• Parasites, Hosts and Diseases
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• 제46권2호
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• pp.109-112
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• 2008

A parasitological investigation on trematode metacercariae was made on 62 freshwater fishes of 13 species in northern Thailand; Cyclocheilichthys apogon, Puntioplites proctozysron, Labiobarbus siamensis, Barbodes gonionotus, Barbodes altus, Henicorhynchus siamensis, Osteochilus hasselti, Notopterus notopterus, Mystacoleucus marginatus, Anabas testudineus, Systomus orphoides, Morulius chrysophykadian, and Hampala macrolepidota. The fish were caught over the summer period (February-May 2007) from 2 Chiang Mai water reservoirs, i.e., the Mae Ngad (UTM 47Q E 503200, 47Q N 2119300) and the Mae Kuang Udomtara (UTM 47Q E 513000, 47Q N 2092600) Reservoirs in Chiang Mai province, Thailand. The prevalence of heterophyid (Haplorchis taichui and Haplorchoides sp.) metacercariae in these fish was 83.9% and 74.2% in the Mae Ngad and Mae Kuang Udomtara Reservoirs, respectively. The highest intensity of heterophyid metacercariae in H. siamensis in the Mae Ngad was 120.4 and that in P. proctozysron in the Mae Kuang Udomtara was 180.0. The fish, A. testudineus, C. apogon, and M. chrysophykadian, were not found to be infected with H. taichui metacercariae. The results show that the freshwater fish in Chiang Mai water reservoirs are heavily infected with H. taichui and Haplorchoides sp. metacercariae.

• 한국환경생태학회지
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• 제9권1호
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• pp.42-48
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• 1995

충청북도 제천시의 상수도 취수를 목적으로 건설하는 취수장 예정지를 중심으로 평창강의 담수어류상을 1994년 9월 25일과 1994년 10월 7일부터 1994년 10월 9일까지 두 차례 조사하고 하천 유지수량의 변동이 어류의 생태에 미치는 영향을 조사하였다. 6개 조사 지역에서 총 6과 21속 28종의 담수어류가 관찰되었으며 천연기념물 및 한국 특산종이 많이 관찰되었다. 평창강은 사행천으로 다양한 담수어류가 서식하기에 적합한 환경과 유지수량을 갖는다. 취수를 위한 급격한 유지 수량의 감소는 평창강의 담수어류가 대부분 멸종할 우려가 매우 높다.

• 환경영향평가
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• 제30권1호
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• pp.1-12
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• 2021

본 연구는 환경DNA 기술을 이용한 국내 담수어류종 탐지방법 도입 및 적용가능성을 확인하기 위해 수행되었다. 환경DNA를 이용한 모니터링 기술은 기존의 현장조사 모니터링 방식에 비하여 교란이 적고 편의성이 높으며 조사에 대한 감도가 높아 급변하는 하천 생태계 모니터링을 위한 효율적인 방법으로 주목받고 있다. 본 연구의 대상지는 경기도 민물고기 생태학습관으로 수족관 내 수조, 생태연못, 양식장에 서식하는 국내 대표적 담수어류종에 대해 7월부터 10월까지 3차례의 물 환경시료를 수집하여 환경DNA 분석을 실시하였다. 국내 담수생태계의 다양한 서식환경을 고려하여 선정된 종에 대해 기 구축된 유전자생물종 DNA 염기서열 특성을 검토하고, 종 검출 여부 확인을 위해 채수된 16개의 환경시료를 Miya et al(2015)에서 제시된 환경DNA 분석 프로토콜에 준하여 분석하였다. 그 결과 대상 어종 총 7목 11과 50종 중 7목 11과 45종(90%)이 검출되었다. 이는 환경DNA 기술과 기 구축된 어류종 DNA DB를 활용하여 다양한 환경조건에서도 단순한 채수 샘플링으로부터 국내 서식하고 있는 주요 민물고기 어종이 검출되었다는 점에서 의의가 있다. 나아가 실험 중 발생된 수족관 내 시료 오염, 불균질한 DNA 채집, 생물종 유전자정보 누락 등의 오차요인들을 분석하여 자연환경에서 적용 시 앞으로의 보완 방향에 대하여 제시하였다.

• 한국환경생태학회지
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• 제21권6호
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• pp.506-514
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• 2007

영랑호 어류군집의 시 공간적 분포를 알아보기 위하여 2005년 9월부터 2007년 4월까지 조사하였다. 채집된 어류는 총 16과 32종이었으며, 일차담수어는 11종(34.38%), 주연성담수어는 18종(56.25%), 해수어는 3종(9.38%)인 것으로 나타났다. 조사 지점 및 시기별 군집의 변화양상을 파악한 결과 갯터짐이 일어나면 생태적 특성에 따라 어종의 출현 비율이 변화하는 것으로 나타났다. 또한 영랑호의 어류상에 대한 과거 자료와 비교해 보았을 때 해수의 유입이 일어나면 주연성담수어와 해수어의 비율은 증가하고 일차담수어의 비율은 점차 감소하는 것으로 나타났다. 이와 같이 석호 내의 어류군집은 갯터짐에 따라 시 공간적으로 그 성격이 매우 달라는 것으로 나타났다.

