• Fisheries and Aquatic Sciences
• /
• v.27 no.7
• /
• pp.421-433
• /
• 2024

Among larger species of fish found in Punatsang chhu, Brown trout (Salmo trutta) and Snow trout (Schizothorax richardsonii) are notable species. Snow trout is a native species, whereas Brown trout is an introduced species. Brown trout is noted to have a negative impact on the population of native species worldwide. This study studied the population dynamics and structure of these species to detect if the introduced species affected the native species adversely. The study was conducted on a 30 km stretch of Punatsang chhu including its major and minor tributaries at about their confluences. In total, 56 sample plots of a 200 m sampling stretch were studied with a 200 m distance between each stretch. Length, weight, maturity, and sex data for both species were collected along with the habitat and water parameters. The two species were found to prefer different areas within a single stretch with a rare overlap. Snow trout were found to be distributed widely within the basin whereas Brown trout were only found in altitudes higher than 1,000 masl ($\overline{x}$ = 1,231.77) and in turbid waters (p = 0.009). Recruitment of Snow trout was not good whereas recruitment of Brown trout was good. Length-frequency graphs indicated good inverse J distribution for the Snow trout population and sporadic for Brown trout. There is an effect of Brown trout introduction to the Snow trout living in the study area. Places invaded by Brown trout have a lesser presence of Snow trout compared to places not invaded by these species.

• BMB Reports
• /
• v.38 no.2
• /
• pp.206-210
• /
• 2005

Gonadogenesis is a complicated process which involves multi-gene interactions. A rainbow trout (Oncorhynchus mykiss) gene spermatogenesis associated 4 (SPATA4) was cloned and characterized from adult rainbow trout testis. The cDNA sequence of rainbow trout SPATA4 contains an open reading frame of 1, 081 nucleatides encoding a putative protein of 259 amino acids. The putative protein from rainbow trout shares a 76.8% homology with zebrafish SPATA4. No trans-membrane regions or signal peptide were detected using bioinformatics methods. Subcellular localization analysis revealed that rainbow trout SPATA4 was a nuclear protein with highest possibility (39.1%). Multi-tissue reverse transcriptase PCR (RT-PCR) was performed to examine the distribution of rainbow trout SPATA4 in eleven organs of adult rainbow trout. The result demonstrated that this gene express specifically in testis and slight amount of expression was detected in ovary. Further analysis of SPATA4 characterization and function in rainbow trout may provide insight into the understanding of gonadogenesis process.

• Archives of Pharmacal Research
• /
• v.20 no.5
• /
• pp.404-409
• /
• 1997

Trout CYP1A-CAT expression construct was generated by cloning -3.5 Kb $5^I$ flanking DNA of trout liver CYP1A gene in front of CAT gene at pCAT-basic vector. Hepa 1 cells, which are known to contain a functional arylhydrbcarbon $receptor^I$ were transfected with trout CYP1A-CAT using lipofectin. 3-Methylcholanthrene (1 nM) was added into hepa 1 cells in culture in order to examine if $5^I$ flanking DNA of trout CYP1A gene could interact with mouse transactivating factors to bring about transcription of the chloramphenicol acetyltransferase(CAT) reporter gene. The level of CAT protein was measured by CAT ELISA and the level of CAT mRNA was determined by RTPCR. The treatment of 1 nM 3-methylcholanthrene resulted in two fold increases in CAT protein as well as CAT mRNA compared to untreated control hepa 1 cells. These data indicate that arylhydrocarbon receptors of mouse hepa 1 cells are functional to activate exogenously transfected trout CYP1A-CAT construct in terms of both transcription and translation of CAT. We also examined the effect of 3-methylcholanthrene on endogenous cyplal activity in hepa 1 cell. 3-Methylcholanthrene (1 nM) treatment to hepa 1 cells trahsfected with trout CYP1A-CAT construct stimulated the level of cyp1a1 mRNA by two folds and the activity of ethoxyresorufin-O-deethylase by two fold compared to that of control cells. In this study we reported that trout CYP1A-CAT reporter gene expression construct could be expressed by 3-methylcholanthrene treatment in mouse hepa 1 cells. Thus trout CYP1A-CAT could serve as a good model to study the mechanism of regulation of CYP1A1 gene expression.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.2
• /
• pp.103-113
• /
• 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
• /
• v.43 no.2
• /
• pp.109-116
• /
• 2010

