• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.1
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• pp.23-31
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• 2024

This study evaluated the utilization of a low fish meal (LFM) diet and black soldier fly (BSF) Hermetia illucens meal and oil as a fish meal (FM) substitute or functional additive for juvenile olive flounder Paralichthys olivaceus at the Jeju fish farm. Two experimental diets replaced FM using animal (tankage, poultry byproduct and tuna byproduct meal) and plant (wheat gluten and soy protein concentrate) protein sources, containing 45% (FM45) and 35% (FM35) of FM, respectively. One experimental diet replaced FM with animal, plant, and BSF meal, fish oil using insect meal and oil (FM35+). After the feeding trial ended, no differences in growth performance, feed utilization, survival and biological indices were observed among all experimental groups. Aspartate aminotransferase and cholesterol levels in the FM35 and FM35+ groups were significantly higher than that in the FM70 group. The linoleic acid level in the muscle was significantly higher in the fish fed with the FM70 diet than in those fed with the FM45, FM35, and FM35+ diets. Thus, the LFM diet is suitable for juvenile olive flounder farming during six months.

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.152-159
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• 2017

For the effective seedling production of the hard shelled mussel, Mytilus coruscus, this study assessed the effects of the dietary value of live food, density, water temperature and salinity on growth and survival rate of the larvae. The optimal survival rate and growth rate were examined under differing conditions of water temperature, salinity, and rearing density for 30 days. The three groups were provided different feeding organisms, such as Isochrysis galbana and Teleaulax suecica. The mixtures were provided at a rate of $5{\times}10^4cell\;mL^{-1}$. The best growth was observed in the group with conditions $21^{\circ}C$ water temperature ($16.2{\pm}9.1{\mu}m$), 33 psu of salinity ($16.82{\pm}3.9{\mu}m$), $2500individual\;m^{-2}$ ($17.2{\pm}5.9{\mu}m$), and fed with $5{\times}10^4cell\;mL^{-1}$ of I. galbana and T. suecica mixture ($16.0{\pm}7.3{\mu}m$). The highest survival rate was found in the group at conditions $18^{\circ}C$ water temperature (66.4%), 33 psu of salinity (24.4%), $2500individual\;m^{-2}$ (65.8%), and fed with $5{\times}10^4cell\;mL^{-1}$ of I. galbana and T. suecica mixture (58.8%). We therefore conclude that the suitable culture conditions for the stable production of hard shelled mussel artificial seedlings was at 18 to $21^{\circ}C$ of temperature, 30 to 33 psu of salinity, 2500 to $5000individual\;m^{-2}$ of rearing density, and feeding supplement of $5{\times}10^4cell\;mL^{-1}$ of I. galbana and T. suecica mixture under semi running water system.

• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.168-173
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• 2018

Mauremys reevesii is a Korean endemic turtle, and designed as an endangered species and national monument in South Korea. Recently, the population of the species has been dramatically declining because of habitat destruction, pollution and illegal capture. Moreover, small population size, difficulty of securing individuals, and lack of research are factors that impede the effective management of the species. In this study, we tested the effect of individual breeding and feeding on the seven juveniles of M. reevesii. Our results showed individual breeding and feeding were guaranteed the effective growth and development. Noticeable growth was confirmed in both body weight and carapace length. Moreover, the size difference among the individuals appeared at the start of this study decreased at the end of this study. Artificial breeding during the wither season was not caused disorders on the growth, behavior and morphology. This individual breeding may lead to effective growth and development, and it will be a way to increase the survival rate when the juveniles released into the wild.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.785-792
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• 2013

Two studies were conducted to investigate the effects of dietary nucleotides (NT) on the growth performance, hematological parameters, and innate immune responses of red seabream Pagrus major. In Expt I, six experimental diets were formulated: a control, four that contained each NT at a level of 0.15% (inosine monophosphate, IMP; adenosine monophosphate, AMP; guanosine monophosphate, GMP; and uridine monophosphate, UMP), and one with a 1:1:1:1 mixture of NTs (IMP, AMP, GMP, and UMP). In Expt II, five experimental diets were formulated that contained 0, 0.1, 0.2, 0.4, and 1.0% IMP (commercial product). Triplicate groups of juvenile (initial body weight 33.1 g) and growing (initial body weight 120 g) red seabream were fed one of the experimental diets to apparent satiation for 8 weeks in Expt I and 12 weeks in Expt II. In Expt I, fish fed diets with NT had higher growth performance than the control group. The nitroblue tetrazolium and lysozyme activities were higher in fish fed the mixed-NT diet, and lowest in the control group. In Expt II, the final body weight and feed utilization of fish fed the 0.1% IMP diet were significantly higher than those of fish fed the control or 1.0% IMP diets. Diet palatability was improved significantly when 0.1% IMP was added. The lysozyme activity was higher in fish fed diets with 0.4-1.0% than in the control group. These results suggest that supplementation of 0.15% IMP and Mixed-NTs in diet can enhance the growth and immune responses in juvenile red seabream. The optimum IMP level appears to be 0.2% in practical feed formulation for growing red seabream.