• 한국어류학회지
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• 제21권sup1호
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• pp.29-37
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• 2009

The tiny fragment of freshwater body is providing home for huge biodiversity and resources for the existence of human. The competing demand for freshwater have been increased rapidly and it caused the declination of biodiversity in recent decades. Unlike the natural process of extinction in gradual progress, the current species extinction is accelerated by human activity. As a result many fish species are already extinct or alive only in captivity in the world and about fifty eight animal species are in endangered in Korea including eighteen freshwater species. Conservation of biodiversity is the process by which the prevention of loss or damage is attained, and is often associated with management of the natural environment. The practical action is classified into in-situ, or ex-situ depending on the location of the conservation effort. Recovery means the process by which the status of endangerment is improved to persist in the wild by re-introduction of species from ex-situ conservation population into nature or translocation of some population. However there are a lot of restrictions to complete it and successful results are known very rare in case. In this article the authors explore some strategies for conservation and restoration of freshwater fish species conducted in Korea for few years. The major causes are discussed in relation with the decline of freshwater fish diversity during few decades and some strategies are evaluated to advance the process of conservation. A study on the Korean bullhead, Pseudobagrus brevicorpus, is introduced as a case for ex-situ conservation and restoration in freshwater ecosystem.

• 한국어병학회지
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• 제15권2호
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• pp.93-97
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• 2002

The scuticociliate, a histophagous ciliate, is known to cause high cumulative mortalities in juvenile olive flounder Paralichthys olivaceus rearing in land-based tank facilities. This study examined effects of bath treatment of 3 chemical agents including formalin, hydrogen peroxide and sodium chloride. and freshwater against scnricociliates infected olive flounder. Although 100 ppm formalin and freshwater did not completeIy eliminale ue scuticociliates within the internal organ of fish, chemicals were effective to prevent scuticociliatosis from spreading. It confirms the efficacy of the chemical with treating the diseased fish for at least 4 consecutive days.

• 한국어병학회지
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• 제8권2호
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• pp.81-90
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• 1995

한국산 민물어류에 기생하는 연충류를 조사하기 위해 본 연구를 시행하였으며, 본 논문에서는 2종류의 흡충류를 동정, 분류하였다. Orientocreadium koreanum n. sp.는 퉁가리의 장에서 검출된 신종이며, O. pseudobagri Yamaguti, 1934는 동자개의 장에서 검출된 한국산 미기록 종이었다. Orientocreadiidae과의 분류학적 문제점들에 관해 고찰하였으며, 분류된 2종에 대해 기존의 기록종들과의 차이점들을 상세히 논하였다.

• 한국어병학회지
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• 제2권2호
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• pp.115-124
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• 1989

• Mycobiology
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• 제47권2호
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• pp.135-142
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• 2019

Many members of the Saprolegniales (Oomycete) cause mycoses and disorders of fishes, of which Achlya and Saprolegnia are most ubiquitous genera worldwide. During a survey of the diversity of freshwater oomycetes in Korea, we collected seven isolates of Achlya, for which morphological and molecular phylogenetic analyses enabled them to identify as Achlya americana and Achlya bisexualis. In Korea, only a species of Achlya, A. prolifera, has been previously found to cause seedling rot on rice (Oryza sativa), but none of the two species have been reported yet. Importantly, A. bisexualis was isolated from a live fish, namely rice fish (Oryzias sinensis), as well as freshwater, and this is the first report of Achlya-causing mycoses on freshwater fishes in Korea. The presence of A. americana and A. bisexualis on live fish in Korea should be closely monitored, as considering the well-known broad infectivity of these species it has the potential to cause an important emerging disease on aquaculture industry.

• Fisheries and Aquatic Sciences
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• 제8권1호
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• pp.38-42
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• 2005

We evaluated the effects of different feeding strategies on the growth of young Nile tilapia, Oreochromis niloticus L., in a freshwater recirculating system during summer. Each of twenty fish (Mean body weight$\pm$ SD; 37. 7$\pm$0.10 g) were randomly distributed into each of 24 tanks. Eight treatments were prepared in triplicate. Control fish were hand-fed commercial feed twice daily without starvation. The other seven treatments employed different feeding and starvation strategies ranging from I day starved and 1 day fed (1DS+ 1DF) to 7 days starved to 7 days fed (7DS+7DF). All fish survived to the end of the 44-day feeding trial. The amount of food supplied was highest for the control fish in the control. Food supplied to fish in the 3DS+3DF and 4DS+4DF treatments was significantly lower than that of fish in the 1DS+1DF and 2DS+2DF treatments, but significantly higher than that of fish in the 5DS+5DF, 6DS+6DF and 7DS+7DF treatments. The weight gain of control fish was significantly higher than that of fish in other treatments. Feed efficiency ratio (FER) for fish in the 7DS+7DF treatment was significantly higher than that of fish in the control group, but it did not differ from that of fish in the 1DS+1DF and 2DS+2DF treatments. We concluded that young Nile tilapia raised with different starvation and feeding regimes during the summer in a freshwater recirculating system did not catch up in growth to fish fed daily. However, the enhanced FER of Nile tilapia in the 7DS+ 7DF, 2DS+ 2DF, and 1 DS+ I DF treatments partly explains the compensatory growth of the fish, although their weight gain was relatively low.