• Fisheries and Aquatic Sciences
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• v.11 no.1
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• pp.36-40
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• 2008

We analyzed the nucleotide sequences of about 500 bp of the mitochondrial NADH dehydrogenase subunit 3 (ND3) gene to estimate the genetic variation of Korean masu salmon (Oncorhynchus masou) populations. DNA samples were collected from 104 river-only specimens and 52 anadromous specimens from three hatcheries and one river. There are no records of artificial release into the river. We amplified the ND3 gene by polymerase chain reaction, targeting areas that included parts of the cytochrome oxidase III gene and the NADH dehydrogenase subunit 4L gene, and defined 14 haplotypes based on 12 variable nucleotide sites in the examined region. Among the haplotypes, ten were specific to river-only specimens within hatchery populations. Haplotype diversity of river-only populations in hatcheries was higher than that of anadromous and wild populations. Pairwise population $F_{ST}$ estimates and neighbor-joining tree analyses inferred that anadromous and river-only populations were distinct. These results suggest that sequence polymorphism in the ND3 region may be a useful marker for analyzing the genetic variation and population structure of masu salmon.

• Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.186-190
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• 2007

We examined the genetic variability of Asian chum salmon (Oncorhynchus keta) populations using nuclear microsatellite (ms) DNA analysis with four polymorphic loci (OKM4, OKM5, OKM7, and OKM8) in 397 individuals from nine populations, including one in Korea, seven in Japan, and one in Russia. The msDNA gene diversity was highest in the Japanese populations, suggesting greater genetic variation in the populations in Japan than in populations in Korea and Russia. The pairwise $F_{ST}$ estimates based on our msDNA data showed that the Korean population was genetically different from the Japanese and Russian populations, and there were higher $F_{ST}$ estimates between Hokkaido and Honshu populations than between other population pairs. A neighbor-joining tree showed that the Korean population was distinct from two other clusters, representing the populations in Honshu and the populations in Hokkaido and Russia. These results suggest that the observed population genetic patterns of Asian chum salmon might be influenced by low or restricted gene flow.

• Journal of agricultural medicine and community health
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• v.15 no.2
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• pp.89-96
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• 1990

The results of infection state of anisakid larvae and parasitic helminths in salmon and sea-trout which caught from Taep'o port. Kang-won do were as follows. 1) From twelve specimens of sea-trout. 122 individuals of anisakid larvae were found and mean infection number of anisakid larvae per individual sea-trout was 10.17. 2) From total extracted anisakid larvae from sea-trout. 37 larvae(30.3%) were found in the muscle. This percentage was lower than that of salmon. but higher than that of other sea-fishes. 3) The taxonomic list of parasitic helminths which found in salmon and sea-trout was as follows. Class Trematoda Family Hemiuridae l. Brachyphallus crenatus(Rudolphi. 1802) 2. Lecithaster salmonis Yamaguti. 1934 Class Cestoda Family Phllobothriidae 3. Pelichnibothrium speciosum Monticelli, 1889-larval form Family Tentacuariidae 4. Tentacularia sp. - larval form 4) Among those 4 species of helminths. B.crenatus. L.salmonis, P.speciosum were the first recording species in Korea.

• Journal of Aquaculture
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• v.10 no.1
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• pp.49-54
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• 1997

Characteristics of sex ratio and morphometric traits of induced allotriploid between female rainbow trout, Oncorhynchus mykiss and male cherry salmon, O. masou were performed. Sex ratios in both rainbow trout and cherry salmon were equally 1:1, while hybrid and allotriploid revealed higher proportion of male offspring (p<0.01). Body trait measurements of allotriploid in head hight/head length, length of dorsal fin base/body length and length of pectoral fin/body length were intermediate to their parental species, while in length of upper jaw/head length, allotriploid much more resembled that of rainbow trout. These facts proved that allotriploidization improved characters in sex ratio and morphometric traits compared to those o their parental species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.894-902
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• 2022

This study investigated the effects of photoperiod (NL 12L:12D and LL 24L:0D) and body sizes (30 g and 50 g) on parr-smolt transformation, post-smolt growth and blood properties in the off-season parr-smolt stage of Atlantic salmon reared in a recirculating aquaculture system (RAS). Potential off-season salmon smolt were reared in a freshwater RAS for 80 days and then all experimental fish were transferred to seawater. In both LL groups (LL-30 and LL-50), we recorded and increase in specific growth rate and reduction in feed conversion, although there were no significant difference in body size. The values of osmolality, and serum Na⁺, Cl^- and cortisol concentrations in the LL groups were maintained at lower levels than in NL group fish, and LL group fish were observed to recover to the pre-seawater adaptation state more rapidly than those in the NL group. ID chips were inserted in all smolts reared in freshwater. These fish were subsequently transferred to full-strength seawater and thereafter individual growth rates were monitored for 120 days. The results indicated that compared with smolt reared under natural photoperiodic condition, 24 h lighting in freshwater contributed to enhancing post-smolt specific growth rate in seawater.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.115-118
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• 2000

