• 한국수산과학회지
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• 제56권2호
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• pp.243-252
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• 2023

Fluctuations in the price of aquaculture products have recently intensified. In particular, wholesale price fluctuations are adversely affecting consumers. Therefore, there is an emerging need for a study on forecasting the wholesale price of aquaculture products. The present study forecasted the wholesale price of olive flounder Paralichthys olivaceus, a representative farmed fish species in Korea, by constructing multivariate long-short term memory (LSTM) and gated recurrent unit (GRU) models. These deep learning models have recently been proven to be effective for forecasting in various fields. A total of 191 monthly data obtained for 17 variables were used to train and test the models. The results showed that the mean average percent error of LSTM and GRU models were 2.19% and 2.68%, respectively.

• 한국수산과학회지
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• 제42권4호
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• pp.322-328
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• 2009

Three-hundred and sixteen Escherichia coli strains from seawater, and a variety of farmed fishes, including oliver flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagrus major) and sea bass (Lateolabrax japonicus) between May to October in 2004, were tested by agar dilution method to determine their susceptibility patterns to 17 antimicrobial agents. Overall, 92.1% of Escherichia coli isolates from samples showed antimicrobial resistance to at least one antimicrobial agent and the multiple resistance was seen in 173 isolates (54.7%). The resistance of E. coli isolates to tetracycline (74.1%) was highest, followed by cephalothin (69.9%), doxycycline (66.5%), streptomycin (47.2%), ampicillin (46.2%), cefazolin (31.6%), enrofloxacin (31.0%). norfloxacin (28.2%). The most frequent resistance pattern was TE-D-CF-CIP-ENO-NOR-AM-S-C-SXT-AmC-CZ (14.7%), followed by CF (6.2%), TE (5.1%), TE-CF (4.5%) in 177 isolates from fishes and TE-D-CF (7.2%) followed by TE-D-CF-S (5.8%), CF and TE-D-S (3.6%) in 139 isolates from seawater.

• Parasites, Hosts and Diseases
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• 제61권3호
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• pp.332-337
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• 2023

Infestations of parasites, particularly those caused by copepods and monogeneans, are a major hindrance to aquaculture and have a big negative economic impact. Sebastes schlegelii, a farmed Korean rockfish, is particularly prone to copepods and monogeneans. This study comprehended how parasitic copepods and rockfish from a farm in Tongyeong-si, Gyeongsangnam-do, Korea, are related to the monogenean trematode Microcotyle sebastis. Our research revealed that monogeneans predominated, with a rate of 98.4% and an average infection intensity of 7 per infected fish. With an average infection intensity of 4 per sick fish, the infection rate for parasitic copepods was equally considerable, coming in at 91.7%. The high co-infection rate of both parasite families, at 90.8%, is noteworthy. Furthermore, Lepeophtheirus elegans and Peniculus truncatus, 2 parasitic copepod species, were discovered to have M. sebastis eggs attached to their bodies. This demonstrates a connection between parasitic copepod infestations in farmed Korean rockfish and the monogenean trematode M. sebastis. These discoveries highlight the necessity for creating more potent parasite control methods for the aquaculture sector and shed light on the intricate relationships between various parasite species.

• 한국어병학회지
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• 제25권1호
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• pp.59-65
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• 2012

인공종묘 생산 철갑상어 사육과정에 복부팽만을 특징으로 하는 질병이 발생하였다. 병어는 위와 소화관의 가스의 이상 축적에 의한 것으로 특히, 위의 분문부에서의 가스 축적이 현저하기 때문에 이상 유영을 하다가 폐사하게 된다. 병어의 위, 양어지의 배출수와 잔사에서는 원인체로 추정되는 Candida sp.가 검출되었다. 먹이와 함께 섭취된 Candida가 대사 과정 중에 발생하는 가스가 위에 축적됨으로서 위가팽창하게 되고, 일부는 식도와 부레로 이동한 것으로 생각된다.

• 한국어병학회지
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• 제16권2호
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• pp.81-90
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• 2003

High mortality with signs similar to viral haemorrhagic septicemia (VHS) such as severe haemorrhages in the skin, muscle and air bladder occurred in the farmed adult rainbow trout, Oncorhynchus mykiss, in Ku-mi and Je-chun area in Korea. The isolates were neutralized by an antiserum against IHNV but not by antisera against VHSV. Electron micrograph of an ultrathin section showed large numbers of bullet-shaped virus particles. The newly isolated rhabdovirus was composed of five structural proteins. In the western blot analysis Ihe anti-DiNV serum strongly reacted with G. N and MI protein. The cumulative mortalities of RTK infected rainbow trout (10-12cm.9-12g) with $10^{3.5}\;and\;10^{1.5}TCID_{50}/m{\ell}$ were 80% and 30%. respectiveIy_ RTJ infected fish showed 50% mortality by infection with $10^{3.5}TCID_{50}/m{\ell}$. Control group and IHNVChAb exhibited no mortality. From these results, the viruses were identified lHNV although diseased fish showed similar sign. with VHS and caused high mortality in large-sized fish.

• 한국동물위생학회지
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• 제36권4호
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• pp.297-301
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• 2013

The present study was to investigate anti-microbial effects of curcumin on major bacterial pathogens for farmed fish, such as Aeromonas hydrophila, A. salmonicida subsp. masoucida, A. salmonicida subsp. salmonicida, Edwardsiella tarda, Vibrio vulnificus, V. paraheamolyticus using disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests. In disc diffusion test, curcumin exhibited concentration-dependent antimicrobial activities to all bacteria pathogens used in the study. Antimicrobial effects of curcumin was found differently depending on bacterial species when determined by MIC or MBC tests. For examples, E. tarda and A. hydrophila was respectively the most sensitive bacterium for bacteriostatic and bacteriocidal effect of curcumin. Collectively, curcumin could be a potential natural drug for controlling pathogenic bacteria in the aquaculture industry.

