• Title/Summary/Keyword: Aquatic-Animals

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Swimming Performance of Aquatic-animals and Their Morphological Adaptation (수중동물의 헤엄침 성능과 형태학적 적응)

  • Sohn, Myong-Hwan;Lee, Seung-Hee;Han, Cheol-Heui
    • Journal of the Korea Institute of Military Science and Technology
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    • v.12 no.6
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    • pp.796-807
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    • 2009
  • The swimming abilities of aquatic-animals are of vital importance to their ecology. The relationship between outer shapes and the swimming ability has been focused just a few centuries ago by engineering community. Present paper surveys the recent studies of the aquatic-animals' swimming performance in the morphological point of view. Also an experimental study is performed in order to investigate the effect of the tail fin's shape on the propulsive performance. The result showed that the morphological study provided valuable data for exploring the secrets of the aquatic-animals' swimming performance.

Consideration for Classification of Pathogens in Aquatic Animals (수산생물병원체의 등급 마련에 관한 고찰)

  • Cho, Miyoung;Min, Eun Young;Choi, Hye Sung;Jung, Sung Hee
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.5
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    • pp.585-595
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    • 2021
  • Even though most of aquatic animal pathogens are considered opportunistic and many pose a low direct risk to personnel, all personnel working with aquatic pathogens and facilities using these organisms must comply with the regulation to prevent the release of the pathogen into the environment and causing disease in aquatic animals. First of all, in order to establish a biosafety system for aquatic pathogen, the list of microorganisms that can infect aquatic animals and humans should be drawn up according to the microorganisms encountered within national boundaries. Second, risk assessment guideline for diseases of livestock and aquatic environment is desperately needed. Third, microorganisms should be classified into risk group based on their potential impact on human and aquatic environment. Fourth, facilities handling aquatic pathogens should ensure that these pathogens are securely contained and safely handled for experimental or commercial development purposes. In conclusion, classification is based on the pathogenicity, mode of transmission and host range of the aquatic microorganisms, availability of effective preventative measures and treatments. Furthermore, risk group of aquatic pathogens should be correlated with physical containment facility requirements according to domestic characteristics.

An Ecological Study on the Aquatic Animal Community in Tan Stream, Seoul (서울 탄천의 수서동물 군집에 관한 생태학적 연구)

  • 배경석;구본관;한선규;신재영;박성배
    • Journal of Environmental Health Sciences
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    • v.23 no.4
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    • pp.1-8
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    • 1997
  • The aquatic animals of Tan stream were composed of 46 species, 28 families, 11 orders, 6 classes in 4 phyla during the survey period of April, 1996 to December, 1996. They were composed of 31 species in aquatic insecta, 6 species in annelida, 3 species in mollusca, 1 species in crustacea, and 5 species in fishes, respectively. Major dominant species in Tan stream were Chironomidae sp.1, Chironomidae sp.2, Chironomidae sp.3, Tubufucidae sp.1, Physa acuta and hirudo niponica. Dominance indices of benthic macroinvertebrates ranged highly from 95.74 to 100.00% at lower stream(site 4), but ranged 50.00 to 95.85% at site 1 through site 3. The aquatic animals ranged from 25 to 32 species at site 1 through site 3, but they were only 3 species at site 4 for survey period. Tan stream in the light of urban stream ecosystem has a little less riffle areas and hydrophyte areas by cementation of riparian area and channel type of water course. Therefore, the species of aquatic animals in Tan stream decreased because of deterioration of water quality according to reduction of self-purifcation ability and loss of microhabitat according to reduction of hydrophyte areas and riparian areas. The tendency of decreasing species of aquatic animals appeared seriously at lower stream From drive licence test authority at Kangnam-ku, Seoul to conjunction point of the Han river.

