A reconstruction of parasite burden reveals one century of climate-associated parasite decline.

Long-term data allow ecologists to assess trajectories of population abundance. Without this context, it is impossible to know whether a taxon is thriving or declining to extinction. For parasites of wildlife, there are few long-term data-a gap that creates an impediment to managing parasite biodiversity and infectious threats in a changing world. We produced a century-scale time series of metazoan parasite abundance and used it to test whether parasitism is changing in Puget Sound, United States, and, if so, why. We performed parasitological dissection of fluid-preserved specimens held in natural history collections for eight fish species collected between 1880 and 2019. We found that parasite taxa using three or more obligately required host species-a group that comprised 52% of the parasite taxa we detected-declined in abundance at a rate of 10.9% per decade, whereas no change in abundance was detected for parasites using one or two obligately required host species. We tested several potential mechanisms for the decline in 3+-host parasites and found that parasite abundance was negatively correlated with sea surface temperature, diminishing at a rate of 38% for every 1 °C increase. Although the temperature effect was strong, it did not explain all variability in parasite burden, suggesting that other factors may also have contributed to the long-term declines we observed. These data document one century of climate-associated parasite decline in Puget Sound-a massive loss of biodiversity, undetected until now.

Parasitic nematodes of the genus Syphacia Seurat, 1916 infecting Cricetidae in the British Isles: the enigmatic status of Syphacia nigeriana.

Oxyurid nematodes (Syphacia spp.) from bank (Myodes glareolus) and field/common (Microtus spp.) voles, from disparate geographical sites in the British Isles, were examined morphologically and genetically. The genetic signatures of 118 new isolates are provided, based primarily on the rDNA internal transcribed spacers (ITS1-5.8S-ITS2) region and for representative isolates also on the small subunit 18S rDNA region and cytochrome c oxidase subunit 1 (cox-1) gene locus. Genetic data on worms recovered from Microtus spp. from the European mainland and from other rodent genera from the Palaearctic, North America and West Africa are also included. We test historical hypotheses indicating that S. nigeriana is a generalist species, infecting a range of different rodent genera. Our results establish that S. nigeriana is a parasite of both bank and field voles in the British Isles. An identical genotype was also recorded from Hubert's multimammate mouse (Mastomys huberti) from Senegal, but Mastomys spp. from West Africa were additionally parasitized by a related, although genetically distinct Syphacia species. We found no evidence for S. petrusewiczi in voles from the British Isles but isolates from Russia and North America were genetically distinct and formed their own separate deep branch in maximum likelihood molecular phylogenetic trees.

New host, geographic records, and histopathologic studies of Angiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment.

To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis and Angiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylus species parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.

A new genus and species of Heligmonellidae (Nematoda: Trichostrongylina) parasitic in Delomys dorsalis (Rodentia: Sigmodontinae) from Misiones, Argentina.

Alippistrongylus bicaudatus gen. et sp. n. (Nematoda: Heligmonellidae) is described from the striped Atlantic forest rat, Delomys dorsalis (Hensel) (Rodentia: Sigmodontinae), from the province of Misiones in Argentina. The new genus and species is characterised by a synlophe of 21 unequal ridges in both sexes without a gradient in size, with two ridges weakly sclerotised and oriented perpendicularly in the dorsal left quadrant; males with a highly dissymmetrical bursa with a hypertrophied right lobe, and females with a dorsal conical appendage just posterior to the vulva, conferring a two-tailed appearance to the female worms.

Checklist of helminth parasites of Chiroptera of North America north of Mexico.

A parasite-host, host-parasite and distribution-based checklist of helminths found in bats (Chiroptera) of North America north of Mexico is presented. The parasite-host checklist includes a total of 93 species (including records without a species identification) of helminth parasites reported in the literature from 30 species of bats. These include 54 trematodes, 11 cestodes, and 28 nematodes. Each helminth species is listed under its most current accepted name, with all known synonyms, distribution by state/province, and references for each geographic location. Lists of helminths reported from individual species of bats as well as states of the United States and provinces/territories of Canada are also provided. The following new combinations are proposed: Paralecithodendrium alaskensis (Neiland, 1962) n. comb. for Prosthodendrium alaskensis Neiland, 1962; Paralecthodendrium longiforme (Bhalerao, 1926) n. comb. for Lecithodendrium longiforme Bhalerao, 1926; and Paralecithodendrium singularium (Byrd & Macy, 1942) n. comb. for Prosthodendrium singularium Byrd & Macy, 1942. The state of knowledge of helminths of bats in North America is briefly discussed.