This study investigated the effects of astaxanthin, which is used to improve the muscle color of fish, on the nutritional composition of rainbow trout (Oncorhynchus mykiss). The trout were fed extruded pellets containing astaxanthin (pigmented rainbow trout) or without astaxanthin (non-pigmented rainbow trout). No significant differences in the contents of crude protein and crude ash between the two muscles of the two groups were observed. However, the crude fat composition of the muscle of pigmented rainbow trout was about two times higher than that of control muscle. In the muscle of pigmented rainbow trout, the contents of docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3), which are functional polyunsaturated fatty acids, were 1.6 fold higher than in non-pigmented muscle. In addition, the contents of minerals such as Zn and Fe, vitamins (B group, C, and E), free amino acids, carotenoids and astaxanthin were increased in the muscle of rainbow trout fed pellets supplemented with astaxanthin. Specifically, the content of the bioactive compound astaxanthin, was increased six times in the pigmented muscle, as compared to the control muscle. The results suggest that a diet supplemented with astaxanthin improves the nutritional composition of rainbow trout muscle as well as improving the muscle color.

• Journal of Aquaculture
• /
• v.11 no.3
• /
• pp.327-335
• /
• 1998

Amplification of brook trout growth hormone cDNA using polymerase chain reactiono (PCR) produced a nucleotide of 1,120 bp which contained the 5'non-coding region (13bp), an open reading frame (ORF) coding a growth hormone polypeptide consisting of 210 amino acids (630 bp), and a 3'non-coding region (477 bp). In open reading frame s signal peptide of 22 amino acid and 2 potential disulfide bond sites deduced by 4 cysteine residues were obser-bed. Brook trout growth hormone has 97.1%, 94.8%, 94.3%, 91.9%, 66.2%, 63.5%, 62.9%, 62.3%, 53.8% and 48.1% amino acid identity with that of Atlantic salmon, chum salmon, rainbow trout, coho salmon, tuna, tilapia, yellow tail, carp, flounder and eel, respectively.

• Journal of Life Science
• /
• v.5 no.2
• /
• pp.70-75
• /
• 1995

The effect of lipoxygenase (LOX) on the oxidation and co-oxidation of lipid fraction was studied in the model system of rainbow trout. For the reaction in model system 1 g of lipid fraction and 50mL of enzyme extract(LOX, 140 unit in 50mL phosphate buffer solution at pH 7, 4)), which were obtained from rainbow trout, were homoginized in the presence of Tween 20 and kept at 23$\circ$C for 3 days. The activity of LOX was decreased to 43% of initial level during the reaction in the model system. The initial composition of rainbow trout lipid was showed to be consisted of trigliceride(TG;82%) and free fatty acid(FFA;0.1%), while this converted to 59% of TG and 20% of FIFA, respectively after reaction in model system. Change of fatty acid composition was also observed and the content of linoleic acid, one of the major fatte acids, was decreased to 13% from 54% in the content of total fatty acids after reaction. The carotenoids in rainbow trout were composed of 0.4% $\alpha$-carotene, 1.6% $\beta$ -carotene, 80% canthaxanthin, 7% lutein and 11% zeaxanthin, thus the canthaxanthin was the major component. This canthaxanthin was the most degraded carotenoid by lipoxygenase catalyzed co-oxidation during the reaction. On the other hand the tocopherol isomers found in the rainbow trout were $\alpha$ and $\beta$ -tocopherol, and $\alpha$-tocopherol had a higher degradation rate by the lipoxygenase catalyzed co-oxidation than of $\beta$-tocopherol in the reaction of model system.

• Korean Journal of Ichthyology
• /
• v.3 no.1
• /
• pp.58-62
• /
• 1991

The genomic DNA from liver tissue of rainbow trout(Oncorhynchus mykiss) was analyzed by agarose gel electrophoresis. The molecular weight of Oncorhynchus mykiss genomic DNA was about 21.3 kilobase pairs.

• Journal of fish pathology
• /
• v.22 no.3
• /
• pp.193-200
• /
• 2009

This study was performed to natural infection of Ichthyophthirius multifiliis and mortalities of two fish species were compared at 10${^{\circ}C}$ and 17${^{\circ}C}$ after artificial infection with the parasite. Subsequently compared to motality by the artificial infection with the different parasite orgin of host at 17${^{\circ}C}$ using rainbow trout Oncorhynchus mykiss. The prevalence of Ichthyophthirius multifiliis in cherry salmon was higher than that in rainbow trout during the periods of low temperature but no difference in high temperature season. The parasite was not detectable in culturing water and detritus except May that of density has been high. Susceptibility to the parasite was higher in cherry salmon than in rainbow trout at 10${^{\circ}C}$ of water temperature but no difference between two fish species at 17${^{\circ}C}$. When rainbow trout were infected with Ichthyophthirius multifiliis from rainbow trout and cherry salmon at 17${^{\circ}C}$, there was no difference in death of host. These results suggest that cherry salmon have higher susceptibility to Ichthyophthirius multifiliis than rainbow trout at low temperature.

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