Discovery And Description Of A New Trichostrongyloid Species (Nematoda: Ostertagiinaw), Abomasal Parasites In Mountain Goat, Oreamnos Americanus, From The Western Cordillera Of North America [With Erratum], Eric P. Hoberg, Arthur Abrams, Patricia A. Pilitt, Emily J. Jenkins

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Marshallagia lichtenfelsi sp. n. is a dimorphic ostertagiine nematode occurring in the abomasum of mountain goats, Oreamnos americanus, from the Western Cordillera of North America. Major and minor morphotype males and females are characterized and distinguished relative to the morphologically similar Marshallagia marshalli/Marshallagia occidentalis from North America and Marshallagia dentispicularis, along with other congeners, from the Palearctic region. The configuration of the convoluted and irregular synlophe in the cervical region of males and females of M. lichtenfelsi is apparently unique, contrasting with a continuous and parallel system of ridges among those species of Marshallagia, including …

Timing The Origin Of Human Malarias: The Lemur Puzzle, M. Andreína Pacheco, Fabia U. Battistuzzi, Randall E. Junge, Omar E. Cornejo, Cathy V. Williams, Irene Landau, Lydia Rabetafika, Georges Snounou, Lisa Jones-Engel, Ananias A. Escalante

Harold W. Manter Laboratory of Parasitology: Library Materials

Background: Timing the origin of human malarias has been a focus of great interest. Previous studies on the mitochondrial genome concluded that Plasmodium in primates, including those parasitic to humans, radiated relatively recently during a process where host switches were common. Those investigations, however, assumed constant rate of evolution and tightly bound (fixed) calibration points based on host fossils or host distribution. We investigate the effect of such assumptions using different molecular dating methods. We include parasites from Lemuroidea since their distribution provides an external validation to time estimates allowing us to disregard scenarios that cannot explain their introduction …

Some Laelapine Mites (Acari: Laelapidae) Ectoparasitic On Small Mammals In The Galapagos Islands, Including A New Species Of Gigantolaelaps From Aegialomys Galapagoensis, Donald D. Gettinger, Fernanda Martins-Hatano, Scott Lyell Gardner

Scott L. Gardner Publications

A collection of laelapine mites from small mammals in the Galapagos Islands are identified and their host distributions reviewed. Two species of native rodents, Aegialomys galapagoensis and Nesoryzomys narboroughii, were infested only with species typical of Neotropical oryzomyine rodents; Rattus rattus was infested with Laelaps nuttalli, a host-specific ectoparasite to Old World Rattus. A synopsis of Gigantolaelaps Fonseca is provided and we describe a new laelapine mite, Gigantolaelaps aegialomys n. sp., from the pelage of the rodent A. galapagoensis on Santa Fe Island. The new species has strong morphological affinities with a subgroup of Gigantolaelaps associated …

Antimicrobial Activity Of Selected Fungi Isolated From Dee And Barrientos Islands, Antarctica., Shamia Mohamedain Abd Elgadir Younis

Student Works (2010-2019)

This study reports the screening of selected fungi isolated from Dee and Barrientos Islands, Antarctica, for their antimicrobial activities using two methods: a) plug assay method and b) disk diffusion method. The plug assay was carried out as preliminary screening forbiological activity against bacteria: Bacillus subtilis, Staphylococcus aureus,Escherichia coli, pseudomonas aeruginosa, and yeast: Candida albicans. The results showed that 35% from species possessed antibacterial activity; and these included: Geomyces sp.50-1/S7, Unidentified 75-1/S1, Geomyces sp.12-1/S21, Penecillium sp.75-1/S10, Geomyces sp.3-1/S5, Geomyces sp.3-4/S5 and Geomyces sp.146/S5. Most of the strains exhibited antibacterial activity against Gram-positive bacteria S. aureus and B. subtilis …

Ectoparasites Of Bats In Mongolia (Ischnopsyllidae, Nycteribiidae, Cimicidae And Spinturnicidae), Ingo Sceffler, Dietrich Dolch, Jargalsaikhan Ariunbold, Nyamsuren Batsajchan, Andreas Abraham, Klaus Thiele

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

For large parts of the world, the knowledge of bat ectoparasites is still scanty. Regarding Mongolia, only few studies exist to date. This paper analyzes results from extensive captures between 2005-2008, carried out in different sites of Mongolia. Discussed ectoparasites include bat fleas, (Ischnopsyllidae), bat flies (Nycteribiidae), and bat bugs (Cimicidae) and spinturnicid mites (Spinturnicidae). A number of species found in this study were new records for Mongolia, and for many species additional sites were reported. For some bat species, the spectrum and frequency of larger ectoparasites could be determined for the first time.

