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Results for “Comparative Parasitology”

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At least 19 recordsLinked to original sources
USGS2006

Update on the distribution of the invasive Asian fish tapeworm, Bothriocephalus acheilognathi, in the U.S. and Canada

The documented range of the invasive and potentially pathogenic Asian fish tapeworm, Bothriocephalus acheilognathi Yamaguti, 1934 in the United States and Canada is updated based on examination of museum depositions and original field collections. Gravid specimens of B. acheilognathi were collected from the fathead minnow Pimephales promelas Rafinesque in Peter Lake, at the University of Notre Dame Environmental Research Center (UNDERC) Land o' Lakes, Wisconsin. A single immature specimen of the parasite was collected from a white bass, Morone chrysops (Rafinesque) in Lake Winnipeg, Manitoba, Canada. This is the first record of B. acheilognathi in Canada and extends its northern range in the interior of the continent by more than 600 miles over the last documented record. The previous record of B. acheilognathi in Canada, from the northern pikeminnow, Ptychocheilus oregonensis in British Columbia, is a misidentification of Eubothrium tulipai. Examination of selected records of intestinal cestodes from native cyprinids, in the Harold W. Manter Laboratory of Parasitology (HWML, n = 9) collection and in the United States National Parasite Collection (USNPC, n = 8), provided evidence of the parasite in Nebraska and possibly in the upper Colorado River basin. Introductions into Wisconsin-Michigan were due to the stocking of golden shiners, whereas the source of the introduction in Manitoba remains unknown.

Comparative Parasitology↗
USGS2002

What are parasitologists doing in the United States Geological Survey?

The United States Geological Survey (USGS) was formed in 1879 as the nation's primary natural science and information agency. The mission of the agency is to provide scientific information to a??describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.a?? Prior to 1996, the USGS comprised 3 divisions or disciplines: geology, mapping, and water. Historically, the agency was most noted for cartographic products that were used widely by both government and private sector. With the inclusion of the National Biological Service into the USGS in 1996 as the Biological Resource Discipline (BRD), a living resources dimension was added to the earth sciences character of the USGS. With the addition of BRD, the bureau is able now to contribute both the physical and biological sciences to address the nation's resource management problems.

Comparative Parasitology↗
USGS2002

Parasites of the slimy sculpin, Cottus cognatus Richardson, 1836, from Lake Huron, U.S.A

One hundred slimy sculpins, Cottus cognatus (Cottidae), collected from Six Fathom Bank Lake Trout Refuge in Lake Huron in June 1995 were examined for parasites. A total of 17 parasite species (3 Digenea, 2 Monogenea, 3 Cestoda, 3 Nematoda, 2 Acanthocephala, 2 Ciliophora, 1 Microspora, and 1 Myxosporea) were found to infect sculpins. Tetracotyle sp. had the highest prevalence, mean intensity, and mean abundance, followed by Diplostomum sp. The most common gastrointestinal helminth species was Echinorhynchus salmonis . Epistylis sp. occurred on the gills of 79 sculpins. The mean parasite species richness ± SD and mean helminth abundance ± SD were 5.4 ± 1.6 and 242.6 ± 264.5, respectively. The mean Brillouin's diversity and evenness values were 0.5773 ± 0.1915 and 0.5248 ± 0.1892, respectively. Although the helminth community of slimy sculpins is dominated by larval trematodes that mature in piscivorous birds, it is believed that few slimy sculpins are eaten by birds at this location.

Comparative Parasitology↗
USGS2017

Distribution of Placobdella hollensis (Whitman, 1892) (Hirudinida: Glossiphoniidae)

Confusion regarding the identification of Placobdella hollensis ( Whitman, 1892 ) (Hirudinida: Glossiphoniidae) has led to an unclear understanding of the distribution of the species. Two specimens of P. hollensis were collected from Merchants Millpond State Park, Gates County, North Carolina, U.S.A., representing a new geographic distribution record. Specimens were confirmed as P. hollensis by morphological and molecular study. Specimens of P. hollensis from North Carolina, had accessory eyes, 2 thin paramedial dark lines, and 3 pairs of pre-anal papillae. Molecular comparison of cytochrome c oxidase subunit I sequence data revealed a 99.0 to 99.7% similarity to specimens of P. hollensis collected from its type locality (Barnstable County, Massachusetts, U.S.A.). From confirmed specimens of P. hollensis , this report supports the assertion that P. hollensis has an Atlantic coastal distribution.

Comparative Parasitology↗
USGS2004

Intestinal helminths in mourning doves (Zenaida macroura) from Arizona, Pennsylvania, South Carolina, and Tennessee, U.S.A.

