• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.266-270
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• 1985

In order to obtain the fishing possibility by acoustic, the two fishes, Lateolabrax japonicus, Mugil cephalus, were bred in a water tank. The feeding sounds from the fishes and the artificial sounds were recorded by a hydrophone and then the frequency and the sound pressure level of the sounds recorded were analyzed by the digital frequency analyzer. These sounds were edited in two manners of which one is emitted for 10 seconds and paused for 10 seconds continuously and the other is emitted for 20 seconds and paused for 20 seconds also. These edited sounds were emitted again into the tank and the respose of fisher were observed. Lateolebrax japonicus showed a positive response and Mugil cephalus responsed a little positively to the emitted feeding sound, The fishes seemed to show a positive response only in emitting a moderate pressure level of feeding sound. Lateolabrax japonicus and Mugil cephalus showed negative response to the emitted artificial sound. It was most effective to increase the sound pressure level that the fishes went away from the sound source to the emitted artificial sound.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.948-956
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• 2013

Seasonal variations in species composition and abundance of the fish assemblages in the coastal waters off Gadeok-do were determined using monthly sample collection by a small otter trawl in 2010-2011. Of a total of 65 fishes collected, the dominant species were Leiognathus nuchalis, Clupea pallasii, Thryssa kammalensis, Engraulis japonicus, Repomucenus valenciennei, Sillago japonica, Trachurus japonicus, Pennahia argentatus, Okamejei kenojei, Cynoglossus joyneri, Pholis fangi, Pleuronectes yokohamae, and Zoarces gillii. These 13 fishes accounted for 92.8% of the total number of individuals collected. The number of fish species, number of individuals, biomass, and species diversity indices fluctuated with the seasons. The peak number of fishes occurred in April, whereas the biomass of fishes was highest in August. The numbers and biomass of fishes were lower in February corresponding with the low temperatures, and diversity indices were lower in January than in any other month.

• Korean Journal of Veterinary Service
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• v.21 no.4
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• pp.431-437
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• 1998

Argulus spp, a small group of parasitic curstaceans called Branchiura, is particularly important in freshwater acquaculture. We investigated the infection of Argulus to several different species of fishes and therapy effect of masoten. Argulus japonicus was collected from Okjeong lake, Chonbuk province and experlmen-tally infected to freshwater fishes from July to August 1998. The results were as follows ; 1. The shape of a Agulus is an oval and dorsoventrally flattened, with first maxillae and second maxillae, and four pairs of legs. 2. The size of the adult stage of A japonicus was 3.2-5.0$\times$2.3-2.9mm in female and 1.5-3.1$\times$1.6-2.9mm in male. 3. In the trial of experimental infection with A japonicus to non-scaled fishes, Parasilurus asotus and Ictalurus punctalus, were infected and some of them died after severe infection. However, A japonica was not infected at all. 4. Masoten treatment for A japonicus was effective at 0.2 ppm once a day for 3 days and parasites on the surface of fishes disappeared after five days.

• Korean Journal of Ichthyology
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• v.20 no.1
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• pp.54-60
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• 2008

This study was conducted to investigate the species composition and distribution patterns of intertidal fishes from the Shandong Peninsula, China from August 2006 to September 2007. The collected fishes were composed of 28 species, belonging to 21 genera, 14 families and 6 orders. Among them, the family Gobiidae was most abundant in both the number of species and individuals, while two species including Hexagrammos agrammus and Sebastes schlegelii were caught in large quantities of young fishes. In this study, Sebastes koreanus and Porocottus leptosomus known as Korean endemic species so far were collected in the Shandong Peninsula, therefore it should be revised that these two species were distributed on the North Yellow Sea and owned by both China and Korea.

• Parasites, Hosts and Diseases
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• v.25 no.2
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• pp.123-128
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• 1987

The author investigated the larvicidal action of liquid nitrogen against the metacercariae of Clonorchis sinensis, with an observation on the freshness and change of taste in the flesh of fishes. The results obtained were as follows: 1. The metacercariae in the mesh of Pseudorasbora parve, which were treated with liquid nitrogen ($-192^{\circ}C$), were not killed within 10 seconds, but completely killed over 30 seconds. In comparison, the metacercariae in the flesh of p. parka kept in a refrigerator ($-12^{\circ}C$) were killed only in 84% in 10-hour exposure group. 2. The freezing speed of fishes by liquid nitrogen was 4 min.(') and 15 seconds(") for Cyprinus carpio, 1'22" for Carassius carassius and only $30^{\circ}C$ for Pseudorasbora larva. 3. As for the freshness and taste of raw fresh water fishes, they were not deteriorated after the treatment with liquid nitrogen. 4. In animal infection experiment of C. sinensis metacercariae after freezing, they were found not infective after they were treated with liquid nitrogen. From the results, it is inferred that the treatment of fresh water fishes for longer than 30 seconds with liquid nitrogen is helpful to reduce the possibility of C, sinensis infection without alteration of the freshness and taste of fishes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2265-2270
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• 2008

