• 한국어병학회지
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• 제22권3호
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• pp.343-352
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• 2009

Natural-killer-cell-enhancing factor (NKEF) belongs to the newly defined peroxiredoxin (Prx) family. It was originally isolated from human erythroid cells. The black rockfish NKEF cDNA was identified through the expressed sequence tag (EST) analysis of PBLs libraries. The full-length NKEF cDNA was 1433 bp long and contained an open reading frame (ORF) of 594 bp that encoded 198 amino-acid residues. The 5' UTR had a length of 39 bp, and the 3’UTR 800 bp. The deduced amino-acid sequence of the black rockfish had a density 93.4, 92.9, 87.8, 85.8, 84.8, 83.8, 80.3, 79.7, 77.2, and 75.2% that of the pufferfish, olive flounder, channel catfish, zebrafish, chicken, common carp, Myotis lucifugus, cattle, human PrxI, rat PrxI, human NKEF-A, and Xenopus tropicalis, respectively. The NKEF gene was expressed in all the tissues of the black rockfish. The RT-PCR indicated that the NKEF transcripts were predominantly in the spleen and gill, less dominantly in the PBLs, head kidney, trunk kidney, and liver, and least in the intestine and muscles. This is the first report on the existence of the NKEF-A gene in black rockfish.

• 수산해양기술연구
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• 제51권1호
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• pp.102-110
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• 2015

The characteristics of aquatic light fields are generally reflected in the visual systems of fishes inhabiting them. Therefore, research on light sensitivity of fish is useful to explain the correlation between the visual function and habitat, behavior and distribution of fish. Rockfish is an important species in coastal ecology and also one of the main species for culturing in Korea. To make a contribution on the maintenance of the fish resources and understanding the ecology of the rockfish, the visual spectral sensitivities of the dark-adapted rockfishes were measured in the range of visible light (405~660 nm) using a light source of light-emitting diodes (LEDs). In order to assess electrophysiological response of the fish, the ERGs (electroretinograms) of the dark-adapted rockfishes were recorded on a data logger (12 bits) and a laptop computer. Juvenile (n=5; weight: $20.3{\pm}5.2g$; total length: $10.3{\pm}0.7cm$) and adult (n=5; weight: $87.8{\pm}21.8g$; total length: $18.1{\pm}1.3cm$) rockfishes were used in experiment. The visual threshold of juvenile and adult rockfish were 11.66 (log quanta/$cm^2/s$) and 11.81 (log quanta/$cm^2/s$) in 574 nm, respectively. The peak wavelength of the spectral sensitivity in the dark-adapted juvenile and adult rockfish was commonly 551 nm (series of green color). Collectively, these results demonstrate that the rockfish has suitable visual capabilities for inhabiting coastal water in Korea.

• 한국수산과학회지
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• 제47권5호
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• pp.603-610
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• 2014

We investigated a nematode infection in the epithelial tissue of rockfish Sebastes schlegeli cultured in Cheonsu Bay, western Korea, from May 2013 to April 2014. Nematodes infected the epithelial tissues of various external organs, including the fins, operculum, nares, mouth, and head. Over a 1-year period, the overall nematode infection rate in rockfish was 55% (n=89/163): 56.7% (n=17/30) in May 2013, 88% (n=29/33) in August 2013, 0% (n=0/30) in October 2013, 70% (n=21/30) in January 2014, and 55% (n=22/40) in April 2014. During this study, the only mass mortality of cultured rockfish in Cheonsu Bay was in August 2013, when we identified skin wounds on the rockfish caused by the nematodes escaping from their hosts. During this period, the accumulated mortality for 2 weeks was 1.4-22.4% in different farms. In addition, several pathogenic bacteria (Photobacterium damselae, Vibrio spp., and Streptococcus iniae) were isolated from the moribund rockfish; these were thought to be transmitted through the skin wounds caused by the nematodes.

• 수산해양기술연구
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• 제55권2호
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• pp.129-137
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• 2019

This study was conducted to investigate the effects of underwater noise caused by pile driving during marine construction on fish. In this study, the three gray rockfish were released about 1 km away from the construction site of wind power generation on July 18, 2018 and traced using two acoustic telemetry techniques. The behavior of the fish was analyzed by calculating the moving distance, swimming speed and direction of the gray rockfish. In the results of the acoustic tracking using the ship, the rockfish moved about 2.11 km for about two hours at a speed of $0.28{\pm}0.14m/s$ (0.94 TL/s). The bottom depth of the trajectory of the rockfish was $1.0{\pm}0.6m$ on average. There was a significant directionality in swimming direction of the gray rockfish, and there was no significant correlation between the swimming direction and tidal current direction. Moving distance during 5 minutes (5MD) during pile driving and finishing operations between rock surface and bedrock were 0.94-0.96 times (76.0-77.0 m) and 1.81-2.73 times (146.0-219.5 m), respectively, compared with no pile driving. This study is expected to be used as a basic data of fish behavior research on underwater noise.

• 해양환경안전학회지
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• 제19권3호
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• pp.241-247
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• 2013

Yellow clay dispersion has been applied to minimize fisheries impact by the red tide Cochlodinium polykrikoides blooms in Korean coasts since 1995. The present preliminary study documents the effect of yellow clay on Korean rockfish, Sebastes schlegelii, in terms of oxygen consumption rate (OCR). The OCR in the low clay suspension (0.05 and 0.23 %, w/w) showed normal level compared to the control. In contrast, the OCR for each one of three replicates in the high clay suspension (1.16 and 5.58 %, w/w) was not returned to the previous level that clay was not treated, indicating that high clay suspension (${\geq}1.16%$, w/w) might give negative effect on Korean rockfish. Overall, this result suggests that field application of clay to control Harmful Algal Blooms (HABs) may not give impact on Korean rockfish once the clay is dispersed in a low concentration (${\leq}0.23%$). In order to understand the changes of OCR in the repeated exposure to clay, it is required to do further studies on the changes of OCR when the fish is exposed to clay repeatedly after recovery in the normal seawater.