We examined 115 hunter-killed mourning doves ( Zenaida macroura ) from 4 states (Arizona, Pennsylvania, South Carolina, and Tennessee, U.S.A.) in 1998 and 1999 to investigate geographical variation in the prevalence and intensity of intestinal helminth infections. Four intestinal helminth species were identified: Killigrewia delafondi , Ornithostrongylus crami , Ascaridia columbae , and Capillaria obsignata . The number of worms (all helminth species combined) per infected bird ranged from 1 to 166 (mean ± SE = 12.7 ± 7.45, median = 2.0). Filarids, Aproctella stoddardi , were found in 2 birds but were probably adhering to the outside of the intestine. Overall, 18% of the doves were infected with 1 or more species of helminths. The percentage of doves infected with at least 1 helminth species varied from 4% in Arizona to 27% in South Carolina. Mixed infections occurred in only 3 individuals (14% of infected birds). We found no significant differences in prevalence of infection among any of the 4 helminths by host age or sex, and prevalences were too low to test for differences among states. The intensity of O. crami was higher in males than in females but did not differ significantly among states. Intensities of the other 3 helminths did not differ by sex or state, and we found no differences in helminth intensity by age. Intestinal length was significantly greater in infected than in uninfected birds.

Arizona, Pennsylvania, South Carolina, Tennessee↗
USGS2004

Parasites of the African clawed frog, Xenopus laevis , in southern California, U.S.A

A total of 230 feral African clawed frogs, Xenopus laevis , from 3 localities in southern California were examined for parasites. The following species were found: 3 species of Protozoa, Nyctotherus sp., Balantidium xenopodis , Protoopalina xenopodus ; 2 species of Monogenea, Protopolystoma xenopodis , Gyrdicotylus gallieni ; 1 species of Digenea, Clinostomum sp. (as metacercariae); 1 species of Cestoda, Cephalochlamys namaquensis ; 2 species of Nematoda, Contracaecum sp. (as larvae), Eustrongylides sp. (as larvae); and 1 species of Acanthocephala, Acanthocephalus sp. (as cystacanth). Of these, the protozoans P. xenopodus and B. xenopodis , both monogeneans, and the cestode have an African origin. Contracaecum sp., Eustrongylides sp., and Acanthocephalus sp. have not been previously reported from X. laevis .

Comparative Parasitology↗
USGS2009

Parasites of the mink frog (Rana septentrionalis) from Minnesota, U.S.A.

Twenty-two mink frogs, Rana septentrionalis , collected from two locations in Minnesota, United States, were examined for helminth and protozoan blood parasites in July 1999. A total of 16 parasite taxa were recovered including 5 larval digenean trematodes, 7 adult digenean trematodes, 3 nematodes, and 1 Trypanosoma species. Infracommunities were dominated by the digeneans in terms of richness and abundance. In particular, echinostomatid metacercariae in the kidneys of frogs were the most common parasites found, infecting 100% of the frogs and consisting of about 90% of all helminth individuals recovered. Gorgodera amplicava , Gorgoderina multilobata , Haematoloechus parviplexus , Haematoloechus breviplexus , Cosmocercoides dukae , and Oswaldocruzia pipiens represent new host records. The survey presented here represents the second known helminth survey of mink frogs conducted in North America. A summary of metazoan parasites reported from mink frogs is included.

Minnesota↗
USGS2011

Parasite distribution, prevalence, and assemblages of the grass shrimp, Palaemonetes pugio, in Southwestern Alabama, U.S.A.

The grass shrimp, Palaemonetes pugio , harbors a number of symbionts within its North American range. Here, we document the distribution and seasonality of 4 taxonomic groups that use P. pugio as a host in coastal Alabama. We conducted a regional survey of 4 symbionts of P. pugio over 3 seasons and compared assemblages across space and time. The most common parasite was the metacercarial stage of the microphallid trematode Microphallus turgidus , which remained consistently prevalent over the 3 seasons surveyed. We also monitored the prevalence of M. turgidus at 2 sites monthly. Prevalence fluctuated significantly among seasons at these sites, but spatial heterogeneity appears to have a stronger influence on regional parasite prevalence. Distributions of 3 of 4 symbionts overlapped in a single geographic area (Mon Louis Island, Alabama, U.S.A.); however, multispecies infections of individual hosts were normally distributed within host populations. Sites surrounding Mon Louis Island had substantially higher parasite prevalence, particularly in the summer months. This area had a high quantity of Spartina marsh habitat, which we found influenced parasite prevalence, suggesting a role for wetland habitat in structuring parasite communities for this host.

