• Journal of Fisheries and Marine Sciences Education
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• v.28 no.4
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• pp.1068-1075
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• 2016

The suitable temperature and salinity for the long-distance transportation for the rockfish were investigated by assessing survival rate, metabolism, histological change. All experimental groups showed survival rates of 100%. Daily Oxygen consumption rhythm was decreased during nights and increased during days. Average oxygen consumption was significantly decreased as temperature and salinity were decreased. Ammonia excretion was significantly increased as temperature and salinity were decreased. Histological changes were observed in the skin and gill of the rockfish exposed to 10 psu under all the temperature conditions, with larger changes at $4^{\circ}C$. Further, nucleus deformation and uniformity in the cytoplasm were also observed.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.2
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• pp.390-398
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• 2015

A feeding experiment was conducted to determine the use of distillers dried grain (DDG) as a partial replacement for fish meal in the diet for juvenile rockfish, Sebastes schlegeli. Four iso-nitrogenous (50% crude protein) and iso-caloric (4.3 kcal/g) diets (designated as DDG0, DDG7, DDG14, and DDG21) were formulated to contain 0, 7, 14, and 21% DDG. Triplicate groups of juvenile rockfish (initial body weight, $10.2{\pm}0.2g$) were fed one of the experimental diets to visual satiety twice a day (09:00 and 17:00) for 8 weeks. At the end of the feeding trial, survival of rockfish was above 97% and not affected by dietary DDG levels (P>0.05). Weight gain, feed efficiency and daily feed intake of juvenile rockfish were significantly decreased with increase of dietary DDG levels (P<0.05). Condition factor, hepatosomatic index and visceralsomatic index of juvenile rockfish were not significantly affected by dietary DDG levels (P>0.05). No significant differences were observed in the contents of moisture, crude protein, crude lipid and ash of the whole body and dorsal muscle in juvenile rockfish fed the experimental diets (P>0.05). Therefore dietary inclusion of DDG as a replacement for fish meal could depress the growth of juvenile rockfish.

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.580-581
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• 2006

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.359-369
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• 2001

Polymerase chain reaction (PCR) amplification of DNA as 30 different arbitrary primers and random amplified polymorphic DNAs (RAPD) analysis were performed on genomic DNA extracted from the blood of the marine rockfish (Sebastes schlegeli) from the Yellow Sea and the Southern Sea. The unique properties of the genomic DNA were used to investigate the features of the population dynamics and origins of the species. Out of 30 primers, seven generated 207 highly reproducible RAPD polymorphic products, producing approximately 2.7 polymorphic bands per primer. About 67.4% of total amplified products (307) were either polymorphic (207) to rockfish. The degree of similarity varied from 0.22 to 0.63 as calculated by bandsharing analysis. Also, the average level of bandsharing was 0.39$\pm$0.02 within the rockfish strains. The electrophoretic analysis of RAPD-PCR products showed the relatively high levels if variation between different individuals in rockfish from the Yellow Sea. However, the RAPD outlines obtained with DNA of different rockfish strains from the Yellow Sea and the Southern Sea in Korea were very similar. Also, a small number of polymorphic bands were identified. Even if further analyses or more rockfish populations are required, this result implies RAPD analysis reflects genetic differences between the geographical strains of the rockfish.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.2
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• pp.84-94
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• 2007

The comparative feeding ecology of greenling Hexagrammos otakii and Schlegel's black rockfish Sebastes schlereli populations was investigated in the Jangbong tidal flat near Incheon, Korea. Monthly samples were taken using a modified otter trawl from November 1999 to January 2001. The stomach contents of 124 greenling and 115 Schlegel's black rockfish were analyzed. The diet of H. otakii was dominated by the amphipods Gammaropsis iaponicus, Caprella scaura, Isaeopsis sp. and Monocorophium acherusicum, the shrimps Latreutes mucronatus and Alpheus japonicus, the mysid Neomysis orientalis and the bivalve Mytilus edulis. In contrast, S. schlegeli mainly fed on the mysids N. orientalis, N japonica, and N. awatschensis, the shrimps Exopalaemon carinicauda, A. japonicus and L. mucronatus, and the fish Pholis fangi and unidentified gobiids. A comparison of the frequency and abundance of food items showed that crustaceans (e.g. amphipods, mysids and shrimps) were important foods for both species. Their main dietary components, however differed which is probably due to differences in the spatial distribution of the two species and their prey items. In conclusion, greenling and Schlegel's black rockfish, despite being sympatric on a tidal flat have distinct food habits and low dietary overlap (Schooner's index: 0.1). These results indicate, to some extent, resource partitioning for the maximum utilization of available foods in the tidal flat.

