Coypus Research Articles

First description of Cryptosporidium ubiquitum XIIa subtype family in farmed fur animals

This study investigated the prevalence of Cryptosporidium in farmed fur animals in the Czech Republic and Poland. A total of 480 faecal samples were collected from fur animals, including 300 American mink (Mustela vison), 60 silver foxes (Vulpes vulpes), 50 long-tailed chinchillas (Chinchilla lanigera), and 70 nutrias (Myocastor coypus), at 14 farms. Samples were examined for the presence of Cryptosporidium using microscopy (following aniline-carbol-methyl violet staining) and sequence analysis of PCR amplified products. Three mink and two chinchillas from two different farms tested positive for Cryptosporidium ubiquitum DNA. The presence of C. ubiquitum DNA was not associated with diarrhoea. Subtyping of C. ubiquitum isolates by sequence analysis of the 60-kDa glycoprotein gene showed that isolates belonged to the XIIa subtype family, which was previously restricted to humans and ruminants. This suggests that C. ubiquitum subtype XIIa has a broader host range than previously reported.

The partitioning of food resources between two rodents in the subtropical region of southern Brazil.

The capybara (Hydrochoerus hydrochaeris) and nutria (Myocastor coypus) are herbivorous semi-aquatic rodents. Although these rodents occur in sympatry in southern South America, little is known about how the two species interact in relationship to food resources. In this context, the aim of this study was to analyze the food resource overlap, the feeding strategy and the diversity of the diet of capybaras and nutria. A micro-histological analysis of feces was used to study the diets. A total of 48 plant species belonging to 10 families were identified in the diet of H. hydrochaeris, and a total of 49 species belonging to 14 families were identified in the diet of M. coypus. According to the Amundsen graphical method, both rodents adopted a specialized strategy for feeding on Poaceae and a generalized strategy for other families. The results of a multivariate analysis of the dietary data showed significant differences between the two rodent species and among the seasons. These differences between diets may be related to the different proportions of each food item eaten. However, the dietary overlap between the two rodents in the Taim wetland was high, suggesting that partitioning of other resources ensured the coexistence of the species.

Evaluating simplistic methods to understand current distributions and forecast distribution changes under climate change scenarios: an example with coypu (Myocastor coypus)

Evaluating simplistic methods to understand current distributions and forecast distribution changes under climate change scenarios: an example with coypu (Myocastor coypus)

History and Current Status of Invasive Nutria and Common Muskrat in Korea

Nutria, or coypu (Myocastor coypus), were introduced to South Korea in 1985 and became an invasive species in the late 1990s. Despite being limited to the Nacdong River system, the nutria population is well established there. The common muskrat (Ondatra zibethicus) invaded North Korea via the Russian and Chinese borders during the 1960s, but the species is still confined to the extreme northeastern portion. In South Korea, muskrats were introduced in 2005. Although muskrat farms are not commercially viable, they have increased. Since 2009, local and federal governments have tried to remove nutria using trappers and bounty hunting. From 2011 to 2015, 11,258 nutrias were removed but a sustainable population still exists. Although complete nutria removal has been achieved in other countries, the eradication campaign in South Korea has not been strictly modeled on these successes. Despite the concern about muskrats, prevention against their possible release has never been implemented. We present the history of nutria and muskrat in Korea and examine the current eradication projects. We propose that unified science-based eradication strategies would be the most likely to succeed, and urge the South Korean government to initiate management designed to avert potentially harmful ecosystem effects of invasive muskrats.

Prospects for crowdsourced information on the geomorphic ‘engineering’ by the invasive Coypu (Myocastor coypus)

AbstractAmong the most invasive species, the Coypu (Myocastor coypus) best exemplifies the widespread effect of alien species on ecosystems. Among the impacts, the induced erosion in riverbanks has an increasing economic and social importance. Despite its significance, this type of erosion is rarely quantified, and the available information is limited to local knowledge, grey literature, and maintenance reports. This research shows the potential of freely and instantly available Structure‐from‐Motion (SfM) photogrammetry to obtain crowdsourced information based on smartphone images. The results highlight how it is possible to provide a rough estimate of the damages with relatively low or null cost of application, and limited expert knowledge and expenditure of time, depending on the scale of analysis. The proposed technique provides a fresh approach to a known long‐standing issue, offering a new source of information for farmers, researchers, wildlife managers, as well as for land managers and planners. The potential applications of such a technique and its unprecedented ease of use and very low cost offer effective tools for management plans and scientific research, providing a basis to relate eroded volumes to the functioning of the drainage system and the connected agroecosystem. The method would also enable the opportunity of participatory and opportunistic crowdsourced sensing. Further scientific research on the crowd‐based data on erosion should encourage standardisation of data gathering and accessibility, together with a public involvement in information exchange, to generate a better understanding and awareness of erosion problems also for other fields of research. Copyright © 2016 John Wiley & Sons, Ltd.

