• Fisheries and Aquatic Sciences
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• 제23권1호
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• pp.1.1-1.14
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• 2020

Background: Dietary protein requirements are dependent on a variety of factors and water temperature is one of the most important abiotic factors affecting protein requirement of fish. This study was, therefore, conducted to investigate effects of water temperature on dietary protein requirement of fry Heteropneustes fossilis which has high demand in most of the Asian markets. Methods: Quadruplicate groups of 30 fish per treatment (2.97 ± 0.65 cm; 5.11 ± 0.34 g) were fed seven isoenergetic diets (17.9 kJ g^-1 gross energy; 14.99 kJ g^-1 digestible energy) containing dietary protein levels ranging from 28 to 52% at two water temperatures (18 and 26 ℃). Experimental diets were fed to apparent satiation as semi-moist cakes thrice daily at 17:00, 12:00, and 17:30 h for 12 weeks. For precise information, various growth parameters, protein deposition, hematological parameters, metabolic enzymes, and stress response were analyzed, and effects of water temperature on dietary protein requirement was recommended on the basis of response from above parameters. Results: Groups held at 26 ℃ attained best growth, feed conversion, and protein deposition at 44% dietary protein indicating that temperature affected dietary protein requirement for optimum growth of H. fossilis fry and protein requirement seems to be satisfied with 44% dietary protein. Interestingly, interactive effects of both dietary protein levels and temperature were not found (P > 0.05). Fish reared at 18 ℃ had comparatively higher values for aspartate and alanine transferases than those reared at 26 ℃ water temperature which exhibited normal physiological value for these enzymes indicating that body metabolism was normal at this temperature. Hematological parameters also followed same pattern. Furthermore, fish reared at 26 ℃ water temperature exhibited more resistant to thermal stress (P < 0.05). The 95% maximum plateau of protein deposition data using second-degree polynomial regression analyses exhibited dietary protein requirement of fry H. fossilis between 40.8 and 41.8% of diet at 26 ℃ water temperature. The recommended range of dietary protein level and protein/digestible energy ratio for fry H. fossilis is 40.8-41.8% and 27.21-27.88 mg protein kJ^-1 digestible energy, respectively. Conclusions: Information developed is of high significance for optimizing growth potential by making better utilization of nutrient at 26 ℃ and, to develop effective management strategies for mass culture of this highly preferred fish species.

• 한국어병학회지
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• 제30권1호
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• pp.41-49
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• 2017

생균제는 성장촉진, 면역증진 및 질병예방에서 넙치 Paralichthys olivaceus 치어의 양식에서 우수한 생산효과로 적용될 수 있다. 성장률, 선천성면역 및 항병력을 증강시킬 수 있는 생균제의 효과를 조사하기위해 Bacillus subtilis, Bacillus licheniformis 및 Lactobacillus plantarum (BSL-LAB)이 혼합되어있는 생균제와 NBS (nitrifying bacteria con- sortium) 분말을 사료에 첨가 또는 수조에 투입하여 시험을 수행하였다. 생균제 첨가사료는 7주간 투여하였고 3가지의 생균제 조합 시험군 모두에서 넙치의 성장과 항병력에서 대조군에 비해 높은 유효성을 발휘 하였다. 어병세균에 대한 항병력의 긍정적인 결과는 생균제에 대한 면역기능의 향상으로 나타난 효과이며 상기 시험결과로 볼 때, 넙치치어 양식에서 생균제의 혼합첨가는 성장 및 선천성면역 뿐만 아니라 질병저항성에 좋은 효과를 나타낼 수 있을 것으로 사료된다.

• 한국수산과학회지
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• 제44권2호
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• pp.141-148
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• 2011

