• Korean Journal of Environmental Biology
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• v.21 no.1
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• pp.42-44
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• 2003

The study of the gill infection of rockfishes, Sebastes spp. by monogenetic trematodes conducted during March 2002 to June 2002 are presented. Three species are reported krom examination of 23 rockfishes collected from Oregon Coast Aquarium and Newport fish market, Oregon. Ten rockishes belonging to three species showed an infection rate of 43.5%. A total of 135 monogenetic trematodes was found in the gills of Sebastes spp. Of 135 worms recovered from the gills of 4 harbor rockfishes, two were Sebastes maliger, 14 S. melanops, 110 S. pinniger, and 9 S. crameri. Prevalence and intensity in Microcotyle seba.fis were 11.9％ and 4.0, and for Trochopus trituba they were 81.5% and 55.0, and for Trochopus australis, they were 6.7% and 2.3, respectively. These worms are mainly found firmly attached to the primary lamellae of the gills of the rockfishes.

• Journal of Environmental Health Sciences
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• v.29 no.4
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• pp.17-20
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• 2003

The results of study of the parasites of rockfishes, Sebastes spp. collected at Oregon coast aquarium during April 6 to June 30, 2002 are presented. Six species of parasites were recovered from examination of 19 rockfishes with an incidence of infection of 42.1 %. This study investigated parasitic infestation of 7 black rock-fish, Sebastes melanops ; 3 quillback rockfish, S. maliger ; 2 yellowtail rockfish, S. flavidus ; 3 canary rockfish, S. pinniger 2 yelloweye rockfish, S. ruberrimus ; 2 tiger rockfish, S. nigrocinctus. Sebastes spp. from aquarium were found to be infested with parasites: Mycrocotyle sebastis, Megalocotyle trituba, Clavella uncinata, Anisakis simplex larvae, Contracaecum sp. larvae, Pseudoterranova decipiens larvae. Prevalence and mean intensity of rockfishes were infected respectively as follows: 21.1%, 4.0 of M. sebastis, 10.5%, 55.5 of M. trituba, 21.1%, 34.3 of A. simplex larvae, 10.5%, 15.0 of Contracaecum sp. larvae, 10.5%, 8.5 of Pseudoterranova decipiens larvae and 10.5%, 5.0 of Clavella uncinata. This study reveled that gills and gastrointestinal tracts of S. pinniger were heavily infested with M. trituba and A. simplex larvae.

• Journal of Environmental Health Sciences
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• v.29 no.1
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• pp.16-18
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• 2003

Seven specimens of Sebastes melanops, black rockfish and three of S. maliger, quillback rockfish, were collected from Oregon Coast Aquarium during the period of September 19 to November 5, 2001 and examined for parasites. One monogenean helminth species and parasitic copepod species were recorded from black and quillback rockfishes, respectively. A total of 26 parasites were collected: 16 Microcotyle sebastis from the gill filaments of black and quillback rockfishes and 10 Clavella adunca were found in the fins of black rockfish. The prevalence of Microcotyle sebastis was 40.0%, and intensity of infection was 2.0(1-11). With regard to Clavella adunca, the prevalence and intensity were 20.0% and 1.4(2-8), respectively.

• Journal of Environmental Health Sciences
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• v.29 no.4
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• pp.55-57
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• 2003

Nine (34.6%) of the 26 rockfishes taken from Newport fish market, Oregon in July 2003 had a total of 135 monogenetic trematodes attached the gills. Microcotyle sebastis, Megalocotyle trituba and Trochopus australis were encountered, occurring in rockfishes examined. In the monogenetic trematodes in Sebastes spp, the prevalence were found to be between 30.8 and 40.0%. Prevalence of M. sebastis was 37.5%, 40.0% on M. trituba and 30.8% on T. australis. Nine of Sebastes spp. were infected with one or two species of monogenetic trematodes. Intensities of infection for M. sebastis, M. trituba and T. australis were recorded as 2.0 (2-12), 22.0 (48-62) and 1.0 (1-3), respectively. It may be that the intensities of infection for M. trituba should be high, and M. sebastis and T. australis little low.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.1
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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.

