Complete Mitochondrial Cytochrome Research Articles

Molecular analysis reveals the evolutionary distinctiveness of the Silver-backed Chevrotain within the genus Tragulus

Abstract The Silver-backed Chevrotain (Tragulus versicolor), a mammal endemic to the unique coastal arid ecosystem in south-central Vietnam, is an enigmatic mouse deer with little information available about its ecology and evolutionary history. The recent rediscovery of the species provides a rare opportunity to clarify its taxonomy and phylogenetic relationship within the genus Tragulus. In this study, we sequenced the complete mitochondrial cytochrome b gene for samples of T. versicolor and T. kanchil from Vietnam. Our molecular results show that the species forms a distinct evolutionary lineage sister to all other species in the genus, confirming the earlier hypothesis based on morphological evidence. However, further research is needed to assess the genetic diversity of the species and design appropriate conservation measures. As the species has not been secured over much of its range, it is recommended that the population in Nui Chua National Park, the only one covered by a protected area, be prioritized for conservation actions. Conserving the species in this unique and imperiled ecosystem will also benefits a suite of locally endemic and threatened species of fauna and flora.

Population tracing analysis and overwintering of Bactrocera dorsalis (Hendel) in newly occurring areas in China

AbstractBactrocera dorsalis (Hendel), a very destructive insect pest of many fruits and vegetables, is widespread in the tropical and subtropical zones of Asia. However, the northward extension of B. dorsalis has been reported in China recently. It is crucial to determine the origin of new populations and to investigate the invasive potential of the species. Here, we investigated B. dorsalis in Nanyang, Henan Province and Heze, Shandong Province using a combined methodological approach. We first detected the hydrogen stable isotope ratios (δ2H) of B. dorsalis samples. The results showed that the δ2H values for B. dorsalis from Nanyang were consistent with those of the local rainwater. In contrast, the samples from Heze were inconsistent with those of the rainwater in Heze. We then sequenced the complete mitochondrial cytochrome oxidase I (mtDNA COI) from the same fruit fly samples for haplotype diversity and phylogenetic analyses. We found a close genetic relationship between the Heze population and Nanyang, Hefei, Sanya, Fuyang and Wuhan populations. Besides, we surveyed the fruit's origin in the wholesale market, and concluded that B. dorsalis trapped in Heze might have come from Hainan and Zhejiang in China. Finally, overwintering potential experiments showed that a small number of pupae could survive during the test periods in Nanyang, whereas no pupae could survive in Heze. Overall, this study reveals that the Nanyang population of B. dorsalis were resident, whereas the Heze population did not colonize and were repeated entries from other areas every spring.

A first species-wide phylogenetic analysis of small mammals from Costa Rica using mitochondrial cytochrome b

Costa Rica is within the Mesoamerican biodiversity hotspot and has about 53 native species of small mammals. This high diversity, along with recent records of new species and indications of cryptic genetic diversity, suggest that application of the DNA barcoding approach would be worthwhile. Here we used 131 tissue samples of small mammals from multiple localities in Costa Rica and sequenced the complete mitochondrial cytochrome b (1140 bp). These samples represented 17 recognized species and two taxa of uncertain status. The new sequence data were supplemented with previously published data from INSDC. Our phylogenetic analyses are consistent with and extend upon recent revisions in Heteromys, Peromyscus and Reithrodontomys and suggest possible new cryptic forms within what are currently named Melanomys chrysomelas, Nyctomys sumichrasti and Proechimys semispinosus. The previously named “Heteromys sp” is indeed likely a new species requiring a full taxonomic description. Moreover, we found new localities for previously described species substantiating recent taxonomic surveys and field guides for the small mammals of Costa Rica. To confirm the presence of cryptic species and major genetic forms in Heteromys, Peromyscus, Reithrodontomys, Melanomys, Nyctomys and Proechimys there needs to be greater sampling, additional genetic markers, morphometrics and other studies. Scotinomys also shows interesting phylogenetic subdivision, requiring further investigation.

High genetic diversity of Echinococcus canadensis G10 in northeastern Asia: is it the region of origin?