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An Eclogical Study on the Aquatic Animals in Jungrang Stream of Seoul (중랑천의 수서동물에 관한 생태학적 연구)

  • 배경석;박종태;조기찬;길혜경;신재영
    • Journal of Environmental Health Sciences
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    • v.23 no.2
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    • pp.89-97
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    • 1997
  • Most of urban streams in Korea have been changed channel forms and suffered from direct inflow of domestic sewage, etc. Therefore, maintenance of structure and function of those ecosystem are hard. The present study was carried out to examine the life survival maintenance ability of the stream by community analysis of aquatic animals in typical urban stream (Jungrang stream) in Seoul. The aquatic animals were composed of 31 species, 18 families, 8 orders, 5 classes in 4 phyla. Seasonal species number showed big fluctuation between 8 species in Winter and 24 species in Autumn. Major dominant species in Jungrang stream were Tubificidae sp.1, Chironomidae sp.1, Chironomidae sp.2 and Physa acuta, and above endurance species for water pollution occupied very high dominance indices. But, Cercion hieroglyphicum, Ischnura asiatica, Rantra chinensis, Herochares striatus, Agabus japonicus in benthic macroinvertebrates of a few individuals are appeared. Also, fry of Carassius auratus and Silurus asotus in fish are occurred. Therefore, we can be inferred on posibility of growth and spawning of above species in the stream. Jungrang stream has a small quantity of natural riffle areas, ponds and watergrass areas by channel form of water course. Aquatic animals in Jungrang stream has been suffered by reduction of self-purification reaction ability and have mass production of attached algae on the stream bed. For analysis of fluctuation of life survival maintenance ability in Jungrang stream, long-term survey is needed.

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Introduction of risk analysis for movement of aquatic animals in Korea (수산동물의 이동에 대한 위험분석의 도입)

  • Seo, Jang-Woo;Park, Myoung-Ae;Choi, Dong-Lim;Kim, Jin-Woo;Cho, Mi-Young;Park, Kyung-Hyun;Jeong, Hyun-Do;Oh, Myung-Joo
    • Journal of fish pathology
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    • v.23 no.1
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    • pp.99-106
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    • 2010
  • Aquatic animal diseases control act which is to assure the prevention of outbreak and spread of aquatic animal diseases in Korea has come into effect since 22 December 2008. In order to prevent outbreak and spread of aquatic animal diseases, risk analysis is newly introduced. The introduction of risk analysis for movement of aquatic animals related to implementation of recommendation of the World Trade Organization (WTO) Agreement on the Application of Sanitary and Phytosanitary Measures and should be conducted in accordance with guidelines of OIE Aquatic Animal Health Code. This report involves gathering and analysing the information of international regulation and situations of risk analysis framework in Korea for movement of aquatic animals.

Swimming Mechanics of Aquatic-Animals (수중동물의 헤엄침 역학)

  • Sohn, Myong-Hwan;Han, Cheol-Heui
    • Journal of the Korea Institute of Military Science and Technology
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    • v.10 no.3
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    • pp.189-199
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    • 2007
  • The present survey paper introduces the research history, characteristics of body and fin shapes, basic principles of various locomotions and propulsion-generation mechanism of aquatic animals in nature, which utilize unsteady flow through a noble mechanism that is different in paradigm from the propulsion generation mechanism of man-made marine vehicles, and so have excellent performance and efficiency. The authors hope that the present paper helps to activate the domestic research interest on the fields of swimming in nature, which is expected to provide great ideas for improvement and innovation of today's marine vehicles.

Evaluation of Sample Testing Scheme for Designated Aquatic Animals (수산동물 지정검역물에 대한 표본검사 계획 검토)

