Explorations of the unique anuran ear: The contributions of Al Feng

Abstract

The anuran inner ear is unique among vertebrate ears in containing three organs for sound detection—the amphibian papilla, the basilar papilla, and the saccule. Al's anatomical, physiological, and behavioral work in several anuran species, from the American bullfrog to the Chinese torrent frog, has significantly furthered our understanding of the evolution and operation of this unusual ear. In this presentation, I will discuss another component of Al's work—his explorations into the development of the bullfrog's auditory periphery. Along with his student, Bill Shofner, Al showed that developmental changes in the tympanum and in the two papillae are reflected in differences in hearing sensitivity over the post-metamorphic span from froglet to adult frog. These experiments inspired new research in my laboratory on the development of hearing in larval (tadpole) life. Following up on Al's pioneering studies, new data on anatomical development of these two organs in tadpoles are presented and discussed in light of published data on auditory sensitivity over the metamorphic transition. The change in biome from wholly aquatic to terrestrial that occurs over metamorphosis in bullfrogs focuses attention on the impact of the environment on the development and sensitivity of hearing.