Seasonal feeding habits of coypu ( Myocastor coypus ) in South Korea

Since their introduction in 1985, coypus ( Myocastor coypus ) have spread widely throughout South Korea and are now considered an invasive species, with negative impacts on both agriculture and native biodiversity. Management of the species began in 2005, and related research has focused on factors influencing population control. Cold weather may cause significant population declines but the basis of that susceptibility has yet to be identified. Therefore, based on the analysis of 28 coypus trapped on Eulsuk Island in theNakdong River over a 12-month period, we sought to: (1) investigate coypu diet and body condition using the relationships between the δ 13 C and δ 15 N stable isotope values of coypu liver and hind-leg muscle tissues, mean temperature, and body condition index (log weight/log body length); (2) clarify the relative use of aquatic and terrestrial food plants, and (3) determine seasonal variations in coypu diet. Carbon and Nitrogen isotope values both differed seasonally and, in winter, between adults and juveniles. Carbon, but not Nitrogen, isotope values were influenced by temperature in the weeks before sampling. The δ 15 N values of liver tissues were influenced by sex and life stage at low temperatures; otherwise, with regard to diet, isotope ratios suggested that coypu primarily fed on aquatic vegetation. Coypus appear to make more use of the heavier nitrogen isotope in hind-leg muscle during winter, presumably associated with muscle tissue metabolism contributing to weight loss. During winter, these higher metabolic requirements together with the decreased availability of aquatic vegetation suggest that baiting near waterways in winter could be an effective method to control invasive coypu populations.

Evaluation of nutria (Myocastor coypus) detection methods in Maryland, USA

Nutria (Myocaster coypus), invasive, semi-aquatic rodents native to South America, were introduced into Maryland near Blackwater National Wildlife Refuge (BNWR) in 1943. Irruptive population growth, expansion, and destructive feeding habits resulted in the destruction of thousands of acres of emergent marshes at and surrounding BNWR. In 2002, a partnership of federal, state and private entities initiated an eradication campaign to protect remaining wetlands from further damage and facilitate the restoration of coastal wetlands throughout the Chesapeake Bay region. Program staff removed nearly 14,000 nutria from five infested watersheds in a systematic trapping and hunting program between 2002 and 2014. As part of ongoing surveillance activities, the Chesapeake Bay Nutria Eradication Project uses a variety of tools to detect and remove nutria. Project staff developed a floating raft, or monitoring platform, to determine site occupancy. These platforms are placed along waterways and checked periodically for evidence of nutria visitation. We evaluated the effectiveness of monitoring platforms and three associated detection methods: hair snares, presence of scat, and trail cameras. Our objectives were to (1) determine if platform placement on land or water influenced nutria visitation rates, (2) determine if the presence of hair snares influenced visitation rates, and (3) determine method-specific detection probabilities. Our analyses indicated that platforms placed on land were 1.5–3.0 times more likely to be visited than those placed in water and that platforms without snares were an estimated 1.7–3.7 times more likely to be visited than those with snares. Although the presence of snares appears to have discouraged visitation, seasonal variation may confound interpretation of these results. Scat was the least effective method of determining nutria visitation, while hair snares were as effective as cameras. Estimated detection probabilities provided by occupancy modeling were 0.73 for hair snares, 0.71 for cameras and 0.40 for scat. We recommend the use of hair snares on monitoring platforms as they are the most cost-effective and reliable detection method available at this time. Future research should focus on determining the cause for the observed decrease in nutria visits after snares were applied.