Current State Of Ixodidae Research In Mongolia, Daniel Kiefer, K. Pfister, D. Tserennorov, G. Bolormaa, D. Otgonbaatar, Ravčigijn Samjaa, E. G. Burmeister, Mathias S. Kiefer

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Our research presents the Ixodidae-fauna in Mongolia. The current taxonomic state in Mongolia shows 19 Ixodidae taxa extracted in 308 locations from 115 bird and mammal species. In 1980, the species Ixodes persulcatus SCHULZE, 1930 and Ixodes berlesei Birula, 1895 were detected in Inget Tolgoi and Ixodes laguri OLENEV, 1929 on Meriones unguiculatus 10 km southeast of Ulaanbaatar for the first time. In 2000 the species Haemaphysalis concinna Koch, 1844 was detected in the Selenge-river area and Argas (Argas) vulgaris FILIPPOVA, 1961 was detected in the Gobi area. From the collection of M. and A. STUBBE 1 N …

Distribution Of Fleas (Siphonaptera) In Bird-Nests, Bird Siphonaptera On Mammalia And The Medical Importance Of Interspecific Flea Transmission In Mongolia, Daniel Kiefer, K. Pfister, D. Tserennorov, D. Otgonbaatar, Ravčigijn Samjaa, D. Sumjaa, E. G. Burmeister, Mathias S. Kiefer

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Starting in the 1960s of the last century a huge amount of material from mammals and birds was collected in Mongolia. The according results were published in Erforschung biologischer Ressourcen der Mongolei, Volume 1-10, and represented on conferences in Halle, Moscow, Irkutsk, Ulaanbaatar, Bratislava and the Entomological Review St. Petersburg.

A big part of the collected material consisted of ectoparasites analyzed by experts from Mongolia, Germany, England, Russia, Poland, Czech Republic, and Slovakia resulting in newly described species along with zoogeographical and ecological profiles.

During the years 1974-2007 material from 321 nests of 38 bird taxa were obtained. 157 …

New Species In The Genus Monoecocesuts (Cestoda: Anoplocephalidae) From Neotropical Rodents (Caviidae And Sigmodontidae), Terry R. Haverkost, Scott Lyell Gardner

Scott L. Gardner Publications

Anoplocephalid cestodes have a worldwide distribution, but relatively few species are known from South American rodents. By examining the collections of the Harold W. Manter Laboratory of Parasitology and the United States National Parasite Collection, 6 new species of Monoecocestus Beddard, 1914, are described, along with a redescription of Monoecocestus mackiewiczi Schmidt and Martin, 1978, based on the type specimens. The discussion includes commentary about uterine development, an important taxonomic character of the family, the vaginal dilation in immature segments (a character of potential taxonomic importance), and the implication of host usage to the evolutionary history and biogeography of species …

How Birds Combat Ectoparasites, Dale H. Clayton, Jennifer A. H. Koop, Christopher W. Harbison, Brett R. Moyer, Sarah E. Bush

Harold W. Manter Laboratory of Parasitology: Library Materials

Birds are plagued by an impressive diversity of ectoparasites, ranging from feather-feeding lice, to feather-degrading bacteria. Many of these ectoparasites have severe negative effects on host fitness. It is therefore not surprising that selection on birds has favored a variety of possible adaptations for dealing with ectoparasites. The functional significance of some of these defenses has been well documented. Others have barely been studied, much less tested rigorously. In this article we review the evidence--or lack thereof--for many of the purported mechanisms birds have for dealing with ectoparasites. We concentrate on features of the plumage and its components, as well …

Where Are The Parasites? [Letters], Susan J. Kutz, Andy P. Dobson, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

First paragraph:

The review by E. Post et al. ("Ecological dynamics across the Arctic associated with recent climate change," 11 September 2009, p. 1,355) paid little heed to parasites and other pathogens. The rapidly growing literature on parasites in arctic and subarctic ecosystems provides empirical and observational evidence that climate-linked changes have already occurred. The life cycle of the protostrongylid lungworm of muskoxen, Umingmakstrongylus pallikuukensis, has changed, and the range of that organism and the winter tick, Dermacentor albipictus, has expanded.

