. The significance of size on auditory tuning in frogs has already been characterized in larger bullfrogs: the larger the body size, the lower the tuning frequency. This pattern remained consistent in the considerably smaller túngara frogs (Engystomops pustulosus; snout to vent length: 22-33 mm). The study therefore delved into an additional variable - ontogeny. As frogs undergo puberty, their auditory structures might specialize in each sex and result in distinct frequency tuning. This hypothesis was tested by measuring the frequencies to which the eardrums and body walls of túngara frogs were tuned throughout live in both sexes. The goals of this study were: to quantify the relationship between body size and the tuning of eardrums and body wall along the ontogeny of a small amphibian; and determine if sex causes a difference in the tuning of the eardrums and body wall when the data are corrected for body size. Individuals were bathed in anesthetic in order to place microscopic retroreflective bead precisely on the center of the eardrum and body wall for data collection. The frog was then placed 50 cm away from a calibrated loudspeaker which played pure tones at the same intensity over a range of frequencies. The vibrations were recording by a laser Doppler vibrometer focused on the bead’s reflective surface while sound was played. Juveniles were tuned to higher frequencies (4kHz) than adults (2-3kHz), and females were tuned to lower frequencies (2-2.5kHz) than males (3kHz). The observed differences in tuning between stages of life and sex indicate that ontogeny does affect auditory tuning. We are currently analysing the data to characterize the allometric relationships and determine the effect of sex.