• Korean Journal of Ichthyology
• /
• v.11 no.2
• /
• pp.163-171
• /
• 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 Ichthyology
• /
• v.8 no.1
• /
• pp.49-55
• /
• 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.

• Journal of Aquaculture
• /
• v.5 no.1
• /
• pp.1-7
• /
• 1992

Digestion rates of protein, carbohydrate, and lipid in the two kinds of extruding processed soybean meals, heated (H-SBM) and raw (R-SBM), were tested for evaluate the effectiveness of soybean meal in the rainbow trout diet. The relation between digestion rate of protein and trypsin inhibitor (TI) was also determined. The protein digestion rate of both H-SBM and R-SBM were increased up to $95{\%}$ by extruding process compared to the none treated soybean meal. The digestion rate of carbohydrate in R-SBM was increased by extruding process whereas the one in H-SBM was not. The activity of trypsin inhibitor was almost diminished by the extruding process and digestion rate of dietary protein was improved. However, the reason of this improvement was not clear whether caused by the deactivation of trypsin inhibitor.

• Journal of Aquaculture
• /
• v.11 no.2
• /
• pp.241-248
• /
• 1998

Effects of A23187 on estradiol$-17^{\beta}$-induced vitellogenin (VTG) induction were electrophore-tically examined in primary hepatocyte cultures in rainbow trout. hepatocytes were predultured for 2 days and then estradiol-$17^{\beta}$(E2, $2{\times}10^{-6}$M) and calcium ionophore (A23187, $10^{-7)$~$10^{-5}$ M) were added to the incubation medium. The hepatocytes were cultured for 7 more days. In addition, effects of A23187 on $E_2$-primed VTG production were investigated for 7 days. The addition of A23187 ($10^{-7)$~$10^{-5}$M) to the incubation medium specifically reduced VTG production by hepatocytes in a concentration-dependent way. The addition of A23187 significantly reduced the rate of $E_2$-primed VTG production to 18% of the control (E2 only) on Day 7. However, $E_2$-primed VTG production was reduced to 47% of the control by withdrawal of $E_2$ from the incubation medium. Therefore, these results suggest that intracellualr sequestered calcium could regulate VTG synthesis at the translational and/or post-translational stage.

• Journal of Aquaculture
• /
• v.13 no.1
• /
• pp.79-85
• /
• 2000

The effects of estrogen and androgens on Vg gene expression were examined in primary hepatocyte culture and livers of the immature male trout. Specific primers of Vg cDNA were designed with already reported Vg gene nucleotide sequences. PCR product was sequenced and verified with Vg cDNA of rainbow trout. Total RNA was extracted from the cultured hepatocytes and livers of steroid-treated rainbow trout and then it was analyzed by reverse transcriptase- polymerase chain reaction (RT-PCR) analysis. The Vg mRNA and Vg protein synthesis were increased in rainbow trout in vivo and in vitro with E$_2$ and methyltestosterone (MT) There were dose and time-related effects of E$_2$ and MT on vitellogesis. Androgens such as progesterone androsterone and testosterone also stimulated Vg mRNA expression in vitro. The results show that androgens as well as E$_2$ can induce expression of Vg mRNA in trout in vivo and in vitro.

• Korean Journal of Environment and Ecology
• /
• v.29 no.3
• /
• pp.401-409
• /
• 2015

The fish community and introduced fish were surveyed at eight stations of Lake Soyang from March to October, 2013. A total of 41 species of twelve families were collected from the survey stations and among them, two species: Hemibarbus mylodon and Siniperca scherzeri (albino type) were identified as natural monument. There were fifteen Korean endemic species (36.6 %) including Acheilognathus yamatsutae. When compared with previous data (2003), A. yamatsutae, Pseudorasbora parva, Sarcocheilichthys nigripinnis morii, Sarcocheilichthys variegatus wakiyae, Orthrias nudus, Leiocassisuss ussuriensis, Oncorhynchus mykiss, and Micropterus salmoides appeared new in the lake. Dominant species were Hypomesus olidus (St. 1, 3, 6, 7, 8), Lepomis macrochirus (St. 2, 4) and Zacco platypus (St. 5). Of the 12 introduced species fishes in Lake Soyang, Anguilla japonica, Hemiculter eigenmanni, H. nipponensis, Rhinogobius giurinus and Tridentiger brevispinis were introduced and released from other native river water zones in Korea but Cyprinus carpio (Israeli type), Carassius cuvieri, O. mykiss, Ictalurus puntatus, L. macrochirus, and M. salmoides originated from foreign countries.

