First evidence of plastics in coypu (Myocastor coypus)'s platforms.

Platforms are structures built by coypus for various purposes, such as reproduction, resting, and thermoregulation. In a coastal wetland of central Italy, during a study aimed at investigating the characteristics of coypu's platforms, it was recorded, for the first time worldwide, the presence of plastic in these structures. Through a transect survey, we censused 83 platforms, among which three (3.61%) were found with presence of macro- and megaplastics (polystyrene, polypropylene, and low-density polyethylene in film form; polyester, polyamide, and expanded polystyrene in fragments). Through the FTIR spectra, it was possible to highlight the degradation of the polymeric materials. To stimulate possible in-depth investigations at the level of the food chain (e.g., coypu predators, including canids) in wet habitats, we discussed possible causes and implications of plastic presence in coypus' nest structures.

Field validation of an eDNA assay for nutria illuminates a role in invasive species management.

Nutria, or coypu (Myocastor coypus), are invasive semi-aquatic rodents present across the United States, Europe, and Asia. Despite successful eradication efforts in certain areas, nutria have resurged in the mid-Atlantic USA, underscoring the need for advanced monitoring tools. Environmental DNA (eDNA) has emerged as a promising technique for species detection and monitoring. Here, an eDNA assay for nutria using qPCR was field-validated in Virginia, USA, showcasing its potential as a tool for post-eradication monitoring. The findings reveal an association between water levels and detection of nutria eDNA, highlighting the importance of water levels in nutria behavior. A painted turtle assay was introduced to confirm nutria absence and demonstrate the potential of passive sampling. The study showcases the sensitivity and efficiency of eDNA assays, emphasizing their value for monitoring and verifying invasive species eradication.

Estimating risk to prevent damage: predicting and preventing coypu (Myocastor coypus) damage to transport infrastructure.

BACKGROUND: A major impact of invasive Myocastor coypus in their introduction range is the collapse of riverbanks and nearby infrastructure, such as railway lines, due to the species' burrowing activities. Because widespread implementation of preventive measures along watercourses is unfeasible, identifying susceptible areas is key to guide targeted management actions. This study used species-habitat models to: (i) identify local environmental features of the railway line/watercourse intersections (RLWIs) that make them particularly susceptible to coypu damage, and (ii) predict species occurrence probability over a wide lowland-hilly area of northern Italy (Lombardy) to identify priority areas for monitoring. RESULTS: Local-scale models identified that the RLWIs most susceptible to burrowing were those surrounded by arable land with interspersed hedgerows locally characterized by high herbaceous vegetation and clay soil. In urbanized areas and areas of intensive agriculture, coypu dens were generally located significantly closer to the railway, increasing the risk of collapse. A landscape-scale species distribution model showed that lowland areas along major rivers and lake shores, and also agricultural areas with a dense minor hydrographic network, particularly in the southeast of the study area, are more likely to be occupied by coypu. CONCLUSION: Local-scale models showed that specific environmental characteristics increase the risk of burrowing near RLWIs. The landscape-scale model allowed us to predict which areas require thorough monitoring of RLWIs to search for such local characteristics to implement preventive management measures. The proposed model-based framework can be applied to any geographical context to predict and prevent coypu damage. © 2024 Society of Chemical Industry.

Improved molecular identification of Strongyloides myopotami in nutrias using fecal samples.

Strongyloides myopotami is an intestinal nematode parasite of nutrias. Identification of S. myopotami is conducted based on the morphological characteristics of adult worms or cultured larvae. To widely and effectively understand the infection in nutrias, it would be preferable to develop the molecular identification using a few grams of the feces. Here, we attempted to identify S. myopotami using DNA extracted from eggs obtained from fecal samples. Among previously reported primer pairs targeting the 18S rRNA gene of Strongyloides spp., most could not be successful. We newly designed primers that successfully amplified the partial sequences in S. myopotami, resulting in being sequenced. Our simple protocol can be useful in nationwide surveys for clarifying the risk of human infection.

A Health Status Update of Myocastor coypus in Northern Italy.