Fisheries Occasional Publication No. 66 - Scientific Review Of The West Coast Demersal Scalefish Fishery, Western Australia, Michael O'Neill, Department Of Fisheries Western Australia

Fisheries Occasional Publications

In December 2008 the Hon Norman Moore MLC, Minister for Fisheries Western Australia appointed two independent experts to assess separately 1) the validity of scientific advice to management and 2) options to manage recreational fishing of west coast demersal scalefish. The following review (1) assesses the validity of research outlining the status of baldchin groper (Choerodon rubescens), West Australian dhufish (Glaucosoma hebraicum) and snapper (Pagrus auratus) as described in the terms of reference. In addition to the terms of reference, an opinion was requested regarding the current appropriateness of the research advice (Wise et al 2007) and the resulting management …

Fisheries Occasional Publication No. 63 - Western Rock Lobster Ecological Risk Assessment, Department Of Fisheries, Western Australia, International Risk Consultants Group Of Companies

Fisheries Occasional Publications

This Ecological Risk Assessment, conducted by IRC Environment (part of International Risk Consultants) and Department of Fisheries WA (FWA) was the result of an initiative by the WA Fishing Industry Council (WAFIC) and (FWA). This report is based on a risk assessment workshop undertaken in February 2001 at the FWA Marine Research Laboratories in Waterman but includes additional background material to justify some of the rankings of the workshop.

The broad intent of the workshop was to provide a register of the potential main ecological risks that arise from the various activities carried out by the western rock lobster (WRL) …

Fisheries Occasional Publication No.057 - Introduced Marine Species In Western Australia, Department Of Fisheries Western Australia

Fisheries Occasional Publications

As the largest State in Australia, Western Australia (WA) has a long and relatively pristine coastline that stretches over 12,500 km, or over 20,700 km if the State’s 3,747 islands are included. The coast ranges over 20 degrees of latitude from the temperate south coast to the northern tip of the tropical Kimberley. There are a wide variety of coastal marine habitats in this vast area. The south coast has extensive white sandy beaches interspersed with granite headlands. A diverse range of nearly 800 species of temperate marine algae, or seaweeds, occurs in the area. With 26 species, the seagrasses …

A Redescription Of Three Species Of Monoecocestus (Cestoda: Anoplocephalidae) Including Monoecocestus Threlkeldi Based On New Material, Terry R. Haverkost, Scott Lyell Gardner

Scott L. Gardner Publications

Because we have new and detailed data on species in the genus, herein we redescribe both Monoecocestus macrobursatus and M. minor based on existing museum specimens. We also redescribe M. threlkeldi (Parra, 1952) using material collected in Bolivia. Based on the specimens representing M. thelkeldi, we affirm that Perutaenia Parra, 1953 should remain a junior synonym of Monoecocestus.

Trematoda (Platyhelminthes) Of The Gulf Of Mexico, Robin M. Overstreet, Joshua O. Cook, Richard W. Heard

Harold W. Manter Laboratory of Parasitology: Faculty Publications

First paragraph:

The platyhelminth class Trematoda, consisting of the subclasses Aspidogastrea and Digenea, contains individuals referred to as digeneans, trematodes, or flukes. Aspidogastreans, not digeneans in the strict sense2 number about 80 species in total (Rohde 2005), but adults in the Gulf of Mexico of 4 species have been reported from teleost and chondrichthyan fishes (Hendrix and Overstreet I 977) and one from a turtle (Wharton 1939). Consequently, this chapter deals with trematodes rather than just digeneans, even though all the records but the 5 refer to digeneans. Trematoda is the largest group of platyhelminths, and trematode adults, other than …