Outbreak of Philophthalmus gralli in four greater rheas (Rhea americana).

Using slit-lamp biomicroscopy, conjunctival biopsy, and morphological identification, a flock of four Greater rheas (Rhea americana) in Arizona were diagnosed with conjunctivitis secondary to Philophthalmus gralli (P. gralli) infection. Aquatic snails from the exhibit's water source were identified as Melanoides tuberculatus, a known vector for P. gralli. Comparison of partial sequences of DNA regions from P. gralli adults removed from the rheas and metacercariae from the aquatic snails demonstrated a 100% match, confirming the source of infection. The flock was divided into two treatment groups: the most severely affected rheas received both manual removal of trematodes and praziquantel 1% ointment OU q12 h and the least severely affected rheas were only given praziquantel 1% ointment OU q12 h. The rheas were permanently relocated away from the infected water source and aquatic snails. Initial resolution was seen at 17 weeks in the most severely affected rhea, which had 675 adult P. gralli removed and topical praziquantel. The two rheas that only received topical praziquantel showed resolution within 3 and 15 weeks. Current recommendations for treating P. gralli include: manual removal of trematodes, topical praziquantel 1% ointment, and relocation away from infected water sources and aquatic snails.

Morphological and molecular differentiation of Staphylocystis clydesengeri n. sp. (Cestoda, Hymenolepididae) from the vagrant shrew, Sorex vagrans (Soricomorpha, Soricidae), in North America.

Staphylocystis clydesengeri n. sp. is described from shrews Sorex vagrans in Montana and Washington, United States. It differs from the only previously known North American representative of the genus, S. schilleri, in having more numerous (37-42 vs. 22-30) and larger (39-44 microm vs. 27-30 microm) rostellar hooks. The two species also differ in several other important characters such as relative length of the cirrus pouch, position of gonads and shape of mature proglottides. Morphological differentiation of the new species from all previously known Palearctic species of Staphylocystis from Sorex is also provided. Differentiation from Staphylocystis parasitic in crocidurine shrews is not provided due to the high level of specificity among shrew hymenolepidids to the host genera and much greater levels of sequence divergence between Staphylocystis from the two groups of shrews. Molecular differentiation based on 2,800 base pair long sequences of nuclear ribosomal RNA (complete ITS region and partial 28S region), 663 base pair long sequences of mitochondrial nad1 gene and 542 base pair long sequences of mitochondrial ribosomal 16S gene strongly support the status of Staphylocystis clydesengeri n. sp. Relative utility of the DNA fragments used in this study for reliable differentiation among closely related species of mammalian hymenolepidids is discussed. Nuclear ribosomal RNA region appears to be too conserved for this purpose. Use of at least one mitochondrial gene in addition to nuclear ribosomal RNA or without it, is recommended. Vampirolepis novosibirskiensis Sawada & Kobayashi, 1994 is transferred to Staphylocystis as a junior synonym of S. furcara (Stieda, 1862). Rodentolepis gnoskei Greiman & Tkach, 2012 is transferred to Pararodentolepis Makarikov and Gulyaev, 2009 as a new combination Pararodentolepis gnoskei (Greiman & Tkach, 2012) n. comb.

Redescription of Chabaudacuaria multispinosa (Pérez Vigueras, 1938) n. g., n. comb. (Nematoda: Spirurida: Acuariidae) based on specimens from Ardea herodias L. and Nyctanassa violacea (L.) (Ardeidae) in Florida.

