• 한국수산과학회지
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• 제51권4호
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• pp.456-460
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• 2018

Little is known about the movements of finless porpoises Neophocaena asiaeorientalis and their relationship with sea surface temperature (SST). A female finless porpoise that was stranded alive on the shore at Busan was rehabilitated for 16 months at the Sea Life Busan Aquarium. The porpoise was released off Geoje Island with a satellite tag on her mid-ridge and tracking data were received for 7 days. The porpoise moved directly to the southern shore of Gadeok Island, where an earlier study reported that finless porpoises were most abundant around the island. The tracking route revealed two other potential primary habitats. The porpoise moved to the middle of the east coast of the Korean Peninsula at Uljin, beyond the distribution boundary known from earlier studies. Satellite infrared images detected a cold water mass off the Uljin coast and the tracking route showed that the porpoise avoided this low-temperature area.

• 한국해양학회지:바다
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• 제25권2호
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• pp.26-41
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• 2020

본 연구는 중형저서동물의 생리·생태적 연구를 위한 생물을 배양하기 위해 다양한 환경 조건을 설정하여 중형저서동물이 실험실 내에서 가장 이상적으로 배양되는 조건을 파악하고자 하였다. 배양에 사용된 퇴적물과 해수는 서해안 만리포 조간대에서 채집하였다. 채집된 중형저서동물은 항온·항습 기능이 있는 챔버 내에 환경 조건을 조절할 수 있는 수조를 제작하여, 수조 내에 채집된 해수와 퇴적물과 함께 배양 실험을 수행하였다. 실험 1은 시료 채집 지역과 유사한 환경을 조성하여 실험을 수행하였다. 실험 2는 실험 1과 같은 조건에 먹이생물 공급 유무의 차이를 확인하였다. 실험 3에서는 빛과 먹이생물 공급의 유무의 차이에 따른 중형저서동물군집의 변화를 확인하였다. 배양 실험 결과, 중형저서동물 군집은 먹이공급을 하지 않은 수조에 비하여 먹이 공급을 한 수조, 빛이 없는 조건보다 12시간 주기의 빛이 있는 조건에서 서식밀도와 출현분류군수가 상대적으로 높게 나타났다. 또한 실험실 내에서 배양된 중형저서동물의 서식밀도는 자연 상태에 비하여 상대적으로 높은 값을 나타냈다.

• 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.

• 한국어병학회지
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• 제34권2호
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• pp.255-259
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• 2021

This is the first report describing acute mass mortality occurred in juvenile olive flounder (Paralichthys olivaceus) caused by gas bubble disease (GBD). A total of 610 fish (average weight = 35 g), which were more than half of the fish acclimated at 17℃ in an aquarium, were killed within two days of acclimation. The dead and moribund fish showed excessively opened opercula and mouths, and occasionally, severe exophthalmia. Through microscopic observation, numerous gas emboli were found in the gills of the dead and live fish, while the fish were not infected with any microbial pathogens. The dissolved oxygen (DO) saturation level of the rearing water and seawater nearby the facility reached 145% and 286%, respectively, whereas other water quality parameters (such as salinity, pH, and chemical oxygen demand) were normal. The extreme saturation rate of seawater in the shore nearby seemed to be due to an enormous algal bloom that occurred there. Through molecular identification based on 18S rDNA sequences, the most dominant algal species was most closely related to Ulva californica (99.87% sequence identity) followed by U. prolifera, U. linza, and U. curvata (99.81%). Therefore, it can be concluded that supersaturated seawater due to mass algal bloom caused gas bubble disease in the olive flounder, leading to mass mortality. After technical adjustment, such as increased aeration, lowered water circulation rate, and inlet water filtration using micro-pore carbon filters, the DO level became normal, no further mortality occurred and the status of the fish was stabilized.

• 한국미생물·생명공학회지
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• 제27권1호
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• pp.70-74
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• 1999

Vibrio vulnificus, a normal bacterial inhabitant of estuaries, is of concern because it can be a potent human pathogen, a causing septicemia, wound infections and gastrointestinal disease in susceptible host. In this survey, total 431 samples were obtained from different sites of the Chonman coastal area during the periods from Mar. 1997 to Feb. 1998. Vibrio vulnificus was isolated from the middle of May to the begining of November of 1997 in Chonman coastal area, as the seawater temperature was at 20$^{\circ}C$ and 15$^{\circ}C$, respectively and was rapidly increased to above 40% from July to September. The isolation rates of V. vulnificus from sediment, seawater, raw seafoods and aquarium water were 52.1%, 49.1%, 32.5%, and 27.3%, respectively and isolation rate was highest in oyster among various collected samples. V.vulnificus was also isolated from 73.1%(38/52) of sampling sites of Chonman coastal area.

