• Title/Summary/Keyword: fish scale

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Comparative Analysis of Market Demand and Individual Demand for Major Fish Species in Korea (한국 주요 어종의 시장수요와 개인수요의 비교분석)

  • Park, Hoan-Jae
    • The Journal of Fisheries Business Administration
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    • v.43 no.1
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    • pp.35-48
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    • 2012
  • Inverse demand models are well established as market demands in theory and practice of the existing literature. However, the derivation and its interpretation of individual demands from the market demands are not well known in the literature. This paper analyzes the fish market in Korea by the inverse demand model and shows how we deduce the consumer's responses from the market responses when the markets determine the prices by the quantities demanded. It illustrates empirically how this can be done applying to the korean fish market data. The empirical results show that all fishes are price inflexible and mackerels and hairtails are scale flexible in the market demand while mackerels, hairtails, and croakers are price elastic and mackerels and hairtails are income inelastic in the individual demand. The methodology and empirics used in the paper will make a contribution to the existing literature especially for the purpose of recovering consumer's demand from the market demand, thus implementing the policies to administer the fish markets.

Studies on the Behaviour of Fish Schools in the Main-net of a Large Scale Set-net using Scanning Sonar-V - The Behaviour of Yellowtail Seriola quinqueradiata School Entrapped in a Large Set-net and the Catching Function of the Funnel-net - (소나 관찰에 의한 대형정치망내 어군행동의 연구 ( V ) - 방어어군의 망내행동과 등망의 어획기능 -)

  • 김문관
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.34 no.1
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    • pp.13-20
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    • 1998
  • The moving behaviour of Yellowtail Seriola quinqueradiata schools in the main-net of a large scale set-net was investigated in relation to the catching function of the funnel-net by a scanning sonar. The investigation was took place in the Kishihata set-net fishing ground located in Nanao city Ishigawa prefecture, Japan from Nov. 9 to Nov. 13, 1992. The obtained results are summarized as follows; 1. Fish schools showed the greatest number at the playground in the morning and at the bag-net in the afternoon. The fish schools remained long time in the main-net. 2. The rate of fish school through the funnel-net was smaller than that of fish school which is though the playground and bag-net. Because the Yellowtail school changed the shape of school in passing the funnel-net. 3. The rate of entering the bag-net was 24%, among the fish school heading to the outer funnel-net. But, the rate of escaping to the playground was 27%, among the fish school heading to the inner funnel-net. It seems that the structure of the outer funnel-net was not enough to lead the fish to the bag-net. However, the structure of the inner funnel-net was very effective at preventing escape. 4. It is appropriate to haul the net in the morning in considering the number of accumulated fish in the bag-net during the survey.

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Model for Price Formation of Fish and Its Demand Structure (어류의 가격형성과 수요구조분석)

  • Park, Hoan-Jae
    • The Journal of Fisheries Business Administration
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    • v.40 no.1
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    • pp.133-152
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    • 2009
  • The purpose of this paper is to model price formation and analyze demand structures for fishes under the restriction of Korean fisheries regulations. This study suggests the model that the price of fish is formed by its quantity, expenditure, and habit persistence. In economic literature, such a fishery market demand is called the inverse demand with dynamic habit persistence. Based upon a static differential price formation model, the paper has generalized it dynamically incorporating habit persistence effects. The empirical results show that all the species have values less than one and (-) sign of price flexibilities, thus being price inflexible. The estimated habit adjustment coefficients are significant at the level of 1%. Especially, TAC species have the smaller values of them than those of other main fish species. The contribution and results are summarized as follows. First, the fishery market demand has a strong dynamic effects from habit persistence. Second, the fishery market demand structure could be analyzed in a way different from the ordinary demand analysis, which is based upon price flexibility, scale flexibility, and cross adjustment flexibility. Third, the limitation of this paper is that it ignores the increasing stock effects by catching restrictions, thus raising consumers' benefit in the future.

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Two Foreign Species of Tongue Soles (Cynoglossidae) (외국산 참서대과(Cynoglossidae) 어류 2종)

  • CHOI Youn
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.2
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    • pp.267-269
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    • 1996
  • Morphology of two foreign species of tongue soles (Cynoglossidae), Cynogiossus browni and C. senekalensis, was observed based on specimens collected from Kunsan fish market from 1992 to 1994. These species are externally similar to Cynoglossus robustus from Korean coast. But these are quite distincitive from Cynogiossus robustus by interlinear scale rows, body size, other counts and proportional measurements of body. The Cynogfossus browni and C. senegalensis are only distributed in western coast of Africa and commercially imported to Korea through Pusan fish market.

