Hymenolepis ackerti n. sp. (Eucestoda: Hymenolepididae) infecting cricetid rodents from the central Great Plains of North America

Abstract

Hymenolepis ackerti n. sp., parasite of rodents from the tallgrass prairie ecoregion of North America is herein characterized. This tapeworm occurs in 3 species of rodents including the hispid cotton rat Sigmodon hispidus, the eastern woodrat Neotoma floridana, and the prairie vole Microtus ochrogaster. A comparison against the other 10 congeneric species known from North America reveals that this species is different based on the size of the scolex, length of rostellar capsule, testicular arrangement, and the size of cirrus sac, seminal receptacle and eggs. A comparison of mitochondrial DNA reveals that tapeworms present in sympatric mammals share the same mitochondrial haplotype and feature similar morphology, supporting their recognition as a single species. The phylogenetic position of H. ackerti relative to other species is still to be resolved, since there are no homologous sequences available for most species in the genus. Given the pervasiveness of these parasites across rodents in the continent, we recommend diligence among scientists to build public archives of tapeworm specimens collected from mammals across North America, and globally. In the present manuscript, we propose a method to sample DNA while still allowing specimens to be postfixed for staining or fluid-preserved for long term storage.