Myocastor coypus is a pest animal present in Africa, Europe, North America and Asia that causes agricultural and ecological damages. Moreover, it has to be considered as a potential risk for public health. Forty-four coypus from the "Parco Naturale La Mandria" (Piedmont region, Northwest Italy) have been analysed. A complete necropsy and a whole histological evaluation of the liver, kidney and lung have been carried out on all the animals. Moreover, the positivity to Hepatitis E Virus (HEV), Encephalomyocarditis virus (EMCV), Francisella spp., Toxoplasma gondii and Neospora caninum have been investigated. None of the animal were positive for HEV, EMCV, Francisella spp. or Neospora caninum. Two animals tested positive for Toxoplasma gondii. A high presence of histological lesions has been identified in different organs, suggesting that lesions could be induced by different pathogens. As previously reported, coypu can act as a host for several pathogens, including important agents for human and animal health, and surveillance is necessary to fully understand the biological role and the importance of coypu as a disease reservoir in our country.

Development and bioassessment of high nutria-omega 5 cookies through animal modeling.

The food industry generates a diverse range of waste byproducts during fruit processing, which can be repurposed to create functional foods and other valuable commodities. In this particular study, leftover agro-waste from pomegranate juice was valorized to obtain pomegranate seed oil (PSO), while utilizing sunflower oilseed cake to produce sunflower meal protein concentrate (SMPC). These two extracted components were then combined as ingredients to produce High Nutria Omega 5 (HNO5) cookies. To ensure the quality and viability of pomegranate seed oil, a comprehensive set of laboratory analytical procedures were employed to evaluate its characteristics. Subsequently, different ratios of pomegranate seed oil and sunflower meal protein concentrate were utilized to develop the HNO5 cookie products. These cookies underwent thorough sensory, physicochemical, storage, and proximate evaluations as well as efficacy studies to assess their overall nutritional quality and shelf-life properties. As compared to the control feed, the findings of the renal and liver functional tests indicated a favorable effect on ALT, AST, ALP, serum urea, creatinine, albumin, globulins, total proteins, and A/G ratio. The results revealed that PSO and SMPC cookies containing 15% PSO and 15% SMPC exhibited stability in numerous physicochemical and sensory assessments. The punicic acid in HNO5 cookies significantly reduced the effects of starvation in rats and progressively improved several metabolic processes and overall health profiles. Graphical Abstract.

Radio Tracking Reveals the Home Range and Activity Patterns of Nutria (Myocastor coypus) in the Macdo Wetland in South Korea.

Nutria (Myocastor coypus) are semi-aquatic rodents that were introduced in South Korea for commercial farming but significantly damaged aquatic ecosystems. Understanding nutria ecological behavior is essential for developing effective control and eradication strategies to mitigate their impacts. Thus, this study aimed to investigate the home range and activity patterns of 24 nutria (12 males and 12 females) in the Macdo wetland in South Korea from 2015-2016 through radio tracking. The average minimum convex polygon home range of the nutria was 0.29 ± 0.55 km2, with a 95% kernel density estimation (KDE) home range of 0.43 ± 0.85 km2 and a 50% KDE home range of 0.05 ± 1.1 km2. The home range of males was larger than that of females; however, the winter home range of females was as large as that of males. The home range also varied seasonally, with the smallest observed in winter. The nutria showed crepuscular and nocturnal activity patterns throughout the year, with no significant difference between sexes. The activities in spring, summer, and autumn showed no significant differences, but the activity in winter was significantly different from that in the other seasons. This study may serve as a basis for developing appropriately timed and scaled management strategies to mitigate the impacts of nutria on ecosystems. In conclusion, several environmental and biological factors contribute to the behavior of nutria in South Korea.

Low potential of persistence and dissemination of antimicrobial-resistant Enterobacterales by wild nutria (Myocastor coypus) in a local river of Gifu Prefecture.

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 ß-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.

Anatomy and Histology of the Eye of the Nutria Myocastor coypus: Evidence of Adaptation to a Semi-aquatic Life.