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Myxobolus episquamalis (Myxosporea: Myxobolidae) on the scales of wild mullet, Mugil cephalus L, in Korea

  • Cho, Jae-Bum;Huh, Min-Do;Kim, Ki-Hong;Kwon, Se-Ryun;Lee, Mu-Kun
    • Journal of fish pathology
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    • v.19 no.1
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    • pp.1-6
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    • 2006
  • Numerous large whitish cysts were found on the scale of wild mullet, Mugil cephalus captured in Jin-Hae bay of southern coastal sea of Korea. The cyst consisted of many trophozoites, mature spores and interstitial tissues of host origin. Spores were 8.25 ㎛ (7.26-9.35) in length, 6.3 ㎛ (5.63-6.78) in width, 4.34 ㎛ (3.96-5.04) in thickness. Polar capsules were 4.45㎛ (3.8-5.4) in length and 2.35 ㎛ (1.62-2.86) in width, and the length of polar filament was about 39.57 ㎛ (26.3-56.33). Based on the spore morphology and the host & tissue specificity, the present specimens were identified as Myxobolus episquamalis Egusa, Maeno & Sorimachi, 1990. Deformation of bony plate of the scales and infiltration of inflammatory cells were observed in the histological sections.

Water Erosion and Its Combating Measures in Loess Plateau, China (중국 황토고원지구의 물침식과 대책)

  • Chun, Kun-Woo;Lim, Young-Hyup;Oh, Jeong-Soo;Yoon, Taek-Seong;Park, Ki-Hyung
    • Journal of Forest and Environmental Science
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    • v.26 no.3
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    • pp.181-192
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    • 2010
  • Water erosion is progressing in the Loess Plateau, especially in gullies, and the sediment runoff to the Yellow River amounts to 975 million tons every year. Natural factors for water erosion include climate, soil, geological feature, terrain and vegetation. Many development projects due to the increasing population reduced the forest coverage ratio to 10%, and 200 million people in the downstream area are suffering from the damage during intense rainfall. Accordingly, the Chinese government is continuously trying to efficiently prevent the erosion by establishing measures for water erosion, including fish-scale pits, terrace technique, and check dams.

Algorithm to determine injection position in olive flounder, Paralichthys olivaceus

  • Cha, Bong-Jin;Kwon, Mun-Gyeong;Kim, Hyun-Young;Park, Myoung-Ae
    • Journal of fish pathology
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    • v.26 no.2
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    • pp.59-64
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    • 2013
  • This study aimed to develop an algorithm to determine the optimal injection position in olive flounder, Paralichthys olivaceus when a vaccine is injected into the fish by using a vision-based automatic equipment measruing the total length (TL), width and weight of the fish. Over a 5-month period, 500 olive flounders were examined to analyze the relation of the fish size and to the shape and location of its abdomen, using radiography, a ruler plate and scale. There were significant correlations between the TL and the shape and location of the abdomen. The abdomen was located 0.232TL - 2.7221 mm ($R^2$=0.8787) from the end of the mouth of the fish. The height and width of the abdomen in the fish were 0.1292TL + 1.8768 mm ($R^2$=0.7935) and 0.183TL-5.9791 mm ($R^2$=0.8641), respectively. The injection point in the abdominal region avoiding organs was determined by calculating the center of gravity of the abdomen volume. This can be expressed as g (0.2759TL - 2.0965, 0.1295TL - 4.2325) on the basis of TL line coordinates. The injection point by the expressed coordinates had errors for the x and y axes as 12.15 mm and 8.28 mm, respectively. These were enough to use the algorithm to injection for the equipment. This automated method to determine the position of any part in the fish can also be used for other purposes, for example, intramuscular injection or auto-tagging of fish.

An influence of mesohabitat structures (pool, riffle, and run) and land-use pattern on the index of biological integrity in the Geum River watershed

