Meeting Abstract

P1.190  Saturday, Jan. 4 15:30  Auditory differences in the lungless salamanders Plethodontidae: from inside caves and out. CAPSHAW, G*; HIGGS, D; NIEMILLER, M; SOARES, D; University of Maryland; Windsor University; Yale University; University of Maryand daph@umd.edu

Salamanders, being early land vertebrates, have many of the structures of terrestrial animals in simple form. The Plethodontidae, commonly called lungless salamanders, are the largest family of extant salamanders with over 350 species. This group is prominent in the Appalachian Mountains in the eastern United States. Members within this group are adapted to stream, arboreal, terrestrial, and underground habitats. We are interested in the hearing characteristics of species that inhabit caves compared to surface habitats. We recorded Auditory Evoked Potentials (AEPs) in two cave species: the Cave Salamander (Eurycea lucifuga), and the Spring Salamander (Gyrinophilus porphyriticus) and three surface stream species: the Red Salamander (Pseudotriton ruber), the Two-lined Salamander (Eurycea bilineata) and the Spotted Dusky Salamander (Desmognathus conanti). All salamanders had similar thresholds and range when placed on a solid surface directly coupled to the speaker. This result in consistent with a bone conduction mechanism that detects vibrations. However, when animals were physically isolated from vibrations via acoustic foam, salamanders showed an increase in auditory threshold. We also created 3D reconstructions of the otic capsules and connections with the lower jaw.