Chabaudacuaria n. g. is erected, as monotypic, for C. multispinosa (Pérez Vigueras, 1938) n. comb. (Spirurida: Acuariidae) [syns Cheilospirura multispinosa Pérez Vigueras, 1938; Acuaria multispinosa (Pérez Vigueras, 1938) Yamaguti, 1961]. This species, a parasite of various ardeid birds, is redescribed by means of light and scanning electron microscopy based on material from great blue herons Ardea herodias L. and yellow-crowned night herons Nyctanassa violacea (L.) in Florida, USA. Chabaudacuaria n. g. resembles Acuaria Bremser, 1811, Cheilospirura Diesing, 1861, Skrjabinocerca Schikhobalova, 1930 and Xenocordon Mawson, 1982 in its straight cordons which do not anastomose. However, it can be distinguished from them by the didelphic-prodelphic uterus and the absence of caudal alae in the males. In the pattern of its cordons (consisting of a row of plates and a longitudinal ridge) and the absence of an area rugosa, the new genus is similar to Chevreuxia Seurat, 1918, Syncuaria Gil'bert, 1927, Aviculariella Wehr, 1931, Skrjabinocara Kurashvili, 1940, Decorataria Sobolev, 1949 and Desportesius Chabaud & Campana, 1949, which are characterised by anastomosing cordons. The didelphic-prodelphic female reproductive system of Chabaudacuaria is intermediate between the didelphic-amphidelphic uterus of Chevreuxia and the monodelphic-prodelphic uterus of Syncuaria, Aviculariella, Skrjabinocara, Desportesius and Decorataria. Therefore, the straight and non-anastomosing cordons are considered to be autapomorphic for Chabaudacuaria.

Lethal Procyrnea infection in a black-backed woodpecker (Picoides arcticus) from California.

The black-backed woodpecker (Picoides arcticus) is a species of management concern in California. As part of a study of black-backed woodpecker home range size and foraging ecology, nine birds in Lassen National Forest (Shasta and Lassen Counties, California) were radio-tracked during the 2011 breeding season. One of the marked birds was found dead after being tracked for a 10-wk period in which it successfully nested. A postmortem examination of the dead bird revealed that it was emaciated and autolyzed, with the presumptive cause being numerous spiruroid nematodes of the genus Procyrnea in the gizzard. This first observation of Procyrnea nematodes in a black-backed woodpecker is notable because the Procyrnea infection was considered lethal and because Procyrnea has been implicated in substantial die-offs in other bird species, including woodpeckers.

Molecular phylogeny supports invalidation of Didelphodiplostomum and Pharyngostomoides (Digenea: Diplostomidae) and reveals a Tylodelphys from mammals.

Alaria, Didelphodiplostomum and Pharyngostomoides are among genera of diplostomid digeneans known to parasitize mammalian definitive hosts. Despite numerous recent molecular phylogenetic studies of diplostomids, limited DNA sequence data is available from diplostomids parasitic in mammals. Herein, we provide the first 28S rDNA and cox1 mtDNA sequences from morphologically identified, adult specimens of Didelphodiplostomum and Pharyngostomoides. Newly generated 28S sequences were used to infer the phylogenetic interrelationships of these two genera among other major lineages of diplostomoideans. The phylogeny based on 28S and a review of morphology clearly suggests that Pharyngostomoides should be considered a junior synonym of Alaria, while Didelphodiplostomum should be considered a junior synonym of Tylodelphys. Pharyngostomoides procyonis (type species), Pharyngostomoides adenocephala and Pharyngostomoides dasyuri were transferred into Alaria as Alaria procyonis comb. nov., Alaria adenocephala comb. nov. and Alaria dasyuri comb. nov.; Didelphodiplostomum variabile (type species) and Didelphodiplostomum nunezae were transferred into Tylodelphys as Tylodelphys variabilis comb. nov. and Tylodelphys nunezae comb. nov. In addition, Alaria ovalis comb. nov. (formerly included in Pharyngostomoides) was restored and transferred into Alaria based on a morphological study of well-fixed, adult specimens and the comparison of cox1 DNA sequences among Alaria spp. The diplostomid genus Parallelorchis was restored based on review of morphology.

Renifer aniarum (Digenea: Reniferidae), an introduced North American parasite in grass snakes Natrix natrix in Calabria, southern Italy.