Echinococcus canadensis consists of 4 genotypes: G6, G7, G8 and G10. While the first 2 predominantly infect domestic animals, the latter are sylvatic in nature involving mainly wolves and cervids as hosts and can be found in the northern temperate to Arctic latitudes. This circumstance makes the acquisition of sample material difficult, and little information is known about their genetic structure. The majority of specimens analysed to date have been from the European region, comparatively few from northeast Asia and Alaska. In the current study, Echinococcus spp. from wolves and intermediate hosts from the Republic of Sakha in eastern Russia were examined. Echinococcus canadensis G10 was identified in 15 wolves and 4 cervid intermediate hosts. Complete mitochondrial cytochrome c oxidase subunit 1 (cox1) sequences were obtained from 42 worm and cyst specimens from Sakha and, for comparison, from an additional 13 G10 cysts from Finland. For comparative analyses of the genetic diversity of G10 of European and Asian origin, all available cox1 sequences from GenBank were included, increasing the number of sequences to 99. The diversity found in northeast Asia was by far higher than in Europe, suggesting that the geographic origin of E. canadensis (at least of G10) might be northeast Asia.

A new mammalian universal primer for the mitochondrial cytochrome b locus

We designed a set of amplification primers to target the mitochondrial cytochrome b gene of the rodent genus Oligoryzomys. Combinations of two sets of primers successfully amplified complete mitochondrial and partial cytochrome b (MT-CYB), from not only Oligoryzomys, but also other mammalian species from the orders Rodentia, Didelphimorphia, Primates, Chiroptera, Cetacea, Carnivora, and Lagomorpha. Preliminary sequencing analyses revealed that these primers generate informative sequences for several mammalian species important for phylogenetic and species delimitation analyses.

Composition, Demographic History, and Population Structures of Trichiurus

Sequences of the complete mitochondrial cytochrome oxidase subunit I gene were used to identify Trichiurus species and examine their population genetic structure and demographic history along the coast of China. Three Trichiurus species were found. Trichiurus japonicus lives in colder waters along the continental shelves in the China Seas, while Trichiurus nanhaiensis lives warmer waters along continental slopes in the South China Sea, and Trichiurus brevis lives in shallow and warmer waters in the South China Sea. The migrations of these species were mainly associated with feeding and spawning preferences. Two major wintering and spawning grounds in the East China Sea and South China Sea were found. All species showed a lack of population genetic structure resulting from their oceanodromous life cycle (the degree of population substructure index NST = 0.000–0.149), but the results of approximate Bayesian computational approaches suggested population declines or stabilization and differentiation. The results of the TMRCA (time to the most recent common ancestor) showed that during glaciations, the Yellow Sea and the East China Sea were completely exposed, and the South China Sea acted as a refugium. Thus, the populations of these three species experienced differentiation during glaciations. This study also examined the limitations of Bayesian skyline plot analysis.

DNA barcoding of the mesic adapted striped mouse, Rhabdomys dilectus in the Eastern Cape and KwaZulu-Natal provinces of South Africa

AbstractSouth African small mammals are under-represented in DNA barcoding efforts, particularly from the eastern forested regions of the country. This study reports DNA barcoding ofRhabdomystaxa from previously unsampled parts of the Eastern Cape and KwaZulu-Natal provinces of South Africa. The complete mitochondrial DNA cytochrome oxidase I (COI) gene was sequenced for 101Rhabdomyssp. individuals from 16 localities from all three main forest groups (coastal, mistbelt, and scarp forests). Molecular data were supplemented with external morphological measurements, including those deemed potential taxonomically diagnostic characters. Findings indicate the area to be inhabited solely byRhabdomys dilectus chakae. Haplotypes distributed across the three forest groups were separated by shallow sequence divergences ranging from 0.001–0.015 (Kimura 2-parameter model) and displayed very little population genetic structure (FST= 0.071787). Morphological data revealed some regional metric differences in external morphology, but all the head-and-body to tail (HB: tail) ratios match that ofR. d. chakae, and consequently, molecular and morphological data are congruent. These data confirm a range extension ofR. d. chakae, supporting the utility of COI barcodes in the identification of small mammalian species.

New arrangement of three genera of fish tapeworms (Cestoda: Proteocephalidae) in catfishes (Siluriformes) from the Neotropical Region: taxonomic implications of molecular phylogenetic analyses.

