The red fox () is an introduced species to Australia whose population and spatial distribution have grown irreversibly. Due to their opportunistic feeding habits, extensive populations of foxes now inhabit urban and rural environments, where they coexist with humans and domesticated animals. The proximity of these predators presents public and animal health concerns as they harbour diseases that can cross between species. Accordingly, monitoring potential disease risk and prevalence in urban foxes is warranted. This study investigated the occurrence of gastrointestinal parasites in urban and rural foxes around Melbourne, Victoria, Australia. The gastrointestinal tracts of 51 opportunistically collected foxes were thoroughly examined to collect adult helminth (i.e., nematode and cestode) parasites from the stomach as well as from the small and large intestines. The results showed that 92.2 % of foxes were infected with at least one gastrointestinal helminth parasite. Based on a morphological identification of worms, the detected nematode parasites were (66.7 %) and (56.9 %) while the identified tapeworms included (39.2 %), spp. (11.8 %) and (5.9 %). Single cases of and sp. infections were detected. This study highlights a human and domestic animal health risk, as a crossover of parasitic infections is possible in areas where these parasites coexist.

Morphological variation was studied in the adult cladorchiid trematodes spp. (Trematoda: Digenea), that parasitize the intestinal tract and caecum of the American manatee (). Specimens were collected from 22 manatees between 1980 and 1998 in Puerto Rico, Cuba, Dominican Republic, Mexico, and Florida. We found statistically significant differences in analyses of variance in 31 morphological measurements from 284 specimens across different geographical regions, consistent with the existence of two species. Some specimens from Florida corresponded to the description for Diesing1838, while specimens from the Dominican Republic, Mexico, Puerto Rico, and some from Florida, previously misidentified as , corresponded to the description of Coy-Otero1989. The latter supports the distinction of two species parasitic on the American manatee. These species differ mainly by the presence or absence of an esophageal bulb, testes shape, position of the genital pore, and shape and distribution of the vitelline follicles.

Tapeworms of the genus are important zoonotic parasites, yet their taxonomy remains unsettled and molecular species-level data from Indonesia are scarce. We examined plerocercoid larvae isolated from Javanese keelback water snakes () collected in East Java, Indonesia. Infection prevalence in was high (84 %), with 143 spargana recovered from subcutaneous tissues, musculatures, and the body cavities of 25 snakes. Morphological and histological features were consistent with . Molecular analysis was used for accurate species-level identification. Partial mitochondrial cox1 sequences from five isolates were generated and analyzed phylogenetically. All sequences clustered unambiguously within the clade (PP = 0.99), alongside global reference isolates. Our analysis also reclassified a 2007 Indonesian isolate, previously assigned to , as , retrospectively clarifying a misidentification. This study provides the first prospective molecular confirmation of in Indonesia, and underscores the role of semi-aquatic snakes in transmission cycles. These findings highlight the urgent need for expanded molecular surveillance and integrative taxonomy to clarify the epidemiology and zoonotic potential of in the region.

Various marine parasites exploit marine mammals as definitive hosts; however, comprehensive parasitological studies remain lacking because of the inherent challenges in host sampling. This study aimed to investigate the pathological effects of on the hepatobiliary system of the narrow-ridged finless porpoise (). We detected a digenean species, , in the hepatobiliary systems of 143 out of 196 (72.96 %) narrow-ridged finless porpoises stranded, bycaught or drifting along the Korean coastline between 2016 and 2024. The morphological analysis confirmed the characteristics of . Phylogenetic analyses based on partial mitochondrial DNA NADH dehydrogenase subunit 3 and large subunit rRNA regions supported previous findings, underscoring the need for a more in-depth genetic characterization of the family Brachycladiidae, a significant digenean group in marine mammals. Gross evaluation revealed hepatic nodules, irregular thickening of the bile duct walls, and signs of cholestasis due to physical obstruction by trematodes. These lesions were observed exclusively in the livers of individuals infected with and were absent in uninfected animals. In some cases, abscess-like lesions and pus-like material within the bile ducts were noted macroscopically, although histologic evidence of suppurative inflammation was lacking. Histopathological examinations identified bile duct dilatation accompanied by granulomatous cholangitis with periductal fibrosis, as well as hepatic granulomas centered on trematode parasites and eggs, surrounded by fibrous connective tissue. These lesions corresponded to grossly observed hepatic nodules and bile duct wall thickening, reflecting chronic inflammatory responses to trematode infection. This study represents the first report of pathological lesions caused by in narrow-ridged finless porpoises and highlights the significance of further investigation involving additional host species to enhance the understanding of this taxonomic group.