Over the past decades, as a result of various human activities involving intentional or unintentional movement of animals, many helminth species have been introduced to new regions with several ecological and epidemiological implications for the native species. A high prevalence of infection with an introduced digenean Renifer aniarum, previously known only from North America, was found in the grass snake Natrix natrix in the Calabria region, southern Italy. Morphological and molecular comparison with North American R. aniarum has confirmed the identity of the Italian specimens. A total of 41 grass snakes were studied for R. aniarum infection. Of 24 snakes sampled between 2009 and 2010, 22 were positive for this parasite. In contrast, all 17 snakes sampled from museum collections between 1983 and 1994 were negative. Our results support the hypothesis that R. aniarum was perhaps introduced into this area during the 1990s by the translocation of the American bullfrog Lithobates (Rana) catesbeianus, a normal second intermediate host of the digenean in its native range in North America. Although the life cycle of R. aniarum is complex and includes 3 host stages, this parasite has found suitable first and second intermediate hosts as well as definitive hosts in Italy. Renifer aniarum was second only to the very common grass snake tapeworm Ophiotaenia europaea in both prevalence and abundance among 9 species of helminths recovered in our study.

Gastric spiruridiasis caused by Mastophorus muris in a captive population of striped possums (Dactylopsila trivirgata).

Striped possums (Dactylopsila trivirgata) are small arboreal marsupials for which limited medical information is known. Mastophorus muris is a gastric spirurid nematode of rodents that uses insects as intermediate hosts. Three cases of gastric spiruridiasis caused by M. muris in captive striped possums are reported for the first time. Diagnosis was made by the presence of adult nematodes in regurgitant and at necropsy. Low numbers of nematode ova shed intermittently in possum feces made evaluation of treatment success difficult. No histopathologic abnormalities were identified in one case. Control of M. muris in captive possum colonies may be achieved by interrupting the life cycle of the parasite.

Eimeria longirostris (Apicomplexa: Eimeriidae) from Vagrant Shrew, Sorex vagrans (Mammalia: Eulipotyphla: Soricidae), from Montana, USA.

PURPOSE: Nothing is known about the coccidian parasites of vagrant shrews, Sorex vagrans Baird, 1868. Here we report, for the first time, the occurrence of Eimeria longirostris Hertel and Duszynski, 1987 from faecal contents of S. vagrans from Montana, USA. METHODS: Faecal samples, collected in July and August 2020 from six pitfall-trapped vagrant shrews as well as faeces from two masked shrews, Sorex cinereus Kerr, 1792, and one American pygmy shrew, Sorex hoyi Baird, 1857 from Missoula County, Montana, USA, were examined for coccidian parasites. Samples were placed in individual vials containing aqueous potassium dichromate. They were examined for coccidia after flotation in Sheather's sugar solution, measured, and photographed. RESULTS: Three (50%) S. vagrans and one (50%) S. cinereus were found to be passing oocysts of Eimeria longirostris Hertel and Duszynski, 1987; the single S. hoyi was negative. Oocysts from S. vagrans were subspheroidal and measured (average L × W) 16.1 × 14.4 µm with an L/W ratio of 1.1. One (typically) to two polar granules was present but a micropyle and oocyst residuum were absent. Sporocysts were ovoidal and measured 9.6 × 6.2 µm with an L/W ratio of 1.6. A Stieda body was present but subStieda and paraStieda bodies were absent. The sporocyst residuum was composed of various sized granules typically scattered between and across the sporozoites but sometimes formed a loose aggregate or compact mass. CONCLUSION: We document a new host and new geographic record for E. longirostris from S. vagrans and report the coccidian from S. cinereus for the third time but the first report from specimens from Montana. This coccidian has now been reported from at least 12 species of shrews within the genus Sorex in 14 US states and two provinces in Canada.

The gastrointestinal nematodes of plains and Grevy's zebras: Phylogenetic relationships and host specificity.