Tapeworms (Cestoda: Proteocephalidae) are the dominant component of communities of intestinal parasites in pimelodid and other catfishes (Siluriformes) from South America. Even though these parasites have been studied intensively over more than one century, molecular taxonomy and phylogenetics have questioned their morphology-based classification, thus raising doubts about the systematic value of traits commonly used to circumscribe individual taxa. In the present study, members of three morphologically well-characterized genera of proteocephalids from pimelodid (Hemisorubim platyrhynchos and Sorubim lima) and auchenipterid (Ageneiosus inermis) catfishes from the Paraná or Amazon River basins were subjected to DNA sequencing of the large subunit nuclear ribosomal RNA (lsrDNA) and complete mitochondrial cytochrome c oxidase subunit I (COI). Phylogenetic analyses revealed the sister relationship between Manaosia bracodemoca and Mariauxiella piscatorum, and among Mariauxiella pimelodi and Ageneiella brevifilis. As a result, Mar. piscatorum and A. brevifilis are transferred to Manaosia and Mariauxiella, respectively, as Manaosia piscatorum n. comb. and Mariauxiella brevifilis n. comb., and the genus Ageneiella is suppressed. Diagnoses of Manaosia and Mariauxiella are amended. In addition, the present study revealed misidentification of tapeworms whose sequences are deposited in the GenBank database.

Phylogenetic relationships among Callosciurus squirrels in the Indochina Peninsula: phylogenetic position of C. pygerythrus from Myanmar

The phylogenetic relationships among seven Callosciurus species from the Indochina Peninsula, including the C. honkhoaiensis which is endemic to Hon Khoai Island, were studied using complete mitochondrial cytochrome b gene sequences (1140 bases). We primarily focused on the phylogenetic position of C. pygerythrus, which is distributed in the western part of the peninsula. We identified two main lineages: 1) C. caniceps, C. honkhoaiensis, C. inornatus, C. phayrei and C. pygerythrus, and 2) C. erythraeus and C. finlaysonii. Estimated divergence time between the two lineages was at the junction of the Zanclean and Piacenzian in the Pliocene. Within the first linage, the divergence time of sub-lineages corresponded to the Pliocene-Pleistocene boundary, although phylogenetic relationships were unclear. These two divergence times estimated in the present study correspond to episodes of global cooling, suggesting that climate may have contributed to the divergence of these Callosciurus squirrels.

Genetic analysis of Carasobarbus Karaman, 1971 (Actinopterygii Cyprinidae) in Anatolia

We sequenced the complete mitochondrial cytochrome b gene (1141 bp) of 70 individuals from ten populations of three Carasobarbus species in Anatolia. Totally eight haplotypes were identified. The intraspecies genetic distance ranged from 0.00% to 0.21%, while it varied from 2.6% to 9.0% for interspecies. Except for Gaziantep samples with low sample size, high haplotype diversity (Hd= 0,590-0,833) and low nucleotide diversity (Pi= 0,05-0,65) values can be explained by the presence of small populations sensitive to genetic drift and founder effects. Phylogenetic analyses constructed with neihgbour joining, maximum likelihood and maximum parsimony generated similar topologies supported by high bootstrap values. Phylogenetic tree topologies showed that the C. apoensis haplotype was located in the C. luteus species. Therefore, the validity of species status of C. apoensis should be checked morphologically. On the other hand, since the Kahta population in C. luteus has a remarkably high genetic diversity, it must be re-evaluated morphologically. The tectonic uplift of the Anatolian Plateau between the African and European plates during the Pliocene period may have probably prevented the presence of Carasobarbus in the west of the Anatolian diagonal.

Integrative taxonomy reveals hidden cestode diversity in Pimelodus catfishes in the Neotropics

AbstractProteocephalid tapeworms are the dominant group of endoparasites in siluriform catfishes in South America, but their interrelationships and actual diversity remain poorly understood. Molecular prospecting of proteocephalids found in pimelodid and other catfishes, especially in Pimelodus spp., along with thorough morphological evaluation, revealed high species diversity of these parasites. Using newly obtained sequences of the partial large subunit nuclear ribosomal RNA (lsrDNA) and complete mitochondrial cytochrome c oxidase subunit I (COI), phylogenetic relationships of the cestodes of Pimelodus catfishes were assessed and a new genus, Pseudoendorchis gen. n., proposed to accommodate P. auchenipteri comb. n. (type species; formerly Endorchis auchenipteri), P. cristata sp. n. from Pimelodella cristata (Heptapteridae), P. felipei sp. n. from Pimelodus fur, P. souzalimae sp. n. from Pimelodus maculatus and another three putative new species. Members of the new genus can be readily distinguished from all known Neotropical proteocephalids by having a large Mehlis’ gland, representing at least 18% of proglottid width, and the vagina always anterior to the cirrus‐sac. Moreover, all phylogenetic, species discovery and validation analyses support validity of Pseudoendorchis. Combining the lsrDNA + COI sequence data appeared to provide the best resolution in phylogenetic analyses, which may be useful to reduce the uncertainty of the interrelationships among Neotropical proteocephalids.

