Environmental pollution caused by antimicrobial resistance is a global public health concern. To investigate the contribution of nutrias (Myocastor coypus) to the presence of extended-spectrum ...β-lactamase (ESBL)–producing Enterobacterales in the Ijira River, prevalence of ESBL–producing Enterobacterales in their feces was examined using deoxycholate-hydrogen sulfide-lactose agar containing cefotaxime. Additionally, the composition of the fecal microbiota of nutria was examined using DNA metabarcoding analysis of the 16S ribosomal RNA gene and compared with that of Amami rabbit, deer, fox, and raccoon dog. The absence of ESBL–producing Enterobacterales and substantially lower abundance of Enterobacterales was observed in the feces of nutrias than in those of other wild mammals. Our results suggest the low potential of antimicrobial-resistant Enterobacterales persistence and dissemination by nutria.
Since its introduction in the 19th century, the coypu was able to spread and colonise numerous parts of Europe. Our research focused mainly on the topic of the spatiotemporal distribution of an ...invasive rodent,
(Molina, 1782), in selected sites of Záhorie region. The study took place in three phases – 2016/2017, 2018/2019 and 2020/2021/2022. It was carried out through two research methods – photo traps and tracking rafts on eight study locations of Záhorie region. From all the positive registrations of this invasive species, we generated a map representation of their spatial distribution and compared it with older data. In the course of the study, the coypu was found in all 14 study areas. Moreover, we describe the process of coypu expansion on the water course Stupavský potok. During our research, we managed to describe the interactions between the coypu and the Eurasian beaver and we documented the first case of coypu predation on unionid mussels in Slovakia. We hope that this study will help in our efforts to mitigate the negative impact of coypu and to prevent its further spread.
Abstract
Background
Enterocytozoon bieneusi
is a zoonotic gastrointestinal pathogen and can infect both humans and animals. The coypu (
Myocastor coypus
) is a semi-aquatic rodent, in which few
E. ...bieneusi
infections have been reported and the distribution of genotypes and zoonotic potential remains unknown.
Methods
A total of 308 fresh fecal samples were collected from seven coypu farms in China to determine the infection rate and the distribution of genotypes of
E. bieneusi
from coypus using nested-PCR amplification of the internal transcribed spacer (ITS) region of the ribosomal RNA (rRNA) gene.
Results
Enterocytozoon bieneusi
was detected with an infection rate of 41.2% (
n
= 127). Four genotypes were identified, including three known genotypes (CHN4 (
n
= 111), EbpC (
n
= 8) and EbpA (
n
= 7)) and a novel genotype named CNCP1 (
n
= 1).
Conclusions
The rare genotype CHN4 was the most common genotype in the present study, and the transmission dynamics of
E. bieneusi
in coypus were different from other rodents. To the best of our knowledge, this is the first report of
E. bieneusi
infections in coypus in China. Our study reveals that
E. bieneusi
in coypus may be a potential infection source to humans.
Nutria (Myocastor coypus) is a semiaquatic rodent species that is invasive across multiple regions within the United States. Here, we evaluated a qPCR assay previously described for use in Japan for ...application across invasive populations in the United States. We also compared two environmental DNA sampling methodologies for this assay: field filtration of large volumes of water passed through filters versus direct sampling of small volumes of water. We validated assay specificity, generality, and sensitivity, compared assay performance between two independent laboratories, and successfully tested the assay in situ on a known wild population. The filtration method required fewer samples for environmental DNA detection than direct sampling, but the choice of methods should be assessed based on specific field conditions and time and budget considerations. Our extensive assay validation and comparison across laboratories suggest that the assay is ready to be applied in environmental DNA monitoring of nutria throughout the United States.
We evaluated a qPCR assay previously described for use in Japan for application across invasive nutria (Myocastor coypus) populations in the United States. We validated assay specificity, generality, and sensitivity, compared assay performance between two independent laboratories, and successfully tested the assay in situ on a known wild population with two environmental DNA sampling methodologies: field filtration of large volumes of water passed through filters versus direct sampling of small volumes of water. Our extensive assay validation and comparison across laboratories suggest that the assay is ready to be applied in environmental DNA monitoring of nutria throughout the United States.
The nutria (Myocastor coypus) is a medium-sized, semi-aquatic rodent valued by the skin and meat industry. This study aimed to describe and systematize the caudal cerebral artery on the brain surface ...in nutria, establishing a standard model and its main variations in this species. The thirty animals used were euthanized according to animal welfare rules. The vessels were filled with latex stained with red pigment and the samples were fixed in formaldehyde. In nutria, the brain was vascularized by the vertebral basilar system. The terminal branches of the basilar artery originated the rostral cerebellar, caudal cerebral, rostral choroidal and middle cerebral arteries, and its terminal branch, the rostral cerebral artery. The terminal branch of the basilar artery projected the caudal cerebral artery, which is usually a single medium-caliber vessel, into the transverse fissure of the brain. The caudal cerebral artery was presented as a single (66.7% of the cases to the right and 76.7% to the left) and double vessel (33.3% of the cases to the right and 23.3% to the left). It originated the rostral mesencephalic artery, the proximal component, and the caudal inter-hemispheric artery. The terminal branches of the rostral and caudal tectal mesencephalic arteries formed a typical anastomotic network. The caudal inter-hemispheric artery emitted central branches, the caudal choroidal artery, hemispherical occipital arteries, rostral tectal mesencephalic branches and distal components, and anastomosed “in osculum” with the terminal branches of the rostral inter-hemispheric artery. The caudal choroidal artery anastomosed with the rostral choroidal artery, where it branched out on the thalamic mass, vascularizing all diencephalic structures and the hippocampus. The caudal cerebral artery and its terminal branches anastomosed with the terminal branches of the rostral and middle cerebral arteries in a restricted region of the caudal pole of the cerebral hemisphere. The vascularization area of the caudal cerebral artery and its central branches in the paleopallial of the piriform lobe is extremely restricted, caudomedially.