and are two sympatric parasites of significant ecological and epidemiological interest in the Mediterranean basin. This study investigated the PCR prevalence of and in two gecko species ( and ) present on Mallorca Island, Spain, using duplex quantitative PCR. A total of 59 geckos were sampled across the island, including 53  and six . Tissue and blood samples were screened by PCR for both parasites. The results revealed the prevalence of infection in adult , with 10/49 (20.41 %) testing PCR positive for only and with 1/49 (2.04 %) for only. Coinfection with both parasites was detected in 3/49 geckos (6.12 %). No positives were identified in , probably due to small sample size. Regarding PCR positivity by tissues, coleomic organs were more likely to be positive for in adult than blood, with a slighter PCR positivity in the liver, spleen and lung. This study provides further insight into the interaction between and geckos in leishmaniosis-endemic areas such as Mallorca.

Although Borneo lies within the highly biodiverse Coral Triangle, its reported isopod diversity remains poorly documented and underexplored. This study documents four species of the corallanid isopod genus collected from elasmobranch hosts in Indonesian and Malaysian Borneo, namely , sp. nov., sp. nov., and sp. nov. Specimens were identified based on detailed morphological characters. sp. nov. is characterised by a posteriorly elongate frontal lamina that is three times longer than its posterior width; eyes separated by ∼34 % of head width; a pleotelson with a sub-truncate posterior margin and dorsal fields of hyaline setae; and uropodal rami barely extending beyond the pleotelson. sp. nov. is distinguished by its short, broad frontal lamina (shorter than wide), small eyes, deeply concave maxillula mesial lobe, and exceptionally long antennae reaching pereonite 7. sp. nov. features a broadly truncate pleotelson, short antennula (extending only to the eye's posterior), and uropodal rami that do not extend past the pleotelson apex. It can be separated from by its broader pleotelson margin, shorter frontal lamina, reduced setation, and the presence of two simple setae on the maxillula mesial lobe. This study describes three new species, reveals novel host associations with four elasmobranch species, and transfers into the genus.

The nematodes spp. are occurring in different mammals of the southern Nearctic and Neotropical region. Six-banded armadillos () are mainly found in South America and act as suitable hosts for different species. Here, a case of an sp. infection in six-banded armadillos from a German zoo is described. A 17-year-old male six-banded armadillo found in poor body condition was euthanized for ethical reasons. The parasitological examination of the gastro-intestinale tract revealed an infection with nematodes of the superfamily Heterakoidea. Sequence analysis targeting the 18S rRNA confirmed high identities with isolates of sp. (accession number: EF180070; 100 %) and (accession number: KX954128; 99.86 %). Analysis of faecal samples of the remaining female armadillo led to similar results. This case description broadens the knowledge about parasitic infections in armadillos from zoological gardens in Europe.

Although parasite probability of infection and intensity are central to understanding parasite distributions and their ecological and evolutionary impacts, the drivers of these parameters remain poorly understood. At a local scale, we examined how host dietary niche partitioning and river landscape processes influence infections of the trematode in a community of watersnakes ( spp.). Host-specific dietary preferences and body size (SVL) were associated with infection probability among sympatric congeners. However, contrary to predictions of the stream drift hypothesis, infection probability increased with distance upstream. Infection intensity, in contrast, was unrelated to stream position and less predictable across host species. Thus, infection probability and intensity were heterogeneous among host species and across the river system. These results highlight that, even at local scales, multiple factors can distinctly shape the infection dynamics of a generalist parasite across closely related, co-occurring hosts.