• 한국어병학회지
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• 제21권3호
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• pp.209-217
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• 2008

A disease with mass mortality characterized exophthalmia and abdominal distension by ascites occurred in farmed starry flounder, Platichthys stellatus in Pohang since October of 2007. Severe necrosis and infiltration of inflammatory cells were observed in tissue histopathological sections from liver, kidney, spleen and heart of the diseased fish. The catalase-negative and gram positive cocci with -hemolysis were isolated from moribund fish. Analysis of the API profiles and the multiplex PCR of the isolates showed that strains were identified as Streptococcus parauberis. In API profiles, S. parauberis isolated from starry flounder differed from those of olive flounder, Paralichthys olivaceus to the test of arginine dihydrolase, D-mannitol, D-sorbitol and α-lactose. And the strains, PH0710 and PH0711, were strongly lethal for starry flounder (LD50 ranging from 4.2×103~4.2×102 cfu/fish at 7 days after intraperitoneally inoculation). This is the first report on a S. parauberis infection in starry flounder.

• 한국어병학회지
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• 제20권3호
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• pp.201-209
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• 2007

Viral Hemorrhagic Septicemia Virus (VHSV)는 유럽과 북미지역의 담수 무지개송어에 심각한 바이러스성 질병을 야기하는 원인체였으나 담수어류 뿐만 아니라 해산어류에서도 심각한 질병을 유발하며 최근 일본과 우리나라 양식 넙치에서 VHSV에 의한 대량 폐사 발생이 보고되고 있다. 본 연구는 VHS에 대한 예방학적 접근의 일환으로서 자연산 어류로부터의 VHSV 검출 및 지리적 분포, 보균 어종에 대한 유전학적인 조사를 목적으로 2003년과, 2005년도에 동중국해역 3지점, 서해안 5지점 그리고 남해안 5지점에서 어류를 채집하였다. RT-PCR을 이용한 연구결과 자연산 해산어류 160마리 중 12종 17마리에서 VHSV가 검출되어 검출율 10.6%를 보였으며 조사된 12종의 어류 중 특히 상어목에서 가장 높은 검출율을 보였다. VHSV G gene을 이용한 계통분류학적 분석결과 염기서열 분석에서 양식산어류의 분리주 (KVHS01-1)와 98.4%～99%, 아미노산 분석에서 97～99% 유사성을 나타내어 본 연구에서 조사되어진 자연산 어류에서 분리된 VHSV는 GenogroupⅠ에 속하였다.

• Fisheries and Aquatic Sciences
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• 제17권1호
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• pp.1-11
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• 2014

The Kenyan aquaculture sector is broadly categorized into freshwater aquaculture and mariculture. Whereas freshwater aquaculture has recorded significant progress over the last decade, the mariculture sector has yet to be fully exploited. The Kenyan aquaculture industry has seen slow growth for decades until recently, when the government-funded Economic Stimulus Program increased fish farming nationwide. Thus far, the program has facilitated the alleviation of poverty, spurred regional development, and led to increased commercial thinking among Kenyan fish farmers. Indeed, national aquaculture production grew from 1,000 MT/y in 2000 (equivalent to 1% of national fish production) to 12,000 MT/y, representing 7% of the national harvest, in 2010. The production is projected to hit 20,000 MT/y, representing 10% of total production and valued at USD 22.5 million over the next 5 years. The dominant aquaculture systems in Kenya include earthen and lined ponds, dams, and tanks distributed across the country. The most commonly farmed fish species are Nile tilapia Oreochromis niloticus, which accounts for about 75% of production, followed by African catfish Clarias gariepinus, which contributes about 21% of aquaculture production. Other species include common carp Cyprinus carpio, rainbow trout Oncorhynchus mykiss, koi carp Cyprinus carpio carpio, and goldfish Carassius auratus. Recently, Kenyan researchers have begun culturing native fish species such as Labeo victorianus and Labeo cylindricus at the National Aquaculture Research Development and Training Centre in Sagana. Apart from limited knowledge of modern aquaculture technology, the Kenyan aquaculture sector still suffers from an inadequate supply of certified quality seed fish and feed, incomprehensive aquaculture policy, and low funding for research. Glaring opportunities in the Kenyan aquaculture industry include the production of live fish food, e.g., Artemia, daphnia and rotifers, marine fish and shellfish larviculture; seaweed farming; cage culture; integrated fish farming; culture of indigenous fish species; and investment in the fish feed industry.

• 한국양식학회지
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• 제18권3호
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• pp.196-199
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• 2005

Farmed red sea breams, Pagrus major, were fed for 60 days with pellets containing different concentrations of benzo(a)pyrene (0, 0.2, 2, 20 mg/kg) to generate a biomarker of the chemical toxicity in the fish. The fish exposed to the chemical concentrations did not show any significant difference in the weight gain, conditioning, factor, and hepatosomatic index. However, some haematological parameters, such as glucose, calcium, magnesium, GOT (glutamic oxalate transaminase), and GPT (glutamic pyruvate transaminase) were influenced by the chemical exposure. Of them, two enzymes, GOT and GPT, increased significantly 60 days after the exposure in a way of concentration dependence (P<0.05). In the study of ecotoxicological biomarker, sensitivity to adverse environments is one of the key available factors. The fish changes in GOT and GPT were an earlier and reliable sign of the fish response against the chemical exposure, rendering the two enzymatic factors as a useful biomarker at least to benzo(a)pyrene exposure in the farming waters.