RESUMO: A nutria (Myocastor coypus) é um roedor semi-aquático de tamanho mediano, apreciado na indústria de peles e carne. Este trabalho tem por objetivo descrever e sistematizar a artéria cerebral caudal na superfície do cérebro em nutria, estabelecendo um modelo padrão e suas principais variações e territórios nesta espécie. Os trinta animais utilizados foram eutanasiados segundo as regras de bem-estar animal, os vasos foram preenchidos com látex, corado em vermelho e as peças foram fixadas em formoldeído. O cérebro foi vascularizado exclusivamente pelo sistema vértebro-basilar. Os ramos terminais da artéria basilar originaram as artérias cerebelar rostral, cerebral caudal, corióidea rostral, cerebral média e seu ramo terminal, a artéria cerebral rostral. O ramo terminal da artéria basilar lançou a artéria cerebral caudal, um vaso normalmente único, de médio calibre, para o interior da fissura transversa do cérebro. A artéria cerebral caudal foi um vaso único em 66,7% à direita e em 76,7% à esquerda e mostrou-se dupla em 33,3% à direita e em 23,3% à esquerda. Ela lançou a artéria tectal mesencefálica rostral, componente proximal e a artéria inter-hemisférica caudal. Os ramos terminais das artérias tectais mesencefálicas, rostral e caudal, formavam uma rede anastomótica típica. A artéria inter-hemisférica caudal lançou ramos centrais, a artéria corióidea caudal, as artérias hemisféricas occipitais, os ramos tectais mesencefálicos rostrais, componentes distais e anastomosou-se “em ósculo” com o ramo terminal da artéria inter-hemisférica rostral. A artéria corióidea caudal anastomosava-se com a artéria corióidea rostral, onde ramificavam-se sobre a massa talâmica, vascularizando todas as estruturas do diencéfalo e hipocampo. A artéria cerebral caudal com seus ramos terminais apresenta anastomoses com os ramos terminais das artérias cerebrais rostral e média em uma região restrita do pólo caudal do hemisfério cerebral. A área de vascularização da artéria cerebral caudal com seus ramos centrais no páleo-palio do lobo piriforme é extremamente restrita, caudo-medialmente ao mesmo.
Abstract We recorded for the first time the lesser dung fly Maculantrops hirtipes (Macquart, 1844) from Brazil, state of Rio Grande do Sul. Twenty-five specimens were reared from the dung of ...Myocastor coypus (Molina, 1782), this is the first record of the feeding substrate for the genus Maculantrops and the second only for the Archiborborinae. In addition, we describe the puparium, provide an updated distribution map and additional photographs of the species.
Resumo Registramos pela primeira vez a mosca-do-esterco Maculantrops hirtipes (Macquart, 1844) no Brasil, no estado do Rio Grande do Sul. Vinte e cinco espécimes foram obtidos em amostras fecais de Myocastor coypus (Molina, 1782). Este é o primeiro registro do substrato alimentar para o gênero Maculantrops e o segundo apenas para subfamília Archiborborinae. Além disso, descrevemos o pupário, fornecemos um mapa de distribuição atualizado e fotografias adicionais da espécie.
Neighboring fetuses may impact their siblings in various respects, depending on their in utero location and sex. The effects of the intrauterine position (IUP) are widely studied in model organisms, ...especially laboratory bred murine strains that are characterized by short gestations and altricial offspring. In some species, the proximity to a male fetus and its higher circulating testosterone masculinizes neighboring female fetuses. In utero testosterone exposure might be manifested as higher testosterone concentrations, which contribute to a variation in morphology, reproductive potential and behavior. In this study, we examined the influence of neighboring an opposite sex fetus on testosterone levels in a feral animal model characterized by a long gestation and precocious offspring. Using necropsies of culled nutria (Myocastor coypus), we accurately determined the IUP and quantified testosterone immunoreactivity in fetal hair. We found that as expected, both male and female fetuses neighboring a male in utero had longer anogenital distance. However, females adjacent to males in utero showed lower testosterone levels than male fetuses, while testosterone levels of females without a male neighbor did not differ from those of males. This surprising result suggests an alternative mode by which local exogenous steroids may modify the local fetal environment. Our study emphasizes the importance of examining known phenomena in species with different life histories, other than the traditional murine models, to enhance our understanding of the evolutionary mechanisms that are driving sexual differentiation.