• Journal of Forest and Environmental Science
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• v.30 no.2
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• pp.218-225
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• 2014

Studies were carried out to standardize and develop a suitable macro-propagation technology for large scale production of superior clonal stock through stem cuttings in Commiphora wightii Arnott (Bhandari), a data deficient medicinal plant of arid region. For the purpose, three experiments were conducted. The first experiment was tried to elucidate the impact of various cutting diameters (0.50-0.75 cm, 0.75-1.00 cm, 1.00-1.50 cm, and >1.50 cm) in combination with varying growing conditions (sunlight, shade house and mist chamber) on shoot sprouting and rooting without using exogenous plant growth regulators. Cutting diameter (size 0.75-1.00 cm) in mist chamber has shown maximum sprouting (90.00%) and rooting (73.33%), primary root (6.67) and secondary root (16.67) followed by 1.00-1.51 cm in mist chamber. Minimum sprouting (40.00%), rooting (33.33%), number of shoot (1.33), primary root (1.00) and number of secondary root (1.00) was recorded in cutting diameter (size >1.50 cm) in sunlight. Second experiment was performed to find out optimum growth regulator concentration of rooting hormone (100, 200, 500 and 1000 ppm) of Indole-3-acetic acid (IAA) and Indole-3-butyric Acid (IBA) on adventitious root formation on cuttings diameter (size 0.25-0.50 cm) in comparison to control. Maximum rooting percentage (93.33%) was recorded in 200 ppm followed by 500 ppm (86.66%) of IBA as compared to control, which showed only 60 per cent sprouting. Third experiment was performed with newly formed juvenile micro-cuttings treated with varying concentrations of IAA and IBA. The juvenile cuttings (size 6-10 cm, basal dia <0.25 cm) were selected as micro-cuttings. The cuttings treated with IBA (500 ppm) showed 64.30% rooting as compared to other treatments. Results of above experiments indicate that cuttings (size 0.75-1.00 cm dia) may be developed in mist chamber for better performance. While using heavier cuttings, no growth promoting hormones is required however; growth regulator 200 ppm concentration of IBA rooting hormone was observed optimum for promoting macro-propagation in stem cuttings of lower diameter class (0.25-0.50 cm).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.4
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• pp.467-473
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• 2016

Several of our recent studies have focused on mass production of the marine Cladoceran Diaphanosoma celebensis, which can serve as a feed substitute for Artemia nauplii in the culture of larval marine fish. We compared the growth and survival rates of tiger puffer Takifugu rubripes fed D. celebensis with those fed Artemia. The group fed D. celebensis showed an increase in growth from 0.10 g to 1.78 g, while the group fed enriched Artemia had a growth from 0.10 g to 0.92 g. The survival rate of fish fed D. celebensis was 86.7% while that of fish fed enriched Artemia was 51.1%, indicating that the former group was superior to the latter both in growth and survival rate. Fatty acid analysis revealed that D. celebensis fed Nannochloropsis oculata and Schizochytrium sp. had an eicosapentaenoic acid (EPA) content of 16.42% and a docosahexaenoic acid (DHA) content of 3.93%. Meanwhile, juvenile tiger puffer fed D. celebensis had an EPA content of 9.12% and a DHA content of 10.69%. Juvenile tiger puffer fed D. celebensis had a similar n-3 highly unsaturated fatty acid content to that of tiger puffer fed enriched Artemia which had an EPA content of 5.82% and a DHA content of 15.90%, indicating that no additional enrichment was required.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.4
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• pp.499-505
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• 2020