Muscleworms, Parelaphostrongylus Andersoni (Nematoda: Protostrongylidae), Discovered In Columbia White-Tailed Deer From Oregon And Washington: Implications For Biogeography And Host Associations, Ingrid M. Asmundsson, Jack A. Mortenson, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Parelaphostrongylus andersoni is considered a characteristic nematode infecting white-tailed deer (Odocoileus virginianus). Host and geographic distribution for this parasite, however, remain poorly defined in the region of western North America. Fecal samples collected from Columbia white-tailed deer (O. v. leucurus) in a restricted range endemic to Oregon and Washington, USA, were examined for dorsal-spined larvae characteristic of many protostrongylid nematodes. Multilocus DNA sequence data (internal transcribed spacer 2 and cytochrome c oxidase subunit 1) established the identity and a new record for P. andersoni in a subspecies of white-tailed deer previously unrecognized as hosts. Populations of …

A Macroevolutionary Mosaic: Episodic Host-Switching, Geographical Colonization And Diversification In Complex Host–Parasite Systems [Special Paper], Eric P. Hoberg, Daniel R. Brooks

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Aim: To integrate ecological fitting, the oscillation hypothesis and the taxon pulse hypothesis into a coherent null model for the evolution of complex host–parasite associations.

Location: Global.

Methods: This paper reviews and synthesizes literature that focuses on phylogenetic analyses and reciprocal mapping of a model system of hosts and their parasites to determine patterns of host–parasite associations and geographical distributions through time.

Results: Host-switching and geographical dispersal of parasites are common phenomena, occurring on many temporal and spatial scales. Diversification involving both co-evolution and colonization explains complex host–parasite associations. Across the expanse of Earth history, the major radiations in host– …

Phylogenetic Approach To The Study Of Triatomines (Triatominae, Heteroptera) = Abordagem Filogenética Em Triatomíneos (Triatominae, Heteroptera), Ester Tartarotti, M. T. V. Azeredo-Oliveira, C. R. Ceron

Harold W. Manter Laboratory of Parasitology: Library Materials

Abstracts

Triatomines are insects belonging to the Hemiptera order, Heteroptera suborder, Reduviidae family and Triatominae subfamily. All members of this subfamily are hematophagous. Triatomines evolved from Reduviidae predators and they are probably polyphyletic in origin. The combination of anatomical, physiological and ethological factors observed in this group, as well as the plesiomorphic and apomorphic characters that differentiate the five tribes and fourteen triatomine genera reinforce the polyphiletic hypotesis. However if we consider the five groups of triatomines, the Rhodniini, Cavernicolini, Bolboderini, Linshcosteini and Alberproseniini tribes constitute monophyletic groups, while the Triatomini tribe is considered polyphyletic. The New World is the …

Proceedings Of The Western Australian Dhufish Workshop 2004, Mark Pagano, Terry Fuller

Fisheries Occasional Publications

The Western Australian Dhufish Workshop 2004 was a joint project between Recfishwest and the Western Australian Department of Fisheries.

The workshop incorporated presentations from the Department of Fisheries, Recfishwest, the Western Australian Fishing Industry Council, Murdoch University and Challenger TAFE to showcase current knowledge relating to the iconic dhufish in Western Australia. The perspectives of a recreational fisher, a commercial wetline operator and a metropolitan charter boat operator were also presented.

Through information sharing and discussion the workshop provided a platform to better understand the fundamental issues that underpin current and future management arrangements for this valuable resource. Both commercial …

Parelaphostrongylus Odocoilei In Columbia Black-Tailed Deer From Oregon, Jack A. Mortenson, Arthur Abrams, Benjamin M. Rosenthal, Detiger Dunams, Eric P. Hoberg, Robert J. Bildfell, Richard L. Green

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Documenting the occurrence of Parelaphostrongylus odocoilei has historically relied on the morphological examination of adult worms collected from the skeletal muscle of definitive hosts, including deer. Recent advances in the knowledge of protostrongylid genetic sequences now permit larvae to be identified. Dorsal-spined larvae (DSLs) collected in 2003–2004 from the lung and feces of six Columbian black-tailed deer (Odocoileus hemionus columbianus) from Oregon were characterized genetically. The sequences from unknown DSLs were compared to those from morphologically validated adults and larvae of P. odocoilei at both the second internal transcribed spacer (ITS-2) of ribosomal DNA and the mitochondrial cytochrome …

