• Journal of fish pathology
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• v.12 no.2
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• pp.101-105
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• 1999

In a survey of net-caged yellowtail Seriola quinqueradiata in the southern parts of Korean Peninsula, we found infestations of ciliate in the gills of the moribund fish during the abnormally elevated temperature. The ciliate was very similar to genus Colpoda Muller, 1773 on morphological and reproductive characteristics. Histopathological changes revealed that the ciliate invaded gills only, causing extensive destruction of the gill filaments including lamella without any clinical signs found in the other organs and tissues. This is the first record of the parasitic ciliate in cultured yellowtail.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.439-443
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• 1997

A total of 135 freshwater fish samples (Oreochromis spp. <85> and Clarias lazera <50>) were collected from different localities (shops and fish markets) in Alexandria Province-Egypt and examined for the presence of parasitic larval stages. The obtained data found the overall mean of the infestation with encysted metacercariae was 71.1% in the examined fish. The rates of infestation with encysted metacercariae were 72.9% and 68.0% in the examined Oreochromis spp. and Clarias lazera, respectively. The highest prevalence of the encysted metacercariae was found in summer (81.8%) in case of Oreochromis spp. and in winter (92.3%) in case of Clarias lazera, all these seasonal differences are statistically significant. The rate of infestation of encysted metacercariae in the anterior third, middle third and posterior third of Oreochromis spp. was found to be 82.3%, 74.2% and 95.2%, respectively, while 88.2%, 88.2% and 91.2%, respectively, in Clarias lazera. Moreover, the rate of infestation of encysted metacercariae in eyes, gills, liver, kidney and branchial cavity of Oreochromis spp. was 91.9%, 70.9%, 20.9%, 46.8% and 32.2%, respectively. In Clarias lazera the infestation rate was found to be 47.1%, 70.6%, 8.8% and 38.2% in the gills, liver, spleen and kidney, respectively. The zoonotic and public health importance of the encysted metacercariae are causes severe visceral pain, abdominal discomfort, intermittent bloody diarrhoea and colic after consumption of inadequately cooked fish especially Tilapia spp. (Oreochromis spp.).

• Journal of fish pathology
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• v.17 no.2
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• pp.99-103
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• 2004

White spot disease by Cryptocaryon irritans broke out among cultured river puffer (Takifugu obscurus) cultured in sea water in Oct. 2001 and May 2004. Many white spots were easily observed on the gills with the naked eyes. The parasites attached on the gills at the base of the gill lamellae. The trophonts penetrated the interlamellar epithelium. Epithelial cell proliferation in interlamellar spaces occurred. PAS- positive mucous cells were prominent in the proliferated epithelium.

• Environmental Analysis Health and Toxicology
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• v.12 no.3_4
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• pp.55-59
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• 1997

Furfural, an organic solvent, is widely used as synthetic component material in producing chemical products. However, furfural has been reported that it shows strong toxicities to human being showing intense stimulus to skin, eyes, mucous membrane and nerve system. It is also known to cause anemia, liver cirrhosis, kidney failure and genetic toxicity in the human being working in the exposed area. LD$_{50}$ of furfural for peritoneal injected mouse has been known around 20mg/kg, but the acute toxicity on aquatic organisms such as fish, daphnid or algae are not well known, compared to those on rodents. In this experiment, we studied on the fish toxicity of furfural using Japanese Medaka (Orvzias latipes) and Common Carp (Cvprinus carpio). We also observed histological changes in the fish organs. The LC$_{50}$ were 12. Smg/L in Japanese Medaka and 21.8 mg/L in Common Carp, respectively. When Common Carps were exposed to 120mg/L of furfural concentration for 30 minutes, blood congestion in gills and lysis of secondary lamella were shown. Though the muscle of caudal fin was not completely eroded, its epidermic cells were shown to be necrotic in various parts. Tissue atrophy and cell necrosis were also shown in the liver of Common Carps exposed to furfural. From these results, furfural seems to cause histological damages on liver, an internal organ as well as on external organs such as gills and fins eventhough the fish were exposed for a short-term.

• Applied Microscopy
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• v.34 no.2
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• pp.139-143
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• 2004

The ultrastructure of the gills of Oplegnathus fasciatus was examined by means of light and transmission electron microscopes. The gills have primary and secondary filaments (lamellae). The following cells are identified and described : epithelial cell, pillar cell, chloride cell and mucose cell. The simple epithelial layer consists of squamous epithelium containing a large nucleus and the surface is covered with some of microridges. The lamella pillar structures are characterized by axial microtubules and lateral membrane interdigitations. Chloride cells contain a lot of mitochondria and specifically developed tubular systems. The rough endoplasimic reticulum and golgi complex, and some of mucous granules were observed in immature mucous cells. The mature mucous cells were AB-PAS positive, globular in shape, and had mucous granules of similar size with various electron densities.