This feeding experiment was conducted to investigate the effects of dietary inclusion of various additives on growth performance, hematological parameters, fatty acid composition, gene expression and histopathological changes in juvenile olive flounder (Paralichthys olivaceus). Eleven isonitrogenous (49% crude protein) and isolipidic (10% crude lipid) experimental diets were formulated: no additives (Con); 5% kelp meal (Ke); 10% krill meal (Kr); 1% garlic powder (Ga); 1% citrus meal (Ci); 3% onion powder (On); 1% ginger powder (Gi); 1% mugwort powder (Mu); 1% licorice powder (Li); 1% wasabi powder (Wa); and a mixture (Mix) of these additives. Three replicate groups of juvenile flounder (average weight of 8.5 g) were fed one of the experimental diets to visual satiety twice a day for 15 weeks. The dietary inclusion of additives did not affect survival, weight gain, specific growth rate feed efficiency, daily feed intake, daily protein intake, protein efficiency ratio, hepatosomatic index and visceralsomatic index of the fish. Plasma triglyceride levels were significantly lower in fish fed the Ke, Ga, On, Gi, Mu, Li, and Mix diets than in fish fed the control diet. Plasma glucose, glutamic oxaloacetic transaminase and total cholesterol did not differ among dietary treatments. No significant difference was observed in fatty acid composition and lipid content of the dorsal muscle in fish fed the experimental diets. Myosin gene expression did not differ significantly among treatments after 5 weeks but was significantly lower in fish fed the Kr, Ci, Li, and Mix diets than in control group after 15 weeks. Histopathological analysis showed mild gill hyperplasia and mild necrosis of liver parenchymal cells in several individuals of each experimental group. These conditions were also observed in the control group and were not thought to be related to the inclusion of feed additives. The present findings indicate that the dietary inclusion of additives did not affect growth performance, fatty acid composition, gene expression, and histopathological changes in juvenile flounder. However, plasma triglyceride content may be reduced by supplementation with 5% kelp meal, 3% onion powder, 1% garlic powder, 1% ginger powder, 1% mugwort powder, and the additive mixture.

• 한국어류학회지
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• 제27권4호
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• pp.293-299
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• 2015

최초 체중 (IBW) 1.14 g 돌돔 (Oplegnathus fasciatus) 치어를 1종 실험 사료 (ED)와 5종 국내 외 상품 사료 (CED)로 28일간 사육한 결과 최종 체중 (FBW), 증체율 (WG) 및 사료 효율 (FE)에서는 유의적인 차이가 나타났지만, 생존율 및 전어체의 일반성분에서는 차이를 나타내지 않았다. 돌돔 치어는 사육 실험 후에는 사료 종류에 따라 FBW가 3.1~7.0 g, WG도 168~516%로 실험 구간에 유의적인 성장 차이를 나타내었다. FE는 65~147%이었으며 성장과 유사한 경향을 나타내었다. DCCD구와 IOCD구에서 각각 6.5 g과 7.0 g으로 가장 높은 FBW를 나타내었으며, 다음으로 ILCD구에서는 5.5 g이었고, DECD구와 IHCD구에서 4.8 g과 4.3 g으로 CED구 중에서는 가장 낮았다. 모든 실험구 중 EDP구는 3.1 g으로 FBW에서도 가장 낮게 나타났으며 실험 구간에 2배 이상의 유의적인 차이 를 나타내었다. 높은 단백질 및 지질을 함유한 국외산 O제품(단백질 66.6%, 지질 13.0% 및 회분 14.3%)과 국내산 C제품(단백질 61.3%, 지질 14.6% 및 회분 13.5%)에서 가장 높은 성장과 사료 효율을 나타내었다. 하지만, 다양한 6종류 실험 사료 또는 상품 사료 공급에 따라 생존율과 전어체의 일반성분인 수분, 단백질, 지질 및 회분은 유사한 결과로 다양한 먹이인 사료 종류에 따라 돌돔 치어의 생존율 및 전어체의 일반성분에는 차이가 없는 것으로 나타났다.

• 수산해양기술연구
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• 제53권4호
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• pp.471-475
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• 2017

This study aims to suggest the methodology to improve to estimate back-calculated fish growth parameters using weighted average. It is to contribute to correct errors in the calculation of back-calculated growth equation with unequal numbers of sample by age. If the numbers of sample were evenly collected by age, each back-calculated length at age was equal between arithmetic and weighted averages. However, most samples cannot be evenly collected by age in reality because of different catchability by fishing gear and limitation of environment condition. Therefore, the estimation of back-calculated length by weighted average method is essential to calculate growth parameters. There were some published growth equations from back-calculated length using a simple arithmetic average with different numbers of samples by age when searching for back-calculated growth equations from 91 relevant papers. In this study, the process of deriving growth equation was investigated and two different average calculations were applied to a fish growth equation, for example of Acheilognathus signifer. Growth parameters, such as $L_{\infty}$, k and $t_0$, were estimated from two different back-calculated averages and the growth equations were compared with growth performance index. Based on the correction of back-calculated length using weighted average by age, the changes by female and male were -14.19% and -5.23% for $L_{\infty}$, and 59.28% and 18.91% for k, respectively. The corrected growth performance index by weighted average improved at 7.05% and 2.46% by female and male, respectively, compared to the arithmetic averages.