• 수산해양교육연구
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• 제28권3호
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• pp.738-745
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• 2016

Aquaculture production of Korean rockfish Sebastes schlegeli has been continuously increased from 2000s and the fish has become the second most important mariculture fish in Korea. However, there are some environmental problems in aquaculture of Korean rockfish recently. In this regards, stress responses to high water temperature was examined via oxygen consumption, blood physiological parameter and endocrinological method. Oxygen consumption of Korean rockfish had significantly increased with rising water temperature. And oxygen consumption during the light time was no different with the dark time. The levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) showed no difference until $27^{\circ}C$, but it had rapidly increased at $30^{\circ}C$. Moreover high water temperature affected to increase in plasma glucose and cortisol levels.

• Fisheries and Aquatic Sciences
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• 제18권2호
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• pp.203-209
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• 2015

Low-value fish is the most commonly used feed in Asian fish farms despite the fact that its application is controversial in regard to the sustainability and biosecurity of aquaculture. In this study, the causal agent of a disease outbreak at a Korean rockfish Sebastes schlegeli farm was investigated to determine whether the low-value fish used at the farm was the source. Infected Korean rockfish and Pacific sand eel used as feed were sampled from the farm, and bacterial cultures recovered from the internal organs of all sampled rockfish were isolated as pure cultures and later identified as Vibrio harveyi. The causal agent of the disease was also isolated from the kidneys of some of the sampled Pacific sand eels. This study provides additional evidence that the low-value fish used as feed at fish farms can be a key source of infectious diseases.

• 수산경영론집
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• 제40권3호
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• pp.69-88
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• 2009

This research was as part of restocking project conducted until 1986. The necessity of its economic and scientific verification on restocking project increased. The economic analysis of this project was intended to measure its effectiveness of rockfish restocking throughout certain water areas. The rockfish restocking in 2008 was carried two regional governments of Gyeongnam and Busan. 3-year average annualized performance is 3.76 million rockfish restocked and 940 million won invested. As Gyeongnam restocked 3.62 million rockfish and invested 890 million won, most of rockfish stocking accomplished in Gyeongnam. The public shipment was the 3-year average amount was about 400 tons. Each Suhyup shipment as follows; TongYong 66.6 tons, Namhae 23.6 tons, Samcheonpo 17.2 tons; Yeosu 13.3 tons, Geoje 4.7 tons, Goseong 3.1 tons, Hadong 1.0 tons. The private shipment was assessed by the interview of relevant market participations. The high percent areas of public ship were Nemaha, Goseong 90% and Geoje 80% or more. Hadong and Samcheonpo were about 50%. TongYong was 10% and the lowest. The private shipment was calculated using the percentage of private shipment surveyed. The total amount of private shipment was 4.8 billion, where 4.5 billion was TongYong, where most of private shipment is being made. The positive economic benefit occurred when the percent of restocked is over 15% in the overall catch. The percentage of restocked investigated with genetic test was 58.2%. With 58.2% ratio of restocked, there was 3.8 times economic benefit according to approximately 3.6 billion won. Economic effects were highly significant. As catch increased according restocking, joint market commission increased. Joint market commission was calculated as total restocked shipment multiplied by the ratio of commission, the calculated commissions were as follows; Hadong 5.0%, Geoje 4.8%, Goseong 4.8%, Namhae 4.8%, Samcheonpo 4.3%, Yeosu 4.3%, TongYong 4.0%. According to calculation results, annual commission fee of ￦60,000,000 was raised during 2006~2008. The fishing catch bulk for entertainment significantly increased in sea area carried with mass restock.

• 한국어병학회지
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• 제23권3호
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• pp.323-334
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• 2010

Bactericidal/permeability-increasing protein (BPI) and lipopolysaccharide-binding protein (LBP) are important components of the mammalian innate defence system against Gram-negative infections. The BPI/LBP cDNA was identified from the black rockfish ConA/PMA or LPS stimulated leukocyte cDNA library. The full-length BR-BPI/LBP cDNA was 2118 bp long and contained an open reading frame (ORF) of 1422 bp that encoded 473 amino-acid residues. The 5' UTR had a length of 57 bp, and the 3' UTR 639 bp. The molecular weight and theoretical isoelectric point (pI) values were calculated 51.4 kDa and 9.72, respectively. Compared with other known BPI or BPI/LBP peptide sequences, the most conserved regions of the black rockfish BPI/LBP peptide were found to be the BPI1 N-terminal, BPI2 C-terminal domains and a LPS binding domain. Phylogenetic analysis based on the deduced amino acid sequence revealed a homologous relationship between the BPI/LBP sequence of black rockfish and that of other teleosts. The black rockfish BPI/LBP gene was predominantly expressed in the PBLs, head kidney, trunk kidney and spleen. The expression of the black rockfish BPI/LBP molecule was induced in the peripheral blood leukocytes (PBLs) from 1 to 24 h following LPS stimulation, with a peak at 12 h post-stimulation.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.261-262
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• 2000

Juvenile black rockfish, Sebastes schlegeli is an important commercial species along the coast of Republic of Korea. The black rockfish possesse some desirable characteristics for aquaculture including tolerance to cold water and handling, and receptivity to induced spawning in captivity. (omitted)