• Journal of fish pathology
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• v.2 no.2
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• pp.75-82
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• 1989

Dactylogyrosis due to Dactylogyrus sp. occured among cultured sea bass (Lateolabrax japonicus) in Geoje, Kyoung Nam Prefecture in July, 1988. Descriptions are given of the opisthohaptor, copulatory organ and also of the structures in Dactylogyrus sp.. Dactylogyrus sp. have one pair of minute anchor (length : $15-22{\mu}m$) and 14 larger hooks. Histopathological changes of the heavily infested gills are showed necrosis, epithelium of the gill filaments underwent hyperplasia with fusion of the lamellae and filamental clubbing. And a bacterial colony is invaded on the surface of lamellar epithelium.

• Journal of fish pathology
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• v.9 no.2
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• pp.127-135
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• 1996

Acanthochondria spirigera is redescribed based on the specimens recovered from the Lophiomus setigerus in the southern coast of Korea. This parasitic copepoda is distinguished from congeners by the possession of spirally twisted egg-strings. Acanthochondria spirigera(Chondracanthidae, Poecilostomatoida) is the first recorded species from Korea. This parasitic copepod was not found on the fish in May. Relative density and prevalence also decreased from January to May. A. spirigera live symbiotically within the pharyngeal cavity of the L. setigerus, and eat oesophageal mucous string of their hosts. The male of the parasitic copepoda is dwarf, and found on the ventral surface of genital segment of the female.

• Mycobiology
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• v.36 no.1
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• pp.24-27
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• 2008

This study was conducted to understand how osmotic potentials in Lentinula edodes tissues are related to water contents and how they change while a mushroom matures. Water content and osmotic potential of L. edodes mushroom tissues from log cultivation and sawdust cultivation were measured and the relationships were analyzed. Osmotic potentials in the tissues were exponentially proportional to their moisture contents and there were strain differences in the potentials. Strain 290 has lower osmotic potential than strain 302, in the tissues at the same water content. As the mushrooms mature, tissue water content maintained ca 94% in head tissues and ca 90% in gills, but significantly decreased from ca 90% to 82% in the stipe tissues. Osmotic potential changes were similar to the tissue water content changes as the mushrooms mature. While osmotic potentials maintained -0.25 to -0.45 MPa in head and gill tissues, the potentials greatly decreased from -0.65 to -1.33 MPa in stipe tissues. Our results show that osmotic potentials in L. edodes tissues are exponentially proportional to tissue water contents, that strains differ in osmotic potential related to water, and that stipe tissues can still have nutritional value when they mature.

• Ocean and Polar Research
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• v.38 no.2
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• pp.103-113
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• 2016

This study aimed to examine the role of two aquaporin isoforms (AQP3 and AQP8) in response to the hyperosmotic challenge of transitioning from freshwater (FW) to seawater (SW) during parr and smoltification (smolt) using the rainbow trout, Oncorhynchus mykiss. We examined the changes in the expression of AQPs mRNAs in the gills and intestine of the parr and smolt stages of rainbow trout transferred from FW to SW using quantitative real-time PCR in an osmotically changing environment [FW, SW, and recombinant AQP3 (rAQP3) injection at two dosage rates]. Correspondingly, AQPs were greater during smoltification than during parr stages in the rainbow trout. Plasma osmolality and gill $Na^+/K^+$-ATPase activity increased when the fish were exposed to SW, but these parameters decreased when the fish were exposed to SW following treatment with rAQP3 during the transition to seawater. Our results suggest that AQPs play an important role in water absorbing mechanisms associated with multiple AQP isoforms in a hyperosmotic environment.

• Fisheries and Aquatic Sciences
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• v.21 no.1
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• pp.2.1-2.8
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• 2018

This study evaluated hemato-histological changes of black porgy in recirculating aquaculture systems (RAS) with three different ozone doses (no ozone, 20 g, and $40g\;ozone/kg\;feed\;day^{-1}$). During the 44-day study, black porgy did not show significant behavior changes or mortalities in both the ozonated systems displaying average total residual oxidants concentrations of 0.12 and 0.25 mg/L. There were no differences in growth and blood parameters among the systems. However, histological alterations on gills and livers were observed in both the treatment systems. In the higher ozone dose, signs of cellular damage were more apparent. Although the ozone doses did not manifest a serious adverse effect on growth and hematological observations in this short-term study, an ozone dose should not exceed $20g\;ozone/kg\;feed\;day^{-1}$ for black porgy based on the histological result. In order to use ozone in a seawater RAS, further studies will be needed to evaluate long-term effects of total residual oxidants.