•Neighboring fetuses may impact their siblings in multiple ways.•The nutria is a rodent with a long pregnancy and precocious offspring.•We determined intrauterine position and measured fetal testosterone by hair-testing.•Nutria females neighboring a male in utero had lower testosterone levels.•Non-model species are important for studying evolutionary mechanisms.
Niche differentiation by spatial segregation facilitates the coexistence of species sharing ecological preferences, which can buffer the impact of biological invasions on native species. The ...introduction of two semi-aquatic rodents, the coypu Myocastor coypus and the muskrat Ondatra zibethicus, to most freshwater ecosystems across Western Europe, has been pinpointed as a cause for the decline of the southern water vole (SWV) Arvicola sapidus. We investigated the co-occurrence of these three species in a river catchment of northwest France and whether spatial habitat segregation took place at two spatial scales, using hierarchical modelling accounting for imperfect detection. At a large spatial scale (river catchment), the occupancy rate of the SWV was 0.52 ± 0.06, i.e. noticeably smaller compared to coypu (0.58) and muskrat (0.80). We found no evidence of a negative effect of the presence of the two invasive rodents on SWV occurrence. At a smaller spatial scale (SWV home range), we found weak evidence of spatial segregation in habitat use with a negative, although not significant, effect of muskrat. Overall, our results suggest that riparian habitats in the study area allow the southern water vole to coexist with two larger invasive rodents, provided that hygrophytic vegetation is preserved alongside rivers. La différenciation des niches par ségrégation spatiale est un processus qui facilite la coexistence d'espèces partageant les mêmes préférences écologiques. Ce processus peut atténuer l'impact des invasions biologiques sur les espèces natives. L'introduction de deux rongeurs semi-aquatiques, le ragondin (Myocastor coypus) et le rat musqué (Ondatra zibethicus), dans la plupart des écosystèmes d'eau douce d'Europe occidentale, a été identifiée comme une cause du déclin du campagnol aquatique (Arvicola sapidus). A l'aide de modèles hiérarchiques tenant compte de la détection imparfaite des espèces, nous avons étudié à deux échelles spatiales différentes la co-occurrence de ces trois espèces dans un bassin hydrographique du nord-ouest de la France. Nous avons cherché à déterminer s'il existait un phénomène de ségrégation spatiale entre les 3 espèces. À large échelle (bassin versant), le taux d'occupation du campagnol aquatique est de 0,52 ± 0,06, c'est-à-dire sensiblement plus faible que celui du ragondin (0,58) et du rat musqué (0,80). Nous n'avons trouvé aucune preuve d'un effet négatif de la présence de ces deux rongeurs envahissants sur l'occurrence du campagnol aquatique. À plus petite échelle (territoire du campagnol aquatique), nous avons trouvé une faible preuve de ségrégation spatiale dans l'utilisation de l'habitat avec un effet négatif, bien que non significatif, de la présence du rat musqué. Dans l'ensemble, nos résultats suggèrent que les ripisylves de la zone d'étude permettent au campagnol aquatique de co-exister avec deux rongeurs envahissants de taille supérieure, à condition que la végétation hygrophile soit préservée le long des rivières.
We present the first documented evidence of interactions between the leopard cat (Prionailurus bengalensis euptilurus) and the invasive coypu (Myocastor coypus) in South Korea, captured through ...camera traps in Hwapocheon wetland park from May 2015 to April 2017. Two interactions were recorded: one showing a leopard cat carrying a carcass of sub‐adult coypu and the other a 4‐min sequence of predation and defense between two species. The observed interactions indicate active predatory behavior by the leopard cat against coypus and cooperative defense by coypus. These findings shed new light on predator–prey dynamics, highlighting the leopard cat's potential role as a predator of coypus and coypus' defensive abilities. Understanding these relationships could facilitate more effective management of invasive species and offer broader implications for ecosystem dynamics and conservation strategies.
This study provides the first documented evidence of interactions between the native leopard cat and the invasive coypu in South Korea, observed in the Hwapocheon wetland park from May 2015 to April 2017. Through camera traps, the research unveils active predatory behavior by leopard cats against coypus and the cooperative defense mechanisms exhibited by the coypus.
Analyses of temporal partitioning and overlaps in activity rhythms are pivotal to shed light on interspecific coexistence between similar species or prey and predators. In this work, we assessed the ...overlap of activity rhythms between the Eurasian beaver Castor fiber and its potential competitors and predators through camera trapping in an area in Central Italy. Interspecific overlaps of temporal activity patterns were estimated for the beavers, potential predators (the red fox Vulpes vulpes and the grey wolf Canis lupus), and a potential competitor, the coypu Myocastor coypus. The beavers showed a mostly crepuscular behaviour. Although high temporal overlap was observed between the Eurasian beavers and the red foxes and grey wolves, the activity of the beavers did not overlap with that of the predators. Accordingly, the beavers were more active on the darkest nights, i.e., avoiding bright moonlight.
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