• Journal of fish pathology
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• v.34 no.2
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• pp.225-231
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• 2021

In biofloc culture for olive flounder, Paralichthys olivaceus, the possibility of antibiotics treatment was investigated against edwardsiellosis. After inducing edwardsiellosis by immersion in Edwardsiella tarda 1.2 × 10⁵/mL suspension, the survival trends on various biofloc water management and some physiological changes were observed. For biofloc water management, six types of water treatments were carried out, which were no exchange without antibiotics as negative control, the exchange to stored biofloc water, the exchange to stored biofloc water with 20% flow-through, the exchange to fresh biofloc water, half fresh biofloc water and half sea water, and the complete flow-through. There was no significant physicochemical change on water qualities in any type. The exchange to fresh biofloc water was shown the highest survival ratio as 72.3%, and in case of stored biofloc water with 20% flow-through, the survival ratio was also significantly high as 62%. Plasma glucose, cholesterol, total protein, calcium, and magnesium were analyzed as physiological index. Mostly, there was no significant change, but plasma cholesterol showed an initial decrease in low survival group, and an initial increase with high survival group. Consequently, antibiotic treatment against a bacterial disease during biofloc culture is possible as long as the biofloc water management follow along properly.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.3
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• pp.239-245
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• 2010

The effects of sediment and water movement on the survival and growth of Campylaephora hypnaeoides J. Agardh were examined in culture to elucidate why this species grows as an epiphytic alga. The survival and growth rates of Campylaephora tetraspores declined as the sediment concentration increased under both water-movement and no-water-movement treatments. After 5-day cultures under various sediment treatments, the respective survival and growth rates ranged from 27.32 to 78.63% and 0.22 to 0.29 $day^{-1}$ under the no-water-movement and from 15.66 to 82.69% and 0.19 to 0.31 $day^{-1}$ under the water-movement treatments. The maximum survival and growth of C. hypnaeoides tetraspores occurred at 20 and 40 ${\mu}mol$ photons $m^{-2}s^{-1}$, respectively. The survival of Campylaephora tetraspores and germlings declined with increasing dark period, but the tolerance of total darkness based on the survival rates was two-times greater for 5-day old sporelings than for tetraspores after 12 days. In conclusion, Campylaephora hypnaeoides grows as an epiphytic alga because its survivorship and growth decline rapidly with greater water movement and sedimentation and with lower light intensities.

• Korean Journal of Ichthyology
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• v.21 no.3
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• pp.158-166
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• 2009

To obtain the fundamental data for the mass seedling production of grunt, Hapalogenys nitens, we investigated the influence of salinity and cold water temperature on hatching and survival of eggs and growth and survival of larvae and fry. In regards to salinity, we surveyed the hatching rate and floating rate of fertilized eggs, the floating rate and survival rate of hatching larvae, and the survival and growth of fry. In respect to cold temperature, we investigated the influence of degree of daily temperature decrease, acute temperature shock, and slow temperature decreases on the survival, feeding and swimming activities of fry. In the salinity experiment, the hatching and floating rates of fertilized eggs, and the floating and survival rates of hatching larvae, were shown to be higher in seawater than in brackish water. Growth and survival of larvae and fry were not different between seawater (25~32 psu) and brackish water (5~20 psu), but were significantly lower in freshwater. In the cold-temperature test, three tests showed that rearing of fry in cold water and acutely decreasing water temperature to less than $10^{\circ}C$ reduced the survival, feeding and swimming activities of the fry. Therefore, we concluded that low salinity (less than 32 psu) could reduce the hatching rate and survival of eggs, but the growth and survival of fry were not influenced by salinity, and cold water (less than $10^{\circ}C$) decreased metabolism of grunt. During winter, we found a low-temperature limit at $8^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.367-376
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• 1997