The nutria is a large, semi-aquatic rodent that, being invasive, is having a growing impact on the ecosystem in western Japan. Knowledge regarding physical adaptations to the nutria's lifestyle and habitual activities would be useful for effectively controlling and preventing their spread. Nutrias spend time on land and in water, feeding on agricultural crops and wild grasses growing near the waterside, as well as aquatic plants and shellfish. In the current study, the nutria's visual organ was analyzed anatomically and histologically, and aquatic and light environmental adaptations were evaluated. The results revealed that the nutria eyeball was almost spherical, and the cornea was rounded. The lens was convex and slightly thicker than previously reported for other rodents. These features were not characteristic of aquatic adaptations observed in the eyes of fish or marine mammals. The ratio of lens diameter to eyeball diameter was 0.6, similar to that of nocturnal species. The pupil was a vertical slit, suggesting an ability to adjust the amount of light entering the eyeball during twilight. Photoreceptors were sparsely distributed across the whole retina, and no fovea was observed. Retinal thickness was 90-100 µm, thinner than that in other rodent species. Visual acuity was 1.44-1.58 cycles/degree, higher than that in other rodents, likely because of the nutria's large eyeball and body. These results suggest that the nutria visual system is adapted to recognize large shadows of distant predators rather than viewing objects in detail.

Alveolar echinococcosis in nutria (Myocastor coypus), invasive species in Slovenia.

The present report describes a case of Echinococcus multilocularis infection in nutria (Myocastor coypus) culled in the central area of Slovenia. Post-mortem exam showed multiple cystic lesions in the liver. Gross examination, as well as parasitological and histopathological examinations, revealed numerous cysts of various sizes, filled with yellow clear fluid and displacing most of the liver parenchyma. The cyst lumina contained numerous protoscolices approximately 100 µm in diameter and calcareous corpuscles. The protoscolices had two visible suckers and a rostellum with birefringent hooks. The lesions were consistent with an E. multilocularis cyst. Molecular analysis confirmed that the nutria was infected with E. multilocularis. To our knowledge, this is the first report of echinococcosis in nutria in Slovenia that presents gross, parasitological, and histological lesions and the result of molecular analysis. Nutrias in Slovenia are dangerous invaders but can also be a relevant bioindicator of the presence of the parasite in the environment.

Update of Cestodes Parasitizing Neotropical Hystricomorphic Rodent.

This review aims at identifying cestodes that are present in hunted rodent species in the neo-tropical region. The rodent species that was investigated were the capybara (Hydrochoerus hydrochaeris, Linnaeus, 1766), lappe (Cuniculus paca, Linnaeus, 1766), agouti (Dasyprocta leporina, Linnaeus, 1758), chinchilla (Chinchilla chinchilla, Lichtenstein, 1829), Trinidad spiny rat (Proehimys trinitatus, Allen and Chapman, 1893), nutria (Myocastor coypus, Molina, 1782), and vizcacha (Lagostomus maximus, Desmarest, 1817). These rodent species are utilized for their meats in many rural communities in the Caribbean and South America. These rodents belong to the hystricomorphic group. Raillietina demerariensis Daniels, 1895 was commonly found in the gastrointestinal tract of D. leporina, C. paca and P. trinitatus. Similarly, in the liver, muscle and subcutaneous tissue the metacestodes on Echinococcus vogeli Daniels, 1895 and Echinococcus oligarthrus was found in the lappe and agouti. The capybara was found to have the most species of cestodes in its gastrointestinal tract when compared to the agouti and lappe. However, metacestodes were not recorded in the tissues of the capybara. This surprising feature shows the effect of the difference in feeding habits between the capybara and the agouti and lappe. The literature reviewed in this study includes scientific publications on cestodes and metacestodes of Hystricomorphic rodents. An exhaustive search was performed using the digital repositories in Google Scholar, Scielo, Redalyc, Scopus and Pubmed. Literature searched spanned the years 1970-2021. Cestodes of zoonotic significance were E. vogeli and E. oligarthrus, with humans becoming infected when consuming eggs of contaminated food and water. The agouti and lappe act as intermediate host in the life cycle of E. vogeli and E. oligarthrus, the definitive host (canids and felids) become infected by consuming of tissue infected with metacestodes. Humans become infected through the ingestion of eggs from the definitive host where cystic lesions develop in the liver, lungs and other abdominal organs.

The effect of feed restriction, sex and age on the carcass composition and meat quality of nutrias (Myocastor coypus).

