• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.4
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• pp.387-398
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• 2023

Conventional aquaculture faces declining productivity, shifting to recirculating aquaculture system (RAS), known for minimizing water usage and maintaining consistent water temperatures for year-round fish growth. Rainbow trout (Oncorhynchus mykiss), a globally important cold-water species and the third most farmed fish in inland waters of Korea, valued for its fecundity and rapid growth. Dissolved oxygen, an important environmental factor affecting fish production and economics, highlights the need for smart aquaculture practices. Since 2018, the rise of intelligent aquaculture platforms, incorporating information and communications technology (ICT), emphasizes the essential role of RAS implementation. This eight-week study aimed to determine the optimal dissolved oxygen concentration for rainbow trout in RAS, utilizing a device for continuous monitoring, control and record. Dissolved oxygen concentrations were set at 5-6 mg/L, 9-10 mg/L, 14-15 mg/L and 17-18 mg/L. The growth rate significantly decreased at 5-6 mg/L, with no significant differences in other experimental groups. In hematological analysis, growth hormone (GH) was significantly highest at 5-6 mg/L, followed by 9-10 mg/L while Insulin-like growth factor-1 (IGF-1) was significantly lowest at 5-6 mg/L. In conclusion, the optimal dissolved oxygen concentration for rainbow trout in RAS is approximately 9-10 mg/L. Higher concentrations do not contribute to further growth or profitability.

• Journal of fish pathology
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• v.16 no.3
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• pp.161-164
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• 2003

An Infectious hematopoietic necrosis virus strain (IHNV-RTK) was isolated from cultured rainbow trout at Kumi and Jechun area in Korea during 2000 and 2001. In the RT-PCR amplification with the specific primer set designed from IHNV G protein region, a 540 bp PCR product was amplified from the RTK strain. The RTK strain showed higher sequence homology with the published IHNV G protein genes (RB-76, LR-73, Col-85, and Carson-89)

• Journal of Aquaculture
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• v.11 no.2
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• pp.279-282
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• 1998

Effects of high concentration of intracellular calcium on estradiol-induced vitellogenin(VTG) induction were examined using ouabain in Primary hepatocyte culture in the rainbow trout Oncorhynchus mykiss. Ouabain increases cytosolic free calcium as a result of inhibition of $Na^+ - Ca^{2+}$ exchanger. Ouabain markedly reduced VTG production to the control level, despite of calcium concentrations in the incubatin medium. Therefore, ouabain would reduce VTG production not by increasing intracellular calcium bt directly by inhibiting $Na^+ - K^+$ ATPase.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1280-1289
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• 2016

This study aims to conduct economic analysis of the Rainbow Trout (Onchorhynchus mykiss) aquaculture farms in Korea. The analysis was performed based on farming cost, market price of the species and fishermen's income. We estimated the farms' economic feasibility using return on sales, the NPV, the IRR and the break-even point. The result indicated that while the profitability depends on current aquaculture production performance and market situation, the business operation is up to price and aquaculture production of species. According to sensitivity analyses of price and yield, aquaculture business becomes poorer with lower price and production.

• Animal cells and systems
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• v.6 no.4
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• pp.323-326
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• 2002

One hundred and three random complementary DNA clones representing rainbow trout intestine were par1i811y sequenced as an approach to analyze the transcribed sequences of its genome. Of the sequences generated, 60.0% of the ESTs were represented by 40 known genes. Thirty-five clones of unknown gene products potentially represented 34 novel genes. The most Bbundantly represented messages were the 28S ribosomal protein (6.5%) and beta actin (5.8%). The genes involved in ribosome formation (18%) accounted for the major gene expression. Development of EST panels representing the genes expressed in a particular tissue will be useful in determining the role of these genes in normal function and in response to developmental, hormonal, environmental and physiological changes.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.559-560
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• 2001

The objective of the present study was to analyze genetic variation and characteristics in rainbow trout(Oncorhynchus mykiss) using amplified fragment length polymorphism(AFLP) method as molecular genetic technique, to evaluate the usefulness of AFLP as genetic markers, and to compared the efficiency of agarose and polyacrylamide sequencing gels. The amplified products were performed by agarose and sequencing gel electrophoresis to detect AFLP band patterns, respectively. Using 9 primer combinations, total of 141 AFLP bands were produced, 108 bands(82.4％) of which were polymorphic in agarose gels. In sequencing gels, total of 288 bands were generated, and 220 bands (76.4％) were polymorphic. The level of bandsharing(BS) ranged from 0.18 to 0.32 for the 9 primer combinations tested, with a mean of 0.24. Consequently, AFLP markers of these rainbow trout could be used as genetic information such as species identification, genetic relationship or analysis of genome structure, and selection aids for genetic improvement of economically importment traits in fish species.

