Exploring the auditory aspects of South American frogs by physiological and morphological methods

• Grant number: 23/10831-9
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: February 24, 2024
• End date: March 31, 2024
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Luis Felipe de Toledo Ramos Pereira
• Grantee: Fernanda Paiva Silva Pinto
• Supervisor: Molly Womack
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Utah State University (USU), United States
• Associated to the scholarship: 22/08274-1 - Hearing sensibility of rheophilic frogs from Hylodidae family, BP.MS

Abstract

Hearing is one of the essential components of acoustic communication in anurans. However, it remains relatively unexplored when compared to acoustic emissions. Over 700 Brazilian species of anurans have had their advertisement calls described, whereas studies on hearing are limited to four out of the over 1,200 known species in Brazil. The auditory system of anurans comprises the inner ears (composed of the amphibian papilla, basilar papilla, and sacculus) and the middle ears (including the tympanic membrane and ossicles). The tympanic membrane is an external structure that acts as an air sound receptor, transmitting it to the ossicles of the middle ear, which in turn convey the sound to the inner ear. However, the tympanic membrane can be reduced or absent in several species. Without this feature, anurans generally rely on extra-tympanic pathways, involving lungs, cranial, or opercularis. Therefore, we propose to explore both the auditory sensitivity and the anatomy of the middle ear in anuran species with different tympanic membrane morphologies from the southern region of South America. More specifically, our goal is to investigate the auditory sensitivity of Ceratophrys ornata (with a conspicuous tympanum) and Lepidobatrachus laevis (with a discrete tympanum) through Auditory Brainstem Response. We also propose to perform microtomography of the middle ear in different species (from the families Ceratophryidae, Cycloramphidae, Hylodidae, and Odontophrynidae) with different types of tympanic membranes (or absence thereof). Thus, our aim is to complement the original project with microtomography data from species of the Hylodidae family and advance our knowledge about the hearing of anurans, especially those with atypical tympanic membranes. (AU)