The production of cultured coho salmon (Oncorhpchus kisutoh) in Korea has being increased year after year. Smolt being reared in freshwater suffer transferring into seawater and are farmed in cages for fattening. This handling processes including transportation, confinement into cages are unavoidable stress to fish in salmon farming and often end up to mass mortality, This study aimed to investigate the impact of handling process on the stress responses of coho salmon. The indicator of stress was measured by cortisol to be a first response, and for the second response test, glucose, triBlyceride, cholesterol, lactate and electrolyte of $K^+, Na^+, Cl^-$ in serum and the activities of alanine aminotrtnferase (ALT), aspartate aminotransferase(AST) and lactate dehydrogenase (LDH) were analyzed. As a result, the concentration of cortisol, glucose as well as LDH activity were significantly increased, whereas others showed no difference comparing with control group. It obviously demonstrated that handling process made fish stressful.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.208-229
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• 1996

Comprative osteology of the chum salmon Oncorhynchus keta, masu salmon O. masou and rainbow trout O. mykiss in Korea was studied. As a result, it was found that there were some differences in the structural features of the cranium and visceral skeleton among the species. Interspecific differencies in glossohyal, supraethmoid, parasphenoid and vomer were distinctive for the species. Chum salmon could be distinguished easily by some characters on form of glossohyal which is thin, long and sharp in shape. It has triangle shape supraethmoid while other two species have oval shape one. The shape of parasphenoid, preopercle, hyomandibular and the number of epurals were evaluated as new taxonomic criteria for the salmons.

• Journal of agricultural medicine and community health
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• v.15 no.1
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• pp.3-8
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• 1990

Seven specimens of salmon(Oncorhynchus keta) purchased directly, in Oct. 10. 1990, in the Taep'o port. Kang-won-do were examined for infection state of anisakid larvae and classification of extracted larvae according to morphological characters. The results were as follows. 1) From seven salmon 202 anisakid larvae were found, and mean infection number of anisakid larvae per individual salmon was 28.86. 2) From total extracted anisakid larvae 198 larvae(98%) were found in muscle. Therefore the distribution of anisakid larvae in intestine was extremely rare compared to in muscle. 3) The percentage of anisakid larvae in II, IV muscle region was 93% and from this we could surmise that most anisakid larvae in salmon did not penetrate to the very distanted muscle from intestine. 4) Three types of anisakid larvae(Anisakis Type I, Contracaecum Type B, Contracaecum Type D) were identified and, among them, Contracaecum Type B was the first recording type in Korea 5) Larvae of Contracaecum it genus were found only in intestine. Therefore it surmised that penetration neture to muscle of Contracaecum larvae was less than that of Anisakis Type I.

• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.163-171
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• 1999

The complete sequences of mtDNA control regions of six salmonines were determined: 1089 bp in lenok (Brachymystax lenok); 999 bp in cherry salmon (Oncorhynchus masou masou) and Ishikawa's cherry salmon (O. masou ishikauiae); 1002 bp in chum salmon (O. keta), and 1003 bp in rainbow trout (O. mykiss) and an albino mutant of rainbow trout. The estimated interspecific sequence divergences from PCR/direct sequencing data ranged from 5.42% to 16.49%. The organization of this region is similar to that of other vertebrates. A 81 bp tandemly repeated sequence, associated with length variation was observed in the 3' end of the salmonids control region in this study. In addition, The phylogenetic tree based on the control region sequences supported that cherry salmon was closer to chum salmon than to rainbow trout, while lenok was most distantly related species among six salmonines.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.578-585
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• 2003

The chum salmon (Oncorhynchus keta) is an anadromous fish distributed all around the North Pacific. Artificial production and release of the juveniles are being made by Korea, Japan, Russia, Canada and the United States. It is important to set up some criteria identifying each stock in order to clarify each nation's right of harvest for the chum salmon resource. As an attempt to build such criteria, we analyzed sequences of a microsatellite DNA Ogo5 and the COIII-ND3-ND4L region of the mitochondrial DNA from chum salmons of Korea, Japan, and the United States. Ogo5 has 4 different alleles: allele A, B-1, B-2, and B-3. Allele B-3 is found only in 3 individuals out of 12 Korea salmons. The Japan salmons have the other 3 alleles and the America salmons have only 2 allots, A and B-1. Heterozygosity index (Ho/He) distinguishes the Korea (1.61) and Japan salmons (1.63) from the America ones (1.09). Seventeen different haplotypes are found in the COIII-ND3-ND4L region from 60 individuals,20 from each stock. The gene genealogy of the haplotypes revealed by TCS program shows that the Korea and Japan salmons are genetically closely linked, but that they are clearly distinguished from the America ones. Ten and eleven individuals of the Korea and Japan salmons have an identical haplotype. Nine individuals of the Korea salmons $(45\%),$ however, are separable from the Japan salmons by their own specific nucleotides. This result presents usefulness of the COIII-ND3-ND4L region as a genetic marker for identification of the chum salmon stocks.