• 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.

• Environmental Analysis Health and Toxicology
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• v.20 no.3 s.50
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• pp.223-228
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• 2005

Rockfish Sebastes schlegeli was exposed to fluoranthene, a ubiquitous polycyclic aromatic hydrocarbon, at 1 and 10 $\mu$g/L for 4 weeks followed by depuration period of 8 weeks. Although the fluoranthene in the p]asma reached only 1.8$\~$1.9 times seawater concentration, it was 6.5 $\~$ 15.7 times higher in the liver, spleen and bile indicating efficient accumulation in the lipid -containing body tissues. When the exposed fish were then maintained in clean water, rapid fluoranthene decline occurred in the initial 2 weeks followed by a rather slow phase. This result suggests that fluoranthene accumulates efficiently provided the existence in the culture medium, but the contaminant disappears rapidly once the chemical source is removed. The fluoranthne residue in fish tissues my be a good indifator for relent PAHs exposure.

• The Korean Journal of Malacology
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• v.24 no.3
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• pp.253-260
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• 2008

A total of 15 different residues of polycyclic aromatic hydrocarbons (PAHs) in each 20 samples of Pacific oysters, dried laver and rockfish obtained from seafood markets were analyzed. The prevalence of samples in which more than one PAH residues were found was 75% in oyster, 35% in rock fish hepatopancreas, 0% in rockfish muscle and laver, respectively. To estimate factors contributing to this residue level difference among organisms, tissue concentrations were analyzed after exposing three organisms to phenanthrene, a representative PAH, with concentration of 0.01 or $0.1{\mu}g/mL$ for 2 weeks. Phenanthrene levels after exposure were higher in the oyster digestive gland, laver and rockfish hepatopancreas, but were lower in the oyster whole meat or rockfish muscle. This finding disproved that any close relationship between the residue difference of market samples and concentrating properties of PAHs. The second possible factor analyzed was total lipid contents in the three organisms. Although higher lipid level in hepatopancreas of rockfish may contribute accumulation of PAH residues in the rockfish, lipid factor did not affect to PAH levels in other organism samples. Activity of 7-ethyoxyresorufin-O-deethylase (EROD), a kind of cytochrome $P_{450}$ enzyme, was measured to evaluate the eliminated amount of PAHs through metabolism. The higher EROD activity in rockfish, compared to that in oyster, was likely to contribute to the lower PAH residues in the rockfish. More factors, such as different exposure history, organisms' ability to escape, ingestion through prey organisms, and post-harvest loss, should be studied in the future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1192-1201
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• 2016

This study was conducted to investigate sensory characteristics and consumer acceptance of sliced raw fish. The two most popular varieties in Korea, flounder and rockfish, were used. Samples of each variety were prepared as follows to create consistent perceptible sensory differences: 'fresh' (consumed within 2 h after sacrifice), 'aged' (stored at $1^{\circ}C$ for 24 h), 'frozen' (frozen at $-16^{\circ}C$ for 23 h then thawed at $23.5^{\circ}C$for 1 h), and 'immersed' (immersed in sterilized water at $1^{\circ}C$ for 24 h). Sensory profiles of samples were determined through quantitative descriptive analysis using 10 trained panelists. Consumer acceptance test was conducted using 47 consumers. Analyses of variance were conducted to test significance of differences in sensory profiles and hedonic ratings among samples. Consumers were clustered according to their overall liking scores, and their preference patterns were cross-checked with sensory profiles. For both fish varieties, 'fresh' was characterized by stronger hardness, cohesiveness, springiness, cartilage-like texture (applied to only rockfish), and fishy flavor, whereas 'frozen' and 'immersed' were distinguished from other samples for their stronger wetness, juiciness, and fresh fish flavor than those of other samples. 'Aged' was significantly less hard, cohesive, and springy than 'fresh' as well as less juicy and wet than 'frozen' and 'immersed'. Consumers significantly preferred 'fresh' flounder and rockfish to others for their strong cohesiveness and springiness, indicating textural attributes were main factors affecting consumer preferences. However, for both flounder and rockfish, 40~50% of respondents preferred 'frozen' and 'immersed' to 'fresh' for their tenderness and fresh fish flavor. For this group of consumers, flavor liking had a greater effect on overall preference than texture preference. The result suggests that cohesive and springy textures and fresh fish flavor are major drivers of preferences for raw fish slices, but their relative importance and optimal levels varied across individual consumers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.315-320
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• 2002