Fungi associated with aquatic invertebrates remain poorly characterized, particularly those inhabiting leeches (Hirudinea), which are key components of freshwater ecosystems. In this study, the fungal communities associated with five species of glossiphoniid leeches were investigated, and isolates were obtained and compared from internal tissues and the body surface. In total, 19 fungal species were identified, including plant pathogens (e.g., , , ) and opportunistic human pathogens (e.g., , , sp.). Notably, , a fungus known to infect invertebrate tissues, was detected inside . The occurrence of several taxa both in the surrounding water and on leeches suggests that leeches may act as vectors of fungal dispersal in aquatic ecosystems. The results highlight the importance of leeches not only as potential dispersal agents of plant pathogens, which may affect vegetation and aquaculture, but also as reservoirs of opportunistic human pathogens.

The trematode is a common parasite of in rocky intertidal biotopes of southern California (USA) and northwestern Baja California (Mexico). Since the original description of . , morphological and molecular data have been lacking. This study aims to characterize the morphological and molecular variation of this trematode to support future inter- and intra-specific comparisons in the genus . Over a year (August 2021-September 2022), ten sampling events were carried out to obtain biological material for morphometric and molecular analyses of . at El Mosquito (n = 9) and Playa Piedra Blanca (n = 1), Baja California. Morphometric data were obtained from 44 specimens, along with Scanning Electron Microscopy (SEM) images. Intra-specific morphological variation was quantified using Principal Component Analysis (PCA). Eight nuclear 28S gene sequences were obtained for phylogenetic analysis (Bayesian Inference and Maximum Likelihood), while 27 mitochondrial Cytochrome C Oxidase subunit I gene (COI) sequences were generated to characterize population genetic variation. The phylogenetic analyses placed . within the Opecoelinae clade of Opecoelidae, as a sister group to . This relationship suggests that may be synonymous with , although broader taxon sampling is required to test reciprocal monophyly and clarify generic boundaries. The PCA revealed marked morphological polymorphism in . . Our morphological analysis detected morphometric characters among . , . , and . that largely overlap with those reported in this study and with the original description of . , suggesting that these taxa may represent junior synonyms of . . Based on the analyzed barcode dataset, . shows high intraspecific genetic variation at both study locations. Future research on populations along the Baja California Peninsula and California may reveal greater genetic and morphological diversity.

Avian haemosporidian parasites (AHPs), which include the genera and , are protist parasites affecting at least 2000 species of birds with near global distribution. Outside of isolated, evolutionarily and immunologically naïve avian populations, the effects of AHPs on wild bird populations are poorly understood but have historically been considered benign. There is growing evidence to suggest, however, that high exoerythrocytic parasite burdens can cause disease and mortality in some host-parasite interactions, even in populations which have co-evolved alongside AHPs. Here, samples from 857 wild birds of 62 species, 27 families and eight orders were collected during post-mortem examinations over a 15-year period as part of a nationwide wildlife disease surveillance scheme and were screened by nested polymerase chain reaction (PCR) for the presence of and . In total, liver and/or spleen tissues from 13.5 % of birds (n = 116) tested PCR-positive, comprising 8.9 % (n = 76) and 4.7 % (n = 40) infected with and spp., respectively. The highest rates of infection were seen in the families Paridae (36.3 %; 4/11 birds examined) and Turdidae (34.5 %; 51/148), consistent with previous reports. Spatial analysis revealed a significant cluster of -positive cases in Southeast England with possible explanations including climatic effects on parasite development or spatial variation in vector abundance. A total of 30 AHP lineages (20 spp. and 10 spp.) were detected, 23 of which have not previously been reported in Great Britain, with four being apparently novel. Tissue samples from a subset of 13 -positive Eurasian blackbirds () underwent histopathological examination, which revealed evidence of exoerythrocytic parasites, or other lesions consistent with avian malaria, in four and five cases, respectively. These changes were considered of equivocal significance in four birds, with only one bird diagnosed with acute malaria as a contributory cause of death.

