Insights on the host associations and geographic distribution of Hymenolepis folkertsi (Cestoda: Hymenolepididae) among rodents across temperate latitudes of North America.

E P Hoberg,K E Galbreath,V V Tkach,R P Eckerlin,A A Makarikov,T N Nims,S Meagher

doi:10.1007/s00436-016-5255-3

E P Hoberg, K E Galbreath + Show 5 more

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https://doi.org/10.1007/s00436-016-5255-3

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Journal: Parasitology research	Publication Date: Sep 14, 2016
Citations: 3	License type: CC BY 4.0

Affiliation: Western Illinois University

Abstract

Synoptic data and an understanding of helminth parasite diversity among diverse rodent assemblages across temperate latitudes of North America remain remarkably incomplete. Renewed attention to comprehensive survey and inventory to establish the structure of biodiverse faunas is essential in providing indicators and proxies for identifying the outcomes of accelerating change linked to climate warming and anthropogenic forcing. Subsequent to the description of Hymenolepis folkertsi in the oldfield mouse, Peromyscus polionotus, additional specimens of hymenolepidids were collected or discovered in archived museum repositories from multiple species of deer mice (Peromyscus maniculatus, Peromyscus leucopus), the golden mouse (Ochrotomys nuttalli), chipmunks (Tamias striatus, Tamias amoenus), the 13-lined ground squirrel (Ictidomys tridecemlineatus), and tree squirrels (Sciurus carolinensis, Sciurus niger) from disjunct localities in the USA spanning southern Georgia, Virginia, Pennsylvania, Connecticut, the Upper Peninsula of Michigan, Wisconsin, and central Idaho. Specimens were largely consistent morphologically with the original description of H. folkertsi. Initial DNA sequence data, from a portion of the mitochondrial NADH dehydrogenase subunit 1, demonstrated intraspecific variation among three apparently geographically isolated populations attributed to H. folkertsi (uncorrected genetic distances of 2.7 % (Idaho and Michigan), 2.4 % (Virginia + Pennsylvania and Michigan), and 1.89 % (VA + PA and ID). Geography rather than host association explains the distribution and occurrence of H. folkertsi, and host colonization among deer mice, chipmunks, and other sciurids within regional sites is indicated. Genetic divergence revealed across localities for H. folkertsi suggests historically isolated populations, consistent with extended evolutionary and biogeographic trajectories among hymenolepidids and species of Peromyscus and Tamias in North America. Field inventory, that revealed these parasite populations, substantially alters our understanding of the distribution of diversity and provides insights about the nature of the complex relationships that serve to determine cestode faunas in rodents.

Highlights

Pennsylvania, Connecticut, the Upper Peninsula of Michigan, Wisconsin, and central Idaho
Coincidental with the description of H. folkertsi, ongoing survey and inventory, contributing to broadening museum archives of specimens and tissues documenting rodent helminth faunas across localities in North America, revealed additional specimens of this hymenolepidid; previously unknown specimens were discovered in privately held collections and among materials archived in the Museum of Southwestern Biology and in the former US National Parasite Collection, within the US National Museum, Smithsonian
A series of gravid specimens are attributed to H. folkertsi from (i) the Upper Peninsula of Michigan, USA [in Peromyscus maniculatus (Wagner), Peromyscus leucopus (Rafinesque), and Tamias striatus (Linnaeus), Sciuridae, Tamias Illiger, subgenus Neotamias Howell]; (ii) from Pennsylvania, USA; (iii) from Virginia, USA; (iv) from Connecticut, USA; (v) from south-central Wisconsin, USA [in T. striatus, Ictidomys tridecemlineatus (Mitchill), Sciurus carolinensis Gmelin and Sciurus niger Linnaeus], and (vi) from central Idaho, USA (Fig. 1)

Summary

Introduction

Pennsylvania, Connecticut, the Upper Peninsula of Michigan, Wisconsin, and central Idaho. New field collections that provide access to comparative materials for integrated morphological/ molecular analyses are essential to enhance our ability to more completely document parasite faunal diversity among Nearctic rodents (e.g., Haukisalmi et al 2010; Hoberg et al 2012; Gardner et al 2014; Makarikov et al 2012, 2013, 2015). Clearly differentiated from seven congeneric species in the Nearctic, including Hymenolepis diminuta (Rudolphi, 1819), with respect to a suite of structural attributes, the type specimens for H. folkertsi were originally fixed in 5 % formalin (Makarikov et al 2015) These specimens were not appropriate for comparisons of molecular sequence data among other species of Hymenolepis which could reflect, through integrated approaches, on species identity, higher level relationships, and biogeography (e.g., Haukisalmi et al 2010). Discovery and collection of these specimens provide the opportunity to complete initial molecular-based comparisons confirming the identity of H. folkertsi and to provisionally place this hymenolepidid in a larger phylogenetic context for the genus

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