The objective of the study was to evaluate the effect of quantitative feed restriction on the carcass composition and physical, chemical, histochemical and sensory properties of meat from male and female nutria at the end of the feed restriction and fattening period. In the experiment, from two to eight months of age, males and females were divided into two groups: one group was fed ad libitum throughout the experiment, and the second group was restricted to two weeks (from 11 to 12 weeks of age). The restricted nutrias received 75% ad libitum feeding. The significant interaction among feed restriction, sex and age was revealed only in the cross-sectional area of all muscle fiber types. Age was the main factor affecting carcass composition and meat quality characteristics. Sex-related differences in carcass composition and some sensory attributes and feed restriction-related differences in carcass composition were observed.

FIELD ANESTHESIA OF FREE-RANGING NUTRIAS (MYOCASTOR COYPUS) FOR SURGICAL REPRODUCTION CONTROL.

The nutria (Myocastor coypus), a rodent native to South America, has been introduced and has established feral populations at numerous locations in North America, Europe, and Asia. As such, the nutria is subject to research and management programs, including investigation of surgical fertility-control techniques. We evaluated the efficacy of a mixture of ketamine and medetomidine, with additional use of isoflurane and reversal with atipamezole, to provide safe, reliable anesthesia for surgical procedures under field conditions. We anesthetized 40 free-ranging nutrias between December 2018 and March 2019, in Turin, Italy, to perform surgical reproduction control techniques. We administered a ketamine and medetomidine mixture (6 mg/kg and 140 µg/kg, respectively) after trapping the animals and weighing them in the cage traps. After induction, we reweighed the rodents and performed a brief clinical examination. The times of loss of palpebral and pedal reflexes were noted. After induction of anesthesia, heart rate, respiratory rate, and percentage of oxygen saturation were monitored and recorded. Isoflurane was delivered through a face mask to 27 nutrias (70%) to maintain an adequate depth of anesthesia. Upon completion of surgery and other procedures, atipamezole was administered to the animals at doses 2.5 higher than those of medetomidine (actual dose: 366±31 µg/kg). Induction times were short (3±2 min), with the animals completely immobilized. The heart rate and respiratory rate both decreased. After administration of atipamezole, recoveries were smooth and complete. There were two deaths after higher doses of atipamezole and longer surgeries. Carprofen (4 mg/kg) was administered subcutaneously for its analgesic effects. The animals were released at the end of all the procedures. Overall, the medetomidine and ketamine mixture, with supplemental isoflurane in most instances, provided a reliable anesthesia in free-ranging nutrias, adequate for performing surgical procedures under field conditions.

Senescent cells in rabbit, nutria and chinchilla testes-Results from histochemical and immunohistochemical studies.

Rabbit, nutria and chinchilla testes were evaluated to compare testicular cellular senescence. There were no major species-specific differences in structure of either seminiferous tubules or interstitial tissue. There, however, were occasional abnormalities in seminiferous tubule structure with there being multinucleated and exfoliated cells present in rabbit testes. Furthermore, there were seminiferous tubules without a lumen that were filled with premeiotic/meiotic cells in nutria; and tubules with vacuolization with there being no post-meiotic cells in chinchillas. There were no differences in distribution or content of acids, total proteins and polysaccharides in the testis of any of the three species. Results using comparative immunohistochemistry procedures indicated the testes contained a few senescent cells in seminiferous tubules with typical morphology and there was a large number of senescent cells in seminiferous tubules of nutrias and chinchillas that had an abnormal structure (P <0.001). Compared to rabbit testes, in which there was the least number of senescent cells in seminiferous tubules, there was a greater abundance of senescence markers in both nutria and chinchilla testes (P < 0.05; P < 0.001, respectively). Furthermore, there were small abundances of caspase 3 and LC3 in the testes of all species. In chinchilla testes, there was a lesser concentration of cholesterol (P < 0.001) and testosterone compared with the other species. Cellular senescence in testes, therefore, can be assessed by detection of morpho-functional disorders of the testis of the three species evaluated in the present study.