Relationship between muscle fibre characteristics and meat sensory properties in three nutria (Myocastor coypus) colour types

Relationship between muscle fibre characteristics and meat sensory properties in three nutria (Myocastor coypus) colour types

Surveillance and management of Echinococcus multilocularis in a wildlife park

The fox tapeworm Echinococcus multilocularis is the causative agent of alveolar echinococcosis, a severe zoonotic disease that may be fatal if untreated. A broad spectrum of mammalian species may be accidentally infected even in captivity. In April 2011, liver lesions due to E. multilocularis were observed during the necropsy of a captive-born nutria (Myocastor coypus) in a French wildlife park, leading to initiation of a study to survey the parasite's presence in the park. A comparable environmental contamination with fox's feces infected by E. multilocularis was reported inside (17.8%) and outside (20.6%) the park. E. multilocularis worms were found in the intestines of three of the five roaming foxes shot in the park. Coprological analyses of potential definitive hosts in captivity (fox, lynx, wildcat, genet, wolf, bear and raccoon) revealed infection in one Eurasian wolf. Voles trapped inside the park also had a high prevalence of 5.3%. After diagnosis of alveolar echinococcosis in a Lemur catta during necropsy, four other cases in L. catta were detected by a combination of ultrasound and serology. These animals were treated twice daily with albendazole. The systematic massive metacestode development and numerous protoscoleces in L. catta confirmed their particular sensitivity to E. multilocularis infection. The autochthonous origin of the infection in all the captive animals infected was genetically confirmed by EmsB microsatellite analysis. Preventive measures were implemented to avoid the presence of roaming foxes, contact with potential definitive hosts and contaminated food sources for potential intermediate hosts.

Parasitic and Bacterial Infections of Myocastor coypus in a Metropolitan Area of Northwestern Italy.

Coypus (Myocastor coypus) are widespread throughout Europe. In northern Italy, they are abundant in the flatland areas, and their high population densities can cause economic loss and ecosystem damage. We examined 153 coypus for selected parasitic and bacterial infections. We found Strongyloides myopotami (63.4% prevalence), Trichostrongylus duretteae (28.1%), Eimeria coypi (86.3%), and Eimeria seideli (6.8%), but did not find Giardia duodenalis or Cryptosporidium spp. We also isolated Staphylococcus aureus (10.1%), Escherichia coli (4.5%), and Streptococcus spp. (3.4%) from lung samples; no Salmonella spp. were isolated from fecal samples. Coypus had antibodies to Toxoplasma gondii (28.9%) and to four serovars of Leptospira interrogans (44.9%); Australis/Bratislava was the serovar most frequently detected. It is clear that coypu can be infected with pathogens of human and veterinary importance.

Do the size and shape of spatial units jeopardize the road mortality-risk factors estimates?

We aimed to evaluate the role of spatial units with different shapes and sizes on road-kill modeling for small vertebrate species. We used the road-kill records of two reptiles, water snake (Helicops infrataeniatus) and D’Orbigny's slider turtle (Trachemys dorbigni), and three mammals, white-eared opossum (Didelphis albiventris), coypu (Myocastor coypus) and Molina's Hog-nosed skunk (Conepatus chinga). Hierarchical partitioning was used to evaluate the independent influence of different land-use classes on road-kill by varying the shape and size of the spatial units. Variables that most explained road-kill were consistent over the different spatial unit types. The standard size seemed to be a reasonable solution for these species. Prior analysis with several sizes and shapes is needed to identify the appropriate spatial unit to model road-kill occurrence for larger vertebrates with different history traits.

영국과 미국에서 침입성 뉴트리아 (Myocastor coypus)의 효과적 관리

It is the better to take preventative measures against the natural intrusion in advance from invasive alien species that reduce biodiversity and cause economic loss to humans. If the prevention of intrusion and spread fails, we need to make active control and eradication. This study aims to introduce nutria (Myocastor coypus) control cases performed in the United Kingdom and the United States and to provide information for the contribution of nutria management measure improvements. The nutria eradication campaign in the United Kingdom was developed as a long-term plan based on sufficient understanding on the management target and objective and suitable support. Sufficient information on nutria was accumulated and the management strategy was flexibly modified according to the changes in management that were proactively reflected in the field. Regarding the eradication project at Chesapeake Bay in the United States, based on long-term ecological information, more advanced capture technology than in the United Kingdom were introduced and the eradication plan, strategy and implementation were configured by analyzing the strengths and weaknesses of the eradication campaign in the United Kingdom. The successful cases in the United Kingdom and the United State provide an information on how to improv the nutria management measure. For the eradication of nutria, it is necessary to reach a consensus between stakeholders and to form a consultative group between related organizations for periodic communication. Opinions on the field must be actively accepted in the consultation process for strategy and policy decision, and the eradication plan needs to be developed based on a management index. The eradication plan is required to be managed, evaluated and adjusted in a systematic way. Scientific management must be introduced and the management performance must be evaluated objectively so that a practical plan can be flexibly adjusted. It is also required to secure a long-term budget support and a stable organization and to input a concentrated budget at the proper period when there is high efficiency of eradication.