Alabama↗
USGS2012

Acanthocephalan parasites of slimy sculpin, Cottus cognatus , and Ninespine Stickleback, Pungitius pungitius , from Lake Michigan, U.S.A.

In total, 288 slimy sculpins, Cottus cognatus , were collected in September 2003 from 6 Lake Michigan, U.S.A., ports, along with 220 ninespine sticklebacks, Pungitius pungitius , from 3 ports. The ports included Waukegan, Illinois; Port Washington (PW) and Sturgeon Bay (SB), Wisconsin; and Manistique (MS), Frankfort (FF), Ludington (LD), and Saugatuck, Michigan. Echinorhynchus salmonis infected sculpins from 6 ports, Acanthocephalus dirus infected sculpins from 4 ports, and Neoechinorhynchus pungitius infected sculpins from 3 ports. Echinorhynchus salmonis infected significantly more sculpins at PW and at FF than at MS and LD. There were several significant differences in the intensities and abundances of E. salmonis among ports. Acanthocephalus dirus significantly infected more sculpins and had significantly higher abundances at FF than at PW, MS, and LD. Echinorhynchus salmonis , A. dirus , and N. pungitius infected sticklebacks from SB, MS, and FF. Neoechinorhynchus pungitius significantly infected more sculpins and more sticklebacks, and it had significantly higher abundances at MS than at FF. Neoechinorhynchus pungitius was the most common acanthocephalan in C. cognatus and P. pungitius at MS. These acanthocephalan species infecting C. cognatus and P. pungitius corresponded in their occurrence to those organisms that serve as their intermediate hosts found in the stomachs of both fish species. Potential changes in the diet of C. cognatus played a role in significant differences found for E. salmonis and N. pungitius at MS. One of these acanthocephalan species was always the most numerous helminth species found in the digestive tracts of P. pungitius and C. cognatus from these Lake Michigan ports.

Illinois;Wisconsin;Michigan↗
USGS2013

Parasites of Bloater Coregonus hoyi (Salmonidae) from Lake Michigan, U.S.A

In total, 158 bloaters Coregonus hoyi collected in September and October 2011 from 4 Lake Michigan, U.S.A., ports were examined for parasites. The ports included Waukegan (WK), Illinois; Port Washington (PW) and Sturgeon Bay (SB), Wisconsin; and Saugatuck (SG), Michigan. Parasites found in bloaters by port were cestodes Cyathocephalus truncatus (WK, PW, and SB) and Eubothrium salvelini (WK, PW, SB, and SG); the nematode Cystidicola farionis (WK, PW, SB, and SG); acanthocephalans Acanthocephalus dirus (WK and PW), Echinorhynchus salmonis (WK, PW, and SB), and Neoechinorhynchus tumidus (SB); and the copepod Salmincola corpulentus (WK and PW). Gravid individuals of all parasite species were found except for E. salvelini and A. dirus. Cystidicola farionis had the highest prevalence at each port, and the highest mean intensity and mean abundance at PW. The numbers of C. farionis at PW were significantly higher than those at WK and SB. Echinorhynchus salvelini had the highest mean intensities and mean abundances at WK, SB, and SG. The values for parasite species richness in bloaters were similar among ports. The total numbers of parasites were similar between WK and PW, but they were higher at these ports than at SB. The parasite faunas of bloaters were characterized by autogenic helminth species.

Comparative Parasitology↗
USGS2013

New host and distributional records for Cryptosporidium sp. (Apicomplexa: Cryptosporidiidae) from lizards (Sauria: Gekkonidae, Scincidae) from the Cook Islands and Vanuatu, South Pacific

Between 1991 and 1993, 295 lizards, comprising 21 species in 2 families (Gekkonidae, Scincidae) from the Cook Islands, Fiji, Palau, Takapoto, and Vanuatu in the South Pacific, were examined for Cryptosporidium oocysts. Only 6 lizards (2%) were found to be passing Cryptosporidium oocysts in their feces, including 2 of 30 (7%) Oceania geckos, Gehyra oceanica , from Rarotonga, Cook Islands, and 4 of 26 (15%) Pacific blue-tailed skinks, Emoia caeruleocauda , from Efate Island, Vanuatu. This represents the largest survey for Cryptosporidium in Pacific island lizards, and we document 2 new host and 2 new locality records for this parasite genus.