Eurasian tundra reindeer () were introduced to Iceland from Norway in the late 18th century and have thrived in Eastern Iceland. In 2003-2005 the parasitic fauna was studied, and Icelandic reindeer were found to lack many parasites common to Norwegian reindeer. This study from 2018 provides an updated comparison. Abomasal content and faeces were collected from the 117 reindeer (63 adults, 22 yearlings, 17 calves, 15 age not recorded), from: 1 - West (N = 29), 2 - Central (N = 44), 3-9 - East (N = 40), not recorded (N = 4) management areas hunted in 2018. Not all animals were examined by all methods. Abomasal nematode counts (N = 81) were carried out in addition to faecal egg and larval counts, using modified McMaster (N = 111) and Baermann (N = 108). Abomasal nematodes were detected in 31 % of samples, with low mean abundance (48) and intensity (160). Males had higher prevalence (46 %) and mean abundance (89) than females (24 %; 29). The sheep gastrointestinal nematode (GIN) predominated, although, for the first time, single specimens of and a male nematode with morphology suggestive of , a minor morph of , were detected. was not detected. Trichostrongylidae and egg prevalence was 35 % (mean abundance eggs per gram, EPG, 12, mean intensity 33 EPG) and 23 % (mean abundance 8 EPG; mean intensity 34 EPG) respectively. No faecal larvae were detected. There were geographic as well as sex related differences in abundance. Trichostrongylidae eggs prevalence, but not abundance, was higher in 2018 compared to 2005, and an opposite trend with abomasal nematode counts was seen. Reindeer in Iceland still have a low prevalence and abundance of GINs, dominated by . The monitoring of GIN in this population provides a simple means of evaluating population health in a time with changing climate.

Since 2012, Guinea worm (GW - ) infections in animals have complicated the Guinea worm Eradication Program's (GWEP) goal to eradicate this parasite. Increased infections in domestic dogs () and cats () have been a concern. Detections of infections in wild felids from Chad and olive baboons () in Ethiopia highlight a significant knowledge gap concerning the role of wildlife in GW transmission. Furthermore, little is known about the diversity of wildlife surrounding villages in Chad and what role these animals may play in GW transmission. We aimed to provide data on the community composition of wildlife surrounding Chadian villages by deploying game cameras to monitor terrestrial wildlife at study sites in the Sarh region of southern Chad. Seven villages were chosen for game camera deployment based on accessibility, spatial independence, and GW disease (GWD) endemicity. Villages were classified by GW transmission levels as either endemic, sporadic, or negative based on reports during a previous surveillance study. Eight game cameras were deployed per village from February-November 2019. A total of 32 mammalian species were recorded from 9280 trap nights. Our results indicate higher wildlife diversity surrounding villages with GWD. Specifically, we found a higher detection of primates and meso-mammals surrounding villages with consistent reports of Guinea worm infections. Single-season occupancy models were fit for the following species: tantalus monkeys (), patas monkeys (), Egyptian mongoose (), and pale fox (). Occupancy of tantalus monkeys, patas monkeys, and Egyptian mongoose was greater in endemic and sporadic villages than villages with no reported cases of GWD. While wildlife host competency remains unknown, our results provide documentation on the wildlife species present around villages in Sarh, Chad, a step towards increasing the understanding wildlife may potentially play in the transmission of GW.

A new species of louse fly in the genus Latreille, 1802 (Diptera: Hippoboscidae) sp. n. is described from the island of La Palma in the Canary Islands. Unlike other species of , this species has a series of horizontal ridges running across the scutellum. Otherwise, the most obvious differences between sp. n. and the most closely related species Bergroth, 1901 are the arrangement of the wing veins and the lack of dark markings on the lateral gena and mesothoracic basisternum in the new species.

Heinze1933 is an intestinal parasite of ornamental cichlids, known for its pathogenic impact in aquaria. Despite its veterinary significance and widespread presence in ornamental aquaculture, limited molecular data and phylogenetic information are available for this species. This study aimed to provide an integrative redescription of based on morphological observations with scanning electron microscopy (SEM) and molecular data, with the determination of epidemiological indices (prevalence and mean intensity). Between September 2022 and November 2023, 414 individuals of 18 ornamental cichlid species were sampled from shipments originating in Indonesia, Sri Lanka, and Thailand. Fish specimens were dissected to screen for gastrointestinal nematodes. Morphological identification was carried out using standard light microscopy and SEM. Molecular analyses targeted the 18SrDNA gene, followed by phylogenetic inference using maximum likelihood, Bayesian inference, and neighbour-joining approaches. was confirmed in three species: (Gill, 1858), (Schultze, 1823), and Heckel, 1840. The highest prevalence and mean intensity were recorded in from Indonesia (52.94 %, MI = 18.7). SEM revealed diagnostic features such as a rounded anterior end, barrel-shaped eggs with fine surface sculpturing, and a subterminal anal pore. Phylogenetic analysis based on the 18S rDNA region confirmed the placement of as a sister taxon to other species parasitising avian hosts, suggesting a complex evolutionary history. This study expands the known host range of by reporting two new host records. The findings highlight the pervasive risk of pathogen introduction via the ornamental fish trade and underscore the critical need for integrating molecular tools into biosecurity and surveillance protocols to mitigate future transboundary spread.

