• Parasites, Hosts and Diseases
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• 제59권1호
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• pp.89-95
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• 2021

Microcotyle sebastis is a gill monogenean ectoparasite that causes serious problems in the mariculture of the Korean rockfish, Sebastes schlegelii. In this study, we isolated the parasite from fish farms along the coasts of Tongyeong, South Korea in 2016, and characterized its infection, morphology and molecular phylogeny. The prevalence of M. sebastis infection during the study period ranged from 46.7% to 96.7%, and the mean intensity was 2.3 to 31.4 ind./fish, indicating that the fish was constantly exposed to parasitic infections throughout the year. Morphological observations under light and scanning electron microscopes of the M. sebastis isolates in this study showed the typical characteristics of the anterior prohaptor and posterior opisthaptor of monogenean parasites. In phylogenetic trees reconstructed using the nuclear 28S ribosomal RNA gene and the mitochondrial cytochrome c oxidase I gene (cox1), they consistently clustered together with their congeneric species, and showed the closest phylogenetic relationships to M. caudata and M. kasago in the cox1 tree.

• Fisheries and Aquatic Sciences
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• 제27권2호
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• pp.66-75
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• 2024

Heavy metals are naturally found in the ecosystem, and their presence in the freshwater river is increasing through anthropogenic activities which pose a threat to living beings. In this study, heavy metal concentrations (Zn, Mn, Cu, Cd, Cu, Cr, Pb, and Ni) in different organs (muscle, skin, and gill) of fish from the Padma River were evaluated to quantify, and compare the contamination levels and related human health risks. The results revealed that the heavy metal concentrations in the water, surface sediments, and fish taken from the Padma River were far below the WHO/USEPA's permitted limits. The estimated daily intake (EDI) value in muscle was less than the tolerable daily intake (TDI). The target hazard quotient (THQ) and hazard indexes (HI) were less than 1, showing that consumers face no non-carcinogenic risk (CR). CR values of Cu, Cd, Cr, Pb, and Ni ranged from 4.00 × 10^-8 to 6.35 × 10^-6, less than 10^-4, and total carcinogenic risk (CRt) values ranged from 9.85 × 10^-6 to 1.10 × 10^-5, indicating some pose a CR from consumption of those fish from the Padma River. To establish a more accurate risk assessment, numerous exposure routes, including inhalation and cutaneous exposure, should be explored.

• 미생물학회지
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• 제31권2호
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• pp.113-122
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• 1993

본 논문은 양식장에서 자연감염된 궤양성 가물치로부터 우점종으로 분리된 Aeromonas veronii 를 건강한 가물치에 접종한 후, 어체 각 기관의 병변 진행사항을 조직학적 측면에서 연구한 것이다. 양식장내에서 자연 간염된 어체에서의 병변과정은 관찰할 수 없었지만, Aeromonas veronii 로 인공감염시킨 어체의 병변은 자연상태에서 감염된 병변과 매우 유사하였다. 인공감염시킨 어체는 감염후 2일째부터 피부를 비롯하여 아가미, 소화관 조직에 뚜렷한 조직괴사가 식별되었고, 5일 후에는 신장, 사망 직전인 9일 후에는 간과 비장까지 조직의 괴사내지는 세포응축을 나타냈다. 병이 진행됨에 따라 가물치는 피부손상을 비롯하여 호흡, 소화흡수, 배설 등 영양대사의 저해를 수반하면서 감염후 9일이내에 사망하는 것으로 나타났다. 자연감염 어체에서 우점종으로 분리된 균주, Aeromonas veronii 는 가물치의 출혈성 궤양증을 유발하는 주된 균증의 하나로 판단된다.