• Fisheries and Aquatic Sciences
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• v.21 no.11
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• pp.32.1-32.7
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• 2018

Trout production is a growing activity in recent years but requires new alternative sources of feed to be sustainable over time. The objective of this research was to determine the apparent digestibility coefficient (ADC) of dry matter (DM), organic matter (OM), crude protein (CP) and digestible energy (DE) of $ka{\tilde{n}}iwa$ (Chenopodium pallidicaule Aellen), kiwicha (Amaranthus caudatus L), quinoa (Chenopodium quinoa Willd), beans (Phaseolus vulgaris L.), sacha inchi, (Plukenetia volubilis L) and jumbo squid (Dosidicus gigas) meal in juvenile rainbow trout. The experimental diets were composed of a 70% basal diet and 30% of any raw materials. The ADC was determined by the indirect method using insoluble ash as a non-digestible marker. Jumbo squid, sacha inchi and quinoa showed the highest values of ADC (%) of DM (84.5, 73.5 and 69.7), OM (89.1, 78.4 and 72.9), CP (93.2, 98.0 and 90.3), and DE (4.57, 4.15 and 2.95 Mcal/kg DM), respectively. The ADC values for $ka{\tilde{n}}iwa$, kiwicha and bean were significantly lower. In conclusion, quinoa meal and jumbo squid meal have an acceptable digestibility but sacha inchi meal is a potential alternative for rainbow trout feeding in the future.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.1
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• pp.79-88
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• 2023

A 12-week feeding trial was conducted to evaluate the effect of different stocking densities on the growth, body composition, stress, antioxidant status, and immune responses of juvenile rainbow trout Oncorhynchus mykiss. Juvenile rainbow trout (32.2±0.5 g) were randomly placed in eight experimental tanks, each containing 2,000 L of water, at stocking densities of 150, 300, 600, and 1,200 individual/m³. The trout were assigned to four treatments (2.4, 4.8, 9.7, and 19.4 kg/m³) in duplicates. Following after the feeding trial, the fish cultured in the less dense group showed significantly higher growth and survival (P<0.05). In terms of proximate composition, the whole body crude protein and lipid contents were lower in the denser group (19.4 kg/m³). Regarding the antioxidant and immune responses, the fish reared in the relatively denser group exhibited lower lysozyme, immunoglobulin M, and superoxide dismutase levels. The stress indicators, glucose and cortisol, were significantly lower in the less dense group (2.4 kg/m³), while the denser group (19.4 km/m³) exhibited higher AST and ALP levels(P<0.05). The results showed that denser stocking has a crowding stress effect and negatively impacts growth and immune responses.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.505-511
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• 2023

This study investigated the effect of transglutaminase (TGase) and polysaccharide kappa carrageenan on the texture, chemical, and microbiological qualities of refrigerated unmarketable rainbow trout Oncorhynchus mykiss. Gel strength increased substantially in TGase-treated samples, and was adding kappa carrageenan resulted in no significant difference. SDS-PAGE results confirmed that the myosin heavy chain band with a molecular weight of 205-250 kDa was weakened in trout meat treated with 1% TGase, which led to cross-linking reactions between proteins. The volatile basic nitrogen (VBN) increased in all samples during storage at 4℃ for 10 days; however, the samples treated with 0.5% and 1% kappa carrageenan had the lowest VBN. The viable cell count increased in all samples treated with TGase and kappa carrageenan; however, an increase in TGase enzyme and kappa carrageenan concentration successfully hindered total bacteria growth. Thus, adding 1% TGase and 1% kappa carrageenan to refrigerated unmarketable rainbow trout formulations can optimize quality characteristics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.2
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• pp.114-121
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• 2014

This study compared the food quality of domesticated(RT-DS) and freshwater (RT-F) rainbow trouts Oncorhynchus mykiss. The proximate composition of RT-DS was 73.8% moisture, 20.6% crude protein, 4.2% crude lipid, and 1.1% ash and was similar to RT-F. No differences were found in the red color, odor and taste intensities, calcium, and potassium between RT-DS and RT-F based on the Hunter a values, volatile basic nitrogen content, odor intensity and using an electronic nose, and taste intensity using an electronic tongue. The crude protein, total amino acid contents, and taurine, glutamic acid, glycine, alanine and anserine contents in free amino acids were higher in RT-DS than in RT-F. There was no difference in hardness between RT-DS and RT-F.