• Parasites, Hosts and Diseases
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• v.49 no.1
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• pp.39-44
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• 2011

The infection status of marine fish and cephalopods with Anisakis simplex third stage larva (L3) was studied over a period of 1 year. A total of 2,537 specimens, which consisted of 40 species of fish and 3 species of cephalopods, were purchased from the Cooperative Fish Market in Busan, Korea, from August 2006 to July 2007. They were examined for A. simplex L3 from the whole body cavity, viscera, and muscles. A. simplex L3 were confirmed by light microscopy. The overall infection rate reached 34.3%, and average 17.1 larvae were parasitized per infected fish. Fish that recorded the highest infection rate was Lophiomus setigerus (100%), followed by Liparis tessellates (90%), Pleurogrammus azonus (90%), and Scomber japonicus (88.7%). The intensity of infection was the highest in Gadus macrocephalus (117.7 larvae per fish), followed by S. japonicus (103.9 larvae) and L. setigerus (54.2 larvae). Although abundance of A. simplex L3 was not seasonal in most of the fish species, 10 of the 16 selected species showed the highest abundance in February and April. A positive correlation between the intensity of L3 infection and the fish length was obvious in S. japonicus and G. macrocephalus. It was likely that A. simplex L3 are more frequently infected during the spring season in some species of fish. Our study revealed that eating raw or undercooked fish or cephalopods could still be a source of human infection with A. simplex L3 in Korea.

• ALGAE
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• v.30 no.1
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• pp.49-58
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• 2015

In September 2007, reports of respiratory irritation and fish kills were received by the Florida Fish and Wildlife Conservation Commission (FWC) from the Jacksonville, Florida area. Water samples collected in this area indicated a bloom of Karenia brevis, the dinoflagellate that produces brevetoxin, which can cause neurotoxic shellfish poisoning. For the next four months, K. brevis was found along approximately 400 km of coastal and Intracoastal waterways from Jacksonville to Jupiter Inlet. This event represents the longest and most extensive red tide the east coast of Florida has experienced and the first time Karenia species other than K. brevis have been reported in this area. This extensive red tide influenced commercial and recreational shellfish harvesting activities along Florida's east coast. Fourteen shellfish harvesting areas (SHAs) were monitored weekly during this event and 10 SHAs were closed for an average of 53 days due to this red tide. The length of SHA closure was dependent on the shellfish species present. Interagency cooperation in monitoring this K. brevis bloom was successful in mitigating any human health impacts. Kernel density estimation was used to create geographic extent maps to help extrapolate discreet sample data points into $5km^2$ radius values for better visualization of the bloom.

• The Korean Journal of Zoology
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• v.11 no.1
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• pp.1-4
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• 1968

1. Infectious glochidia are attached only on the young fish of Zacco platypus which ranged from 2 to 4 cm in total body length. 2. The attachment of the glochidia on the fish was found at the beginning of April. 3. The glochidia per infectious fish are shown to be 1.6 in average number. 4. the glochidia were dropped from the infectious fish completely from late April through early May. 5. Most glochidia released from mother shell are attached on the fins on infectious fish, and also on the eyes, nose, mouth and gill. 6. The largest number of the glochidia was attached on the caudal fins of infectious fish, and the next was pectoral fins.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.117-119
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• 1970

A goby Synechogobius hasta (TEMMINCK et SCHLEGEL) was studied on the length-weight relation-ship, and the fish were sampled from the closed tributary and the lower part of the Naktong River, near Pusan, during the period from November of 1967 to December of 1968. The data for this study were taken from 1,050 fish. The relationships between the body length (X) and body weight (Y) are indicated as follows: 7.5cm to 32.5cm: $Y=0.09863X^{2.17926}$ 7.5cm to 19.5cm: $Y=0.04995X^{2.472l6}$ 28.5Cm to 32.5Cm: $Y=0.0004127X^{3.67265}$ The normal relative growth was not found in fish between 20.5cm and 27.5cm in body length, because of the maturity of gonads and spawning.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.4
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• pp.281-289
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• 2016

Spinyhead sculpin Dasycottus setiger, a species of cold water fish, is distributed along the eastern coastal waters of Korea. A series of fishing experiments was carried out in the waters near Uljin from June, 2002 to November, 2004, using the experimental monofilament gill nets of different mesh sizes (82.2, 89.4, 104.8, and 120.2 mm) to describe the selectivity of the gill net for the fish. The SELECT (Share Each Length's Catch Total) analysis with maximum likelihood method was applied to fit the different functional models (normal, lognormal, and bi-normal models) for selection curves to the catch data. The bi-normal model with the fixed relative fishing intensity was selected as the best-fit selection curve by AIC (Akaike's Information Criterion) comparison. For the best-fit selection curve, the optimum relative length (the ratio of fish total length to mesh size) with the maximum efficiency and the selection range ($R_{50%,large}-R_{50%,small}$) of 50% retention were obtained as 2.363 and 0.851, respectively. The ratios of body girth to mesh perimeter at 100% retention where the selection curve of each mesh size represented the optimum total length were calculated as the range of 0.86 ~ 0.87.

• Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.491-496
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• 2014

A total of six specimens (57.03-100.72 mm in standard length) belonging to the family Diodontidae were collected around Jeju Island, Korea between July and August 2013. On the Basis of morphological and molecular analyses, we identified the specimens as Cyclichthys orbicularis (Bloch, 1785), a new record to the Korean fish fauna. Morphologically, the species is characterized by nine caudal fin rays, immovable spines on the head and body except the caudal peduncle, and small black spots dorsally. Some morphometric characters changed disproportionately with growth, which was a new finding. Caudal peduncle length, body width and preanus length to standard length tend to grow at a rate different from that of overall growth. When the 601 base pairs of mitochondrial DNA cytochrome c oxidase subunit I sequences of our specimens were compared with those of other diodontid fishes, our specimens clustered tightly around C. orbicularis (d = 0.000-0.002) in an NJ tree, with a high bootstrap value (99%). We herein describe the morphological and molecular traits of the specimens, and propose a new Korean name, "gud-ga-si-bok-sok" for the genus Cyclichthys, and "dung-geun-gud-ga-si-bok" for C. orbicularis.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.2
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• pp.78-82
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• 1988

Near sea trawlers of Korea sometimes catch pelagic fishes like file fish by using midwater trawl gear even though usually catch bottom fish. It is reasonable to use the specific otter board as well as specific net in bottom trawling and in midwater trawling respectively. But, the trawlers are so small ranging 100 to 120GT, 700 to 100ps that it is very complicated to use different otter board for bottom trawling and for midwater trawling. The otter board for bottom trawling. is also used for the midwater trawling without any change even though the net is changed into the specific one. Although the otter board in the midwater trawling should be lighter than that for bottom trawling, to use otter board for bottom trawling directly for the midwater trawling without any change makes the net easily touch the sea bed and also make the horizontal opening of the otter boards be limited owing to the length of warp in the southern sea of Korea, main fishing ground of midwater trawling, which is 100m or so in depth. That is why the otter board for the midwater trawling should be made lighter than that in the bottom trawling, even if temporary. The authors carried out an experiment to achieve this purpose by attaching a large styropol float on the top of the otter board. In this experiment, underwater weight of the otter board was 630kg and buoyancy of the float was 510kg. To determine the depth and horizontal opening of the otter board, two fish finder was used. A transmitter of 50KHz fish finder was set downward through the shoe plate of otter board to determine the elevation of otter board from the sea bed, and a transmitter of 200KHz fish finder was set sideways on the starboard otter board to be able to detect the distance between otter boards. The obtained results can be summarized as follows: 1. The actual towing speed in the experiment varied 1.1 to 1.8 m/sec. 2. The depth of otter board was within 41 to 25m with float on the top and 45 to 26m without float in case of the warp length 100m, whereas the depth 68-44m with float and 74-46m without float in case of the warp length 150m. This fact means that the depth with float was 9-4% shallower than that without float. 3. The horizontal opening between otter boards was within 34-41m with float and 30-38m without float in case of the warp length 100m, whereas the opening was 44-50m with float and 37-46m without float in case of the warp length 150m. This fact means the opening with float was 10% greater than that without float in case of the warp length 100m, and 15% greater in case of the warp length 150m. 4. The horizontal opening between wing tips by using the otter board with float was 1m greater than by without float in case of the warp length 100m, whereas the opening by with float was 2m greater than by without float in case of warp length 150m. From this fact, it can be estimated that the effective opening area of the net mouth by using the otter board with float could be made 10% greater than by without float in case of warp length 100m, whereas the area with float 20% greater than by without float in case of warp length 150m.

• Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.298-310
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• 2022

Although giant and large fish species are highly important as a keystone species in the marine ecosystem, there have been no or few studies on their spatio-temporal variations around the Korean peninsula. For this, we analyzed daily reports made by observers at 57 fishery landing sites in Korea over 6 years, from 2011 to 2016. In total, 153 fish species were re-identified based on photos and descriptions recorded by Korean observers, of which five species were classified as a giant fish over 5 m in maximum total length (MTL) and 17 species as a large fish from 3 m to 5 m MTL according to the data presented by Froese & Pauly (2021). Among the giant and large fish species, Mola mola was the most abundant species, with 75 individuals landed as by-catch. The second most abundant species was Isurus oxyrinchus (31), followed by Mobula mobular (23), Lamna ditropis (17), Masturus lanceolatus (16), Sphyrna zygaena (14), and Prionace glauca (12). As a result of cluster analysis based on the number of individuals of giant and large fish species by year and sea, six years were separated into two clusters (2011-2013 vs. 2014-2016), with high contribution of M. mola, I. oxyrinchus, and M. lanceolatus; and three seas were separated into two clusters (eastern + southern seas vs. western sea), with high contribution of M. lanceolatus, L. ditropis, and I. oxyrinchus. The largest number of M. mola accounted for 64% of the total in 2014 and 2016, and 71% in summer (June-August). It is assumed to have a correlation between seawater temperature fluctuation and the occurrence of giant and large fish species. Our study highlights importance of longterm monitoring of giant and large fish species, and can help to understand the life cycle such as natal or nursery migration of giant and large fish species around the Korean peninsula.

• Journal of Aquaculture
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• v.12 no.4
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• pp.255-266
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• 1999

The early development, growth, and morphological changes of Tiger puffer Takifugu rubripes are described on the basis of a seres of a series of reared specimens. Detailed o수 the early developmental stages are illusrtated withe special reference to morphological transformation. Egg and sperm of puffer fish Takifugu rubripes were obtained from mature adults under natural conditions, ferilized artificially and incubated in the laboratory. The incubation period of fertilizd eggs was 160 to 180 hours at a temperature of $15.1~ 18.0^{\circ}C$. Larvae were fed successively with rotifer, Artemia nauplii and artificial food for 90 days. The mean total length of newly-hatched larvae was about 2.8mm. Mouth opening occurred on the 1- day yolk-sac larvae and initial feeding was observed on th 4-5 days after hatching . The morphological transitions from the larvae to juvenile and juvenile and juvenile to young stages occurred when fish reached about 10mm in total length(about 30 days after hatching) and about 32mm in total length(about 60days after hatching) , respectively. The coefficient of variation in total length distribution increased with growth. Following the appearance of its peak at the size of about 18mm in total length, the coefficient value declined. Many changes in proportion of the body parts to total length were observed at about 9~10mm and 30~33mm in total length, corresponding to the transformations from larvae to juvenile and from juvenile to young, respectively. Also one big morphological change was observed at about 18mm in total length that divide the juvenile stage into two sub-stages.

• Journal of Nutrition and Health
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• v.31 no.4
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• pp.697-707
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• 1998

This study was designed to observe the effect of dietary fiber and fat on colon tumor incidence and cell proliferation. Male Sqraue Dawley rats(n=225) at 7 weeks of age, were divided into 3 groups depending on the type of fat b(beef tallow, corn oil and DHA-rich fish oil) and each group was again divided into 3 groups depending on type of fiber(fiber-free, perctin and cellulose) . The experimental diet containing dietary fat at 15%(w/w) and fiber at 6%(w/w) levels was fed for 25 weeks. At the same time, each rats was intramuscularly injected with DMH two times a week for 6 weeks to geive total dose of 180mg/kg body weight. Cell proliferation was measured by in vivo incroporation of bromodeoxyuridine (BrdU) into DNA. Fish oil decreased the tumor incidence (9.67%) compared with beef talow (33.39%) and corn oil (21.21%). Tumor incidence was decreased in all groups that fed cellulose (11.67%) compared with those of fiber-free(21.74%) and pectic(19.70%). Most of tumors was distributed at the site of the distal colon. The rats fed both fish oil and cellulose significantly decreased th enumber of tumors and tumor incidence compared to other groups. Fish oil was more effective in preventing cell prolofieration by decreasing crypt length and labeling index(LI) compared with beef tallow(p<0.05). Cell proliferation in distal colon was more developed to the upper part of the crypt compared to proximal colon. Overall tumor incidence and cell proliferation were more affected by dietary fat. But the effect of dietary fiber was different depending on type of fat in the experimental diet. These results suggest that a DHA -rich fish oil may has more decisive effect in inhibiting the cell proliferation in colon.