Systematic position of the enigmatic Quentinia mesovitellinica (Rêgo, 1967) (Cestoda, Cyclophyllidea)

The systematic position of Quentinia mesovitellinica (Rêgo, 1967) (Cestoda, Cyclophyllidea) from the hystricomorph rodent Galea spixii (Wagler) (Caviidae) in Brazil is reevaluated based on published information. Quentinia mesovitellinica is generally thought to belong to the family Catenotaeniidae, being thus the only catenotaeniid cestode parasitizing hystricomorph rodents and also the only catenotaeniid in South America. However, the present study shows that Q. mesovitellinica differs fundamentally from Catenotaenia Janicki, 1904 sensu lato and other catenotaeniids with respect to several morphologic features, but shares these features with Monoecocestus Beddard, 1914 sensu Beveridge (1994), a genus in the family Anoplocephalidae sensu stricto (i.e. sensu Spasskii, 1951). However, Q. mesovitellinica is not assigned here to Monoecocestus, because the latter is a morphologically heterogeneous genus and will probably be split when subjected to a comprehensive phylogenetic and taxonomic analysis. Instead, Quentinia Spasskii, 1969 is considered a valid genus in the family Anoplocephalidae s. s. The morphologically closely related Monoecocestus eljefe Haverkost & Gardner, 2010 from Galea musteloides Meyen in Bolivia is assigned to Quentinia as Q. eljefe (Haverkost & Gardner, 2010) n. comb. An amended diagnosis is provided for Quentinia.

Trichostrongylina (Nematoda) from Malagasy Muridae. III--description of a new species of Heligmonoides Baylis, 1928 (Heligmonellidae) parasitic in Mus musculus

Heligmonoides variabilis n. sp. (Heligmosomoidea, Nippostrongylinae) a parasite of Mus musculus from Madagascar is related to H. afghanus (Tenora, 1969), H. ikeharai Hasegawa, 1990 and H. josephi (Wertheim & Durette-Desset, 1976), all having the dorsal ray divided anterior to the arising of rays 8. H. ikeharai a parasite of Tokudaia muenninki (Muridae) from Japan is the most closely related species with rays 8 arising at mid-length along the dorsal ray. It is differentiated from the new species by very long spicules (almost half of body length) and by the length of the vestibule (almost one millimeter). A new definition of the genus Heligmonoides Baylis, 1928 is proposed with a dichotomic key of the species. The biogeographic distribution and the host spectrum of the genus are described.

Morphological Characterisation of Andrya Railliet, 1893, Neandrya n. g. and Paranoplocephala Lühe, 1910 (Cestoda: Anoplocephalidae) in Rodents and Lagomorphs

The taxonomic significance of the main morphological features of the 25 species allocated to Andrya Railliet, 1893 and Paranoplocephala Lühe, 1910 is re-evaluated in the light of the recent molecular phylogenetic hypotheses for anoplocephaline cestodes. The present analysis and the existing phylogenetic data suggest that the structure and complexity of the early uterus are not, as previously assumed, the main phylogenetic or systematic determinants for anoplocephaline cestodes. Instead, the position of the early uterus with respect to other organs, combined with the morphology of the female genitalia, appear to allow a fairly straightforward discrimination of the three genera recognised here, without contradicting current phylogenetic hypotheses. A new genus, Neandrya n. g., is proposed for N. cuniculi (Blanchard, 1891) n. comb. (previously in Andrya), amended diagnoses are provided for Andrya and Paranoplocephala and a diagnostic key to these three genera is presented.

Description ofParanoplocephala yoccozin. sp. (Cestoda: Anoplocephalidae) from the snow voleChionomys nivalisin France, with a review of anoplocephalid cestodes of snow voles in Europe

We describe Paranoplocephala yoccozi n. sp. (Cestoda: Anoplocephalidae) from the snow vole Chionomys nivalis in Bourg-Saint-Maurice, French Alps, compare it with several related species from rodents, and review the anoplocephalid cestodes of snow voles in Europe. Paranoplocephala yoccozi n. sp. is primarily distinguished from the related species by its large scolex of characteristic shape, robust neck region, and the structure of the cirrus sac, vitellarium and vagina. We show that the anoplocephalid cestodes of snow voles in Europe, representing the genera Anoplocephaloides and Paranoplocephala, include at least seven species. This fauna consists primarily of species that snow voles share with other voles inhabiting the high-mountain areas. Some of the species, including P. yoccozi n. sp., appear to have a very localized distribution, which is assumed to be a consequence of the historical fragmentation of snow vole populations.

