• Journal of Species Research
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• 제1권1호
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• pp.100-103
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• 2012

Nutria Myocastor coypus is one of a well known invasive riparian mammal found species around world from North America to Eurasia and Africa. In South Korea, feral nutrias inhabit areas from the Nakdonggang and Namgang (River) to their tributaries and Upo Wetland where they have had devastating effects on environment. Nevertheless, there has been little research about nutrias in Korea. This study is to analyze the genetic structure of the nutria population in the Upo Wetland and identify the origin of the source populations. Twenty individuals from the Upo Wetland were genotyped using 25 microsatellite loci. When compared with another introduced population, that of the Blackwater Nation Wildlife Refuge in U.S., the Upo population contains considerable genetic variations. Tests for Hardy-Weinberg equilibrium and Bayesian clustering analysis suggest the Upo population is genetically structured and has at least two source populations. This preliminary study presents the need for further in-depth studies about this species which should combine genetic and ecological studies.

• Parasites, Hosts and Diseases
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• 제56권4호
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• pp.375-378
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• 2018

A total of 44 adult or juvenile nutrias were necropsied for disease survey. A large nodule was found in the liver of a nutria. The histopathological specimen of the hepatic nodule was microscopically examined, and sectional worms were found in the bile duct. The worms showed a tegument with spines, highly branches of vitelline glands and intestine. Finally, we histopathologically confirmed fascioliasis in a wild nutria. In the present study, a case of fascioliasis in a wild nutria is first confirmed in Korea.

• 한국동물위생학회지
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• 제40권2호
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• pp.139-142
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• 2017

A six-year-old male captive nutria (Myocastor coypus) maintained in a closed space with a small vent was found dead in his cage. Gross findings showed multifocal nodules in varying sizes, small 0.5 to large 5 cm in diameter, intermixed with normal parenchyma were scattered all over the surface of the lungs and a kidney, which the cut surface was smooth, compact and whitish in color. Microscopically, small round to oval neoplastic cells with modest to slight amounts of cytoplasm formed acinar and gland-like structures. Immunohistochemically, cells were strongly positive for E-cadherin and slightly reactive for thyroid transcription factor-1 (TTF-1). Based on those diagnostic features, the neoplasia was diagnosed as primary pulmonary adenocarcinoma (small cell type) and metastasized into the kidney. This is the first case report of malignant pulmonary tumor and its metastasis in the nutria.

• Parasites, Hosts and Diseases
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• 제52권5호
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• pp.531-535
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• 2014

Surveys on helminthic fauna of the nutria, Myocastor coypus, have seldom been performed in the Republic of Korea. In the present study, we describe Strongyloides myopotami (Secernentea: Strongyloididae) recovered from the small intestine of feral nutrias. Total 10 adult nutrias were captured in a wetland area in Gimhae-si (City), Gyeongsangnam-do (Province) in April 2013. They were transported to our laboratory, euthanized with ether, and necropsied. About 1,300 nematode specimens were recovered from 10 nutrias, and some of them were morphologically observed by light and scanning electron microscopies. They were 3.7-4.7 ($4.0{\pm}0.36$) mm in length, 0.03-0.04 (0.033) mm in width. The worm dimension and other morphological characters, including prominent lips of the vulva, blunted conical tail, straight type of the ovary, and 8-chambered stoma, were all consistent with S. myopotami. This nematode fauna is reported for the first time in Korea.

• 환경영향평가
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• 제22권3호
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• pp.241-254
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• 2013

