• Journal of Fisheries and Marine Sciences Education
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• v.26 no.1
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• pp.10-21
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• 2014

The aquatic disease inspector is not classified as an occupation in the current Korean Standard Classification of Occupations(KSCO). Therefore, the roll of the aquatic disease inspector in the medical treatment and the prevention against the aquatic organism disease is underestimated. The aquatic disease inspector is in a more disadvantageous position than the pharmacist and the veterinarian. The purpose of this study is to approve the aquatic disease inspector as an occupation in KSCO. The important contents of this study are as follows. In the first place, this study looks around the general requirements of classifying the occupations in KSCO. The aquatic disease inspector satisfies the most general requirements. But, because of the similarities of job between the aquatic disease inspector and the veterinarian, the aquatic disease inspector do not satisfy the requirement for 'the principle of exclusiveness'. In the second place, this study looks around the classification system of KSCO. The classification system of KSCO is consists of multi steps. This study makes the plan for the appropriate occupation classification of the aquatic disease inspector. In the third place, this study looks for the legal methods to classify the aquatic disease inspector as an occupation in KSCO. In order to classify the aquatic disease inspector as an occupation in KSCO, many regulations of the laws about the aquatic disease inspector and the veterinarian are to be amended and the number of the aquatic disease inspectors is to be increased by the innovative measures.

• Journal of fish pathology
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• v.25 no.3
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• pp.271-277
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• 2012

The practical monitoring was performed to survey the mortalities in aquaculture farms of olive flounder, rockfish, rainbow trout, Japanese eel, white shrimp and abalone in South Korea from May to November, 2011. The aquatic organism disease inspectors, who have the national licenses for the diagnosis and prevention of aquatic disease and have close relationship with the farms, investigated the rates and causes of mortalities according to the standard manual. In 70 flounder farms, the cumulative mortalities rate was 27.9%, and the mortalities were caused by scuticociliatosis, streptococcosis, VHS, non-infectious loss, vibriosis and gliding bacterial disease. The moralities rate of 30 rockfish farms was 13.6%, and those were mainly contributed by gill flukes and streptococcosis. Most of mortalities of rainbow trout were caused by non-infectious loss and protozoan white spot disease. The mortalities rate of Japanese eel was 0.6% by edwardsiellosis, protozoan white spot disease and gill flukes. The loss rate of white shrimp was 71.2%, and most of them was related with non-infectious ones, such as carnivalization, transportation loss, and the rest was caused by viral white spot disease. The mortalities rate in the abalone farms was 10.7% and all of them were related with non-infectious loss.

• Journal of fish pathology
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• v.27 no.1
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• pp.77-83
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• 2014

The monitoring was performed to survey the mortalities and medications occurred in the inland aquaculture farms of olive flounder in South Korea from May to October, 2012. Both of the indirect inquiry for entire inland farms and the sample survey for selected farms were carried out. The aquatic organism disease inspectors, who have the national licenses for the diagnosis and prevention of aquatic organism diseases and have close relationship with the farms, investigated the rates and causes of mortalities according to the standard manual. The cumulative mortalities rate by the indirect inquiry on 565 farms, was calculated to 27.18%, and the mortalities rate by infectious diseases was 22.64%. Otherwise, the mortalities rate by sample survey on 60 farms was 25.50%, 19.33% of them were caused by infectious diseases. The high mortality rates were recorded by scuticociliatosis, non-infectious loss, streptococcosis, VHS, artificial eliminations, vibriosis and gliding bacterial disease. Streptococcosis and non-infectious mortality caused to serious loss in productivity and economy of the farms, because of their outbreaks in the flounder groups over 600 g. The monitoring of medications in the selected farms revealed that formalin for the treatment of external parasites, such as scuticociliates, was the most commonly used drugs in the farms. As the antibiotic medications, amoxicillin and florfenicol for streptococcosis, and oxytetracycline and neomycin expecting wide antibacterial spectrum, were frequently prescribed.