Phylogeography of the circumpolarParanoplocephala arcticaspecies complex (Cestoda: Anoplocephalidae) parasitizing collared lemmings (Dicrostonyxspp.)

The Paranoplocephla arctica complex (Cyclophyllidea, Anoplocephalidae), host-specific cestodes of collared lemmings Dicrostonyx, include two morphospecies P. arctica and P. alternata, whose taxonomical status now must be considered ambiguous. The genetic population structure and phylogeography of the P. arctica complex was studied from 83 individuals sampled throughout the Holarctic distribution range using 600 bp of the mitochondrial cytochrome c oxidase subunit I gene (COI). The mitochondrial DNA (mtDNA) phylogeny divides the species complex into one main Nearctic and one main Palaearctic phylogroup, corresponding to the main phylogenetic division of the hosts. In the Palearctic phylogroup, the parasite clades correspond to the host clades although the parasites from Wrangel Island form an exception as the host on this island, D. groenlandicus, belongs to the Nearctic phylogroup. In the Nearctic, northern refugia beyond the ice limit of the Pleistocene glaciations are proposed for the hosts. All reconstructions of parasite phylogeny show a genetically differentiated population structure that in the Canadian Arctic lacks strict congruence between phylogeny and geography. The parasite phylogeny does not show complete congruence with host relationships, suggesting a history of colonization and secondary patterns of dispersal from Beringia into the Canadian Arctic, an event not proposed by the host phylogenies alone.

Description of Paranoplocephala etholeni n. sp. (Cestoda: Anoplocephalidae) in the meadow vole Microtus pennsylvanicus, with a synopsis of Paranoplocephala s. l. in holarctic rodents

Paranoplocephala etholeni n. sp., parasitizing the meadow vole Microtus pennsylvanicus in Alaska and Wisconsin, USA, is described. Paranoplocephala etholeni is morphologically most closely related to the Nearctic Paranoplocephala ondatrae (Rausch, 1948). Available data suggest that P. etholeni is a host-specific, locally rare species that may have a wide but sporadic geographical distribution in North America. The finding of P. ondatrae-like cestodes in Microtus spp. suggests that this poorly known species may actually be a parasite of voles rather than muskrat (type host). A tabular synopsis of all the known species of Paranoplocephala s. l. in the Holarctic region with their main morphological features is presented.

Trichostrongylina (Nematoda) from Malagasy muridae. II--Description of two new species of Heligmonina (Heligmonellidae) in Nesomys rufus and Eliurus tanala

Two new species of Heligmonellidae from Madagascar are described, Heligmonina madagascariensis n. sp. in Nesomys rufus and Heligmonina tanala n. sp. in Eliurus tanala. Both species belong to the Heligmonina species with a pattern of type 1-3-1 for the right lobe of the caudal bursa and 1-4 for the left lobe. In H. madagascariensis, H. dupuisi (Desset, 1964) and H. praomyos Baylis, 1928, left ray 6 arises before ray 3 from the common trunk to rays 3 to 6 while in H. tanala and the other species, it arises at the same level. H. madagascariensis is differentiated from H. dupuisi and H. praomyos by the symmetry of the branches of the dorsal ray. H. tanala is differentiated from H. malacomys Sakka & Durette-Desset, 1988, the closely related species by a different pattern of the cuticular ridges at mid-body, by the sharpness of the tips of the spicules and by the ratio of the length of the spicules on the length of the body (6.9, 8.8% versus 25-27.8%). Heligmonina chippauxi (Desset, 1964) a parasite of Oenomys hypoxanthus from the Republic of Central Africa is considered a valid species.