Vibrio vulnificus is a gram-negative, halophilic, oxidase-positive, lactose-positive, motile, rod shaped bacterium that has been associated with primary septicemia and wound infection. Elucidating the growth and survival of V. vulnificus in ecological conditions is of great importance to develop sanitary measure against this microorganism. Thus we simulated the ecological conditions and evaluated the effect. About $10^5\;CFU/ml$ of V. vulnificus was inoculated to fresh water, brackish water $(1\%\;NaCl)$, sea water $(3\%\;NaCl)$, and bottom deposit solution. The same concentration of V. vulnificus was also inoculated to distilled water, $1\%\;NaCl$ solution and $3\%\;NaCl$ solution as controls. These were stored at 4, 15 and $25^{\circ}C$, respectively and were used to assess the effects of temperature and salinity on the survival of V. vulnificus. In fresh water V. vulnificus could not survive regardless of storage temperature. In case of brackish water and sea water survival time of V. vulnificus was the longest at $25^{\circ}C$, and the number of V. vulnificus was decreased most rapidly at $4^{\circ}C$. V. vulnificus survived longer in brackish water than in any other conditions. In bottom deposit solution containing brackish water, the survival time of V. vulnificus was longer and the rate of decline was slower than that in brackish water. These results indicate that both biological and physicochemical factors such as temperature and salinity could affect survival of V. vulnificus. V. vulnificus, damaged in normal fresh water, did not grow on TCBS agar of selective plating medium but grew on BHI agar plate; However, V. vulnificus was recovered by addition of salt and nutrient materials.

• The Journal of Fisheries Business Administration
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• v.42 no.3
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• pp.79-93
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• 2011

Water temperature of Oliver flounder farm affects Oliver flounder growth and mortality rate. In laboratory experimental tanks, optimal water temperature was $22.5^{\circ}C$($21{\sim}24^{\circ}C$) and cultivatable water temperature was $12{\sim}28^{\circ}C$. The purpose of this study is to identify applicable and useful water temperature of Oliver flounder farm in case of actual farming. The data applied in the analysis was collected from Jeju island. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows : First, growth rate on the Oliver flounder culture farms was related to mean of water temperature, variation of water temperature and low water temperature. Second, survival rate on the Oliver flounder culture farms was related to mean of water temperature. In case of including Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, survival rate strongly related to mean of water temperature, variation of water temperature, cultivating capability and stocking density. Third, production weight per $m^2$ of water surface area was strongly related to mean of water temperature, low water temperature and cultivating capability. Growth rate and survival rate was analyzed into mediate variable character.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.49-55
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• 1985

The survival of Escherichia coli in river water was comparatively studied by laboratory and in sity study methods. The survival by two methods was evaluated as a function of E. coli strain, indigeneous predator, level of water pollution, and water temperature in different season. The survival rate of E. coli examined by laboratory method was lower than that by in situ method. That was found to be due to the fact that higher number of predator was maintained in labortory study than in in situ study. The survival rates of E. coli in gradually polluted river waters could be differentiated by in situ study, but not by laboratory study. Therefore, an in situ method rather than labortory method was thought to be a choice of study method for the survival of E. coli in river waters.

• Journal of Sport and Applied Science
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• v.6 no.3
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• pp.1-7
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• 2022

Purpose: The purpose of this study is to provide basic data for developing an educational program that can be practically applied in the field of survival swimming education. Research design, data, and methodology: This study reviewed prior literature including governmental reports, journal articles related to survival swimming programs at home and abroad. Based on the basic data collected through literature, domestic and foreign educational institutions and national educational programs were cataloged and analyzed. Results: The study found that among the goals of swimming education, the prevention of water accidents and the cultivation of water safety skills along with improving swimming ability are very important educational goals. Currently, domestic survival swimming education programs are divided into classes and training sessions, so it is necessary to develop an educational program according to each individual's swimming ability and a unified and systematic program through education for each level of survival swimming learners. Conclusions: It is thought that the reinforcement of the leader's capacity for quality improvement will have a positive effect for the development of survival swimming. Further implications were discussed.