• 한국환경보건학회지
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• 제14권1호
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• pp.103-113
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• 1988

This experiment was performed to study the sequential accumulation of mercury in selected tissues of gold fish (Carassius auratus) exposed to 2, 6, 30, 120 and 300 $\mu$g Hg/1 as HgCl$_2$. In order to prepare treatment groups suitable for the present study, one control and five experimental groups, which were composed of I (2 $\mu$g/l), II (6$\mu$g/l), III (30$\mu$g/l), IV (120$\mu$g/l), V (300 $\mu$g/l), were used in 180 liter glass aquaria. The experiment was started by transfering 20 fish of average total length 140 $\pm$ 20 mm to each of the six tanks and allowing the uptake to take place for 12 weeks period. Fish were killed after time periods of 1, 2, 4, 8, and 12 weeks, and samples were disected by five parts gill, kidney liver, muscle and egg. The summarized results were as follows: 1. In control group, low concentrations of mercury(range 0.01-0.11 $\mu$g/g)were determined in the all selected tissues. 2. In experimental group, the average levels of mercury residues in the gill, kidney, liver muscle and egg were 3.61-189.54 $\mu$g/g, 13.91-182.58 $\mu$g/g, 8.56-66.49 $\mu$g/g, 0.30-20.33 $\mu$g/g, and 1.63-23.76$\mu$g/g, respectively. 3. The mercury residues in selected tissues of the experimental group were generally 230-9100 times higher than those of the control group. 4. The amounts of methylmercury per total mercury in the muscle after 12 weeks were 0.10/0.30 $\mu$g/g(33.33%) in the I group, 0.14/1.18$\mu$g/g(11.86%) in the II group, 0.25/5.76 $\mu$g/g(4.34%) in the III group, 0.39/11.48$\mu$g/g(3.40%) in the IV group and 0.40/20.33 $\mu$g/g(1.97%) in the V group.

• 한국수산과학회지
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• 제38권5호
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• pp.304-308
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• 2005

The effects of diethylhexyl phthalate (DEHP) on various oxidative stress responses in liver, kidney and gill tissues of freshwater bagrid catfish Pseudobagrus fulvidraco were investigated under laboratory conditions. Bagrid catfish were intraperitoneally injected with sunflower seed oil containing nominal concentrations of 0, 300 or 900mg DEHP per kilogram of body weight for 3 days and the effects after last injection were assessed in liver, kidney and gill tissues of the exposed organisms. The oxidative stress responses of fish were evaluated by analyzing the level of glutathione (GSH), as well as the activities of antioxidant enzymes such as glutathione S-transferase (GST), glutathione peroxidase (GPx) and glutathione reductase (GR). After exposure to the DEHP, there were significant decrease in GR, GPx activity and GSH content in liver of fish exposed to 900 mg DEHP per kilogram of body weight compared to the control group. Compared with the control group, significant decreases in renal GPx and GR activity were observed in the DEHP treatment groups (900 mg $kg^{-1}$ bw). However, no significant difference was observed in any oxidative stress responses in gills between the DEHP-treated and the untreated group of fish. The findings of the present investigation show that DEHP induce oxidative stress and the liver was the most affected organ followed by the kidney and gills. Furthermore, the changes of GPx and GR activities may be important indicators of oxidative stress responses but additional study is required to confirm the oxidative stress of DEHP.

• 한국수산과학회지
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• 제24권2호
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• pp.99-110
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• 1991

본 연구는 연안생물군집에서 먹이 그물과 영양단계간 물질의 이동을 이해하기 위한 연구의 일환으로 경상남도 삼천포시 신수도 연안에서 1차적으로 어류군집의 구조를 파악한 것이다. 어류는 1984년 2월부터 1985년 1월 사이에 삼중자강으로 해월 1회이상 채집하였다. 조사해역에서 동정된 어종수는 32종이며, 월평균 출현종수는 11종이었다. 이 중 연중 출현하면서 풍도가 높은 어종은 노래미, 쥐노래미, 볼락 및 농어이었고, 기타 어종은 특정 계절에 국한하여 일시적으로 출현하였다 어류군집에서 이들 4종이 차지하는 연평균 조성비는 개체수에서 $73.9\%$, 중량에서 $78.1\%$였다. 채집시기중 5월에 출현량이 가장 많았고, 1월에 가장 적었다. 월평균 종다양도 지수는 1.856이었고, 종다양도 지수가 가장 높은 달은 10월(H'=2.255), 가장 낮은 달은 4월이었다(H'=1.340). 그리고 우점 4종의 연령조성을 보면, 노래미와 볼락은 0세부터 4세까지, 쥐노래미는 0세부터 3세까지, 농어는 0세부터 2세까지이다.