Equids are chronically infected with parasitic strongyle nematodes. There is a rich literature on horse strongyles, but they are difficult to identify morphologically and genetic studies on strongyles infecting other equid species are few, hampering studies of host specificity. We sequenced expelled worms from two sympatric zebra species in central Kenya to expand the strongyle phylogeny and used DNA metabarcoding on faecal samples to genetically characterize zebra nemabiomes for the first time. We generated sequences for several species new to public genetic reference databases, all of which are typical strongyles in wild zebras (i.e., the three species of Cylindropharynx and Cyathostomum montgomeryi), and identified their closest relatives. We also discovered an apparent fungus infecting a quarter of the expelled Crossocephalus viviparus worms, a hyperabundant nematode species in the family Atractidae, hinting at the possibility that zebra host-parasite dynamics may involve a zebra-fungus mutualism. The two zebra species had similar nemabiomes; we found a complete overlap in the list of nematode species they carry and very similar prevalence (i.e., proportion of hosts infected) for the different nematode species. Our study suggests limited host-specificity in zebra strongyles and high potential for transmission between the plains zebra and the endangered Grevy's zebra.

A new cyclocoelid (Digenea) genus from the grey-winged trumpeter, Psophia crepitans (Aves: Gruiformes: Psophiidae), from Guyana.

Six specimens representing a new genus of cyclocoelid, Psophiatrema greineri n. gen., n. sp. (Digenea: Cyclocoelidae: Cyclocoelinae), were collected from the air sacs of a common or grey-winged trumpeter, Psophia crepitans (Gruiformes: Psophiidae), from Guyana on 19 January 2001. The bird was being maintained in an aviary at Emerald Forest Bird Gardens, Fallbrook, California. The new genus has an intertesticular ovary forming a triangle with the testes, placing it in Cyclocoelinae. There are currently 2 genera recognized in Cyclocoelinae: Cyclocoelum and Selfcoelum. The new genus is most similar to Selfcoelum by having a postpharyngeal genital pore, but differs from both Cyclocoelum and Selfcoelum by having the vitelline fields confluent posteriorly. A revised key to the Cyclocoelinae is provided to include the new genus, and the subfamily diagnosis is emended to reflect that the vitelline fields can be either confluent or not posteriorly.

Transmammary infection of free-ranging Florida panther neonates by Alaria marcianae (Trematoda: Diplostomatidae).

Two freshly-dead female Florida panther (FP) neonates, Puma concolor couguar (=Puma concolor coryi), an 11-day-old and a 17-day-old, were collected in the Florida Panther National Wildlife Refuge (26 degrees 14'N, 81 degrees 36'W), Collier County, Florida. The 2 neonates were siblings and had presumably fed only on milk from the dam since birth. A 12-day-old female FP neonate was collected in the Big Cypress National Preserve (26 degrees 05'N, 81 degrees 15'W), Collier County, Florida and had also fed only on milk from the dam since birth. Milk was the only food item found in the gastrointestinal tract of these neonates. Mesocercariae and diplostomula of Alaria marcianae were collected from the lungs of the 3 neonates, indicating a transmammary route of infection. No mesocercariae, diplostomula, or mature A. marcianae were seen in the stomach or small intestine. The probable paratenic host for the A. marcianae infection in the adult Florida panther is the raccoon (Procyon lotor).

First record of entodiniomorph ciliates in a carnivore, the maned wolf (Chrysocyon brachyurus), from Brazil.

The entodiniomorph ciliates (Ciliophora: Entodiniomorphida) are endosymbiotes widely found in the intestines of herbivorous mammals. These commensals commonly occur in the Artiodactyla and Perissodactyla and have also been described in the Proboscidea, Primates, Rodentia, and Diprotodontia. This study reports the first finding of a ciliate in a member of order Carnivora, the maned wolf (Chrysocyon brachyurus). Fecal samples from wild and captive maned wolves were screened using ethyl acetate sedimentation. Prevalence in fecal samples collected from free-ranging maned wolves in Brazil was 40% (6 of 15). Fecal samples from two of four captive individuals from the St. Louis Zoo also had the same species of ciliate. The largely frugivorous diet of the maned wolf likely explains the occurrence of these normally herbivore-associated endosymbiotes in a carnivore.