• Journal of Aquaculture
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• v.12 no.3
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• pp.213-220
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• 1999

This study was performed to investigate the effects of water temperature and stocking density and rotifer density on the mass production of larval red marbled rockfish, Sebastiscus tertius. Total length of the marbled rockfish larva grown in $23^{\circ}C$ of water temperature were 10.80mm, which was the best, while those grown in $29^{\circ}C$ of water temperature were 6.28mm, which was the lowest. The survival rates of red marbled rockfish larvae grown in $20^{\circ}C$ and $23^{\circ}C$ were 24.0% and 18.5%, respectively. However, the survival rate of red marbled rockfish larvae grown in $26^{\circ}C$ was $7^{\circ}C$ and no larvae survived in $29^{\circ}C$. The total length of red marvled rockfish larva stocked at the density of 5 and 10 larvaper liter of water were high, which were 11.52 mm and 11.22 mm, respectively, but those stocked at the density of 30 larva per liter of water were 7.55mm, which was the lowest. The survival rate of red marbled rockfish larva stocked at the density of 2.5 larva per liter of water was 52.0%, which was the best, but the lowest, 18.0% for the red marbled rockfish larva stocked at the density of 30 larva per liter. There was a trend toward decrease in survival rate of red marbled rockfish larva as their stocking density increased. The survival rates of red marbled rockfish larva fed rotifers at the density of 10 and 5 individuals per ml were high, 48.5% and 48.0%, and their total lengths were 11.92 and 11.89mm, respectively, which grew relatively fast. The survival rate and the total length of red marbled rockfish larva fed rotifers at the density of 30 individuals per ml were the lowest, which were 8.40mm and 21.5%, respectively. Also, red marbled rockfish larva fed rotifers at the density of more than 20 individuals per ml achieved poor survival and growth. These results indicated that the proper conditions for the mass production of larval red marbled rockfish were $23^{\circ}C$ of water temperature, fish larva stocking density of 5 to 10 larva per liter of water and rotifers density of 5 to 10 individuals per ml as live feed.

• The Korean Journal of Malacology
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• v.13 no.2
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• pp.203-210
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• 1997

As a prioiminary study on usage of metabolic charateristics of the indicator species for indirect estimation of environmental water quality, effects of environmental pollutants on survival, filtration and oxygen consumption rates in Corbicula aeana were investigated at 17$^{\circ}C$ and $25^{\circ}C$ in 10 day afrer treatmint of pollutants. In case of glucose and complex fertilizer, the survival rates of the clams were 100% without any relation to individual sizes and water temperatures. In small sizes at $25^{\circ}C$, the survival rates of the clams by NH$_{4}$CI concentration were shown 95% at 10 mg/1 and 15mg/1, and 90% at 20mg/1, respectively. But the survival rate was 95%at 20 mg/1 of NH$_{4}$CI concentration in small size at 17$^{\circ}C$. The higher filtration and oxygin consumption rates were shown in small size at higher water timperatures(over $25^{\circ}C$), and generally filtration and oxygen consumption rates decreased with increase of glucose, complex fertilizer and NH$_{4}$CI concentrations, respectively. In general, effects of filtration and oxygen consumption rates at NH$_{4}$CI concentrations were shown slightly larger than those of glucose and complex fertilizer.

• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.199-204
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• 2014

This study evaluated the effect of water content in the substrate during pre- and post-grafting period on the survival rate and quality of tomato plug seedlings. Nine combinations of three water levels (high, medium, and low) were set up in the substrate of both scion and rootstock. The water content in the substrate of the scion did not affect the survival rate of grafted tomato seedlings, while the survival rate was statically different among the various water contents in the substrate of the rootstock. The maximum survival rates (100%) were observed in seedlings treated with high water levels in the substrate of the rootstock, and the survival rates declined with decreasing water content in the rootstock substrate. The growth characteristics were not significantly affected by different water content in the scion substrate, while they were statically different among the seedlings treated with various water contents in the rootstock substrate. The growth characteristics decreased with decreasing water content in the rootstock substrate. The highest value of compactness was observed in grafted seedlings, which combined medium water level in the scion and high water level in the rootstock substrate treatment. The root morphology of tomato seedlings was also affected by water content in the rootstock substrate. The total root surface area, total root length, and number of root tips decreased with deceasing water content in the rootstock substrate.