• 한국어병학회지
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• 제11권1호
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• pp.69-76
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• 1998

매년 폐사가 발생해 온 서해안 연안의 고창과 태안에서 채집한 양식 바지락에서 복합포자충류인 Perkinsus sp.가 관찰되었다. 기생충에 감염된 바지락은 육안적으로 아가미와 육질의 표면에서 유백색의 결절이 나타났다. 기생충의 영양체는 편재된 핵을 가지고 있으며, 아가미와 외투막, 간 췌장, 생식소 조직에서 이분열에 의해 증식하며, 육아종의 형성과 혈구의 침윤을 유발하였다. 감염된 바지락을 FTM에 배양한 결과 영양체의 크기가 커지면서 루골용액에 의해 검게 염색된 구형의 유주자낭들 형성하였다. Perkinsus sp.의 평균 감염율은 9개월의 조사 기간 동안 고창이 73.1%, 태안이 94.8%로 나타났으며, 감염율은 각장의 크기가 클수록 증가하는 경향을 나타내었다. Hemacolor kit는 바지락의 대량폐사와 밀접한 연관이 있는 Perkinsus sp.의 영양체의 신속진단에 유용한 것으로 나타났다.

• 수산해양기술연구
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• 제46권3호
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• pp.223-231
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• 2010

This paper showed the difference between the selectivity of gill net by least square method with polynomials in Kitahara's and that by maximum likelihood analysis for Japanese sandfish and Korean flounder. Catch experiments for Japanese sandfish using commercial vessels off the eastern coast of Korea were conducted with six different mesh sizes between October and December 2007 and those for Korean flounder with five different mesh sizes between 2008 and 2009. The mesh size of 50% probability of catch corresponding to biological maturity length of fish was not different between that by least square method and that by maximum likelihood analysis for Japanese sandfish, however, a little different for Korean flounder, that is, those mesh sizes of 50% probability of catch for biological maturity length of Korean flounder were 10.6cm and 10.1cm by least square method and maximum likelihood analysis, respectively.

• Applied Microscopy
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• 제34권2호
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• pp.139-143
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• 2004

돌돔 아가미의 미세구조를 광학현미경과 투과전자현미경을 이용하여 관찰하였다. 아가미는 새궁 앞, 뒤 2열로 된 빗모양의 많은수의 새엽과 그리고 각 새엽은 전후 두 개의 새판(gill lamellae)이 근접하여 2열로 배열되어 있다. 상피세포층은 단층으로 큰 핵을 가진 편평상피로 구성되고 표면에는 미세융기가 잘 발달되어 있다. 새판의 기둥 구조는 세로 방향의 미세소관들과 측면 membrane interdigitation을 가지며, 염세포는 수많은 미토콘드리아와 tubular system이 잘 발달되어 있다. 미성숙된 점액세포는 조면세포체와 골지체가 잘 발달되었으며 일부 발달된 점액 과립을 가지고 있다. 성숙한 점액세포는 AB-PAS에 푸른 색을 띄었으며 구형이고 다양한 전자밀도를 가진 거의 같은 크기의 점액과립을 가지고 있다.

• 수산해양기술연구
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• 제51권1호
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• pp.16-25
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• 2015

Visual census and hydro-acoustic survey was carried out at Ulju small scale marine ranching area (MRA) to estimate demersal fish aggregations on September and November 2013. In this hydro-acoustic survey, the authors combined an image sonar with a scientific echo sounder to monitor an underwater situation and compare two acoustic data. Consequently, visual census survey was useful to estimate fish species composition for hydro-acoustic survey, because it is easy to identify aggregated fish species and overcome limits on a fishing depth and ability of an conventional fishing gear like a bottom gill-net or a fish trap at marine ranching area. Mean fish density was estimated as $0.757g/m^2$ on September and $0.219g/m^2$ on November and Fish abundance was finally calculated as 1.51ton (coefficient of variation, CV=13.1%) on September and 0.44ton (CV=47.7%) on November, respectively. Hydro-acoustic survey combined with the image sonar was useful to monitor fish aggregations and estimate fish stocks around artificial reefs at shallow coastal MRA. We were able to easily identify the underwater structures like an artificial reef and a fishing rope as well as fish aggregations from image sonar data. Therefore, the method was effective to separate unwanted echo signals in acoustic data of scientific echo sounder.