Trichostrongylina (Nematoda) from Malagasy Muridae. I--Description of two new species of Heligmonellidae in Nesomys spp

Two new species of Heligmonellidae, Heligmonina wrightae n.sp. (Nippostrongylinae) and Nesomystrongylus fissicauda n.gen., n. sp. (Brevistriatinae) are described from Madagascar in Nesomys rufus and N. audeberti (Muridae). In Nesomys audeberti, the species are coparasites. Heligmonina wrightae is differentiated from all the other species of the genus, except H. malacomysi Sakka & Durette-Desset, 1988, by the ratio of the length of the spicules on the length of the body (25-27.8% versus 9.5-7%). It differs from H. malacomysi by the pattern of the caudal bursa and by the angle of the axis of orientation of the cuticular ridges on the sagittal axis. Nesomystrongylus fissicauda is related to the genus Fissicauda Durette-Desset & Krishnasamy, 1976, by the absence of the carene, by the ridges discontinuous on all the sides of the body and by the deeply divided dorsal ray. It differs from this genus by a different structure of the ridges, by the pattern of the caudal bursa, (very tiny rays 2 and strongly developed rays 3, rays 8 arising from common trunk of rays 2 to 6) and by the presence of a caudal tip in the female.

Echinococcus multilocularis on Svalbard: introduction of an intermediate host has enabled the local life-cycle

The taeniid tapeworm Echinococcus multilocularis is here reported for the first time at the Svalbard Archipelago in the Norwegian Arctic. This new finding is interesting because the establishment of E. multilocularis is due to a recent anthropogenic introduction of its intermediate host--the sibling vole Microtus rossiaemeridionalis at Svalbard. The parasite itself has probably become naturally transferred to Svalbard due to migratory movements of its final host--the arctic fox Alopex lagopus between source areas for E. multilocularis in Siberia and Svalbard. We report macroscopically determined prevalence of E. multilocularis from a sample of 224 voles trapped in August in 1999 and 2000. The prevalence was among the highest ever recorded in intermediate hosts and was dependent on age and sex of the hosts approaching 100% in overwintered males. The high prevalence and the simplicity of the vole-arctic fox-E. multilocularis system at Svalbard makes it an eminent model system for further epidemiological studies.

Biogeography of helminth parasitism in Lemmus Link (Arvicolinae), with the description of Paranoplocephala fellmani n. sp. (Cestoda: Anoplocephalidae) from the Norwegian lemming L. lemmus (Linnaeus)

We describe the gastrointestinal helminth fauna of true lemmings (Lemmus spp., Arvicolinae) based on published and original material throughout the Holarctic range of these hosts. According to the existing data, the helminth fauna of true lemmings consists of three widespread and/or locally common taxa: Hymenolepis horrida (sensu lato) (Hymenolepididae), Anoplocephaloides lemmi (Anoplocephalidae) and Heligmosomoides spp. (Heligmosomidae). Despite the taxonomic boundaries and ancient phylogenetic splits in the hosts, there are no major faunistic differences for parasites within western (Siberian) L. sibiricus and L. bungei, and eastern (North American) L. trimucronatus throughout their distribution range. In contrast, the Norwegian lemming L. lemmus, which is a Fennoscandian endemic and closely related to the western populations of L. sibiricus, has only a single host-specific helminth, the cestode Paranoplocephala fellmani n. sp. (Anoplocephalidae). We describe the new species and show that it differs consistently from related species by its long and slender cirrus-sac. However, there are also a number of other significant differences, e.g., P. fellmani n. sp. and Andrya primordialis in Tamiasciurus hudsonicus (Sciuridae) evidently have a unique (sub)type of uterine development among Andrya/Paranoplocephala spp. Because P. fellmani n. sp. was also found to occur in Alaska (host L. trimucronatus), this species seems to follow the same biogeographical pattern as the other specialist helminths of Lemmus. We suggest alternative explanations for the absence of three major helminth taxa in the Norwegian lemming in Fennoscandia.

Description and morphometric variability of Paranoplocephala serrata n. sp. (Cestoda: Anoplocephalidae) in collared lemmings (Dicrostonyx spp., Arvicolinae) from Arctic Siberia and North America

