Journal of Parasitology最新文献

{"title":"INTEGRATING MOLECULAR AND MORPHOLOGICAL METHODS FOR GREGARINE SPECIES DELIMITATION: A REVISION AND PHYLOGENY OF THE BLABERICOLIDAE WITH RECOGNITION OF NEW SPECIES OF BLABERICOLA AND PROTOMAGALHAENSIA INFECTING BLAPTICA DUBIA, THE GUYANA SPOTTED COCKROACH (BLATTODEA: BLABERIDAE).","authors":"Richard E Clopton, Debra T Clopton","doi":"10.1645/25-4","DOIUrl":"https://doi.org/10.1645/25-4","url":null,"abstract":"<p><p>Integrated morphological and molecular methods were used to reexamine, revise, and expand the gregarine species that are known members of the Blabericolidae infecting blaberid cockroaches of the subfamilies Blaberinae and Oxyhaloinae. Here, Protomagalhaensia serpicula n. sp. and Blabericola blaberae n. comb. are described from the Guyana spotted cockroach Blaptica dubia, and 3 new synonymies are recognized: Blabericola cubensis (=Blabericola princisi = Gregarina princisi) parasitizing Blaberus discoidalis and Blaberus boliviensis; Protomagalhaensia granulosae (=Protomagalhaensia vipera) parasitizing B. discoidalis and Eublaberus posticus; and Protomagalhaensia wolfi (=Protomagalhaensia richardsoni) parasitizing Nauphoeta cinerea and Henschoutedenia flexivitta. One new combination also is recognized, Blabericola cerastes n. comb. (=Protomagalhaensia cerastes) parasitizing Phoetalia pallida. This study revealed that gregarine species delimitation errors can be avoided by integrating morphological and molecular methods with multiple conspecifics as a reference framework. This approach is preferred for delimiting gregarine species. Blabericolidae and its component genera, Blabericola and Protomagalhaensia, are monophyletic groups with a likely Pangean origin whose members speciated as New World and Old World groups following the breakup of Gondwana. Patterns of speciation appear to be largely vicariant, but host switching through human introduction of pest host species may also have played a role in gregarine radiation. The gross alimentary anatomy of B. dubia is described, and the effects of gamont morphology and phylogeny on patterns of site specificity are discussed.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"111 3","pages":"233-249"},"PeriodicalIF":1.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144004813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THE BROAD FISH TAPEWORMS DIBOTHRIOCEPHALUS SPP., THE SEALWORM PHOCANEMA CATTANI, AND OTHER ENDOHELMINTH PARASITES IN THE RETURNING NONNATIVE CHINOOK SALMON, ONCORHYNCHUS TSHAWYTSCHA, IN THE VALDIVIA RIVER BASIN, CHILE.","authors":"Patricio Torres, Hélène Yera, Alonso Rubilar, Célia Rouges, Victor Leyán, Ricardo Silva","doi":"10.1645/24-71","DOIUrl":"https://doi.org/10.1645/24-71","url":null,"abstract":"<p><p>In the present study, we examined nonnative returning Chinook salmon caught between 2018 and 2023 in the Valdivia River basin, Chile, for endohelminth parasites. Zoonotic endohelminths were identified by morphological and molecular methods, based on a multiplex PCR or PCR and sequencing targeting the cytochrome c oxidase gene of diphyllobothriids or Ascaridoidea mitochondrial DNA. A total of 5,350 larvae of helminths were detected in the salmon, with 3.6% corresponding to the cestodes Dibothriocephalus latus and Dibothriocephalus dendriticus, with freshwater life cycles, and 96% to \"Scolex pleuronectis,\" 0.2% to Hepatoxylon trichiuri, 0.1% to Nybelinia sp., and 0.1% to the nematode Phocanema cattani, all with a marine life cycle. All salmon had plerocercoids of Dibothriocephalus spp., with the highest percentage in the peritoneum and intestine. Only D. latus was identified in the muscles of 40% of salmon, with up to 7 larvae per host and a mean density of 0.1 larvae per 200 g. The present results indicate that most (63.6%) of the plerocercoids of Dibothriocephalus spp. can survive during the migration of Chinook salmon to the ocean and their return to freshwater. The sealworm P. cattani was found for the first time in Chinook salmon with a prevalence of 20% in the muscles. \"Scolex pleuronectis\" was abundant in the intestine and pyloric caeca, representing 96% of the identified endohelminths. One-third of the salmon had H. trichiuri in the body cavity, and Nybelinia sp. in the intestine wall. Plerocercoids of Dibothriocephalus spp. were mostly encapsulated and a few free in different organs. Histologically, the free larvae of Dibothriocephalus spp. were associated with an infiltrate of mononuclear and polymorphonuclear cells suggesting damage to their tegument. Larvae of Nybelinia