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.1013-1016
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• 1996

Since 1993, sudden and massive death has occurred among penaeid shrimp, Penaeus orientalis cultured in Korea. We investigated the pathological characterizations on the spontaneously and experimentally infected penaeid shrimp. The major gross findings of the spontaneous cases were 2-6mm sized-white spots on the inside of the carapace and reddish discolorization. Histopathologically, massive necrosis of lymphoid organ, degeneration and necrosis of epithelia of epidermis and foregut were observed in both spontaneous and experimental cases. Amphophilic to basophilic intranuclear inclusion bodies were readly observed epithelia of epidermis, foregut and gills. Electron microscopy revealed enveloped, non-occuluded ellipsoid to rod shaped virus particles, within the nucleus, in the lymphoid organs and interstitial cells of hepatopancreas of both spontaneously and experimentally infected shrimps. The size of the virion was $375{\times}167nm$, and the nucleocapsid was $290{\times}75nm$. The causative agent causing massive death in penaeid shrimps in Korea resembles baculovirus associated with white spot syndrome (WSBV) occurred in Taiwan in virus morphology and gross and histological changes of the shrimps.

• Journal of fish pathology
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• v.13 no.2
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• pp.75-86
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• 2000

Monogeneans(Phylum Platyhelminthes) have been known as common parasites onto the skin and gills of cultured freshwater fishes. Infestation with these parasites result in a great loss in aquaculture industry. Some classification studies on these parasites have mostly been conducted in Japan but rarely in Korea. For the purpose of classifying monogenean parasites infesting two Korean freshwater fishes, eel (Anguilla japonica) and catfish(Parasilurus asotus), samples captured from March 1998 to April 2000 were examined. Here we report for the first time in Korea that four different species of monogeneans are identified: Pseudodactylogyrus bini and P. anguillae in eels; Ancylodiscoides infundibulovagina and Ancylodiscoides sp. in catfish.

• Journal of fish pathology
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• v.13 no.2
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• pp.87-96
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• 2000

Monogeneans(Phylum Platyhelminthes) have been known as common parasites onto the skin and gills of cultured freshwater fishes. Infestation with these parasites result in a great loss in aquaculture industry. Some classification studies on these parasites have mostly been conducted in Japan but rarely in Korea. For the purpose of classifying monogenean parasites infesting two Korean freshwater fishes, carp(Cyprinus carpio) and loach(Misgurnus anguillicaudatus), samples captured from March 1998 to April 2000 were examined. Here we report that three different species of Monogeneans, Diplozoon nipponicum, Dactylogyrus extensus from carp and Gyrodactylus paralatus from loach, respectively. Of these the latter two parasites have never been identified in Korea.

• Journal of fish pathology
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• v.8 no.1
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• pp.1-11
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• 1995

Two species of the parasitic copepods, Nothobomolochus thambus (Poecilostomatoida, Bomolochidae) and Mitrapus heteropodus (Siphonostomatoida, Lernanthropidae), were recovered on the gills of a marine fish, Konosirus punctatus (Temminck and Schlegel) taken from Kamak Bay in Korea. N. thambus is very distinguishable in the armature of maxilliped from all other species of Nothobomolochus; one of the two strong, hairy setae has become naked. M. heteropodus is very distinguishable in the armature of leg 4; the inner process (endopod) is only about one - fifth the length of the outer process (exopod), Both parasitic copepod species are new to the Korean fauna.

• Journal of fish pathology
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• v.21 no.2
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• pp.139-148
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• 2008

Vertebral deformity in hatchery-reared black sea bream (Acanthoparus schlegelii) fingerlings occurred. Deformed fish had a good appetite but no clinical signs were found except the vertebral abnormality and darkness around the dorsal skin of the deformed vertebra. As more than 90% of the hatchery-reared fish exhibited vertebral abnormality, the fingerlings could not be used for commercial seeds any more. No morphological change in the swim bladder was observed. Histopathological changes on the deformed vertebra, gill, liver, and spleen were observed to clarify the cause of the deformity. The vertebra were irregularly deformed upward with the shape of "V" in an alphabetic character causing the spinal cord and dorsal aorta suppressed. The diameters of the muscle fibers around the deformed vertebra, especially, in the dorsal part, were much smaller and more irregular than those in normal fish, and the gabs between the fiber bundles were enlarged. No evidence of inflammatory responses in the lateral musculature were found. On the basis of normal inflation of the swim bladder, cultural environments for growth of the fingerlings, and histopathological alterations in the muscle, vertebra and gills, it is suggested that high speed of water current in the culturing aquaria between 23 to 30 days after hatching was responsible for the development of vertebral abnormality.