Threats from wildlife trade: The importance of genetic data in safeguarding the endangered Four-eyed Turtle (Sacalia quadriocellata)

Wildlife trade has been considered one of the largest threats to biodiversity in Southeast Asia. Many vertebrates, such as pangolins, elephants and turtles have been heavily hunted as a result of high demand from emerging markets in China and other countries in the region. In Vietnam, over-exploitation of turtles over several decades to supply the international trade has extirpated numerous populations and driven several species to the brink of extinction. To reverse this trend, conservation measures, such as re-introduction of confiscated or captive-bred animals to their native habitats, should be implemented to recover severely declined local populations. For species with a complex phylogeographic structure, however, it is crucial to understand geographic patterns of genetically-distinct populations to avoid releasing animals of unknown origin to wrong localities. In this study, we investigate the phylogeographic pattern of the Four-eyed Turtle (Sacalia quadriocellata), a widely traded species, which occurs in southern China, northern and central Laos and much of Vietnam, using samples with known localities and those collected from the local trade. Our range-wide phylogenetic and network study, based on the complete mitochondrial cytochrome b gene, recovered at least three major clades and seven subclades within the species range. Amongst these, two subclades, one from northern Annamites, Vietnam and the other from north-eastern Laos, are newly discovered. The fine scale phylogeographic analysis helped us to assign misidentified sequences from GenBank and those from confiscated animals with unknown origin to well-defined geographic populations. The results highlight the importance of incorporating samples collected from the local trade and the wild in genetic analyses to support both ex-situ and in-situ conservation programmes of highly-threatened species in accordance with the IUCN’s One Plan Approach.

Echinococcus granulosus (sensu stricto) (G1, G3) and E. ortleppi (G5) in Pakistan: phylogeny, genetic diversity and population structural analysis based on mitochondrial DNA

BackgroundCystic echinococcosis (CE) is a serious tapeworm infection caused by Echinococcus granulosus (sensu lato) which infects a wide range of animals and humans worldwide. Despite the millions of livestock heads reared in Pakistan, only a few reports on CE prevalence and even fewer on the genetic diversity are available for the country. Meanwhile, the available reports on the genetic diversity are predominantly based on short sequences of the cox1 gene.MethodsTo close this knowledge gap, this study was designed to investigate the genetic diversity and population structure of Echinococcus spp. in Pakistan using the complete mitochondrial cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes.ResultsBased on BLAST searches of the generated cox1 and nad1 gene sequences from a total of 60 hydatid cysts collected from cattle (n = 40) and buffalo (n = 20), 52 isolates were identified as E. granulosus (s.s.) (G1, G3) and 8 as E. ortleppi (G5). The detection of the G5 genotype represents the first in Pakistan. The phylogeny inferred by the Bayesian method using nucleotide sequences of cox1-nad1 further confirmed their identity. The diversity indices indicated a high haplotype diversity and a low nucleotide diversity. The negative values of Tajima’s D and Fu’s Fs test demonstrated deviation from neutrality suggesting a recent population expansion.ConclusionsTo the best of our knowledge, this report described the genetic variation of E. granulosus population for the first time in Pakistan using the complete cox1 and nad1 mitochondrial genes and confirms E. ortleppi as one of the causative agents of CE among livestock in Pakistan. While this report will contribute to baseline information for CE control, more studies considering species diversity and distribution in different hosts across unstudied regions of Pakistan are highly needed.