sp. in the muscular layer of the intestine were surrounded by a thin capsule to which they were attached by the tegument; mononuclear and polymorphonuclear cells were observed outside the capsule and in some areas in contact with the larva. Plerocercoids of D. latus and Nybelinia sp. were associated with abundant mast cells in the intestinal wall. The presence of the zoonotic Dibothriocephalus spp. and P. cattani in returning salmon would increase their potential risk of transmission to the human population in the Valdivia River basin area. Similarly, salmon carcasses could facilitate the potential transmission of Dibothriocephalus spp. and P. cattani to wild and domestic mammals and wild birds.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"111 3","pages":"210-226"},"PeriodicalIF":1.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144015310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"OCCURRENCE OF TRICHINELLA SPIRALIS ANTIBODIES IN SWINE BACKYARD FARMS IN VERACRUZ, MEXICO.","authors":"José Luis Bravo-Ramos, María Guadalupe Sánchez-Otero, Sokani Sánchez-Montes, Gerardo Gabriel Ballados-González, Luis Arturo Ortiz-Carbajal, Leonardo Avendaño Vela","doi":"10.1645/25-3","DOIUrl":"https://doi.org/10.1645/25-3","url":null,"abstract":"<p><p>Trichinosis is a parasitic disease caused by Trichinella spiralis that affects pigs, rodents, and some wild animals. Poor sanitation facilitates the spread of disease in swine, posing a risk to public health. In Mexico, pig farming ranks third in meat production and operates at 3 primary levels: industrial, semi-industrial, and backyard farming. In Mexico, backyard pig farming is a common practice primarily because it provides a source of meat at minimal or no cost. However, these pigs can act as reservoirs, sustaining the parasite's life cycle and potentially introducing it into domestic environments. Although human and pig infections with T. spiralis have been documented in Mexico, data on its prevalence and distribution remain inconsistent. For this reason, this study aimed to investigate the occurrence of antibodies against T. spiralis in backyard pigs from Veracruz, Mexico. Blood samples were collected from 472 backyard pigs and examined using an enzyme-linked immunosorbent assay. A detailed questionnaire (farm management, origin of animals, type of production, type of feed, presence of rodents, evidence of wildlife and domestic animals, exposure to pig carcasses and carcasses of other animals) was designed to gather information about potential exposures. The seroprevalence for T. spiralis was 1.6%; however, antibodies were only found in 4 localities and distributed in 4 municipalities. Proper pig management practices are crucial for controlling intestinal parasites in animals. This study advocates for public health education and promoting good pig farming practices.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"111 3","pages":"206-209"},"PeriodicalIF":1.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144014941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PROFILES FOR SOME KEY CYTOKINES AND AUTO-ANTIBODIES IN LATENT TOXOPLASMOSIS IN ABORTED WOMEN.","authors":"Salah Alnisani, Ahmed Rebai","doi":"10.1645/23-88","DOIUrl":"https://doi.org/10.1645/23-88","url":null,"abstract":"<p><strong>Abstract: </strong>Toxoplasma gondii infects between 20 and 80% of the world population, with 80-90% of patients being asymptomatic. The risk of maternal transmission of the parasite to the fetus is relatively low (15-20%) during the first trimester of pregnancy, but high by the third trimester, (60%), and can result in hydrocephalus, microcephaly, and mental impairment. In this work, we investigate the prevalence of T. gondii infection in women who have had spontaneous abortions in Samarra city, Iraq, and evaluate their serum levels of key cytokines and auto-antibodies. The main objective is to measure correlation between toxoplasma status and cytokines, as well as with auto-antibodies, as biomarkers of autoimmune diseases. A sample of 153 women who got a spontaneous abortion in Samarra hospital or private lab in Samarra city between April 2021 and April 2022 was included in the study, 103 (67.3%) of which were found toxo-positive. General and clinical variables were collected using a questionnaire, and blood samples were taken from consenting women to measure the levels of Toxoplasma antibodies IgG, IgM, cytokines (IL4, IL6, IL10, IL17, TNF-α) and auto-antibodies (anticardiolipin, aCL; antiphospholipid, aPL; anti-beta-2 glycoprotein, anti-B2GPI; antinuclear Ab, ANA; anti-thyroperoxidase, ATPO; anti-glutamic acid decarboxylase, anti-GAD; and anti-sperm, ASA). Our results show that the 3 interleukins IL4, IL6, and IL10 as well as ASA, ATPO, and aCL were significantly higher in toxo-positive aborted women compared to toxo-negative ones, whereas IL17 and aCL were higher in toxo-seronegative aborted women.