Evidence from captive populations indicates that lemurs are particularly vulnerable to toxoplasmosis, a parasitic disease caused by In wild populations, however, seroprevalence in lemurs remains low. This may be partly due to their predominantly arboreal behavior, which limits exposure to environmentally transmitted oocysts. Alternatively, or additionally, low seroprevalence could reflect high mortality following infection due to limited evolutionary exposure to the parasite and, consequently, a lack of evolved resistance. In this study, we assess whether the evolutionary history of primates with felids influences susceptibility to infection, independent of ecological exposure. Specifically, we predicted that (1) species with greater terrestriality would exhibit higher exposure risk, (2) species longevity would be positively associated with their seroprevalence to and (3) primate superfamilies with longer histories of co-occurrence with felids would show higher seroprevalence than Lemuroidea at similar levels of terrestriality and longevity. Serum samples from 435 free-ranging lemurs were tested for antibodies and a literature review of seroprevalence in free-ranging primates was conducted. The overall seroprevalence in Lemuroidea was 5.4 %, significantly lower than that observed in Ceboidea (11.8 %) and Cercopithecoidea (27.6 %). Notably, seroprevalence in lemurs was lower than expected based on their terrestriality, suggesting that evolutionary isolation from felids may underlie heightened vulnerability. Longevity modifies the risk profile in a lineage-specific way where seroprevalence increases with lifespan in Cercopithecoidea but not for lemurs. Collectively, our findings support the hypothesis that lemurs are immunologically naïve to , and in the face of expanding domestic cat populations and increasing habitat fragmentation, the parasite may pose an underrecognized conservation threat.

is a vector-borne parasite infecting the eyes of domestic and wild animals, as well as humans, across Europe. In Spain, it is endemic in several regions, with high prevalence reported in dogs and cats, but data on wildlife remain scarce. This study investigated the prevalence of in Iberian wolves () from northwestern Spain and explored epidemiological factors associated with infection. Between 2016 and 2025, 182 wolves from Asturias and Galicia (A Coruña, Lugo, Ourense and Pontevedra) were sampled after necropsy. Eyeworms were collected and identified using morphological and molecular methods, with all specimens corresponding to genotype h1. The overall prevalence was 17 %, with higher rates of infection in Galicia (18.2 %) than Asturias (8.7 %). Infections were restricted to Ourense (37.2 %) and Lugo (26.5 %). Parasite burdens were higher in females and immature wolves (1-3 years) compared to older animals and those in good body condition (BC 4-5). The distribution of infected wolves was associated with the vegetation around Miño and Sil river basins, which may favor the development of the vector . Lower prevalence in pups could be linked to smaller eye size and lower body condition, while sex- and age-related differences may reflect behavioral or immunological factors. These results indicate that Iberian wolves can act as reservoirs of in northwestern Spain, underscoring the need for further research into their role in the epidemiology of this zoonotic parasite.

is a parasitic protozoan for which family Felidae serves as the definitive hosts. In regions where native felids are absent, introduced domestic cats () act as reservoirs of , posing a threat of infection to various wildlife population. A population of feral cats has been identified on Amami-Oshima Island located in the southern part of the Japanese Archipelago, and molecular examination confirmed that the they harbour has spread to endemic mammals. In this study, we aimed to detect in the Amami Woodcock (), a bird species endemic to Amami-Oshima Island. DNA was extracted from the brain tissue of twenty-two birds, and molecular detection of . was performed using a commercial detection kit based on real-time polymerase chain reaction. Two birds (9.1%) tested positive. The determined nucleotide sequences were 100% identical to that of the . Histopathological examination and ultrastructural analyses revealed terminal colonies in the cardiomyocytes of one bird, which were immunohistochemically confirmed as . Here, we report the first record of infection in the Amami Woodcock. Given its endangered status, ongoing research on the prevalence and pathogenicity of is warranted.

