Altitudinal Distribution of the Protozoan Cepedietta michiganesis in the Salamanders Plethodon glutinosus and Plethodon jordani in Eastern Tennessee

During 1966 and 1967, 392 Plethodon glutinosus and 988 P. jordani, collected in the Great Smoky Mountains National Park and Knox County, Tennessee, were examined for the intestinal ciliate, Cepedietta michiganensis. There was no difference in infection rate between the two salamander species at comparable altitudes. Infection rates were inversely proportional to altitude and infections are apparently limited to altitudes below 1400 m. Infection rates were significantly lower in spring than in autumn and this was attributed to winter extremes of temperature. The possible role of various factors which might affect per cent infection and altitudinal distribution of C. michiganensis is discussed. It is suggested that temperature, directly or indirectly, is the major factor that controls and/or limits the vertical distribution of C. michiganensis.