Genetic diversity and origins of invasive black rats (Rattus rattus) in Benin, West Africa

Black rats (Rattus rattus) are native to the Indian subcontinent but have now colonized most continents and islands following human movements and international trade. They are involved in the circulation and transmission to humans of many zoonotic agents as well as in massive damage to food stocks and native biodiversity in the regions they have settled. This study investigates the genetic diversity and possible origins of black rats from Benin, West Africa. We sequenced the complete mitochondrial cytochrome b gene in 90 individuals from nine localities in Benin. These sequences were subsequently compared to 390 other cytochrome b haplotypes from individuals from various European, Asian, American and African localities. Nucleotide polymorphism analysis, haplotype network and maximum likelihood phylogenetic tree reconstructions showed low mitochondrial diversity in black rats from Benin. Our results also suggest at least two distinct introduction events: one introduction probably occurred during the spice trade (15th-17th century) through the Indies Road connecting Europe to Asia. Other introduction events could have occurred more recently following the intensification of globalized trade from the eighteenth century, and onwards.

Morphological and genetic characterizations of Avitellina tapeworms from domestic ruminants in Senegal: An evidence of specificity among sheep and cattle host.

Avitellina tapeworms are common intestinal parasites of ruminants with a worldwide distribution. In Senegal, only Avitellina centripunctata tapeworm has been reported to date, and genetic diversity was previously confirmed by enzymatic analysis. This study aims to clarify the diversity of Avitellina tapeworms isolated from sheep and cattle in Senegal. In total, 613 adult Avitellina tapeworms were collected from sheep and cattle. Morphological analysis by the light microscopy and scanning electron microscopy identified three Avitellina "morphospecies": A. centripunctata and Avitellina sp.2 were detected in sheep while Avitellina sp.3 was identified in cattle. Molecular phylogenetic analysis based on the complete mitochondrial cytochrome c oxidase subunit 1 gene (cox1) sequences revealed that 101 Avitellina tapeworms were divided into 54 haplotypes grouped into three clades, of which two were specific to sheep and one specific to cattle. Three morphospecies corresponded to each of three clades and the maximum pairwise divergence among the clades ranged from 9.7 to 18.5% in cox1. The present study demonstrates the unexpected diversity of Avitellina tapeworms in domestic ruminants, and emphasize the necessity of re-evaluation of the taxonomy of the genus.

Species Boundaries within Morphologically Cryptic Galagos: Evidence from Acoustic and Genetic Data

Describing primate biodiversity is one of the main goals in primatology. Species are the fundamental unit of study in phylogeny, behaviour, ecology and conservation. Identifying species boundaries is particularly challenging for nocturnal taxa where only subtle morphological variation is present. Traditionally, vocal signals have been used to identify species within nocturnal primates: species-specific signals often play a critical role in mate recognition, and they can restrict gene flow with other species. However, little research has been conducted to test whether different “acoustic forms” also represent genetically distinct species. Here, we investigate species boundaries between two putative highly cryptic species of Eastern dwarf galagos (Paragalago cocosand P. zanzibaricus). We combined vocal and genetic data: molecular data included the complete mitochondrial cytochrome b gene (1,140 bp) for 50 samples across 11 localities in Kenya and Tanzania, while vocal data comprised 221 vocalisations recorded across 8 localities. Acoustic analyses showed a high level of correct assignation to the putative species (approx. 90%), while genetic analyses identified two separate clades at the mitochondrial level. We conclude that P. cocos and P. zanzibaricus represent two valid cryptic species that probably underwent speciation in the Late Pliocene while fragmented in isolated populations in the eastern forests.

Molecular and Morphological Characterization of Cysticercus tenuicollis in Red Deer (Cervus elaphus) from Turkey.

Cysticercus tenuicollis, the metacestode stage of Taenia hydatigena has a worldwide distribution and is particularly common in rural areas and developing countries. In rare cases, T. hydatigena infection may result in the death of its host due to severe damage or secondary bacterial infections. Generally, when multiple cysts are attached to the liver, it causes economic losses. The infection can be detected using morphological, histopathological and more recently, molecular investigations. In the present study, we describe molecular and morphological characterization of C. tenuicollis detected in a 3month-old female red deer (Cervus elaphus) during necropsy. Cystic samples were stained with haematoxylin-eosin (HE) and Masson's trichrome stain for histopathological examination, and molecular characterization of the complete mitochondrial cytochrome c oxidase subunit 1 (cox1) gene region was performed. This study provides the first morphological, histopathological, and molecular data on C. tenuicollis isolated from red deer in Turkey.

Variations in mitochondrial cytochrome b region among Ethiopian indigenous cattle populations assert Bos taurus maternal origin and historical dynamics.