Comparative analysis of the morphology and histochemistry of the duodenum of the coypu (Myocastor coypus bonariensis) during its prenatal and postnatal development

The objective of this study focused on the comparative morphological and histochemical analysis of the duodenum of fetuses, juveniles and adult coypu (Myocastor coypus bonariensis), the major socioeconomic wildlife resource of Argentina. Histological and histochemical procedures for in situ characterization of glycoconjugates (GCs) were used. This study evidenced that fetal mucins differ histochemically in many respects from their adult counterparts. Only in fetuses from 90 days-post coitus (dpc) glycogen-rich sites were observed throughout the duodenal epithelium. The goblet cells appeared from 105 dpc and their secretory content varied considerably after birth. Duodenal glands presented scanty neutral and sulphated GCs in the 30-day juveniles; in adults the proportion of these GCs increased, and carboxylated and sialylated GCs were also observed. The results obtained in this work may be used in future studies to evaluate the effects of diet and intestinal pathologies in the glycosylation pattern of GCs. Also, knowledge of the normal glycoprofile of the duodenum of M. coypus bonariensis during its ontogenetic development may constitute a basis for the study of this organ in other Hystricognathi rodents.

Carcass composition and meat quality of Czech genetic resources of nutrias (Myocastor coypus)

The effects of sex and colour type on carcass composition, nutrients content, and muscle fibre characteristics of hind leg meat of nutrias raised under intensive conditions were the focus of this study. Thirty-six eight-month-old nutrias of both sexes with three colour types (Standard nutria, ST; Moravian Silver, MS; and Prestice Multicolour, PM) were studied. Live weight was affected by colour type (P < 0.05) and sex (P < 0.001); however, no effects of these variables were found for the dressing out percentage. Crude protein content was significantly higher in males than in females, whereas crude fat content was higher in females. A significant interaction between colour type and sex was found for hydroxyproline and ash contents. Fatty acids were affected primarily by the sex of nutrias. No effect of colour type on the distribution of muscle fibres in the Biceps femoris muscle was found. However, females had fewer βR (P < 0.05) and more αR fibres (P < 0.001) than males.

Ecological conditions and isotopic diet (13C and 15N) of Holocene caviomorph rodents in Northern Patagonia

This work improves our knowledge about the relationship between diet and environment among Northern Patagonian caviomorph rodents. In order to characterize long-term individual diets, we present δ13C and δ15N data from osteological remains of the caviomorph rodents Dolichotis patagonum, Myocastor coypus, Lagostomus maximus, Lagidium viscacia, Microcavia australis, Galea leucoblephara and Ctenomys sp., recovered from archaeological and recent contexts. These data are analyzed by temporal and geographic context and compared with the previous dietary studies based on macrorremains and microhistological analysis. Significative differences were found between rodents from Monte and Patagonian phytogeographic provinces, as well as between archaeological and modern members of the genus Ctenomys, indicating diet changes between Late Holocene and recent times individuals, that could confirm the climatic variations and/or the recent overgrazing effect. The results indicate trends in rodent diets of 20th and 21st centuries were different to those of the Late Holocene, suggesting a decrease in precipitation and/or an increase of the summer pattern of the same, and/or an increase of mean annual temperature. In addition, this work confirms the generalist strategy of several taxa, although mainly in Ctenomys, which its diet co-varies with these environments.

Genetic and morphological characterization of Trichuris myocastoris found in Myocastor coypus in the Czech Republic.