• 한국미생물·생명공학회지
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• 제29권1호
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• pp.56-61
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• 2001

For the development of probiotics in aquaculture of marine organisms, three strains having psychrophilic and salt tolerant characteristics were isolated from Kimchi. Amng the isolated strains. MG19, MG89 and MG208 were identified as Lactobacillus brevis, Enterococcus faecium and Lactobacillus plantarum, respectively. The neutralized culture broth of isolated strains were tested in order to evaluate the antibactrial activity, 조초 showed high antibacterial activity against Edwardsiella tarda, Vibrio cholerae andPseudomonas fluorescens. In mixed culture of pathogens and isolated strain,pathogens were signifi-cantly inhibited after 2 days of cultivation but the isolated strains showed normal growth. When the Edwardsiella tarda was cultured with three isolated strains, its growth was completely inhibited after 254 hours of cultivation. The effect of isolated three strains as probiotics was investigated based on the changes in body weight of aquacultured flounder. After 50 days feeding trial, it was found that the mean body weight gain of the tested group fed freeze-dried isolated cells was significantly greater than that of the control group. These results suggest that these isolated strains can play an important role as probiotics in aquaculture.

• 수산경영론집
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• 제48권4호
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• pp.1-10
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• 2017

The study analyzed the current status of fisheries port market and presented the direction of developments. The fisheries port market has become increasingly widespread due to the aging of the facilities and the scale of the fish product trade, and the number of distribution workers has also increased. The problems of fisheries port market are as follows. First, the transaction structure was changed as the proportion of aquaculture products increased. Second, the trading structure has changed, but it has failed to keep pace with the changes in the production structure. Third, the volume and amount of fish traded in aquaculture products and fish stocks increased. As a result, the growth rate of the fisheries port market is decreasing and profitability is deteriorating. The development direction of the fisheries port market is as follows. First, it is necessary to standardize the fisheries port market facilities, according to the type of fish products. Second, it needs to diversify its trade targets such as processed fish products and imported fish products. Third, it is necessary to diversify the business of the fisheries port market in order to increase profitability.

• 한국어병학회지
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• 제7권2호
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• pp.113-117
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• 1994

어병 세균에 대해 쑥(Artemisia princeps var. orientalis) 추출물인 정유의 항균성을 조사하였다. Aeromonas hydrophila, Aeromonas salmonicida, Aeromonas sorbia, Edwardsiella tarda 와 Streptococcus sp. (yellowtail)는 1,000~2,000 ppm 에서 증식이 억제되었다. 즉 억제 농도는 A.salmonicida 가 1,000 ppm A.hydrophila, A. sorbia, E. tarda 와 Streptococcus sp. (yellowtail)는 1,500 ppm 이었다. 그러나 Vibrio anguillarum, Vibrio ordalii, Edwardsiella ictaluri와 Streptococcus sp. (SF-1)는 100~2,000 ppm 농도에서 현저한 억제 효과는 없었다.

• 대한임베디드공학회논문지
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• 제16권6호
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• pp.299-305
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• 2021

Dissolved oxygen, pH, and temperature are the most important factors for fish farming because they affect fish growth and mass mortality of the fish. Therefore, fish farm workers must always check all pools on the farm, but this is very difficult in reality. That's why we developed a control system for smart fish farms. This system includes a gateway, sensor gatherers, and a PC program using LabVIEW. One sensor gatherer can cover up to four pools. The sensor gatherers are connected to the gateway in the form of a bus. For the gateway, the ATmega2560 is used as the main processor for communication and the STM32F429 is used as a sub-processor for displaying LCD. For the sensor gatherer, ATmega2560 is used as the main processor for communication. MQTT (Message Queuing Telemetry Transport), RS-485, and Zigbee are used as the communication protocols in the control system. The users can control the temperature and the dissolved oxygen using the PC program. The commands are transferred from the PC program to the gateway through the MQTT protocol. When the gateway gets the commands, it transfers the commands to the appropriate sensor gatherer through RS-485 and Zigbee.

• 한국수산과학회지
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• 제42권1호
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• pp.56-62
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• 2009

Feeding regimens was investigated for the growth and survival rate of juvenile Maroon clownfish (Premnas biaculeatus) in order to establish a seed production technique for this fish. Three types of feeding regimens were used, and growth and survival were highest under the following regimen: rotifer from day 0, Artemia from day 4, copepod from day 9 and artificial food from day 15, respectively (P<0.05). The average body lengths of the larvae were $6.76{\pm}0.55\;mm$, $7.63{\pm}0.50\;mm$ and $7.33{\pm}0.43\;mm$ in the Nannochloropsis oculata, Isochrysis galbana and control treatments conducted with 3 larvae/L, respectively (P<0.05). There were significant differences in larval growth between the treatments and controls conducted with 6 larvae/L and 9 larvae/L, respectively (P<0.05) but there was no significant difference between the N. oculata and I. galbana treatments (P>0.05). There were no significant differences in larval growth between the treatments at densities of 3-9 larvae/L (P>0.05). At highest density level, the larvae reared in I. galbana had the highest survival rate whereas survival was lowest in the control.