Myxozoan Genera: Definition And Notes On Taxonomy, Life-Cycle Terminology And Pathogenic Species, Jiří Lom, Iva Dyková

Harold W. Manter Laboratory of Parasitology: Library Materials

A list of myxozoan genera is presented in the current taxonomical scheme. These genera are defined; their type species and most important pathogens along with their hosts are listed. Simultaneously, definitions of actinospore stages representing sexual stages of the myxosporean life cycle are given; altogether, 17 actinospore collective groups with 180 types have been described. Life cycles of the two classes of the phylum Myxozoa, Malacosporea and Myxosporea, are briefly outlined with specification of the appropriate terms. Up to now, 4 malacosporean and 2,180 myxosporean species assigned to a total of 62 genera, have been established. The surviving classification of …

A Monkey’S Tale: The Origin Of Plasmodium Vivax As A Human Malaria Parasite, Ananias A. Escalante, Omar E. Cornejo, Denise E. Freeland, Amanda C. Poe, Ester Durrego, William E. Collins, Altaf A. Lal

Harold W. Manter Laboratory of Parasitology: Library Materials

The high prevalence of Duffy negativity (lack of the Duffy blood group antigen) among human populations in sub-Saharan Africa has been used to argue that Plasmodium vivax originated on that continent. Here, we investigate the phylogenetic relationships among 10 species of Plasmodium that infect primates by using three genes, two nuclear (β-tubulin and cell division cycle 2) and a gene from the plastid genome (the elongation factor Tu). We find compelling evidence that P. vivax is derived from a species that inhabited macaques in Southeast Asia. Specifically, those phylogenies that include P. vivax as an ancient lineage from …

Possible Recent Range Expansion Of Alcataenia Longicervica (Eucestoda: Dilepididae) Parasitic In Murres Uria Spp. (Alcidae) Into The North Atlantic [Short Communications], Sabir B. Muzaffar, Eric P. Hoberg, Ian L. Jones

Harold W. Manter Laboratory of Parasitology: Faculty Publications

A wide range of helminths has been recorded from murres Uria spp. (Threlfall 1971, reviewed by Hoberg 1984a, Muzaffar & Jones 2004). Of the cyclophyllidean cestodes that parasitize murres, the genus Alcataenia Spasskaya 1971 (Dilepididae) is represented by ten species, eight of which are restricted and specific to the auks; the other two species occur in gulls (Laridae). The intermediate hosts of Alcataenia are euphausiid crustaceans such as species of Thysanoessa (Shimazu 1975), which also form an important dietary component of breeding and wintering murres, particularly Thick-billed Murres Uria lomvia (Gaston & Noble 1985, Birkhead & Nettleship 1987, Elliot et …

Contributions To The Mammalogy Of Mongolia, With A Checklist Of The Species Of The Country, David S. Tinnin, Jon L. Dunnum, Jorge A. Salazar-Bravo, Nyamsuren Batsaikhan, M. Scott Burt, Scott Lyell Gardner, Terry L. Yates

Harold W. Manter Laboratory of Parasitology: Faculty Publications

We present accounts for 40 species of mammals collected from 15 localities in the Mongolian People's Republic. Accounts include taxonomic, morphometric, reproductive and ecological information, as well as trap effort and success. In addition, we include a brief history of mammalogical work within Mongolia, a taxonomically updated species list for the country, and a list of institutions with holdings of Mongolian mammals.

Protostrongylus Stilesi (Nematoda: Protostrongylidae): Ecological Isolation And Putative Host-Switching Between Dall’S Sheep And Muskoxen In A Contact Zone, Eric P. Hoberg, Susan J. Kutz, John Nagy, Emily Jenkins, Brett Elkin, Marsha Branigan, Dorothy Cooley

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The occurrence of Protostrongylus stilesi in a population of introduced muskoxen, Ovibos moschatus wardi, on the Arctic Coastal Plain, Yukon Territory (YT) and Northwest Territories (NT), Canada, is consistent with a contemporary colonization event from Dall’s sheep, Ovis dalli dalli, which indicates that host specificity may be ecologically based and contextual for this parasite. Colonization of muskoxen by P. stilesi may be a predictable event in zones of sympatry with Dall’s sheep; exposure to infection may coincide with occupation of winter ranges of Dall’s sheep by muskoxen during the summer season. Disruption of contemporary ecological isolating barriers can …