• Journal of Ginseng Research
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• 제33권1호
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• pp.48-54
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• 2009

Epileptifrom discharges were induced in the telencephalon of the adult zebrafish via perfusion with pentylenetetrazole (PTZ), bicuculline methiodide, kainic acid-treated artificial cerebrospinal fluid (aCSF), and $Mg^{2+}$-free aCSF. Ginseng total saponin [GTS ($50{\mu}g/ml$)] was shown to attenuate the occurrence rate of epilpetiform discharges by 50-75%, compared to the control. Ginsenoside $Rg_1$ ($130{\mu}M$) reduced the epileptiform discharges in the isolated telencephalon and delayed the occurrence of behavioral seizures observed from the adult zebrafish placed in the PTZ (10 mM)-containing aquarium water. However, Re was not effective in the suppression of epileptiform discharges and behavioral seizures. These results indicate that $Rg_1$ may be useful in the control of epileptiform discharges and effective in controlling behavioral seizures, and that the zebrafish can be used as a model animal for the testing of potential anticonvulsant drugs.

• Animal cells and systems
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• 제16권5호
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• pp.400-407
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• 2012

Plant growth regulators are the chemicals that are found in plants and produced synthetically. In agricultural applications, plant hormones are used in minor quantities for fixing the problems. In our research, we studied the effects of 2,4 diclorophenoxyacetic acid (2,4D), which is an auxin used in agricultural applications. Auxins are the group that are used most popularly in plant growth regulators. In our study, different doses of 2,4 diclorophenoxyacetic acid are given to zebrafish, and ovarium tissues are observed histomorphologically. We generated one control and three experiment groups from the stock solution. The experiment was carried out in 20 liter capacity complete glass aquarium at $24{\pm}1^{\circ}C$ water temperature. After five days of application, fishes were dissected. Histomorphological changes of the ovarium were investigated under a light microscope. A decrease in the number of oocytes in zebrafish ovarium was observed when compared with the control group. Many deformed and underdeveloped oocytes were detected. An increase in the number of atretic oocytes was observed. It was deduced that acute doses of 2,4 diclorophenoxyacetic acid decelerates oogenesis in fishes.

• 한국수산과학회지
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• 제37권6호
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• pp.492-497
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• 2004

Waste concentration and waste generation rate in seawater aquaria by common conger (Astrocongey myriaster) and olive flounder (Paralichyhus olivaceus) were investigated. The initial fish density of common conger and olive flounder were $3{\%}\;and \;2.8{\%}$ of total weight of aquarium water, respectively Wastes in the seawater aquaria, such as protein, total suspended solid (TSS), ammonia, turbidity and chemical oxygen demand (COD) increased with days after stocking. Protein generation rate of common conger increased until 1 day after stocking while that of olive flounder increased until 3 days. The average protein generation rates of common conger and olive flounder were $0.28g/kg{\cdot}day\;and\;0.21g/kg{\cdot}day$, respectively. The trends of other waste generation rate were similar to protein generation rate.

• Animal Systematics, Evolution and Diversity
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• 제37권1호
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• pp.9-14
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• 2021

Invasive species threaten global biodiversity as well as human livelihood and much of the global lands are vulnerable to these threats. Numerous freshwater turtles from the northern hemisphere have been introduced in East Asian countries, including the Republic of Korea. Knowing turtle's behavioral ecology is valuable to manage introduced populations and a distinctive behavior is basking for behavioral thermoregulation. To understand the possibility of using basking to enhance trapping, we tested thermotaxis in the river cooter (Pseudemys concinna). Turtles were placed in an aquarium containing heated and non-heated mats under controlled water and air temperature, air humidity and light. We found that P. concinna stayed significantly longer on heated mats than on unheated control mats in 11 out of 18 trials, demonstrating that heat source is a potential attractant for P. concinna. We recommend the use of heat source to bait traps used for population control of invasive freshwater turtles.

• Fisheries and Aquatic Sciences
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• 제26권10호
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• pp.583-592
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• 2023

Celebes rainbow (Marosantherina ladigesi) is one of Indonesia's exported ornamental fish commodities, but the exploitation of this fish only relies on wild catches. The rise of unlimited fishing, especially those using poison, has changed the aquatic environment, threatening sustainability and causing fish extinction. This study aimed to evaluate the effectiveness of several types of feed in improving the absolute growth rate (AGR), specific growth rate (SGR), survival rate (SR), feed conversion ratio (FCR), feed efficiency (FE), hematology, and immune response of Celebes rainbow. The fish used in this study were male ornamental Celebes rainbow (M. ladigesi) weighing 1.32 ± 0.21 g/ind, reared in 54 L-aquariums at a stocking density of 30 individuals/aquarium for six weeks. The fish were fed according to the test diet consisting of live Tubifex sp worms, dry Tubifex sp worms, Spirulina platensis, and crumble pellets. The parameters observed were AGR, SGR, SR, FCR, FE, hematology, intestinal histology, liver histology, and a challenge test with the pathogenic bacteria Aeromonas hydrophila. The results showed that fish-fed live Tubifex sp worms had better AGR, SGR, SR, FCR, FE, hematology, and disease resistance compared to all other treatments. These results indicate that live Tubifex sp worms are the best feed for rearing Celebes rainbow.