• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.2
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• pp.103-113
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• 2014

This study compared the food quality of freshwater rainbow trout Oncorhynchus mykiss cultured (in Pyeongchang, Pyeongtaek, Jecheon and Geochang) with that of imported salmon Oncorhynchus keta. The proximate composition of the four types of rainbow trout was 74.4-75.7% moisture, 18.3-19.4% crude protein, 3.1-4.3% crude lipid, and 1.3-1.7% ash. There were slight differences in the proximate composition of the four types of rainbow trout. No significant (P>0.05) differences were found in the red color and odor and taste intensities of the four types of rainbow trout based on the Hunter a values, volatile basic nitrogen content, odor intensity using an electronic nose and taste intensity using an electronic tongue. The crude protein, total amino acid, and mineral contents of rainbow trout cultured in Pyeongtaek were superior or similar to those of the trout cultured in the other three places. The rainbow trout cultured in Geochang had the highest hardness, at 858.5 g.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.621-623
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• 2017

Mariculture of rainbow trout Onchorhynchus mykiss has been initiated in or around olive flounder Paralichthys olivaceus farms, where viral hemorrhagic septicemia virus (VHSV) is often detected in some fish. In the present study, we investigated VHSV infection in seawater-reared rainbow trout because VHSV has never been detected in salmonids in Korea. A total of 104 adult fish were tested for the presence of VHSV by reverse transcription-polymerase chain reaction, followed by virus isolation with the fathead minnow caudal trunk cell line. Cytopathic effects were observed in two samples but the virus was identified as infectious hematopoietic necrosis virus. Thus, VHSV was not isolated from seawater-reared rainbow trout.

• Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.185-187
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• 2005

We tested the in vivo ability of a DNA chip to detect virus-specific genes from virus-infected olive flounder Paralichthys olivaceus and rainbow trout Oncorhynchus mykiss. Target cDNA was obtained from total RNA of virus infected cell lines by reverse transcription (RT) and was labeled with fluorescent dye (Cy5-dUTP). The results show the successful detection of infectious hematopoietic necrosis virus (IHNV) and viral hemorrhagic septicaemia virus (VHSV) genes in the virus-infected fishes.

• Development and Reproduction
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• v.4 no.1
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• pp.1-6
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• 2000

Ultrastructure of the zona radiata the micropyle and fertilization process in the rainbow trout (Oncorhynchus mykiss) were examined by light, scanning and transmission microscopes . The egg micropyle of rainbow trout consists of a funnel-shaped vestibule and a tapered canal transversing the zona radiata. The micropyle showed the type with a flat pit leading into a long canal and the micropylar wall showed the clockwise spiral structure. There were a great number of microvilli secreting adhesive materials having trapping function attracting the spermatozoa in the vicinity of micropyle. It was apparent that ridges extended between the projections. In the initial stages of penetration, the spermatozoon still within the micropylar canal attached perpendicularly at its apical tip to the egg surface, then the sperm head was rapidly engulfed by the folded egg surface with its many microvilli. The spermatozoon disappeared from the outer surface of the egg before the fertilization cone completely retracted 250 seconds after insemination. No interconnecting ridges was present in the egg surface. In short, the block to polyspermy to permit entry of a single sperm is considered to be mechanical by the morphological design of the micropyle and fertilization cone.

• Korean Journal of Ichthyology
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• v.8 no.1
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• pp.49-55
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• 1996

The growth of total length(TL), total weight(TW) and somatic weight(SW) of rainbow trout, Oncorhynchus mykiss alevin at yolk absorption period was expressed by the Gompertz growth model as $TLt=2.7e^{-1.24{\cdot}e^{-0.11t}}(r^{2}=0.66)$, $TWt=1.8e^{-2.03{\cdot}e^{-0.11t}}(r^{2}=0.66)$ and $SWt=1.8e^{-5.41{\cdot}e^{-0.13t}}(r^{2}=0.83)$ respectively. Yolk length, yolk height and yolk volume of rainbow trout decreased linearly. The relative growth of total weight-total length, somatic weight-total length, yolk length-total length, yolk height-total length, yolk volume-total length, yolk weight-total length, yolk weight-total weight, yolk weight-yolk height and yolk weight-yolk length at yolk absorption period revealed the pattern of yolk absorption in rainbow trout.