Foundations For An Integrative Parasitology: Collections, Archives, And Biodiversity Informatics, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Burgeoning awareness about biodiversity emphasizes the fundamental importance of museum collections and the contributions of systematists and taxonomists in documenting the structure and history of the biosphere. An essential role is served by this infrastructure in collecting, preparing, analyzing, and disseminating information about the specimens that represent species, document a range of complex biological associations from symbioses to parasitism, and form the tapestry and the myriad facets of biodiversity (e.g., Wilson, 2000). As parasitologists we can examine how we may contribute to this broader documentation and understanding of global biodiversity, and we can articulate and communicate our role as vital …

Development Of The Muskox Lungworm, Umingmakstrongylus Pallikuukensis (Protostrongylidae), In Gastropods In The Arctic, Susan J. Kutz, Eric P. Hoberg, John Nishi, Lydden Polley

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Development of the muskox protostrongylid lungworm, Umingmakstrongylus pallikuukensis, in its slug intermediate host, Deroceras laeve, was investigated under field conditions in the Arctic. Every two weeks, from 19 June to 28 August 1997, groups of ten experimentally infected slugs were placed in tundra enclosures in a mesic sedge meadow near Kugluktuk, Nunavut, Canada. First-stage larvae (L1) infecting slugs on or before 17 July developed to third-stage larvae (L3) in 4–6 weeks. Intensity of L3 in slugs peaked at 6–8 weeks post infection (PI) and then progressively declined by 10, 12, and 48–50 weeks PI. Abundance of L3 in …

Morphological Variation Of Allocreadium Lobatum (Digenea: Allocreadiidae) In The Creek Chub, Semotilus Atromaculatus (Osteichthyes: Cyprinidae), In Nebraska, Usa, Monte S. Willis

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Allocreadium lobatum Wallin 1909, a parasite of fresh-water fish, was originally described as having distinct lobate testes, and subsequent descriptions have left this original description unchanged. The present study quantifies the observation of distinctly non-lobate testes that could be categorized as round or asymmetrical in addition to the previously described lobate testes. Six hundred thirty-six A. lobatum were collected from 228 Semotilus atromaculatus over a 9 month period. Overall, 21.3%, 61.6%, and 16% were found to be round, asymmetrical, and lobate testes respectively (N = 1,071). Analysis of testis morphology found the increasing presence of lobate testis as …

Onchocercosis In Red Deer (Cervus Elaphus) From Spain, Mónica Santín-Durán, José M. Alunda, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Onchocercosis, caused by Onchocerca flexuosa, was observed in red deer (Cervus elaphus) from Spain for the first time. Adult specimens of O. flexuosa were found in nodules in subcutaneous tissues in 42 of 125 (33%) red deer between October 1994 and September 1995; intensity of infection 6 SD was 3.93 ± 5.26 nodules per infected host. A clear seasonal pattern in the distribution of nodules was observed, with higher values of prevalence and intensity in fall and winter in contrast to spring and summer. Significant differences were found among age groups in prevalence, but not in the …

New Host And Geographic Records For Two Protostrongylids In Dall's Sheep, Susan J. Kutz, A. M. Veitch, Eric P. Hoberg, B. T. Elkin, Emily J. Jenkins, L. Polley

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Biodiversity survey and inventory have resulted in new information on the distribution of Protostrongylidae in Dall’s sheep (Ovis dalli dalli) from the Northwest Territories (Northwest Territories, Canada) and from Alaska (Alaska, USA). In 1998, Parelaphostrongylus odocoilei adults were found for the first time in the skeletal muscles of Dall’s sheep in the Mackenzie Mountains (Northwest Territories). Adult P. odocoilei were associated with petechial and ecchymotic hemorrhages and localized myositis; eggs and larvae in the lungs were associated with diffuse granulomatous pneumonia. Experimental infections of the slugs Deroceras laeve and Deroceras reticulatum with dorsal-spined first-stage larvae assumed to be …