Systematization, distribution, and territories of the caudal cerebral artery on the surface of the brain in nutria (Myocastor coypus) / Sistematização, distribuição e territórios da artéria cerebral caudal na superfície do cérebro em Nutria (Myocastor coypus)

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.(AU)

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.(AU)

Preputial gland adenoma in a wild nutria (Myocastor coypus): a case report.

Tumor incidence in wild mammals is reportedly very low. Wild nutria, a large rodent, is known to carry many infectious diseases, but rarely exhibits neoplastic diseases. We necropsied a male wild nutria and found a large nodular mass in the left inguinal region, adjacent to the penis. Histopathologically, the mass was diagnosed as preputial gland adenoma. Spontaneous preputial gland adenomas are extremely rare in all animals. Moreover, reports of tumors in nutrias have been limited to adenocarcinomas of the lungs and uterus, as well as subcutaneous fibromas. Here, we describe preputial gland adenoma in a wild nutria.

Preputial gland adenoma in a wild nutria (Myocastor coypus): a case report

Genetic Diversity and Population Structure of Nutria (Myocastor coypus) in South Korea.

The nutria (Myocastor coypus) is an invasive alien species that have had major adverse effects on biodiversity and the agricultural economy in wetland habitats. Since 2014, the Ministry of Environment in South Korea has been carrying out the Nutria Eradication Project, and we investigated nutria distribution and genetic diversity of nutria populations in South Korea. We estimated that 99.2% of nutria habitats are in the mid-lower Nakdong River regions. To further analyze the genetic diversity in eight major nutria populations, we performed a genetic analysis using microsatellite markers. Genetic diversity levels of the eight nutria populations in South Korea were relatively lower than those in other countries. The probability of migration direction among nutria populations was predicted from genetic distance analysis. Genetic structure analysis showed little difference among the nutria populations in South Korea. These results suggest that nutrias in South Korea originated from a single population. Our results provide important data for establishing management strategies for the successful eradication of nutria populations in South Korea, as well as in other countries with alien invasive species.

Wild Nutria (Myocastor coypus) Is a Potential Reservoir of Carbapenem-Resistant and Zoonotic Aeromonas spp. in Korea.

The emergence and spread of antibiotic-resistant Aeromonas spp. is a serious public and animal health concern. Wild animals serve as reservoirs, vectors, and sentinels of these bacteria and can facilitate their transmission to humans and livestock. The nutria (Myocastor coypus), a semi-aquatic rodent, currently is globally considered an invasive alien species that has harmful impacts on natural ecosystems and carries various zoonotic aquatic pathogens. This study aimed to determine the prevalence of antibiotic-resistant zoonotic Aeromonas spp. in wild invasive nutrias captured in Korea during governmental eradication program. Three potential zoonotic Aeromonas spp. (A. hydrophila, A. caviae, and A. dhakensis) were identified among isolates from nutria. Some strains showed unexpected resistance to fluoroquinolones, third-generation cephalosporins, and carbapenems. In carbapenem-resistant isolates, the cphA gene, which is related to intrinsic resistance of Aeromonas to carbapenems, was identified, and phylogenetic analysis based on this gene revealed the presence of two major groups represented by A. hydrophila (including A. dhakensis) and other Aeromonas spp. These results indicate that wild nutrias in Korea are a potential reservoir of zoonotic and antibiotic-resistant Aeromonas spp. that can cause infection and treatment failure in humans. Thus, measures to prevent contact of wild nutrias with livestock and humans are needed.

A review of productive parameters, nutritive value and technological characteristics of farmed nutria meat (Myocastor coypus).

The nutria (Myocastor coypus) is a prolific herbivorous rodent originating from southern South America. The nutria is farmed in many countries mainly for its pelt through selected animals called nutria "mutations", with different kinds of fur color and, up until now, nutria meat has been considered as a by-product. However, taking into account the growing interest of consumers to access novel and exotic meat, nutria meat could be proposed as an attractive and nutritional delicacy. The data presented in this review shows that the nutritional value of nutria meat is adequate for human nutrition, taking into account the protein content and amino acids composition. The fatty acids present in nutria meat are in line with health concerns for lipids nutrition in humans. Furthermore, the mineral composition of farmed nutria makes it a good source of iron, zinc, copper and selenium, all needed for human nutrition, especially iron when it comes to children and women.