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"111 3","pages":"227-232"},"PeriodicalIF":1.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144023419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"VOLATILES IN FECES OF RATS INFECTED WITH THE TAPEWORM HYMENOLEPIS DIMINUTA.","authors":"Anne C Jones, Mason C Martin, Tappey H Jones, Roger Ramirez-Barrios, Ashleigh B Smythe","doi":"10.1645/24-137","DOIUrl":"https://doi.org/10.1645/24-137","url":null,"abstract":"<p><p>It has been known for over 25 yr that feces from rats infected with the tapeworm Hymenolepis diminuta are more attractive to tenebrionid beetle intermediate hosts than feces from uninfected rats. Although it has been demonstrated that a volatile chemical (or chemicals) in infected rat feces attracts the intermediate host Tribolium confusum, the volatile chemical(s) have never been identified. This study aimed to identify and compare the volatiles in the feces of rats before and after infection with H. diminuta. Four 8-wk-old female Sprague Dawley rats were infected with H. diminuta. Fecal samples pre- and postinfection were collected, and volatiles were trapped by vacuum on a polymer adsorbent and identified with gas chromatography-mass spectrometry analysis. Limonene was detected in preinfection but not postinfection feces. Five carboxylic acids were isolated only from postinfection feces. Butanoic acid was found in the greatest relative amount, but also 3-methylbutanoic acid, 2-methylbutanoic acid, pentanoic acid, and hexanoic acid were found. This is the first report identifying the volatiles found in the feces of rats infected with H. diminuta.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"111 2","pages":"188-194"},"PeriodicalIF":1.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143998041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CONTEXT-DEPENDENT EFFECTS OF TREMATODE PARASITES ON SNAIL HOST FEEDING, MOVEMENT, AND BEHAVIOR.","authors":"Carter E Watson, William T Ellis, Kailah Massey, Taylor English, Emlyn J Resetarits","doi":"10.1645/24-21","DOIUrl":"https://doi.org/10.1645/24-21","url":null,"abstract":"<p><p>Parasites can alter their hosts in a myriad of ways, including their physiology, movement, and behavior. In this study, we investigated how trematode parasites impact the movement and behavior of their first intermediate host, the keystone grazer Pleurocera proxima, in both the lab and the field. Trematode parasites frequently castrate their snail first intermediate hosts and can increase metabolic needs. Therefore, we predicted that infected snails would have increased feeding rates, prefer eating food over spending time with conspecifics, and move significantly less than uninfected snails. To test this, we conducted a series of experiments. First, we conducted a field experiment to quantify feeding rates of infected and uninfected P. proxima snails. We found that infected snails consumed 14% more than did uninfected snails. Next, we conducted a laboratory preference experiment to quantify the amount of time spent with either food or a conspecific. We found that snails, regardless of infection status, spent more time with conspecifics than with food. We then investigated how infection influenced movement in both a social context and an isolated context under laboratory conditions. We found that infected snails moved less than did uninfected snails in a social context but more than did uninfected snails in an isolated context. We also investigated whether these differences in preference and movement would translate into altered dispersal in the field. We found no effect of infection status on the distance or direction traveled in the field. This work demonstrates that parasites can influence host movement and behavior in substantial ways and, importantly, that these effects can be dependent on social context. Future work on parasite-mediated behavior should be conducted to investigate these effects under different biotic (as we have done) and abiotic contexts to establish a robust understanding of the role parasites play in shaping our ecosystems.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"111 2","pages":"178-187"},"PeriodicalIF":1.