The City of Hammond, Louisiana began discharging secondarily-treated municipal effluent into Four Mile Marsh in the northwestern Joyce wetlands during fall of 2006. At the time discharge began, these ...wetlands had been isolated from virtually all freshwater inflow from the surrounding watershed for over a half century, due primarily to the construction of canals and spoil banks. Immediately following effluent discharge in 2006, there was robust growth of herbaceous vegetation. By late fall 2007, the emergent wetlands in the immediate vicinity of the effluent discharge began to decline, and within months nearly the entire marsh south of the discharge pipe had converted to open water or mudflat. By 2010, there had been substantial recovery of the marsh. A number of hypotheses have been presented to explain the degradation of the marsh to open water and mudflats, including herbivory by the introduced rodent nutria (Myocastor coypus), excessive nutrients, reductions in above- and belowground biomass, increased soil decomposition due to high nutrients, prolonged inundation, toxicity, increased pH, and disease. Intensive field and mesocosm studies provide conclusive data that the marsh loss was primarily caused by nutria herbivory, and secondarily by waterfowl herbivory, and that recovery of the herbaceous vegetation occurred as a result of aggressive nutria control (>2000 eliminated). Marsh recovery has been most intensive near the point of discharge. Mature baldcypress growing in the area of discharge had growth rates that were five times those of trees not receiving effluent in the lower Joyce area and Maurepas swamp. Field and mesocosm studies show that nutrients increased both above- and belowground biomass and did not increase decomposition rates of herbaceous vegetation. Increased flooding due to lack of drainage from the area is hindering marsh recovery.
In December 2021, a wildlife conservation base in Hunan, China, reported illness and death among its captive Myocastor coypus population. A gram-positive pathogen was isolated from the affected ...animals. The 16S rDNA sequence of the isolated strain was approximately 1,500 bp long and exhibited 98.4% homogeneity with Staphylococcus cohnii found in sea cucumbers. Interestingly, the biochemical reactions of the isolated strain were consistent with the characteristics of S. cohnii. The LD100 for BALB/c mice was 1.2 × 107 CFU/g, while the MLD was 0.6 × 107 CFU/g. Inflammatory cell infiltration was observed in the liver, spleen, and kidneys of infected mice, accompanied by widespread systemic bacteremia and focal hepatic and splenic necrosis. Moreover, mycelium was detected in the liver and kidney. The isolated strain possessed both HLB and PVL virulence genes. To the best of our knowledge, this is the first study to report a highly pathogenic strain of S. cohnii isolated from M. coypus, possessing both HLB and PVL virulence genes. The findings contribute to yielding a better understanding of the pathogenic mechanisms of S. cohnii and have significant implications for disease control in M. coypus, as well as for public health safety and the prevention of zoonotic diseases.
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.
•The nutria (Myocastor coypus) is a rodent native to South America with a commercial live weight of 5–6 kg.•Protein, amino acids content and fatty acids present in nutria meat are in line with human nutrition requirements.•Nutria meat is a good source of iron, zinc, copper and selenium.•Reported color, pH, and emulsion capacity of nutria meat, make it suitable for technological process.•Nutria meat could be a good candidate to be offered as an attractive and nutritive delicacy.
The emergence and spread of antibiotic-resistant
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 (
), 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
spp. in wild invasive nutrias captured in Korea during governmental eradication program. Three potential zoonotic
spp. (
,
, and
) were identified among isolates from nutria. Some strains showed unexpected resistance to fluoroquinolones, third-generation cephalosporins, and carbapenems. In carbapenem-resistant isolates, the
gene, which is related to intrinsic resistance of
to carbapenems, was identified, and phylogenetic analysis based on this gene revealed the presence of two major groups represented by
(including
) and other
spp. These results indicate that wild nutrias in Korea are a potential reservoir of zoonotic and antibiotic-resistant
spp. that can cause infection and treatment failure in humans. Thus, measures to prevent contact of wild nutrias with livestock and humans are needed.
Anthropogenic plastic litter is widespread in all environments, with particular emphasis on aquatic habitats. Specifically, although freshwater mammals are important as they are at the top of food ...web, research mainly focus on marine animals, while only few studies have been carried out on freshwater mammals. The main gap is that microplastics (MP) are completely understudied in freshwater mammals. Here, we reported the first evidence of the presence of anthropogenic particles (including MP) in coypu
(Myocastor coypus
)’ faeces. Coypu is a rodent mammal inhabiting rivers and wetland areas, and we discussed our preliminary data suggesting the use of these tracks as possible future bioindicator of MP pollution in wetlands and freshwaters. We collected 30 coypu’s faeces in “Torre Flavia wetland” nature reserve. Then, in laboratory, faeces were digested in 30 ml hydrogen peroxide (30%) for a week a 20 °C and analysed under stereoscope. All the suspected found MP were isolated in a petri dish, using FT-IR analysis to confirm the polymers. Overall, we recorded 444 natural and anthropogenic particles with most of items being fibres. FT-IR analysis of the 10% of the particles recovered revealed that 72% of them was not MP (mainly, polyethylene, polyethylene terephthalate, and polyamide). Also, the number of anthropogenic particles is not correlated with the faecal weight. Given that alien species, such as coypu, are widespread species, our results might have a great importance as these species and MP in faecal tracks may be used as undirect proxy of environmental bioavailability of MP pollution.