Comparative Parasitology↗
USGS2014

New host and distribution records of the leech Placobdella sophieae Oceguera-Figueroa et al., 2010 (Hirudinida: Glossiphoniidae)

Placobdella sophieae Oceguera-Figueroa et al., 2010 (Hirudinida: Glossiphoniidae) is reported from Oregon, California, and British Columbia for the first time. New hosts reported for P. sophieae include Taricha granulosa (rough-skinned newt), Rana pretiosa (Oregon spotted frog), and Anaxyrus boreas (western toad). Placobdella sophieae exhibits relatively low host specificity and all amphibians occurring in the Pacific Northwest are potential hosts.

Comparative Parasitology↗
USGS2022

Eimeria albigulae (Apicomplexa: Eimeriidae): New host and distributional record from the Bryant's woodrat, Neotoma bryanti (Rodentia: Cricetidae), from California, U.S.A.

Fecal samples, collected in July 2020 and April–May 2021 from 17 Bryant's woodrats, Neotoma bryanti Merriam, from 3 sites in San Diego, Orange, and San Bernardino counties, California, were examined for coccidial parasites. Three of 8 (38%) woodrats from a single site in San Diego County were found to be passing oocysts of Eimeria albigulae Levine, Ivens, and Kruidenier, 1957. Subspheroidal oocysts measured (average length [L] × width [W]) 23.5 × 21.4 µm with an average L/W ratio of 1.1. A micropyle was absent, but an oocyst residuum as well as a single polar granule was present. Ovoidal sporocysts measured (average L × W) 10.1 × 7.5 µm with an L/W ratio average of 1.4. A nipple-like Stieda body was present, but sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum was composed of loosely packed granules between and around the sporozoites. This woodrat represents the sixth host to harbor this coccidian. We document a new host as well as a geographic distribution record for E. albigulae .

California↗
USGS1998

An epizootic of common loons in coastal waters of North Carolina: Concentrations of elemental contaminants and results of necropsies

A 1993 die-off of common loons ( Gavia immer ) in the coastal waters of North Carolina was investigated with emphasis on comparing mercury, selenium, arsenic, and lead between birds from the epizootic and reference specimens. Die-off specimens were emaciated but contained no ingested foreign bodies and no lesions suggestive of infectious disease. Results of bacteriology, virology, parasitology, and botulism testing were unremarkable. The geometric mean concentrations (wet weight) of liver mercury (10.9 ppm), and arsenic (0.96 ppm) did not differ between specimens from the die-off and reference loons from the same area that died of other causes. The geometric mean liver selenium concentration of die-off specimens (10.4 ppm) was significantly higher than that of reference loons. Liver lead concentrations were < 0.20 ppm in all but one sample (5.83 ppm). The geometric mean mercury concentration in the primary remiges of die-off specimens (5.44 ppm dry weight) was significantly lower than in reference birds. Liver mercury significantly correlated with liver selenium on a molar concentration basis. We interpret the range of liver mercury concentrations in birds from the epizootic, similar liver mercury concentrations in reference loons, and higher mercury concentrations in reference loon feathers as evidence that factors other than mercury were primarily responsible for the emaciation diagnosed as the cause of mortality.

North Carolina↗
USGS2024

Linking avian malaria parasitemia estimates from quantitative PCR and microscopy reveals new infection patterns in Hawai'i

Plasmodium parasites infect thousands of species and provide an exceptional system for studying host-pathogen dynamics, especially for multi-host pathogens. However, understanding these interactions requires an accurate assay of infection. Assessing Plasmodium infections using microscopy on blood smears often misses infections with low parasitemias (the fractions of cells infected), and biases in malaria prevalence estimates will differ among hosts that differ in mean parasitemias. We examined Plasmodium relictum infection and parasitemia using both microscopy of blood smears and quantitative polymerase chain reaction (qPCR) on 299 samples from multiple bird species in Hawai'i and fit models to predict parasitemias from qPCR cycle threshold (Ct) values. We used these models to quantify the extent to which microscopy underestimated infection prevalence and to more accurately estimate infection patterns for each species for a large historical study done by microscopy. We found that most qPCR-positive wild-caught birds in Hawaii had low parasitemias (Ct scores ≥35), which were rarely detected by microscopy. The fraction of infections missed by microscopy differed substantially among eight species due to differences in species’ parasitemia levels. Infection prevalence was likely 4–5-fold higher than previous microscopy estimates for three introduced species, including Zosterops japonicus , Hawaii’s most abundant forest bird, which had low average parasitemias. In contrast, prevalence was likely only 1.5–2.3-fold higher than previous estimates for Himatione sanguinea and Chlorodrepanis virens , two native species with high average parasitemias. Our results indicate that relative patterns of infection among species differ substantially from those observed in previous microscopy studies, and that differences depend on variation in parasitemias among species. Although microscopy of blood smears is useful for estimating the frequency of different Plasmodium stages and host attributes, more sensitive quantitative methods, including qPCR, are needed to accurately estimate and compare infection prevalence among host species.