• Korean Journal of Ichthyology
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• v.19 no.1
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• pp.35-43
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• 2007

Age and growth of black rockfish, Sebastes schlegeli sampled from the Tongyeong marine ranching area in Korea waters were determined from 1,173 otoliths from July, 2001 to May, 2004. Examination of outer margins of the otolith showed that the opaque zone was formed once a year. Marginal increment of the otolith formed annual ring from July. The von Bertalanffy growth curve had the growth parameters estimated from non-linear regression were $L_t=48.45(1-e^{-0.2139(t+0.4313)})$, $W_t=1,837.93(1-e^{-0.2139(t+0.4313)})^{3.02}$ 3.02 for females and, $L_t=49.32(1-e^{-0.1775(t+0.7403)})$, $W_t=1,887.83(1-e^{-0.1775(t+0.7403)})^3$ for males, where t is age (year) and Lt is body length (mm) at age t. Growth at the age of male and female shows significant difference (p<0.01).

• Journal of fish pathology
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• v.18 no.3
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• pp.293-300
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• 2005

This study was conducted to investigate the effect of bisphenol A (BPA; 4,4' -isopropylidenediphenol) on haematological parameters of Korean rockfish, Sebastes schlegeli in laboratory condition, Fish were randomly distributed into three treatment groups which were received of 0.1, 1 and 10 mg BPA $kg^{-1}$ body weight. They were injected four times intraperitoneally at days 0,3,7 and 12 with BPA. Control group was subjected to the same regime using an equal volume of 60% ethanol-mixed PBS carrier injection only. Fish from each group were sacrificed on day 15 after first injection for haematological assay. Observations on haematological parameters indicated BPA-treatment induced lower level of red blood cell counts and hemoglobin concentration. Serum chloride, calcium, glucose, bilirubin and blood urea nitrogen concentrations increased following exposure to BPA at 10 mg $kg^{-1}$ body weight. In contrast, serum cholesterol in fish exposed to BPA decreased. Serum transaminase and lactate dehydrogenase activities after the highest level of 10 mg $kg^{-1}$ PBA was significantly increased. These results demonstrate that BPA have induced adverse impact on haematological parameters in the Korean rockfish, Sebastes schlegeli.

• Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.23-25
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• 2000

To compare the respiratory burst activity potential of the phagocytes isolated from head kidney, spleen, and peripheral blood 1ll cultured rockfish (Sebastes schlegeli), chemiluminescent (CL) response analysis was performed. The phagocytes isolated from peripheral blood showed greater and faster CL response to the opsonized zymosan compared to that of the phagocytes isolated from kidney or spleen. This may imply a significant role of the blood phagocytes in defence mechanism of rockfish. The different responses found in the CL analysis among the phagocytes isolated from peripheral blood, kidney, and spleen may reflect differences in activation state or activity of phagocytes.

• Fisheries and Aquatic Sciences
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• v.5 no.4
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• pp.308-310
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• 2002

Effect of 4-nonylphenol (4-NP), endocrine disrupting compounds (EDCs), on glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) were investigated in the plasma of juvenile rockfish, Sebastes schlegeli. Fish were injected with 4­NP (10, 50, 100 and 200 mg/kg body weight) in $70\%$ ethanol twice at 3-day intervals and plasma sampling were extracted at 7 days after the last injection. Controls received solvent only. 4-NP significant increased GOT in a dose-dependent manner. GPT was markedly elevated to $61\%$ (P<0.05) and $82\%$ (P<0.01) than that of the control at the 4-NP doses of 100 and 200mg, respectively. These results suggest that the estrogenic activity of 4-NP increase plasma GOT and GPT by toxic effect on hepatocyte.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.769-773
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• 2001

In order to obtain the fundamental data on the underwater sound of fishes for marine ranching. The underwater sound of Red Seabream(Pagrus major) and Schlegel's black rockfish(Sebastes schlegeli) were measured, which character were summarized by FFT analysis.