• Journal of fish pathology
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• v.21 no.2
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• pp.93-105
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• 2008

Goldfish, Carassius auratus (wt 13 g) was intramuscularly infected with Aeromonas hydrophila (4.3x106 cfu / ml). Infected gills showed edematous lamellae with bacterial invasion into the capillaries and gill congestion on 12th day. By 24th day post-infection, histological analysis revealed irregular aggregates of macrophages in gill lamellae, large amount of mucus cells, gill lamellae edematous with bacterial invasion into capillaries, gill congestion and damaged gill epithelium with hyperplasia. Inflammation of the gill filament and hemorrhage globe was associated with the development of severe necrosis on the 36th day in the infected fishes. In infected and herbal treated fish the regenerative responses like fibrosis and infiltration of the leucocytes (neutrophils and monocytes) occurred on 12th day; moderate hypertrophy in the gills was noticed on the 36th day. These results suggest that phytotherapy ensures better protection and regenerative response against A. hydrophila infection in goldfish, C. auratus.

• The Korean Journal of Malacology
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• v.26 no.3
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• pp.179-183
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• 2010

In other to understand the effect of yellow soil to mortality of Korean scallops, P. yessoensis, We investigated its mortality at indoor tanks. The environmental conditions such as water temperature, Salinity, Do and pH were continued constantly during the experimental periods. The 100% of survival rate showed in two experiments groups such as 0.1% and 0.4% of concentration of yellow soil and the other groups as 0.05% and 0.2% of concentration of yellow soil was appeared one dead scallop at each group for 8 days of the experiment periods. the gills of scallop in high concentration of yellow soil (0.2% and 0.4% groups) were covered by yellow soil particles so that this group's scallop should be got a high stress from yellow soil. I think this situation will be more continued for long time the scallop will become to dead. The results of bacteriological analysis did not isolated from haemolymph of scallops and no Perkinsus infectious disease in scallops and the scallops showed necrosis and degeneration on digestive grand and gills of scallop.

• Mycobiology
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• v.49 no.2
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• pp.173-182
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• 2021

Recently, Cryptococcus pseudolongus has been reported as a new pathogen of shiitake (Lentinula edodes). However, its pathological properties are not much known. To further understand its impact on the mushroom, we investigated the pathogen's interactions with the mycelium of shiitake, histopathological properties, host range, and sensitivity to diverse antifungal agents. The strain C. pseudolongus DUCC 4014 inhibited the mycelial growth of L. edodes strain (cultivar Sanjo 701ho) and caused browning in the mycelia confronted with the yeast on PDA. Spray inoculation of the yeast caused an abnormal browning symptom on the cap and/or gills of three shiitake cultivars grown on sawdust media in vinyl bags. Scanning electron microscopic images of the abnormally browned parts of shiitake fruit body illustrated that mushroom tissues were loosed and dispersed in the middle and edge of the cap and the arrangement of basidiospores borne on basidia in the gills was disturbed compared to those of normal shiitake fruit body. Spray inoculation also led to developing abnormal browning on the harvested fruit body, indicating C. pseudolongus could be a problem during mushroom storage. But the yeast was not able to induce abnormal browning on mushrooms of Pleurotus ferulae, Pleurotus fostreatus, and Agaricus bisporus. But it induced browning only on button mushroom (A. bisporus) when they were inoculated after wounding. Tests with 16 kinds of fungicides revealed that the cell growth of C. pseudolongus could be inhibited by benzalkonium chloride at MIC 7 ㎍/ml and benomyl at MIC 3 ㎍/ml.

• Journal of fish pathology
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• v.36 no.2
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• pp.369-378
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• 2023

In this study, clinically healthy Korean rockfish were provided by a farm and then raised in a lab for 14 days at three different temperatures (10℃, 15℃, and 20℃) to establish hematological, blood biochemical, and histopathological reference intervals against normal fish. Hematocrit, MCV, MCHC, total protein, BUN, and GPT values in the blood showed significant differences among temperature groups. As the water temperature increased, neutrophil, thrombocyte, and lymphocyte counts also rose, while the monocyte value peaked at 15℃. The histopathological score revealed significant variations in the gills, stomach, and inflammation indices by temperature group; the gills and inflammation indices peaked at 20℃, whereas the stomach index peaked at 15℃. It is expected that information on these normal values will serve as a fundamental collection of data for further studies related to laboratory-based experiments.

• Journal of fish pathology
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• v.36 no.2
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• pp.395-401
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• 2023

Myxosporeans are widespread cnidarian endoparasites in marine and freshwater ecosystems and several species were reported to be a threat to cultured fish causing serious diseases with mass mortality. In the present study, we found a myxosporean species in the genus Thelohanellus from the gills of the cultured common carp (Cyprinus carpio) fingerling for the first time in Korea. The morphological observation showed 500 ㎛ ~ 1 mm size, oval to circular shaped plasmodia containing spores which are pyriform at the anterior end and round at the posterior end (average size 20.1 ㎛ × 9.1 ㎛), with 5 to 6 turns of a single polar filament located in the polar capsule with an average size of 10 ㎛ × 4.6 ㎛. The 18S rRNA sequence was closest to the sequence of T. wangi among Thelohanellus species infecting gills but was not completely identical. Based on the morphological characteristics and molecular analysis results, we classified the present myxosporean parasite as Thelohanellus sp., temporarily. The prevalence and infection intensity of Thelohanellus sp. in the common carp fingerling were very high, which was thought to be the main cause of high mortality.