Hawai'i↗
USGS2021

Plague transforms positive effects of precipitation on prairie dogs to negative effects

Rodents characteristically benefit from increased precipitation, especially in typically dry habitats; “good years” of high precipitation improve their forage and water balance. However, Yersinia pestis (plague), a flea-borne pathogen of mammals that was introduced to western North America, has the greatest negative impact on at least some species of rodents during years of above-average precipitation. In the absence of plague mitigation, negative effects of plague in wet years might overwhelm the otherwise beneficial effects of increased moisture. In Montana and Utah, USA, where plague now occurs enzootically, we investigated the influence of precipitation on finite rates of annual population change (2000–2005) for 3 species of prairie dogs ( Cynomys spp.) in replicated plots treated with deltamethrin dust and in non-treated plots for paired comparisons. There was a significant interaction between precipitation and treatment. When we reduced plague vector fleas, prairie dog visual counts tended to increase with increasing precipitation. Simultaneously, there was a negative relationship between counts and precipitation on paired plots where plague was not managed, suggesting that plague transformed and reversed the otherwise beneficial effect of increased precipitation. Are the good years gone for prairie dogs? Even if the good years are not gone, they are perhaps relatively scarce compared to historic times prior to the invasion of plague. This scenario might apply to other ecosystems and may pose broad conservation challenges in western North America.

Montana, Utah↗
USGS2018

Museum metabarcoding: a novel method revealing gut helminth communities of small mammals across space and time

Natural history collections spanning multiple decades provide fundamental historical baselines to measure and understand changing biodiversity. New technologies such as next generation DNA sequencing (NGS) have considerably increased the potential of museum specimens to address significant questions regarding the impact of environmental changes on host and parasite/pathogen dynamics. We developed a new technique to identify intestinal helminth parasites and applied it to shrews (Eulipotyphla: Soricidae) because they are ubiquitous, occupy diverse habitats, and host a diverse and abundant parasite fauna. Notably, we included museum specimens preserved in various ways to explore the efficacy of using metabarcoding analyses that may enable identification of helminth symbiont communities from historical archives. We successfully sequenced the parasite communities (using 12S mtDNA, 16S mtDNA, 28S rDNA) of 23 whole gastrointestinal (GI) tracts. All GI tracts were obtained from the Museum of Southwestern Biology (MSB), USA, and from recent field collections, varying both in time since fixation (ranging from 4 months to 16 years) and preservation method (70% or 95% ethanol stored at room temperature, or flash frozen in liquid nitrogen and stored at -80°C). Our proof of concept demonstrates the feasibility of applying NGS techniques to authoritatively identify the parasite/pathogen communities within whole GI tracts from museum specimens of varying age and fixation, and the value of future preservation of host-associated whole GI tracts in public research archives. This powerful approach facilitates future comparative examinations of the distributions and interactions among multiple associated groups of organisms through time and space.

International Journal for Parasitology↗
USGS2003

Relationship of tadpole stage to location of echinostome cercaria encystment and the consequences for tadpole survival

The effect of echinostome infections on the survival of Rana pipiens tadpoles was examined in relation to developmental stage of tadpoles. Individual tadpoles of Gosner stages 25, 27, 32–33, and 37–39 were exposed to 1 of 4 levels of cercariae (0, 20, 50, or 100). Only tadpoles at stage 25, the earliest stage infected, died within a 5-day experimental period. This stage-specific mortality rate could be explained, in part, by the stage-specific location of encystment of cercariae, which was documented in a separate experiment. In accordance with kidney development, cercariae predominately encysted in the pronephroi during early stages of tadpole development (stages 25 through 31–32) and only in the mesonephroi and associated ducts at later stages (stages 37 through 46). As the mesonephros develops, renal capacity presumably increases. Thus, tadpoles died only when metacercariae concentrated in the functional portion of the kidney with the most limited renal capacity. As tadpoles aged, they also became less susceptible to infections. On average, 69.5% of cercariae that were exposed to stage 25–26 tadpoles successfully encysted, compared with only 8.4% of cercariae exposed to stage 37–38 tadpoles. Exposures of metamorphic frogs (poststage 46) to cercariae revealed that these individuals can become infected with echinostomes. Collectively, our data highlight the host stage–dependent dynamics of tadpole–echinostome interactions.

Journal of Parasitology↗