• Journal of fish pathology
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• v.34 no.1
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• pp.117-121
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• 2021

An ayu (Plecoglossus altivelis) farm in Korea recently experienced an epidemic of vertebral column deformities where about 90% of fry displayed a vertebral column that was grossly opaque along either the cranial part of the column or its entire length. Abnormal fish were lordotic, scoliotic and/or kyphotic about midway down the spine. Examination of serial sections of whole fish showed only histological lesions in the vertebral column and suggested some disturbance in the early development of the vertebral centrum. Such abnormalities included a frayed spinal or notochord sheaths with irregular thickening and compression, mal-absorbed notochord cells, thickening of around cell layer and hypercellularity on both facets of the notochord sheath. No parasites, fungi, or bacteria were detected. While this lesion has only been reported once in the past, this is the first report of histopathological findings.

• Journal of fish pathology
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• v.26 no.1
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• pp.45-50
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• 2013

Enrofloxacin is one of the normally used flouroquinolones in mammalian and fish but its withdrawal time and studies were remain obscure. The residual contents of enrofloxacin in fish muscle were analyzed by using HPLC-FLD. More than 0.1 mg/kg of ENR was detected in muscle tissues and the residues were found over 1 year after treatment. The concentration of ENR in Paralichthys olivaceus was not affected by water temperature and lasted for an extended amount of time. The spike recoveries of ENR in the muscle tissue ranged from 78% to 85%. From this results, we need the prescription by veterinarian or aquatic organism disease inspector in ENR usage to assure safety of fish. Future research is required to determine the recommendation dose of ENR for side effects and safety.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.2
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• pp.174-178
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• 2014

In this study, 6-10 clinically healthy farmed abalone, Haliotis discus hannai were obtained from Jeollanam-Do Wando Soan-myeon, Bogil-myeon, and Nohwa-eup monthly for 1 year 7 months and were examined histopathologically. As a result, the adductor muscle had severe cellular swelling and myonecrosis. These lesions were stained with hematoxylin and eosin and Giemsa. The lesions were not caused by infection of bacteria or parasites. We investigated the relationship between lesion frequency and water temperature and discovered that increased water temperature was associated with increasing lesion frequency. As water temperature is related to growth rate, increased growth rate was closely related to increased lesion frequency. We considered that these lesions could be a useful factor in measuring shellfish health.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.688-696
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• 2022

Obesity could cause immune-physiological disorders in fish. Yet, little is known about the impact of obesity on stress and histological responses. This study aimed to determine histological and physiological changes in and vulnerability of overfeeding-induced obese rainbow trout Oncorhynchus mykiss exposed to stress condition. Control, intermediate and overfed groups were fed at 1.5, 2.5 and 3.09% of their body weight per day, respectively, for eight weeks. Weight gain, body mass index, hepatosomatic index and serological parameters, and histology of liver were measured in five fish from each group at week 0, 2, 4, and 8. At week 8, 20 fish from each group were exposed to heat stress by increasing water temperature at a rate of 3℃ per day from 15 to 25℃ and maintaining the final temperature for 10 days. Overall, overfed fish showed significantly higher weight gain, body mass index, and serological parameters than those of fish in the other groups. Fish in the overfed and intermediate groups displayed multifocal infiltration of inflammatory cells in hepatic parenchyma. Mortality rate and serological parameters of fish in the overfed group exposed to heat stress were significantly higher than those of fish in the other groups, indicating increased vulnerability to environmental stress.