We describe Paranoplocephala serrata n. sp. (Cestoda, Anoplocephalidae) from collared lemmings Dicrostonyx torquatus and D. groenlandicus (Arvicolinae, Rodentia) in Arctic Siberia and North America. The new species was recorded from the Yamal Peninsula (type-locality), Yana Delta, Kolyma Delta, Wrangel Island, Alaska and Victoria Island/Kent Peninsula (Northwest Territories). P. serrata n. sp. is characterised by a long, ribbon-like strobila, distinctly serrated segments, a small scolex, unilateral or infrequently alternating genital pores and testes confined to the antiporal part of the segment. It differs from the related species (Andrya bairdi, Parandrya feodorovi and Paranoplocephala manseri) by several morphological features, including the distribution of testes (several testes antiporal to ventral longitudinal osmoregulatory canal), structure of the cirrus-sac and vagina, and large eggs (0.053-0.068 mm in the type-material). The material of P. serrata n. sp. from North America differs from the Siberian material by the shorter cirrus-sac, smaller dimensions of the female reproductive organs, larger seminal receptacle and larger eggs. However, the statistical differences in the dimensions of reproductive organs mainly reflect the larger size of mature segments in Siberian specimens compared with North American specimens. The main diagnostic features, i.e. the size and form of scolex and suckers, number and distribution of testes, position of female glands, vagina/cirrus-sac ratio and morphology of reproductive organs, do not differ markedly between the Palaearctic and Nearctic specimens. According to the structure of the early-stage uterus, A. bairdi Schad, 1954 belongs to the genus Paranoplocephala. Parandrya Gulyaev & Chechulin, 1996 is probably a synonym of Paranoplocephala. A redescription is provided for Paranoplocephala bairdi n. comb.

Disease patterns in field and bank vole populations during a cyclic decline in central Finland

Declining field vole (Microtus agrestis) and bank vole (Clethrionomys glareolus) populations were sampled (117 field voles and 34 bank voles) in south-central Finland during the winter of 1988-89. The last surviving field voles were caught in April and bank voles in February. A subsample (16) of the April field voles were taken live to the laboratory for immunosuppression. The histopathology of the main internal organs and the presence of aerobic bacteria and certain parasites were studied. In the lungs, an increase in lymphoid tissue, probably caused by infections, was the most common finding (52% of all individuals). The prevalences in the voles, in the whole material, of Chrysosporium sp. and Pneumocystis carinii in lungs were 13 and 10% in field voles, and 9 and 0% in bank voles, respectively. Cysts of Taenia mustelae (9 and 27%) were the most common pathological changes in the liver. Enteritis was also rather common (14 and 34%). In field voles the prevalences of Frenkelia sp. in the brain and Sarcocystis sp. in leg muscles were low (both 6%). Bordetella bronchiseptica was commonly (31%) isolated from field vole lungs and Listeria monocytogenes from the intestines (34%). Salmonella spp. could not be found. The dynamics and abundance of inflammations in the lungs and intestines, as well as B. bronchiseptica isolations from the lungs, indicate that obvious epidemics took place in declining vole populations. Of the Luhanka subsample of 16 field voles brought to the laboratory in April, one died of listeriosis, two of Bordetella, and five died for unknown reasons. Even if small mustelids are the driving force in microtine cycles, it is possible that diseases also contribute to the decline.

Blood parasites of shrews from Pennsylvania

We examined 30 Sorex cinereus, 5 Sorex fumeus, and 21 Blarina brevicauda collected from Pennsylvania in 1995 for blood parasites. Trypomastigotes of Trypanosoma sp. were visible in 13% of the S. cinereus. Ten percent of S. cinereus, 20% of S. fumeus, and 14% of B. brevicauda were infected with Bartonella sp. (or spp.). In S. cinereus, we detected no concurrent Trypanosoma and Bartonella infections.

Lung parasites of shrews from Pennsylvania

We examined lung parasites of three species of soricids, Sorex cinereus (n = 58), Sorex fumeus (n = 23) and Blarina brevicauda (n = 45) collected from Pennsylvania (USA), from 1990 to 1995. Yeast-like cells of Hisfoplasma capsulatum var. capsulatum were found in lung sections stained with Grocott's modification of Gomori's methenamine silver, periodic acid-Schiff, Giemsa, and hematoxylin-eosin in two (3%) S. cinereus, eight (35%) S. fumeus and two (4%) B. brevicauda. The number of spores of H. capsulatum in the lungs was low and no inflammatory reaction was evident. The infection was not disseminated to other organs. This is the first report of H. capsulatum infection in any species of shrews of the genus Sorex and the prevalence in S. fumeus was remarkably high compared to those reported for other wild mammals. A nematode, possibly Angiostrongylus michiganensis, was found in the lungs of one S. fumeus on necropsy and in a stained lung section of one S. cinereus. In both cases the host was also infected with the fungus. Pneumocystis carinii, which is the most common lung parasite in Sorex araneus (the numerically dominant Eurasian species of shrew), was not found in any of the North American species of shrew examined in this study.