This paper represents a rare case in parasitology where a reversal of the Principle of Priority of the International Code of Zoological Nomenclature (ICZN) would be beneficial to all users, including not only scientists but also the general public. In some rare cases, a long-established name turns out to be a junior synonym when an older, less-known name claims the priority. Unfortunately, such situations have the potential to disrupt intergenerational continuity of parasitological nomenclature. After 193 years, one of the best-known European fish parasites could have lost its well-established name in favor of its senior synonym, long forgotten by history and predating the now junior synonym by 49 years. The parasite under scrutiny is von Nordmann, 1832. In the interest of nomenclatural stability, however, we propose to maintain prevailing usage by reversal of precedence under Article 23.9 of the Code. Our paper, in addition to its taxonomic aspects, may have a profound effect on the use of this name in parasitology, zoology, and the study of fish diseases.

spp. (Apicomplexa: Coccidia) are obligate heteroxenous protozoa that infect a wide range of host species. Transmission follows a predator-prey cycle involving an intermediate host (IH) and a definitive host (DH). For many species, only IHs have been identified, while DHs remain unknown. DHs can be infected with multiple spp. at the same time, which complicates species identification. We aimed to determine the prevalence and species diversity of infections in free-ranging wolves in Switzerland using both coprological and molecular methods. A further goal was to evaluate the utility of Third-generation sequencing for resolving mixed infections. A total of 87 wolf intestinal content samples were collected between 2017 and 2023 and analyzed coproscopically by a sedimentation-flotation method. oocysts/sporocysts were detected in 76 % (66/87). DNA was obtained from 57/66 positive samples and 55/57 resulted positive in a rRNA screening PCR. Additionally, mitochondrial cytochrome oxidase subunit I () gene PCR and a real-time PCR targeting were performed. PCR products from conventional PCRs were submitted for Sanger sequencing. Monoinfections were identified in 16 % (9/55) and mixed infections in 84 % (46/55) of the samples. A subset of five samples was analyzed by Third-generation sequencing (Pacific Biosciences) of the rRNA full-length and fragment PCR products. BLAST and phylogenetic analysis were used to validate taxonomic classification. Molecular analysis identified nine known species: and . Newly developed pipelines for the Third-generation sequencing data provided high-resolution species-level identification in samples with mixed infections. These findings confirm the Eurasian wolf as natural DH for multiple species for the first time, including , , and . Further complementary studies on prey species are needed to clarify host-parasite dynamics.

Hemoprotozoa are blood-borne protists with complex life cycles. Despite their high prevalence, diversity of hemoprotozoa in reptiles remains poorly documented. We analyzed blood smears, histopathology, and PCR-amplified 18S rDNA and cytochrome oxidase c subunit I () sequences from ten reptiles representing five species imported into Taiwan. In elongated intraerythrocytic gamonts and hepatic merogonic stages were documented. The near full-length 18S sequence formed a deeply divergent lineage consistent with a novel taxon, for which we propose sp. nov. In and , hemococcidian sporozoites were identified morphologically. Based on 18S rDNA phylogenetic inference, the lineages derived from were placed within . In addition, all haplotypes from clustered with a previously reported lineage based on phylogenetic inference. In , intraerythrocytic were present, and 18S phylogenies formed a well-supported clade closest to . In , trophozoites and meronts of were detected. Analyses of partial 18S rRNA and sequences each placed the newly generated sequence as a separate lineage that did not cluster with available reference sequences. In , intraerythrocytic gamonts matched morphologically and phylogenetically, representing the first record from Taiwan. The current study provides molecular and morphological evidence of multiple hemoprotozoan genera infecting reptilian pets in Taiwan, highlighting the need for further investigation into the diversity, host-pathogen relationships, and potential impacts on native herpetofauna in the global exotic pet trade.