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143998673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THE IMPACTS OF ROCK DOVE (COLUMBA LIVIA) PREEN OIL ON WING LOUSE (COLUMBICOLA COLUMBAE) BEHAVIOR AND SURVIVAL.","authors":"Christopher W Harbison, Jaimie M Abraham, Christopher J Bertola, Joseph C Celeste, Albert J Chhay, Keira G Cohen, Riley A Mangieri, Danial S Rehman","doi":"10.1645/24-126","DOIUrl":"https://doi.org/10.1645/24-126","url":null,"abstract":"<p><p>The avian uropygial gland secretes preen oil, a complex blend of lipids that birds spread on their feathers during preening. Although preen oil is known to help birds maintain feather condition, there has been increasing evidence suggesting preen oil also affects other organisms that reside on bird feathers, such as bacteria, mites, and lice. In a series of experiments, we investigated the effects of Rock Dove (Columba livia) preen oil on the behavior and survival of feather-feeding wing lice (Columbicola columbae). These lice spend the majority of their lives hidden between flight feather barbs to avoid bird preening. However, because lice cannot feed on flight feathers, they regularly migrate to bird body regions to consume thinner insulative feather barbs. We found that lice strongly preferred to spend time on body feather regions treated with preen oil compared with untreated feather regions, but this preference disappeared when lice encountered preen oil on either flight feathers or on filter paper arenas. As lice are only known to feed on body feathers, our data suggest that preen oil may be consumed by lice or that lice prefer to feed in preen oil-rich regions to increase the chances of encountering and perhaps consuming bacteria or mites that feed on preen oil. Contact with preen oil also influenced louse locomotion, with lice reducing the turn rate (though not velocity) while walking on arenas treated with preen oil, which is also consistent with a preference for preen oil. However, in vitro survival analyses showed that lice kept on preen oil-treated body feathers experienced a moderate but significant reduction in survival compared with lice on untreated body feathers. In contrast, lice on treated and untreated flight feathers showed similar rates of survival. Overall, our behavioral data and survival analyses suggest that louse interactions with preen oil are more complex than previously thought. Further research is needed to determine how these in vitro impacts of preen oil on louse behavior and survival influence bird-louse interactions in more natural settings.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"111 2","pages":"195-201"},"PeriodicalIF":1.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143998453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SEROEPIDEMIOLOGY OF TOXOPLASMA GONDII INFECTION IN DAIRY FARMS FROM AGUASCALIENTES, MEXICO.","authors":"Carlos Cruz-Vázquez, Enrique Sánchez-Herrera, Irene Vitela-Mendoza, Leticia Medina-Esparza, Erika Rangel-Muñoz, Miguel Ramos-Parra","doi":"10.1645/24-99","DOIUrl":"https://doi.org/10.1645/24-99","url":null,"abstract":"<p><p>The objective of the study was to identify the prevalence of anti-Toxoplasma gondii antibodies and estimate their possible association with some risk factors in intensive management and small-scale dairy farms from Aguascalientes, Mexico. Blood samples were collected from 240 clinically healthy cows from intensive management and small-scale dairies distributed in 5 municipalities from Aguascalientes State, Mexico. Serum samples were processed by indirect immunofluorescence taking the 1:64 dilution as the cutoff point. The association between seroprevalence and possible risk factors was estimated. The general seroprevalence was 43% (103/240). In the group of intensive management dairies, seroprevalence was 40% (48/120), and in the group of small-scale dairies seroprevalence was 46% (55/120); these values were not significantly different. In all municipalities and dairies, seropositive animals were identified. Among the municipalities, the seroprevalence was 29-65%, and among dairies seroprevalence was 20-80%. Coexistence with other animals (odds ratio = 1.8) and not having a rodent control program (odds ratio = 2.1) were identified as risk factors. The identified seroprevalence is considered important regardless of the management system and suggests a high exposure to the parasite.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"111 2","pages":"202-205"},"PeriodicalIF":1.