• Journal of fish pathology
• /
• v.11 no.1
• /
• pp.51-60
• /
• 1998

Concerned to the lyfe cycle of Ichthyophthirius multifiliis, the experimental infection and development of the parasites were studied in the several freshwater cultured fishes. Opitimum conditions for the propagation of the parasite by serial passage with the rainbow trout fry was observed. Visiable white spots were examined in the body surface, fins and gills of the healthy fries, and a stable infection has been maintained for 2 months in the experimental system (Temperature: $18{\pm}1^{\circ}C$ DO: 7-7.5 ppm; pH: $7{\pm}0.2$). Induction conditions for artificial infection of the parasite by interms of the host fishes, stages of the parasites, and rearing temperature regimes was investigated. Rainbow trout fries showed a positive infection which was resulted from exposure of theront at $18^{\circ}C$. The rainbow trout fries induced white spots on the body surface at 3-7 days exposure to the theronts at $18^{\circ}C$. It was found that exposure of the rainbow trout fries exposed to 1,000 theronts per fish (10 theront/ml) for 45-60 minutes at $18^{\circ}C$ would consistently produce infection. Perfect infection (100%) was induced when the fries were exposed to 1,500 theront per fish (15 theront/ml) under laboratory condition. Development of I. multifiliis in the rainbow trout was observed for 7 days postexposure (PE). The parasite increased in average diameter from $54{\mu}m$ on the 1st day PE to $426{\mu}m$ on the 7th day PE. In the initial infestation period, the parasites were found on the gill epithelium, and on the 3rd day PE they invaded into the basal part of the gill filament adjacent to the major blood vessels, particularly the afferent vessels. Morphological change of buccal apparatus were observed on the 2nd day PE. Contractile vacuoles were more prominent on the 4th day PE, and they had notable changes on the 7th day PE.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.29 no.3
• /
• pp.357-368
• /
• 1996

To utilize the ascidian tunic as a natural pigment and dietary sources for rainbow trout (Oncorhynchus mykiss), juvenile were fed on experimental diets containing enzymatic hydrolysates of ascidian tunic treated with three commercial mined enzymes (ultrazyme, cellulase, viscozyme) for 12 weeks. From the results of feeding experiment, similar growth rate was checked in the enzymatic hydrolysis group compared with control, and those were a higher than of ascidian tunic powder group. The total acetone extractable pigment in muscle of the enzymatic hydrolysates group was lower than that of the ascidian extracts group and carophyll pink group until 8 weeks, but the level of those pigment of the enzymatic hydrolysates was similar to the ascidian extracts and carophyll pink group after 12 weeks. The lipid content was increased with the pigment concentration in the all experimental group. But the ascidian tunic pigment did not influence on the composition of the fatty acids in the muscle and liver. From the consideration of results for pigmentation, the enzymatic hydrolysates of ascidian tunic were suitable for both a natural pigment and dietary protein and carbohydrates sources as a substitute synthetic pigment for aquaculture use.

• Journal of Life Science
• /
• v.3 no.4
• /
• pp.209-215
• /
• 1993

어류의 대량폐사의 원인은 여러 가지가 있을 수 있는데 가장 중요한 것 중의 하나가 바이러스 감염에 의한 것이다. 우리나라 송어양식의 경우, 바이러스성 질병에 의한 대량폐사가 발생하여 매년 수천만마리의 치어가 폐사되어 왔는데 이 질병의 원인을 조사한 결과, 전염성 췌장 괴사 바이러스(Infectious Pencreatic Necrosis Virus ; IPNV)와 전염성 조혈기 괴사 바이러스(Infectious Hematopoietic Necrosis Virus ; IHNV)가 분리되어 이들의 대량폐사의 병원체임읠 밝혀내었다. 따라서 본 총설에서는 연어과 어류중 양식 대상종인 무지개송어 양식시 전염성과 병원성이 강해 치어기에 들어 대량폐사를 유발시키는 IHNV에 대해 최근 연구 결과를 중심으로 바이러스 분리 및 동정, 신속진단, 바이러스 백신 기초 기술 개발순으로 기술하고자 한다.

• The Korean Journal of Food And Nutrition
• /
• v.6 no.2
• /
• pp.73-80
• /
• 1993

In order to examine food components of coho salmon and rainbow-trout, We analyzed the composition of protein, amino acids and total lipids. The coho salmon muscle contained about 19.3% of protein with the composition of 29.9% in sarcoplasmic protein, 56.3oA in myofibrillar protein 12.5% alkali soluble protein and 2.6% in stroma. Those of rainbow-trout contained 34.1%, 56.4%, 8.3% and 2.9%, respectively. The sarcoplasmic and myofibrillar protein were composed of 13 subunits in coho salmon, and 16 and 15 subunits in rainbow-trout. Judging from the contents of essential amino acids, both muscle proteins were complete proteins. The most remarkable feature of free amino acids was that a large amount of dipeptide anserine was present with fairly lower levels of 1 methyl histidine, taurine, histidine, alanine and glycine in both muscle extracts. The total fatty acids of coho salmon was composed of 31.49% polyenes, 43.79% monoenes and 24.73% saturates. The composition of total fatty acid of coho salmon muscle was not different from that of rainbow-trout muscle.