Trichuris sp. individuals were collected from Myocastor coypus from fancy breeder farms in the Czech Republic. Using morphological and biometrical methods, 30 female and 30 male nematodes were identified as Trichuris myocastoris. This paper presents the first molecular description of this species. The ribosomal DNA (rDNA) region, consisting of internal transcribed spacer (ITS)-1, 5.8 gene and ITS-2, was sequenced. Based on an analysis of 651bp, T. myocastoris was found to be different from any other Trichuris species for which published sequencing of the ITS region is available. The phylogenetic relationships were estimated using the maximum parsimony methods and Bayesian analyses. T. myocastoris was found to be significantly closely related to Trichuris of rodents than those of ruminants.

Persistent organochlorine pesticides in internal organs of coypu, Myocastor coypus

A highly selective and sensitive method based on gas chromatography-tandem mass spectrometry (GC-MS/MS) to identify and quantify persistent organochlorine pesticides, (18 compounds including primary compounds and metabolites), in animal internal organs (kidneys, liver, and brain) has been developed. Tandem mass spectrometric conditions were individually optimized for each target compound in Multiple Reaction Monitoring (MRM) mode to obtain maximum sensitivity. Prior to instrumental analysis, a sample preparation method based on matrix solid phase dispersion (MSPD) followed by acidic digestion with sulfuric acid to reduce matrix co-extractives was employed. Analyses of real samples were carried out on coypus (Myocastor coypus) from the autumn slaughter of 19 animals. In the analyzed samples, three of the target compounds, namely DDE-pp′ (DDT metabolite), HCB and lindane, were detected. Their concentration levels fell in the ranges of 0.003–0.007, 0.003–0.025, and 0.003–0.021 mg kg−1 (0.005, 0.010, and 0.010 mg kg−1 on average) in the case of DDE-pp′, HCB and lindane, respectively. Although low quantities of organochlorine pesticides do not pose an immediate danger to consumers' health, they should be of public health concern considering long-term, low-dose exposure.

System response, nutria herbivory, and vegetation recovery of a wetland receiving secondarily-treated effluent in coastal Louisiana

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.

Modeling the spread of invasive nutrias (Myocastor coypus) over Iran

Nutria (Myocastor coypus) is a native aquatic rodent to South America, and was introduced to Europe, Asia, Africa and North America for fur farming. The South American nutria or coypu is now considered a pest in the area of introduction, because of its negative impact on biological diversity and ecological relationships. Having information on the invasion range of exotic species is crucial for understanding the ecology of invasive spread and for making good conservation and management planning to address this problem. At the beginning of the 20th century, nutria was introduced into Asia. Nutria was recorded for the first time in Iran in 1995. In the present study we proposed a multiple spatial scale approach to predict the invasion trends of the nutria in Iran, and to define up the “suitable scale” for predicting the invasion trends of this species. Our results highlighted the importance of environmental variables including vegetation density (for food and nesting) and water resource (streams, rivers, and lakes) in distribution of the nutria. Potential areas for the presence of the nutria are located near the Caspian Sea, west and central Iran which receive more precipitation than other parts of the country. Therefore, these parts of Iran may face a much greater risk of invasion risk in the future. Moreover, these results can show the possible risk of nutria invasion to the northern and western neighbors of Iran.

Distribution, spread and habitat preferences of nutria (Myocastor coypus) invading the lower Nakdong River, South Korea

Nutria (Myocastor coypus) were introduced into South Korea in 1985 for fur farming and meat production. However, failures of nutria farm management in the late 1990s resulted in the accidental and/or intentional release of nutria into the wild, and they have spread and become serious pests. The successful management of invasive species like nutria somewhat depends on the comprehensive knowledge of distribution patterns. Therefore, this study aimed to identify the distribution, spread, and habitat preferences of nutria invading the lower Nakdong River in South Korea to facilitate current control and eradication endeavours. Nutria populations were recorded in 45 of 236 sites investigated. The distribution patterns revealed that the spread of nutria from farming sites has mainly proceeded along rivers via tributaries. Important factors associated with the establishment of new populations were food availability, levees with suitable burrow materials, and slow water flow. The winter climate was also important, and the total number of days below −4 °C significantly affected nutria occurrence. To date, efforts to control or locally eradicate nutria populations have had little success due to insufficient budgets and the lack of coordinated management activities between local governments. To improve the efficiency of nutria eradication programmes, local governments must establish an integrated and coordinated strategy that is overseen by a single, national agency. To ensure the success of the programmes, this agency should make the best use of ecological information about nutria distribution, and utilize optimal control techniques and timing.