The nutria(Myocastor coypus) that is originated from South America is a representative Invasive alien species in Korea. invasive alien species is one of the biggest causes for the loss of biodiversity and it may threaten the conservation and function of ecology as well as the welfare of mankind. Intense habitation has been made around the Nakdong River basin area that this study has analyzed the habitat density of nutria for the subject of 3 survey sites in the Nakdong River basin area. As a result of survey on habitation density in 2011 and 2012, under St.1 it was shown $2.01{\pm}0.21$/ha in 2011 and $0.69{\pm}0.55$/ha in 2012. Under St.2, it was shown $0.91{\pm}0.37$/ha in 2011 and $0.55{\pm}0.39$/ha in 2012. Under St.3, it was shown $5.31{\pm}0.72$/ha in 2011 and $3.99{\pm}2.31$/ha in 2012. The wet survey areas of St.1 and St.3 had shown relatively high habitation density compared to St. 2, the river survey area, and the average annual habitation density of the survey area was $2.74{\pm}2.29$/ha in 2011 and $1.74{\pm}1.18$/ha in 2012 that it has shown slightly reducing trend. As a result of measuring the morphology by capturing the habitation individuals, the average body length of adults is $92.23{\pm}9.41cm$, the length from the head to body for $53.90{\pm}5.15cm$, tail length for $38.33{\pm}4.83cm$, hind foot length for $13.82{\pm}1.00cm$, front foot length for $6.02{\pm}0.56cm$, and weight for $5.48{\pm}1.08kg$. As a result of comparing the types between genders, male showed a slightly higher figure in all parts compared to female and it showed significantly difference in total body length, head-body length, front foot length and total weight. As a result of analysis for each head-body length, other measured parts, weight and relativity for each measured part, all bodily part is shown to have the higher volume of correlations. The condition index of individuals in the survey area was shown in the average of $35.67{\pm}4.78$ with female for an average of $36.60{\pm}5.19$ and male for an average of $34.73{\pm}4.34$. The winter temperature in the southern area of Korea is considered for not greatly impacting on the habitation and development of nutria that, if there is no artificial control, it is considered to have certain concern of showing drastic breeding and territory expansion for the habitation group.

• 환경영향평가
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• 제26권1호
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• pp.1-10
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• 2017

본 연구는 제주도에 도입된 외래 포유동물인 뉴트리아의 서식현황과 생물학적 특성을 밝히기 위하여 2013년 5월부터 2016년 8월까지 수행되었다. 연구를 통해 트랩으로 5개체가 포획되었고, 사체 2개체를 수집하였다. 이중 부패가 심해 생물학적 정보가 불분명한 1개체는 분석에서 제외했다. 조사한 암컷 4개체와 수컷 2개체는 모두 백색계통이었고, 눈동자는 적색이었다. 외부형태와 두개골형질 분석, 해부학적 관찰결과들은 포획된 암컷들이 성적으로 성숙한 상태였으나 번식활동은 이루어지지 않았음을 알 수 있었다. 수컷 성체의 신체크기는 내륙의 성체와 유사하였다. 2013년 7개체 수집 이후 2014년 5월, 무인카메라에 1개체가 촬영되었으나 포획되지는 않았다. 이후 연구지역에서 지속적으로 모니터링을 실시한 결과, 서식하는 개체가 더 이상 확인되지 않아 자연사했거나 이주한 것으로 판단된다. 한정된 공간에서 토착 동물들과 유입종이 공존하는 제주지역의 특성에 맞는 뉴트리아의 관리방안을 마련하기 위해서는 제주도의 환경적 특성이 고려되어야 할 것이다. 이 연구 결과는 뉴트리아의 생물학적 특성을 이해하고, 제주도의 자연생태계 보호 프로그램을 마련하는 데 유용한 정보로 활용될 것이라 판단된다.

• 환경영향평가
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• 제22권5호
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• pp.491-511
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• 2013

In this study, three survey areas in Changnyeong, Miryang and Jinju of the confirmed the habitation of nutria and carried out the performance on the plant diet resource. From the habitat trace survey in the nutria habitat, a total of 336 trace points was shown. There were 181 trace points (54%) confirmed from St. 1 as the highest showing, followed by 52 trace points (15.4%) from St. 2, and 103 trace points (30.6)% from St. 3. The vascular plants distributed in the habitat area were a total of 182 taxonomic group with 57 families, 99 genus, 16 hybrids, and 1 race. The vascular plant living types in the habitat area are 1-year plant (Th, Th(w)) for 63class groups (34.6%), hemicryptophyte (H) for 42class groups(23.1%). plants, trees, crop plants were included. As a result of analyzing the overseas research cases on the diet plants of nutria, there are 195 taxonomic groups in a total of 39 families, 126 genus, 183 breeds, and 12 hybrids. In the study areas, feeding the plants was confirmed by the 7 taxonomic groups, aquatic plant, terrestrial From the total of 182 taxonomic groups discovered in the habitat area, 20 class groups, in 3 habitation region, 10 class groups of commonly appearing 49 class groups were shown to be the breed confirmed for diet in existing case studies, and assuming from it basis, the nutria habitating in the survey area is considered to have the supply of diverse diet resource to have flawless habitation. This is implication of having potential breeding possibility.

