• 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 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.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.5
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• pp.539-546
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• 2019

The major cultured marine fishes in sea off the coast Gyeongsangnam-do Province, South Korea, were assessed and included 9.3% rockfish Sebastes schlegelii, 7.8% red seabream Pagrus major, and 2.1% rock bream Oplegnathus fasciatus. The number of insurance payments related to disease mortality in cultured fish in 2017 was fourfold that in 2016. Economic loss in aquaculture due to disease in cultured fish is high and represents an important inhibitory factor affecting marine fishery productivity. In 2018, diseases led to severe production losses in several aquaculture species: 40.0% in rockfish, 11.4% in olive flounder Paralichthys olivaceus, 10.0% in filefish Thamnaconus modestus, and 9.3% in red seabream. Fish-parasitic pathogens such as Microcotyle sebastis, Alella spp., and Dactylogyrus spp. enter mainly via the gills and skin surface. Among bacterial pathogens, Vibrio species were most common, with Vibrio harveyi being the dominant species causing infections in these fishes. The bacterium Lactococcus garvieae is thought to exhibit host specificity in fish. The fish species in the present study exhibited a higher tendency for infection by heterologous pathogens than by a single pathogen; therefore, it is necessary to devise new strategies for treating diseases in cultured fish.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.3
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• pp.432-442
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• 2020

Diagnostic monitoring in Korean rockfish cages was performed to survey the prevalence of pathogens in cultured Korean rockfish Sebastes schlegeli from May 2013 to July 2016. A total of 1,945 fish samples collected from the western (Cheonsu Bay and Heuksando), southern (Tongyeong and Namhae), and eastern coasts (Pohang) of Korea were tested for parasites, viruses, and bacteria. In this study, 1,264 and 334 fishes were infected with Microcotyle sebastis and Clavinema mariae, respectively. The prevalence rates of C. clavinema in fishes from Cheonsu Bay, Heuksando, and Tongyeong were 35.3%, 3.9% and 1.9%, respectively. No C. clavinema infection was detected in cultured rockfish from Namhae and Pohang. Furthermore, bacteria including Photobacterium damselae (8.9%), Photobacterium piscicola (2.3%), Photobacterium spp. (8.9%), Aeromonas salmonicida (1.8%), Aeromonas spp. (0.9%), Vibrio scophthalmi (1.5%), Vibrio spp. (3.3%), Streptococcus iniae (1.2%), and others (8.0%) were detected in 373 of 1,364 fishes. No virus was detected in any fish investigated in this study.