Variability of sex ratio, mating probability and egg production in an intestinal nematode in its fluctuating host population

In dioecious parasites, the chances of co-occurring with the opposite sex depend on the sex ratio, abundance and distribution pattern of parasites within the host population. Theory suggests that if the abundance and degree of aggregation are very low, mating probability may decrease so much that the parasite population is vulnerable to extinction. Our aim is to determine the factors affecting the mating probability and egg production in Heligmosomum mixtum (Heligmosomidae), an intestinal nematode of the bank vole, Clethrionomys glareolus, at Pallasjärvi, Finnish Lapland. We also search for factors responsible for the persistence of H. mixtum in its fluctuating host population. The results showed that during high parasite abundance practically all nematode females co-occurred with males, but during a phase of very low abundance only 15% of females had a chance to mate. Comparison of observed mating probabilities and those predicted by a theoretical model (May & Woolhouse, 1993) showed that deviation from the assumption of complete aggregation between males and females results in underestimation of the mating probability. Sex ratio and the degree of aggregation showed a minor effect on mating probability. The sex ratio (proportion of females) of H. mixtum, which was female-biased (0.58), showed a negative correlation with the mean intensity of infection in the monthly samples (decreasing female-bias at high mean intensity), but no significant relation to the intensity of infection (number of worms in a host individual). The long-term persistence of H. mixtum in its strongly varying host population seems to be due to the high transmission efficiency and long life-span of the parasite.

Pneumocystis carinii and helminth parasitism in shrews Sorex araneus and Sorex caecutiens

The prevalence of Pneumocystis carinii was compared in two species of shrews, Sorex araneus and Sorex caecutiens in Finnish Lapland. The overall prevalence of P. carinii in S. araneus was 70% and in S. caecutiens was 17%. The prevalence for S. araneus is the highest reported for wild animals. The interspecific differences in prevalence were significant for all sex and age groups except for adult males. Based on multiway contingency tables (log-linear models), there was no dependence between sex or age of S. araneus and occurrence of P. carinii. In individual S. araneus the intensity of P. carinii was not related to the total number of helminths or the number of helminth species, and no dependence was observed between the presence of P. carinii and various helminth species.

Blood chemistry and endoparasites of the mountain hare (Lepus timidus L.) in high and low density populations

In order to study the effect of high population density on the condition, blood characteristics and helminth parasitism of mountain hares (Lepus timidus), 12 specimens were shot in December 1982 and 12 more in February 1983 on the west coast of central Finland (group 1, dense population). In addition 14 hares were shot in December 1982 about 100 km from group 1 (group 2, dense population). Group 3 consists of 15 hares from stable, rather low density populations shot in southern Finland during three previous winters. The hares in group 1 were the lightest, had the least fat and were the most seriously infected with Protostrongylus pulmonalis and Trichostrongylus retortaeformis, while those in group 2 were the heaviest and had the highest Ca, Mg, alkaline phosphatase and creatinine values. The group 3 hares had the most fat. The group 1 animals shot in February 1983 had higher Ca, Mg, triglyceride and cholesterol values than those shot in December 1982. It seems that high population density combined with a lack of suitable food leads to poor condition and high endoparasite abundances. The differences in Ca and Mg are probably due to diet. The higher creatinine values in group 2 and in the hares with little or no T. retortaeformis infection may be due to the greater muscle mass.

Parasitism by helminths in the grey-sided vole (Clethrionomys rufocanus) in northern Finland: influence of density, habitat and sex of the host

We have studied helminths from 532 grey-sided voles (Clethrionomys rufocanus) in two localities in northern Finland, representing different biogeographic zones, during 1978-1983. The helminth communities in the two study areas were similar, characterized by a small number of species (eight) compared to eastern Siberia and Japan, and by the dominance of a single anoplocephalid cestode Andrya kalelai. The prevalence of this helminth varied significantly among habitats, possibly because of differences in the distribution and abundance of the intermediate hosts, oribatid mites. Vole density did not explain the habitat differences in A. kalelai, nor did the prevalence of A. kalelai increase between 2 yr of sustained high density in the host population. A between-year increase in the prevalence of the larval cestode Taenia tenuicollis at Kilpisjärvi was probably due to a simultaneous increase in the abundance of its definitive hosts, mustelids. The prevalence of A. kalelai was always higher in males; no sexual differences were detected in the larval T. tenuicollis.