It was studied to the displacement and the amount of catch for migratory fishes with NOAA/AVHRR SST(Sea Surface Temperature) from 1988 to 2000 in the Korean Seas. The analyzed results from SST data showed generally the oceanic warming trend in the Korean Seas. On the increasement of SST, the distributed areas of migratory fishes which living in the warm waters were displaced gradually to the northward directions(high latitude) and then the amount of catch was increased during this studied periods against to migratory fishes which living in the cold waters.

• Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.344-354
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• 2023

Food and feeding habits of large cyprinid fishes (Labeobarbus intermedius, Labeobarbus nedgia, and Labeo forskalii) had been investigated in the upper Blue Nile River, Ethiopia. Four sampling sites were selected and specimens were sampled during the post-rainy (November 2016) and dry (March 2017) seasons by gillnets of 6 cm, 8 cm, 10 cm, 12 cm, and 14 cm mesh sizes. Totally 401 fishes were collected and about 30.4% (122) of the samples were documented with empty guts and 279 (69.6%) of them were with non-empty guts. The whole contents of all non-empty gut specimens were taken, labeled, and preserved using a 5% formaldehyde solution for further analysis. In the laboratory, gut contents were examined and identified using compound and stereo microscopes. The relative importance of different food items in the diet compositions was analyzed using a frequency of occurrence and volumetric analysis. During the post-rainy season, insects and phytoplankton were mostly ingested as food items. However, during the dry season, phytoplankton was the most important food item in the diet of all cyprinid fishes of the river. Based on current study results, L. intermedius and L. nedgia might be omnivores in their diet but Labeobarbus forskalii seemed to be detritivorous.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.1
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• pp.56-62
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• 2003

To investigate the entrapping behavior of blue crab, rock shell and green ling, which are mainly caught with the other trap nets in the coastal area of Yellow Sea, by the using duration of trap nets through the water tank experiment. We select the three kinds of trap nets which have different using duration such as new, 6 months and 12 months used one, and observe the entrapping ratio into the trap nets, respectively. In the mean while, in order to obtain the basic data for the estimate of mesh selectivity of the other trap nets, the entrapping behavior into the trap nets for green ling which has high activity compared to blue crab and rock shell, are examined to the three kinds of mesh size (35mm, 50mm and 65mm). The results are as follows ; 1. The mean entrapping ratio of blue crab by the using duration of trap nets in high with 4.4 fishes (44.0%) in the 6 months used one, become lower with 2.9 fishes (28.0%) in the new one, and with 2.0 fishes (20.0%) in the 12 months used one. 2. The mean entrapping ratio of rock shell by the using duration of trap nets in high with 7.3 fishes (36.7%) in the new one, and become lower with 7.2 fishes (35.8%) in the 6 months used one, and with 5.7 fishes (28.3%) in the 12 months used one. 3. The mean entrapping ratio of green ling by the using duration of trap nets in high with 3.4 fishes (34.0%) in the 6 months used one, and become lower with 3.0 fishes (30.0%) in the new one, and with 2.8 fishes (28.0%) in the 12 months used one. 4. The mean residual ratio of green ling by the mesh size of trap nets is high with 2.4 fishes (24.0%) in the 35mm mesh size, and become lower with 2.2 fishes (22.0%) in the 50mm mesh size and 2.0 fishes (20.0%) in the 65mm mesh size.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.4
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• pp.576-585
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• 2009

The aim of this study is to indicate that how to select the releasing fishes for the nourishment of fisheries resources in small ranching area around the Gunsan coastal seas. The collected data were analysed, and revealed that the proper fisheries for releasing around the seas are Limanda Yokohame, sebastes schlegeli, paralichthys olibaceus, black porgy and little clam.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.643-646
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• 2016

Fishes usually form a group in water to minimize drag coefficient and this fish schooling is one of representative problems in computational fluid dynamics. In this research, we simulated two fishes as a rectangle. We arranged rectangle horizontal and vertical, then we changed distance between two rectangles and simulated pressure of fluid and drag coefficient. We could find the best distance and position of two fishes that makes minimum drag coefficient.