  • Pak, Son-Il
    • Journal of Veterinary Clinics
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    • v.29 no.1
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    • pp.58-62
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    • 2012
  • To protect aquatic animal health of importing countries from the potential risks associated with exotic diseases introduced through international trade of live aquatic animals, inspection of designated commodities at ports of entry is a critical component of the safeguarding system. The only way to be 100% confident that no fishes in a shipment are infected with a specific agent is to test every fish in the commodity imported with a perfect diagnostic test. For the majority of cases, this is unrealistic since the group of interest may very large particularly for aquatic animals, or imperfect tests are often available. It is, therefore, more common to test a fixed proportion of a group by preplanned sampling schemes. However, decision making based on results of testing the sample can provide quite a chance that infected groups may be misclassified as uninfected, depending on sampling strategy employed. The objective of this study was to determine the possibility that one or more fishes in the group imported being infected but tests negative after inspecting samples. This question is critical to government authorities to examine whether sampling plan is sufficient to achieve the purpose intended for. At fixed population size, the maximum number of infected fishes when all tests negative was decreased as the sampling fraction increased. The probability of including at least one undetected but infected fish in a group for negative tests increased with the number of fish tested or true prevalence. The risk was much lesser where high sensitivity test was assumed; when increasing test sensitivity from 0.9 to 0.99, this risk was dramatically reduced to about a tenth or a fourth for prevalence ranges from 2 to 10%, given sample size ranges from 10 to 200. Based on the preliminary analysis, the author concluded that current sampling plan testing 4-8% of the import proposal for human consumption still can yield high false negative results. Therefore, from the quarantine inspection point of view, an enforced commodity-specific sampling design that accounts for the cost of testing with an imperfect test at the specified design prevalence is urgent.

Disease monitoring of wild marine fish and crustacea caught from inshore and offshore Korea in 2018 (2018년 국내 연근해 수산생물의 전염병 모니터링)

  • Hwang, Seong Don;Lee, Da-Won;Chun, Won Joo;Jeon, Hae-Ryeon;Kim, Dong Jun;Hwang, Jee-Youn;Seo, Jung-Soo;Kwon, Mun-Gyoung;Ji, Hwan-Sung;Kim, Jung Nyun;Jee, Bo-Young
    • Korean Journal of Environmental Biology
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    • v.37 no.4
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    • pp.474-482
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    • 2019
  • Disease monitoring in wild aquatic animals is necessary to obtain information about disease occurrence, disease agents, and the transmission of diseases between wild and cultured species. In this study, we monitored viral diseases in wild marine fish and crustacea caught by trawl in Korea in April and October 2018. We monitored the viral diseases in 977 fish from 39 different species and 287 crustacea from 14 different species. In fish, we collected kidney and spleen to detect viral hemorrhagic septicemia virus (VHSV), red sea bream iridovirus (RSIV), marine birnavirus (MABV), hirame rhabdovirus (HRV), and lymphocystis disease virus (LCDV). In crustacea, we monitored white spot syndrome virus (WSSV), infectious hypodermal and hematopoietic necrosis virus (IHHNV), taura syndrome virus (TSV), infectious myonecrosis virus (IMNV), yellowhead disease virus (YHDV), and white tail disease virus (WTDV) using pleopods, pereiopods, gills, muscle, and hepatopancreases. Although none of the viral diseases tested in this study were detected in the samples, these results will help disease control between aquaculture species and wild aquatic animals.

ELECTRICAL FISHING METHOD OF PENAEUS JAPONICUS BATE (보리새우의 전기 어법)

  • KO Kwan Soh;KIM Sang Han;YOON Gab Dong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.5 no.4
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    • pp.115-120
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    • 1972
  • The data Presented in this Paper, on the body and Jumping voltage of Penaeus japonicus BATE, are part of a current study on shrimp behaviour in order to improve fishing efficiency of the fishing gear. The experiments concerning electrical stimuli was mostly carried out at the Marine Laboratory of Busan Fisheries College in 1972. The following are the results obtained from the present investigations : 1. When the voltages between a pair of electrodes were fixed constant, the voltage drops between them showed almost constant electrical field. 2. Threshold voltages of the animals varied with body direction to the electrical field, i. e., 200 -500 mV for parallel, 500-1400 mV for vertical and 300-800 mV for diagonal ($45^{\circ}$) settings. 3. Jumping voltages of the animals also varied with the body direction to the electrical field; i. e., 250-1000 mV for parallel, 800-2500 mV for vertical and 400-1300 mV for diagonal settings. 4. The shrimp, in general, were more sensitive to the electrical stimuli when oriented to the cathode rather than the anode. 5. Jumping voltages decreased when the interrupted current was applied to the animals, i. e., less than 200 mV for paralled and 500mV for vertical direction of the body to the electrical field.

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