• Journal of fish pathology
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• v.34 no.1
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• pp.63-70
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• 2021

As a part of research to elucidate the pathogenesis of so called Soft Tunic Syndrome(STS), that caused mass mortalities in the cultured sea squirts, Halocynthia roretzi, the epidemiological and pathological analysis were done to both clinically normal and diseased groups of the farms of Tongyoung and Geoje coastal areas in southeast sea from February to July, 2008. In the histological finding of the tunic, most of individuals showed tunic softness syndromes that included the disarrangement and destruction of tunic fiber with the simultaneous presence of flagellates-like cells, recently suspected as main agents of tunic softness syndromes. Simultaneously, the intensive degenerative changes of the skeletal muscle of diseased sea squirts were recognized. The changes were characterized with the hyalinization and condensation of muscle fibril and hemocytic infiltration in the muscle fibers. Those were thought to be a kind of typical Zenker's necrosis as in the skeletal muscle of higher vertebrates. Besides of the diseased sea squirts, Zenker's necrosis of skeletal muscles were seen in the normal ones. Epidemiological inquiry for diseased groups revealed that the higher incidences of tunic softness syndrome were recorded in the fast growing groups and in the sites presuming the organic pollution. And Higher malondialadehyde(MDA) and glutathione peroxidase(GPx) activity were detected in the groups showing STS. Those results suggested that Zenker's necrosis of body muscles was a kind of"nutritional myopathy" by oxidative stress. Conclusively, it was considered that Zenker's necrosis of body muscles gives an important clue for elucidating pathogenesis of STS of cultured squirts. And it seems that the necrosis were caused by the oxidative stress to body muscle during abnormal rapid growth of sea squirts.

• Journal of fish pathology
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• v.33 no.1
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• pp.23-34
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• 2020

In recent years, global warming is causing dramatic environmental changes and deterioration, such as hypoxia, leading to reduced survival rate and growth performance of farmed aquatic animals. Hence, understanding systemic immuno-physiological changes in fish under environmental stress might be important to maximize aquaculture production. In this study, we investigated physiological changes in rainbow trout exposed to hypoxic stress by monitoring changes in blood chemistry, leukocyte population, and expression levels of related cytokine genes. Hematological and serological factors were evaluated in blood obtained from rainbow trout sampled at a dissolved level of 4.6 mg O₂ L^-1 and 2.1 mg O₂ L^-1. Blood and head kidney tissue obtained at each sampling time point were used to determine erythrocyte size, leukocyte population, and cytokine gene expression. The level of LDH and GPT in fish under progressive hypoxia were significantly increased in plasma. Likewise, the (Granulocyte + Macrophage)/lymphocyte ratio (%) of fish exposed to hypoxia was significantly lower than that in fish in the control group. Such changes might be due to the rapid movement of lymphocytes in fish exposed to acute hypoxia. In this study, significant up-regulation in expression levels of IL-1β and IL-6 gene appeared to be involved in the redistribution of leukocytes in rainbow trout. This is the first study to demonstrate the involvement of cytokines in leukocyte trafficking in fish exposed to hypoxia. It will help us understand systemic physiological changes and mechanisms involved in teleost under hypoxic stress.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.2278-2291
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• 2023

Imported ornamental fish should be quarantined because they can have dangerous diseases depending on their habitat. The quarantine requires a lot of time because quarantine officers collect various information on the imported ornamental fish. Inefficient quarantine processes reduce its work efficiency and accuracy. Also, long-time quarantine causes the death of environmentally sensitive ornamental fish and huge financial losses. To improve existing quarantine systems, information on ornamental fish was collected and structured, and a server was established to develop quarantine performance support software equipped with a text search engine. However, the long names of ornamental fish in general can cause many typos and time bottlenecks when we type search words for the target fish information. Therefore, we need a technique that can correct typos. Typical typo character calibration compares input text with all characters in a calibrated candidate text dictionary. However, this approach requires computational power proportional to the number of typos, resulting in slow processing time and low calibration accuracy performance. Therefore, to improve the calibration accuracy of characters, we propose a fusion system of simple Artificial Neural Network (ANN) models and character preprocessing methods that accelerate the process by minimizing the computation of the models. We also propose a typo character generation method used for training the ANN models. Simulation results show that the proposed typo character correction system is about 6 times faster than the conventional method and has 10% higher accuracy.