Host Specificity in the Appalachian Leech Placobdella biannulata

The Appalachian leech Placobdella biannulata is a presumed host generalist for an array of amphibian species. One species commonly parasitized by this leech is the salamander Desmognathus quadramaculatus because of its semiaquatic nature and relatively large size. We tested the null hypothesis that this leech species exhibits equal prevalence in large species of Desmognathus with the same level of aquatic tendency. We compared leech prevalence between D. quadramaculatus and sympatric Desmognathus folkertsi, which has the same extent of aquatic tendency. While smaller than D. quadramaculatus, D. folkertsi is still among the largest members of the genus. We found leech parasitism on 38/182 (21%) D. quadramaculatus from 2 different streams. Only 3 D. folkertsi out of 179 (<2%) from the same streams were parasitized. We concluded that the leech P. biannulata is more host specific than previously believed.