• Journal of Food Hygiene and Safety
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• v.17 no.4
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• pp.206-209
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• 2002

From February through March 2002, sixteen rockfishes representing three species were collected from Oregon Coast Aquarium and Newport fish market and examined far nematodes. During this study, a total of 157 Anisakis type larvae were recovered from Sebastes spp. and parasitized for an average infection prevalence of 50.0%. The yellowtail rockfish, S. flavidus, darkblotched rockfish, S. crameri, and canary rockfish, S. pinniger examined were infected with 110 Anisakis simplex larva, 30 Contracaecum spp. larva and 17 Pseudoterranova decipiens larva. Of the rockfishes examined, 75.0% carried Sebastes crameri, and 12.5% S. flavidus and S. crameri, respectively. The sites of infection far Anisakis type larvae were the intestine, omentum, and stomach walls. A. simplex larvae infected 60.0% on S. crameri and 33.3% on S.flavidus and S. pinniger respectively. The prevalence of Contracaecum sp. larvae and Pseudoterranova decipiens larvae on S. pinniger was 33.3%. The intensities of A. simplex larvae ranged from 1 to 87 in S. flavidus, S. crameri, and S. pinniger. The intensity of Contracaecum spp. larvae and P. decipiens larvae ranged from 0 to 30 in S. pinniger.

• Journal of Environmental Health Sciences
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• v.29 no.2
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• pp.77-79
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• 2003

Seventeen metazoan parasites were recovered from Sebastes crameri collected from Newport fish market. Nine Trochopus australis and 8 Neobrachiella robusta were found on gill arches of canary rockfishes. The commonest sites of metazoan parasites were the posterodorsal region and second gill arches of Sebastes crameri. T. australis were most commonly found on the second gill arches, but in N. robusta. the first gill arches were the most frequented position. No N. robusta were discovered on the fourth gill arch. Metazoan parasites infected gill arches I, II, and posterodorsal regions of S. crameri, occurring less frequently on the gill arches III, IV anteriorventral and middle regions.

• Korean Journal of Environmental Biology
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• v.21 no.4
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• pp.366-367
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• 2003

Nineteen rockfishes representing two species in the family Scorpaenidae were collected from Oregon Coast Aquarium in July 2003 and examined for parasitic copepods. The parasitic copepods were taken from the gills of Sebastes crameri and fins of S. melanops. With regard to the prevalence of copepod 22.2% of the fishes were infected by C. uncinata, and 30.0% by N. robusta. Intensity of infections of Clavella uncinata to Sebastes melanops, showed a range of 4 to 6 with a mean of 5.0 per fish while Neobrachiella robusta to S. crameri was 1 to 6 with a mean of 2.7.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.2
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• pp.179-187
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• 2015

Experiments designed to measure the effect of LED (light-emitting diode) light wavelength on the growth of fingerling rockfishes (Sebastes inermis) were conducted. Fingerling rockfishes (average body weight of individual: 1.13g) were divided into two groups by wavelength of the LED light [light power: 1,620 mW; wavelength: 518 nm (green color), 622 nm (red color)]. Triplicate groups of 180 individuals were reared over 7 weeks. Lighting duration was 14 hours from 06:00 to 20:00. A water tank exposed on the natural light in a room through the windows was used as a control. At results of the first experiment [initial average body weight (BW) of individual: 1.13 g; standard deviation (SD): 0.13 g], the final individual BW exposed on the green color was increased 0.39 g than the red color, and decreased 0.12 g than the natural light in the room. At results of the second (initial individual BW: 5.07 g; SD: 0.70 g) and the third experiment (initial individual BW: 10.67 g; SD: 0.67 g), the final individual BW exposed on the green color was increased 1.07 g and 2.55 g than the red color, respectively, and increased 0.57 g and 0.84 g than the natural light, respectively. The relative growth rate of the green color was higher about 8% significantly (p<0.05) than the natural light. In the case of the red color the relative growth rate was lower significantly (p<0.05) than the natural light.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.177-180
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• 2003

Four genera of metazoan parasites were recovered from 3 of 6 Sebastes pinniger examined during January 2003. Two hundred forty-five metazoan parasites were recovered. Trochopus trituba Sekerak and Arai, 1977 and Anisakis larvae were found to he infected S. finniger Gill and te be abundant in this rockfish. One hundred eleven worms of monogenean trematodes and 134 larval anisakine nematodes were also found in this fishes. Precise positions with regard to gills, fins, and gastrointestinal tracts were recorded on S. pinniger to determine distribution of metazoan parasites of Trochopus trituba, Anisakis simplex larva, Contracaecum sp. larva, and Pseudo terranova decipiens larva. The monogenean trematodes, T. trituba were attacked to the gill arches and fin, and the larval anisakine nematodes, A. simplex, Contracaecum sp.,and P. decipiens were found on the visceral organs such as intestine, omentum and stomach wall. The second gill arches were the most heavily infested and posterodorsal region of the gill arches contained most monegenenn trematodes. The nam site of infestation of larval anisakine nematodes were the intestine.