ObjectiveThis study was carried out to assess the haplotype diversity and population dynamics in cattle populations of Ethiopia.MethodsWe sequenced the complete mitochondrial cytochrome b gene of 76 animals from five indigenous and one Holstein Friesian×Barka cross bred cattle populations.ResultsIn the sequence analysis, 18 haplotypes were generated from 18 segregating sites and the average haplotype and nucleotide diversities were 0.7540±0.043 and 0.0010±0.000, respectively. The population differentiation analysis shows a weak population structure (4.55%) among the populations studied. Majority of the variation (95.45%) is observed by within populations. The overall average pair-wise distance (F ST) was 0.049539 with the highest (F ST = 0.1245) and the lowest (F ST = 0.011) F ST distances observed between Boran and Abigar, and Sheko and Abigar from the indigenous cattle, respectively. The phylogenetic network analysis revealed that all the haplotypes detected clustered together with the Bos taurus cattle and converged to a haplogroup. No haplotype in Ethiopian cattle was observed clustered with the reference Bos indicus group. The mismatch distribution analysis indicates a single population expansion event among the cattle populations.ConclusionOverall, high haplotype variability was observed among Ethiopian cattle populations and they share a common ancestor with Bos taurus.

Phylogeography of Angiostrongylus cantonensis (Nematoda: Angiostrongylidae) in southern China and some surrounding areas.

Angiostrongylus cantonensis is of increasing public health importance as the main zoonotic pathogen causing eosinophilic meningitis or meningoencephalitis, which has been documented all over the world. However, there are very limited studies about its phylogeography and spread pattern. In the present study, the phylogeography of A. cantonensis in southern China (including Taiwan) and partial areas of Southeast Asia were studied based on the sequences of complete mitochondrial cytochrome b (Cytb) gene. A total of 520 individuals of A. cantonensis obtained from 13 localities were sequenced for the analyses and grouped into 42 defined haplotypes. The phylogenetic tree (NJ tree and BI tree) revealed a characteristic distribution pattern of the four main lineages, with detectable geographic structure. Genetic differentiation among populations was significant, but demographic expansion could not be detected by either neutrality tests or mismatch distribution analysis, which implied a low gene flow among the local populations in different regions where the samples were collected. Two unique lineages of the A. cantonensis population in Taiwan were detected, which suggests its multiple origin in the island. Populations in Hekou (China) and Laos showed the highest genetic diversities, which were supported by both genetic diversity indices and AMOVA. These results together infer that the area around Thailand or Hekou in Yunnan province, China are the most likely origins of Angiostrongylus cantonensis.

Specific status of Echinococcus canadensis (Cestoda: Taeniidae) inferred from nuclear and mitochondrial gene sequences

The specific status of Echinococcus canadensis has long been controversial, mainly because it consists of the mitochondrial lineages G6, G7, G8 and G10 with different host affinity: G6 (camel strain) and G7 (pig strain) with domestic cycles and G8 (cervid strain) and G10 (Fennoscandian cervid strain) with sylvatic or semi-domestic cycles. There is an argument whether the mitochondrial lineages should be recognised as separate species which correspond to the biological or epidemiological aggregation. In the present study, the specific status of E. canadensis was investigated using mitochondrial DNA and single copy nuclear DNA markers. Nucleotide sequences of complete mitochondrial cytochrome c oxidase subunit 1 (cox1) and partial nuclear phosphoenolpyruvate carboxykinase (pepck) and DNA polymerase delta (pold) were determined for 48 isolates of E. canadensis collected from different hosts in a wide range of regions. The mitochondrial phylogeny of cox1 showed that all the isolates were clearly divided into three clades corresponding to G6/G7, G8 and G10. Five and three alleles were confirmed at pepck and pold loci, respectively. These alleles were generally divided into two groups corresponding to G6/G7 or G8 and G10. However, allele sharing was confirmed among individuals belonging to different lineages. The allele sharing occurred primarily in regions where different mitochondrial DNA lineages were found in sympatry. The resultant nuclear mitochondrial discordance suggests the genetic exchangeability among E. canadensis isolates belonging to different lineages. An apparently mosaic parasite fauna that reflects faunal mixing due to natural and anthropogenic disturbance, including introductions and invasion, precludes us from designating each of G6/G7, G8 and G10 into a different species.