spp., common parasites of vertebrates, remain poorly studied in wildlife. This study describes the novel
species adapted to nutrias (
). A total of 150 faecal samples of feral nutria were collected ...from locations in the Czech Republic and Slovakia and examined for
spp. oocysts and specific DNA at the
, actin,
70, and
loci. Molecular analyses revealed the presence of
(
= 1),
subtype family XIId (
= 5) and
n. sp. XXIIa (
= 2), and XXIIb (
= 3). Only nutrias positive for
shed microscopically detectable oocysts, which measured 4.8-5.2 × 4.7-5.0 µm, and oocysts were infectious for experimentally infected nutrias with a prepatent period of 5-6 days, although not for mice, gerbils, or chickens. The infection was localised in jejunum and ileum without observable macroscopic changes. The microvilli adjacent to attached stages responded by elongating. Clinical signs were not observed in naturally or experimentally infected nutrias. Phylogenetic analyses at
, actin, and
70 loci demonstrated that
n. sp. is distinct from other valid
species.
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.
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Nutria (Myocastor coypus) are an introduced invasive species expanding their range in North America and may have detrimental effects on wetlands. Little is known about habitat covariates that may ...limit or enhance range expansion of nutria, especially when combined with predicted changes in climate. We used a hierarchical modeling approach to develop broad- and local-scale maximum entropy (MaxEnt) models based on nutria harvest records in the eastern United States from 2006–2015. We developed models for current conditions and for climate change projections in 2050. At a broad scale, nutria habitat was located in areas with ≤80 annual freezing days. At local scales, nutria were found in areas with high proportions of freshwater forested-shrub wetlands close to other wetlands. Managers who are concerned about possible nutria range expansion can use this hierarchical modeling framework to identify areas for surveillance and prioritize control efforts.
Managing invasive alien species (IAS) is a critical issue for many countries to preserve native biodiversity, ecosystem services and human well-being. In western France, we analyzed data of captures ...of aquatic invasive alien rodents (AIARs), the coypu and muskrat, by the local permanent control program from 2007 to 2022 across 26 municipalities encompassing 631 km2. We found that control activities removed up to 10.3 AIARs per km2 annually. The number of coypus removed per trapper per year increased by 220%, whereas it decreased by 85% for muskrats. The number of trappers increased from 2007 to 2014, peaking at 70, and then decreased by 50% in 2022. The number of AIARs captured per trapper per year increased with the density of ponds. The number of coypus captured per year decreased with an increasing amount of woodland per municipality, whereas it increased with road density. Finally, other tested landscape variables did not affect the number of AIARs removed per trapper per year. Our results are discussed in the context of control activities implemented against IAS in other countries. We advocate for stakeholders to assess whether control activities against AIARs effectively mitigate the impacts on social-ecological systems in France.
Blastocystis is an anaerobic unicellular protist frequently detected in the gastrointestinal tracts of humans and animals worldwide. However, the prevalence and subtype distribution of Blastocystis ...in the coypu (Myocastor coypus) population have not been reported so far. The aim of this study was to determine the prevalence, genetic characteristics, and zoonotic potential of Blastocystis isolates detected in coypus in China.
A total of 308 fecal samples were collected from coypus in seven regions across China and subsequently examined. Blastocystis was detected in 44 (14.3%) specimens by nested PCR amplification of the small subunit ribosomal rRNA (SSU rRNA) gene. Further DNA sequencing and phylogenetic analyses resulted in the identification of two zoonotic known subtypes, ST4 and ST5, and an unknown subtype. ST4 was the most predominant subtype observed in the samples. ST5 infections were only observed in three coypus. Factors that were associated with prevalence of Blastocystis included age, geographical region and subtype. Interestingly, this is the first report about a potentially novel subtype infecting coypus.
This is the first comprehensive report of Blastocystis in M. coypus across a wide geographic range of China. A moderate degree of genetic divergence was observed. The presence of zoonotic subtypes in farmed M. coypus suggests that these animals have the potential to transmit blastocystosis to both humans and domestic animals. These findings provide a better understanding of the genetic diversity of Blastocystis in rodents and contribute towards the establishment of efficient blastocystosis control strategies in the investigated areas.
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