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.

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.

Cytogenetic tests are used to assess the influence of physical and chemical factors with potential mutagenic and genotoxic properties on the animal organism. The test results make it possible to eliminate mutagens, as well as helping predict possible genetic consequences in animal cells and assess animal resistance. The aim of this study was to examine, using cytogenetic tests, the spontaneous chromosome and DNA damage in coypu lymphocytes. Four tests: fragile site (FS), bleomycin (BLM), micronucleus, (MN) and comet were used for the first time in coypu cells. The averages with standard deviations obtained in the research were as follows: 3.30 ± 0.80 fragile sites/cell; 0.63 ± 0.80 BLM damage/cell; 6.10 ± 0.53% binucleated cells with MN; and 3.24 ± 0.63% DNA in tail. The present analysis showed high interindividual variation in spontaneous chromosomal and DNA damage levels. In the case of micronucleus, fragile sites, and comet assays, the differences between animals were statistically significant. The data suggest that these assays are sensitive enough to detect some effects on an individual animal and can be proposed as tools for coypu biomonitoring.

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.

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.