  • Calderon, Martha S.;An, Kwang-Guk
    • Journal of Ecology and Environment
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    • v.40 no.2
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    • pp.107-119
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    • 2016
  • Background: Previous studies on the biological integrity on habitat and landuse patterns demonstrated ecological stream health in the view of regional or macrohabitat scale, thus ignored the mesoscale habitat patterns of pool, riffle, and runs in the stream health analysis. The objective of this study was to analyze influences on the mesohabitat structures of pool, riffle, and run reaches on the fish guilds and biological integrity in Geum-River Watershed. Results: The mesohabitat structures of pool, riffle, and run reaches influenced the ecological stream health along with some close relations on the fish trophic and tolerance guilds. The mesoscale components altered chemical water quality such as nutrients (TN, TP) and BOD and these, then, determined the primary productions, based on the sestonic chlorophyll-a. The riffle-reach had good chemical conditions, but the pool-reach had nutrient enrichments. The riffle-reach had a predominance of insectivores, while the pool-reach has a predominance of omnivores. Also, the riffle-reach had high proportions of sensitive fish and insectivore fish, and the pool-reach had high proportions of tolerant species in the community composition. The intermediate fish species in tolerance and omnivorous fish species in the food linkage dominated the community in the watershed, and the sensitive and insectivorous fishes decreased rapidly with a degradation of the water quality. All the habitat patterns were largely determined by the land-use patterns in the watershed. Conclusions: Trophic guilds and tolerance guilds of fish were determined by land-use pattern and these determined the stream health, based on the Index of Biological Integrity. This study remarks the necessity to include additional variables to consider information provided by mesohabitats and land-use distributions within the selected stream stretch. Overall, our data suggest that land-use pattern and mesohabitat distribution are important factors to be considered for the trophic and tolerance fish compositions and chemical gradients as well as ecological stream health in the watershed.

Aquatic Resources of Cameroon

  • Chuba, Leunga Didier
    • Journal of Marine Bioscience and Biotechnology
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    • v.3 no.1
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    • pp.7-12
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    • 2008
  • Cameroon is a country in Western Africa with 16 million inhabitants. Located between Nigeria and Equatorial Guinea, the country is bordered by the Bight of Biafra. It has a 402 km long coastline. It covers an area of about 475,440 sq km. Cameroon obtains its fish supply from five distinct sources notably-small scale maritime Fisheries, inland fisheries, industrial fisheries, aquaculture and importation. Despite its enormous potential, Cameroon produces only 180,000 metric tons fish annually. The total artisanal annual catch is estimated to be 55,000 t of which bonga/Sardinella, white shrimp and demersal fish contribute 58%, 27% and 15% respectively. The industrial fleet expanded rapidly during the sixties and by 1973 there were 29 trawlers and 13 shrimpers which landed a total of about 17,600 t of fish and shrimp. The total catch of the industrial fisheries peaked at about 20,400 t in 1976 and since then catches have generally declined. The per capita fish consumption in Cameroon stands at about 17.9 kg per inhabitant per year. This means that the demand of fish in Cameroon stands at about 280,000 tons. There is a deficit of in fish supply for which the government always resort to massive importation of fish products to meet the local demand. The main fish product for export from Cameroon is the prawn (Panacus duorarum). The main export market of Cameroon's prawn is the European Union (EU). Between 1998 and 2003, Cameroon's export value has been on the decline, dropping from 1,836 metric tons of prawns for a value of 264 millions USD in 1998 to 51 tonnes, for an estimated value of 315,000 USD in 2003. This drastic drop in exportation is consequential to Cameroon's auto suspension from the exportation of prawns towards the EU as a result of non compliance with EU standards. Today, a good quantity of the catches is being exported illicitly through neighbouring countries.

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Optimization and Scale-up of Fish Skin Peptide Loaded Liposome Preparation and Its Storage Stability (어피 펩타이드 리포좀 대량생산 최적 조건 및 저장 안정성)

  • Lee, JungGyu;Lee, YunJung;Bai, JingJing;Kim, Soojin;Cho, Youngjae;Choi, Mi-Jung
    • Food Engineering Progress
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    • v.21 no.4
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    • pp.360-366
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    • 2017
  • Fish skin peptide-loaded liposomes were prepared in 100 mL and 1 L solution as lab scales, and 10 L solution as a prototype scale. The particle size and zeta potential were measured to determine the optimal conditions for the production of fish skin peptide-loaded liposome. The liposome was manufactured by the following conditions: (1) primary homogenization at 4,000 rpm, 8,000 rpm, and 12,000 rpm for 3 minutes; (2) secondary homogenization at 40 watt (W), 60 W, and 80 W for 3 minutes. From this experimental design, the optimal conditions of homogenization were selected as 4,000 rpm and 60 W. For the next step, fish peptides were prepared as the concentrations of 3, 6, and 12% at the optimum manufacturing conditions of liposome and stored at $4^{\circ}C$. Particle size, polydispersion index (pdI), and zeta potential of peptide-loaded liposome were measured for its stability. Particle size increased significantly as manufacture scale and peptide concentration increased, and decreased over storage time. The zeta potential results increased as storage time increased at 10 L scale. In addition, 12% peptide showed the formation of a sediment layer after 3 weeks, and 6% peptide was considered to be the most suitable for industrial application.