We investigated growth, survival and stress response depending on salinity changes in hybrid grouper (Epinephelus fuscoguttatus ♀×E. polyphekadion ♂, BCG) juvenile. Experiment I (Exp I), the hybrids were stocked at 32 psu and reared for 30 days under decreasing salinity at a rate of 5-7 psu per day (25, 20, 15, 10, 5 psu). Experiment II (Exp II), the salinity was decreased from 32 psu to 5 psu during a period of 24, 48 and 72 h. Experiment III (Exp III), acclimatized BCGs were exposed from 5 psu to decreasing salinity at 0, 1, 2, 3, 4 psu. In the Exp I, 90% survival only in the 5 psu. Growth were 5 and 32 psu had significantly low growth than other treatment. In the Exp II 100% survived by the end of the experiment. The plasma cortisol level was highest in the treatment the salinity rapidly dropped, but all the treatment recovered quickly after 24 h of salinity reduction. In the Exp III, the lower the salinity, the faster the mortality occurred in salinity below 5 psu. It is therefore concluded that the BCGs are highly tolerant of low salinity and the salinity tolerance threshold is 5 psu.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.2
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• pp.125-133
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• 2008

To investigate the effect of repeated food deprivation and refeeding on the hyperphagia, compensatory growth, feed efficiency, body composition, hepatosomatic index (HSI), and survival rate of the juvenile olive flounder Paralichthys olivaceus, an experiment was conducted for 90 days. Feeding treatments consisted of the following five regimes for 90 days from August to October, 2005: C: daily satiation feeding (control), S1: 1-day satiation feeding after 1-day food deprivation, S2: 1-day satiation feeding after 2-day food deprivation, S3: 1-day satiation feeding after 3-day food deprivation and S4: 1-day satiation feeding after 4-day food deprivation, respectively. Although the monthly feed intake (MFI) of the control was significantly higher than that of all of the starved groups, the daily feed intake (DFI) was more higher in S1, S2, and S3 than that in the control as a result of hyperphagia after starvation. While the feed efficiency in the summer (to day 30) decreased in all of the starved groups with prolongation of the starvation period, the feed efficiency in the autumn (to day 90) was increased with prolongation of the starvation period. The whole body proximate composition and HSI were also affected by starvation. The crude protein, lipid, and HSI decreased with prolongation of the starvation period, whereas the crude ash and moisture increased. The growth rate and condition factor also decreased in proportion to the starvation period. The survival rate was highest in the control and was the lowest in S4. In this study, although hyperphagia occurred in the deprived groups, we knew that the compensatory growth did not always occur.

• Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.219-227
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• 2021

The effects of various feeding ratios on the growth, body composition, and blood chemistry of the juvenile mandarin fish Siniperca scherzeri (initial body weight 9.6 g) were examined in recirculating freshwater system equipped with 21, 300 L tanks at 20 fish per tank. The triplicate groups of seven feeding ratios treatments were prepared: 100% (control), 95%, 90%, 85%, 80%, 75%, and 70% of satiation. The feed amount of control group was determined by supplying with apparent satiation and then the feed amounts of the other six feeding groups were determined based on the feed amount of the control group. Fish were hand-fed with test diet (55.4% crude protein) for 10 weeks. Weight gain (WG) and specific growth rate of fish fed to 100% satiation were not significantly (p > 0.05) different from those of fish fed to ≥ 80% satiation but were significantly higher than those of fish fed to 75% and 70% satiation. Feed efficiency, protein efficiency ratio, and protein retention of 100% satiation were not significantly different from those of 95% and 90% satiation but were significantly (p <0.05) lower than ≤ 85% satiation. Condition factor, hepatosomatic index, and coefficient variation were not significantly (p > 0.05) affected by feeding ratio. Whole body composition and contents of hematocrit, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, glucose, total protein, and high-density lipoprotein cholesterol in blood serum were not significantly (p > 0.05) affected by the feeding ratio; however, content of total cholesterol tended to decrease as the feeding ratio decreased. Using broken-line analysis of WG, it was suggested that the optimum feeding ratio of juvenile mandarin fish, ranging from 9.0 g to 37.0 g, appeared to be 87.7% of satiation without growth inhibition.

• Korean Journal of Ichthyology
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• v.35 no.1
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• pp.39-43
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• 2023

The water temperature and salinity have an important effect on the growth and survival of rearing fish. This study investigates the effect of water temperature and salinity on larvae and juveniles of Platycephalus indicus. The experimental water temperature was set to 13, 16, 19, 22, and 25℃, respectively, and the salinity was set to 7, 14, 21, 28, and 32 psu, respectively. Ten individuals were randomly collected daily and measured the total length using a stereo microscope. The growth rate was the highest at 25℃ (21.62±0.14 mm), 28 psu (15.02±0.05 mm) and the lowest at 13℃ (7.04±0.05 mm), 7 psu. The survival rate was the highest at 22℃ (69.2%), 32 psu (84.1%) and the lowest at 13℃ (15.1%), 7 psu. This study demonstrates that the water temperature and salinity affected the survival and growth of Platycephalus indicus larvae and the juvenile.