The multifunctional compound such as conjugated linoleic acid (CLA) was used to producing of functional larval rockfish. Artemia, livefoods for larval fish, enriched with highly unsaturated fatty acids (HUFA) and CLA ($0.5\%$, $1.0\%$, $2.5\%$ and $5.5\%$ group) was fed to larval rockfish. Artemia, enriched with $2.5\~5.0\%$ of CLA, negatively affects the quality of larval rockfish. But $1.0\%$ CLA fed group shown to good specific growth rate, feed efficiency, n-3/n-6 PUFA ratio, DHA/EPA ratio and hematology results. The CLA deposited in muscle lipids of larval rockfish was reached 6.57 to $19.69\%$.

• Korean Journal of Environmental Biology
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• v.33 no.4
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• pp.412-418
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• 2015

The objective of this study was to evaluate the effects of acute hypoxia on the physiological stress responses (plasma cortisol as the primary response, and hematocrit, hemoglobin, plasma glucose, sodium, chloride, osmolality, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) as the secondary responses) of Korean rockfish. The mortality in Korean rockfish started at $0.7mg\;L^{-1}$ and $0.8mg\;L^{-1}$ levels at $12^{\circ}C$ and $20^{\circ}C$, respectively. And the time required for the mortality in experimental fish was 274 and 148 minutes at $12^{\circ}C$ and $20^{\circ}C$, respectively. Levels of hematocrit, hemoglobin, AST, ALT, ion concentration, osmolality, glucose and cortisol had significantly increased with decreasing dissolved oxygen at $12^{\circ}C$ and $20^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.777-784
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• 2013

This study compared the effects of diets consisting of experimental extruded pellets (EP), commercial soft extruded pellets (SEP), and raw-fish-based moist pellets (MP) on the growth, flesh quality, and histology of the Korean rockfish Sebastes schlegeli. Three replicated groups of 60 fish each (initial mean weight 152 g) were fed one of two experimental EPs (EP1 and EP2), two commercial SEPs (SEP1 and SEP2), or MP for 11 weeks. The survival, weight gain, and final mean weight of the fish did not differ significantly among the groups. The highest feed efficiency was in fish fed MP (P<0.05), and the protein efficiency ratio of fish fed MP was significantly higher than that of fish fed EP1, EP2, or SEP1, but not significantly different from that of fish fed EP2. The daily feed intake of the fish fed the EPs and SEPs was significantly higher than that of the fish fed MP (P<0.05). The condition factor, Hepatosomatic Index, and Viscerasomatic Index of the fish did not differ significantly among the groups. No notable differences in the textural properties of the dorsal muscle, plasma biochemical parameters, or histological features of the fish were observed in fish fed any diet. This suggests that extruded pellets can be used to feed growing Korean rockfish without compromising growth, flesh quality, or histopathological change in comparison to raw fish-based moist pellets.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.546-551
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• 2013

This study examined the effects of the dietary inclusion of Porphyra and sea tangle Laminaria japonica on the growth, feed utilization, body composition, and plasma chemistry of juvenile Korean rockfish Sebastes schlegeli. Eight hundred and forty juvenile fish averaging 5.0 g were allocated 40 fish per tank to 21 180-L flow-through tanks. Seven experimental diets were prepared: control (Con) without additive, 0.5 and 1% Porphyra extract (PE), 3% Porphyra powder (PP), 0.5 and 1% sea tangle extract (STE) and 3% sea tangle powder (STP), referred to as PE-0.5, PE-1, PP-3, STE-0.5, STE-1, and STP-3, respectively. Each additive was included in the experimental diet at the expense of the same amount of wheat flour. Each experimental diet was fed to triplicate groups of fish. The experimental diets had no effect on the survival, weight gain or specific growth rate of the fish, feed consumption, feed efficiency ratio, protein efficiency ratio, protein retention, hepatosomatic index, condition factor, moisture or crude protein content of the entire body excluding the liver or moisture, crude protein or crude lipid content of the liver. None of the plasma parameters were affected by the experimental diets. Based on these results, the dietary inclusion of Porphyra and sea tangle did not affect the growth, feed utilization, body composition or plasma chemistry of juvenile Korean rockfish.