• Korean Journal of Ichthyology
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• v.27 no.3
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• pp.183-188
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• 2015

Recently, mariculture of rainbow trout (Oncorhynchus mykiss) has been initiated in the coast areas of Korea. In the present study, we investigated the effect of fish viruses on mariculture of rainbow trout. The pathogenicity of infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV) isolated from freshwater rainbow trout was tested against major cultured marine fish species, including olive flounder (Paralichtys olivaceus), rock fish (Sebastes schlegeli), rock bream (Oplegnathus fasciatus), red seabream (Pagrus major) and sevenband grouper (Epinephelus septemfasciatus). The pathogenicity of marine birnavirus (MABV), hirame rhabdovirus (HIRRV) and nervous necrosis virus (NNV) isolated from marine fish species was also tested against rainbow trout. No mortality was observed in marine fish species challenged with IHNV or IPNV. However, olive flounder and rock bream were infected by IHNV and IPNV. A mortality of 8.3% was observed in rainbow trout challenged with HIRRV. The fish was infected by both MABV and NNV. These results suggest that the mariculture of rainbow trout might be affected by fish viruses.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.270-276
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• 2016

This study investigated the sensory characteristics (texture, odor, taste and color) of jerky produced from ground sea rainbow trout (SRT) Oncorhynchus mykiss frame muscle (FM). The hardness of the ground SRT-FM jerky was 453.9±91.0 g/cm², which was lower than that of commercial animal jerky (893.5±404.6 g/cm²) and commercial fish jerky (1,394.4±363.5 g/cm²). The difference in the hardness values of the ground SRT-FM jerky and commercial animal jerky was not significant. The volatile basic nitrogen content of the ground SRT-FM jerky was 48.3±1.6 mg/100 g, which was higher than that of commercial fish jerky (21.6±6.2 mg/100 g) and commercial animal jerky (18.2±6.3 mg/100 g). However, the fish odor of the ground SRT-FM jerky was masked by the presence of various additives. The hydrophilic and lipophilic browning indices of the ground SRT-FM jerky were higher than those of the commercial jerky. The total taste value of the ground SRT-FM jerky was 169.0, and the major amino acids were glutamic acid and aspartic acid. These results suggest that ground SRT-FM jerky would be acceptable to consumers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.263-269
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• 2016

Large quantities of by-products—such as fish frame, head, skin and viscera—are generated during seafood processing, and these by-products are not utilized extensively. Therefore, sea rainbow trout Oncorhynchus mykiss (SRT) frame muscle (FM) jerky was prepared by grinding SRT-FM, followed by mixing with seasoning, forming and drying. The nutritional and microbiological characteristics of the SRT-FM jerky were then investigated. The proximate composition of the SRT-FM jerky was 19.1% moisture, 38.7% crude protein, 7.9% crude lipid and 4.4% ash. The viable bacterium count of the SRT-FM jerky was 3.9 log CFU/g, and Escherichia coli and Staphylococcus aureus were not detected. The total amino acid content of SRT-FM jerky was 37.3 g/100 g, and the major amino acids were aspartic acid, glutamic acid, leucine and lysine. Based on the recommended daily intake of fish jerky (100 g), the most abundant mineral was potassium. The fatty acid composition of the SRT-FM jerky was 26.2% saturated acid, 34.5% monoenoic acid and 39.3% polyenoic acid, and the major fatty acids were 16:0, 18:1n-9, 18:2n-6, 20:5n-3 and 22:6n-3. These results suggest that SRT-FM jerky has high nutritional value.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.254-261
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• 2018

From 2014 to 2017, mortalities of seawater-cultured rainbow trout Oncorhynchus mykiss, were observed in the Goheung and Jeju areas of Korea, with Vibrio anguillarum (seven strains: RT1, 2, 3, 4, 5, 6, and 7) identified as the etiological agent. The phenotypic (based on API 20NE, API ZYM, and E-test kits), serotypic (slide agglutination tests with O1, O2, O3, O4, and O7 antisera), and genotypic (16S rRNA and ompU sequencing) characteristics of the seven RT strains were analyzed and compared to those of seven additional V. anguillarum stains (SF, isolated from sweet fish; FM, isolated from flathead mullet; ATCC43305; ATCC43311; ATCC43307; ATCC43308; and KCTC2711). The phenotypes of the RT strains showed variance, while the slide agglutination tests of the RT1-7, SF, and FM strains all showed positive reactions with serotype O1 antiserum. The 16S rRNA and ompU sequences of the RT1-7, SF, and FM strains were affiliated with V. anguillarum ATCC43305 (Serotype O1), but the ompU sequence of the SF strain differed from those of the RT1-7, FM, and ATCC43311 strains, including one amino acid substitution. We thus confirmed that serotype O1 V. anguillarum, with multiple phenotypes, continues to infect seawater-cultured rainbow trout in Korea.