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144008122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PREVALENCE OF DIROFILARIA MICROFILARIA IN AMERICAN BLACK BEARS (URSUS AMERICANUS) IN PENNSYLVANIA, 2018-2020.","authors":"Alia Mazzatosta, Christopher A Cleveland, Michael J Yabsley, Ellen Haynes, Hannah S Tiffin, Erika T Machtinger, Joshua B Johnson, Mark Ternent, Emily Carrollo, Justin D Brown","doi":"10.1645/24-51","DOIUrl":"10.1645/24-51","url":null,"abstract":"<p><strong>Abstract: </strong>Dirofilaria ursi is a filarial nematode of American black bears (Ursus americanus) transmitted by black flies (Simuliidae). Overt clinical disease associated with D. ursi infection of bears has not been reported; however, adult or larval (i.e., microfilarial) stages of the parasite can be found incidentally in the subcutis, connective tissues of the abdomen and thorax, or on blood films. Over the last 60 yr, D. ursi has been reported in black bears throughout the northern United States and Canada. However, very few surveys have been conducted since 2000, particularly in the northeastern United States where black bear populations have expanded significantly over recent decades. During 2018-2020, blood films collected from 129 black bears from Pennsylvania during all seasons were examined for microfilariae. Microfilariae that were morphologically consistent with D. ursi were identified in 33 (25.6%) of the 129 sampled black bears. The average number of microfilariae per positive blood film was 27.4 (range: 1-282). Age, sex, and season did not have a significant effect on detection of Dirofilaria infection in black bears. Molecular identification of Dirofilaria species via polymerase chain reaction (PCR) and sequencing of the 18S rRNA gene region was conducted for 11 whole blood samples whose blood films contained microfilariae (average of 17.3 microfilariae/film; range: 1-55). Ten of the 11 whole blood samples were PCR positive for Dirofilaria, and the sequences were highly similar to sequences of Dirofilaria repens available in GenBank. The results of this study are consistent with those of previous D. ursi surveys in North American black bears and indicate that Dirofilaria infection is common in black bears in Pennsylvania but does not appear to be associated with overt disease.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"111 2","pages":"172-177"},"PeriodicalIF":1.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A NEW MYXIDIUM SPECIES FROM THE LEAST KILLIFISH HETERANDRIA FORMOSA IN LOUISIANA.","authors":"Christopher M Whipps, Emily C Ogburn, William F Font","doi":"10.1645/24-65","DOIUrl":"10.1645/24-65","url":null,"abstract":"<p><p>In a parasitological survey of the least killifish, Heterandria formosa (Girard), from Ward Creek in Louisiana, we encountered a myxozoan parasite in the gallbladders of this host bearing myxospores consistent with a Myxidium species. Prevalence was 72.2% in 18 hosts examined, with infection characterized by the presence of sheetlike to discoid plasmodia, approximately 1-2 mm across, floating freely in the gallbladder. Myxospores were observed in the plasmodia and found floating freely in the bile and were elliptoid and fusiform in valvular and sutural views respectively. The myxospore poles were slightly pointed away from the midline of the sutural plane of the myxospore. The myxospore valve surface had 9-12 striations. Mean myxospore dimensions (range, μm) were 13.7 (13.0-14.2) long, 6.5 (5.4-7.2) wide, and 6.4 (6.1-6.7) thick. Two equal-sized polar capsules were broadly ovoid to spherical, oriented to opposite extremes of the myxospore, and contained a tubule with 4-6 coils. Mean polar capsule dimensions (and range) were 4.3 (3.6-4.9) long and 3.6 (3.2-4.4) wide. Morphologically, the myxospores of this species were distinct from those of most other Myxidium species, and for the few species where dimensions overlapped, the average dimensions were different, and host and locality were also distinct. As such, we described this as Myxidium fonti n. sp. in honor of William F. Font. Phylogenetically, M. fonti is sister to Myxidium phyllium from another poeciliid host, and these species fall into a larger biliary tract lineage of myxosporeans. The relationships support previous work that suggests that tissue specificity, with some exceptions, is important in the phylogeny of myxosporeans.</p>","PeriodicalId":16659,"journal":{"name":"Journal of Parasitology","volume":"111 2","pages":"163-171"},"PeriodicalIF":1.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143730482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}