• 환경영향평가
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• 제27권1호
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• pp.33-55
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• 2018

생물다양성 감소의 가장 주요한 원인으로 외래생물의 유입이 지적되고 있으며, 특히 침입외래종으로 인한 서식지 파괴, 경제적 손실, 인체 피해 등이 가속화되고 있다. 국내에 유입된 외래생물은 2167종으로 생태계위해성평가를 통해 위해성이 높은 꽃매미(Lycorma delicatula), 붉은불개미(Solenopsis invicta), 뉴트리아(Myocastor coypus), 갯줄풀(Spartina alterniflora) 등 21종이 생태계교란 생물로 지정되어 있다. 국내에 유입될 경우 생태계에 부정적인 영향을 줄 수 있는 위해우려종은 생태계위해성심사를 통해 127종이 지정되어 있다. 이처럼 외래생물을 목록화하여 유입을 사전에 예방하고, 유입된 외래생물에 대한 피해를 최소화하기 위해 생물다양성 보전 및 이용에 관한 법률이라는 국가차원의 관리제도가 마련되었으나, 위험도에 따른 체계적인 관리체계 구축이 부족한 실정이며, 위해성 예측시 평가기준 및 분류군별 생태적 특성을 반영한 위해성평가표가 개발되어야 할 것이다.

• 한국환경생태학회지
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• 제36권6호
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• pp.582-591
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• 2022

본 연구는 제주특별자치도에 유입된 Myocastor coypus Molina, 1782 (Nutria)의 퇴치를 위해 이루어졌다. 서식확인 및 퇴치는 2013년 9월부터 2013년 11월까지 이루어졌고, 그후 퇴치 성공여부를 확인하기 위해 2022년 6월까지 조사가 이루어졌다. 서식 확인 및 포획은 무인카메라, 청문조사, 문헌조사, 먹이유인을 통한 트랩 포획법을 사용하여 진행하였다. 후속조사는 Nutria의 행동반경을 감안하여 조사범위를 비교적 넓게 설정하여 서식지역(퇴치지역)을 중심으로 4.0km² 내 습지 및 하천 조사를 진행하였다. 그 결과 서식 확인지역은 제주특별자치도 제주시 구좌읍 송당리 소재의 송당목장에서만 발견되었으며, 방목장 내 수로와 연못에서 서식흔적(족적, 배설물, 굴)이 확인되었다. 포획개체는 총 8개체였으며, 암컷 4개체, 수컷 3개체였다. 1개체는 서식확인 시 확인되어 부패 정도가 심해 암·수의 구별이 어려웠다. 후속조사는 설정한 조사범위 내 항시 물이 있는 성읍저수지, 천미천, 몰순이못을 중심으로 서식지와 그 주변을 정밀조사하였으나 서식흔적이 확인되지 않았다. 따라서, 제주도에 서식하는 Nutria는 완전히 퇴치된 것으로 판단된다. 제주특별자치도에서 Nutria의 퇴치가 성공적으로 이루어진 것은 Nutria의 서식 확인 후 빠른 포획을 통해 정착단계 초기에 퇴치가 이루진 것과 제주도 지질 특성상 물이 항시 고여있는 습지가 드물어 확장의 시기가 늦어진 것이 시너지 효과를 일으켜 성공적인 퇴치가 이루어진 것으로 판단된다. 이 결과들은 외래종의 유입에 대한 대처는 그 종의 생태특성을 신속하게 파악하고, 올바른 대처를 통해 확장단계 이전 정착 초기 단계에서 관리 및 퇴치를 통해 교란이 일어나기 전 또는 교란 초기에 차단하는 것이 매우 효과적인 방법임을 시사한다.

• Journal of Veterinary Science
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• 제21권1호
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• pp.1.1-1.4
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• 2020

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.