• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.60 no.3
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• pp.228-234
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• 2024

To determine the diet of Ridged-eye flounder, Pleuronichthys cornutus in the South Sea of Korea, a total of 207 individuals were collected in 2022 (February, April, May, August, and November) and 2023 (January, February, April, July, and October) by the Fisheries science survey vessels of NIFS. The total length (TL) range of these specimens was from 14.1 to 33.9 cm, and the stomach contents of 100 individuals, not on an empty stomach, were analyzed. Polychaeta was the most important prey component in the diets of P. cornutus based on an Index of relative importance (%IRI) of 55.5%. Followed by amphipoda with a %IRI value of 21.3%. Polychaeta was an important component in diets across all size classes (< 20.0 cm, 20.0-25.0 cm, ≥ 25.0 cm) of P. cornutus; as they grew, the %IRI value of amphipoda decreased and the %IRI value of anthozoa and holothuroidea increased. There was also a significant increase in the mean weight of prey per stomach with growth. P. cornutus consumed polychaeta in all seasons, with spring and autumn being the most dominant seasons. In summer, gastropoda was the dominant prey, and in winter, holothuroidea was the dominant prey.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.601-607
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• 1997

This study was designed to investigate the biochemical pollutant marker for diagnosis of marine pollutions by the changes in lipid components of the flounder (Pleuronichthys cornutus) in the Yellow Sea of Korea. Hemoglobin levels in serum of wild flounders in the yellow Sea were significantly lower $(15\~30\%)$ than those of wild flounder in Pohang (control) of the East Sea. Triglyceride (TG) contents in serum of wild flounders in the Yellow Sea were higher $(15\~50\%)$ than those of wild flounder in Pohang. Total and low density lipoprotein (LDL)-cholesterol contents in serum of flounders in the Yellow Sea were significantly higher $(20\~25\%\;and\;15\~35\%,\;respectively)$ than those of wild flounder in Pohang. Atherogenic index (Al) in serum of wild flounders in the Yellow Sea were significantly higher $(10\~60\%)$ than these of wild flounder in Pohang but T-Chol/PL ratios showed almost no change in serum of flounders in the Yellow Sea we examined. These results suggest that near-coastal water as well as neritic water of the Yellow Sea might be affected by pollutant input.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.306-313
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• 1994

In order to estimate the degree of genetic divergence between the two types of finespotted flounder, Pleuronichthys cornutus which is important commercially in Japan, isozyme analysis was carried out by starch gel electrophoresis. Twenty two loci coding for fourteen enzymes were scored in two types of finespotted flounder and three completely divergent loci (Acp, Idh-2 and Mdh-2), with no common alleles, were observed between these two types. Nei's genetic distance between two types was 0.46592. However, the expected average heterozygosity was 0.120 in type A (Hon meitagarei) and 0.095 in type B (Bake meitagarei) These results mean that the existence of two types of finespotted flounder was established in this study which may have had genetic divergence and the divergence time of these two types may have been about $2.3{\times}10^6$ years ago.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.43-48
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• 2021

There are prior studies that describe in detail the classification and shape of 26 species of Korean flounder, but it is difficult to make them out and they are used interchangeably or misused. It is intended to present the taxonomic standards of Pleuronichthys cornutus and Pleuronichthys japonicus and use them as tourism education materials using aquatic resources. Morphological comparison was made through counting and measurement. The two fish species were generally flattened in an oval shape with a low body height and a wide body width, and the anal fin developed and sized similar to the dorsal fin, and the caudal fin was widely spread out. Among the hyoid bones, in three parts of the coccyx, the main part, the ischial part, and the cardinal process, there were differences in the degree of curvature, the open angle, and the shape of the ischial part and the lateral process, which corresponded to the representative classification characteristics. In addition, it will be expected that it will serve as a basis as a fishery and marine education material for marine tourism that classifies and categorizes the characteristics as a genus of flounder and categorizes the characteristics, and reduces misuse of scientific names and names in the future.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.515-516
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• 2001

본 연구는 1998년 3월부터 2000년 4월까지 서해안 금강하구에 위치한 고군산 열도에서 채집한 조피볼락, 쥐노래미, 문절망둑, 도다리(Pleuronichthys cornutus) 및 수조기(Nibea albiflora)와 서남해의 완도에서 채집한 쥐노래미의 장내에 기생하는 흡충류의 종분류를 조사한 바, 4종의 흡충류가 검출되었기에 보고하는 바이다. (중략)

• Journal of Fisheries and Marine Sciences Education
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• v.11 no.1
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• pp.98-113
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• 1999

Demersal fishes as second study for the protection-nourishment of fisheries resources in Chinhae Bay were analysed using fish samples collected by a small otter trawler at bimonthly-interval from August, 1997 to June, 1998. Of the 55 species identified, Hexagrammos otakii, Pleuronichthys cornutus, Leiognathus nuchalis, Thrissa koreana, Callionymous lunatus, Acanthogobius flavimanus and Trachurus japonicus predominated in abundance. Especially, Hexagrammos otakii, Pleuronichthys cornutus and Leiognathus nuchalis were always collected at anywhere around a year in the bay. The seasonal fluctuation of number of species is very large as the ranging from 14 species in August to 25, December. The diversity index of individual number and biomass by month and station is 0.68(February)~1.13(October), 0.38(February)~1.06(October) respectively. The indices above mean that the number of species were not distributed broadly over the bay and also concentrated in several species only owing to the local pollutant extent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.614-619
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• 1997

This study was designed to investigate the biochemical pollutant markers for diagnosis of marine pollutions by changes in cholinesterase activity of the flounder (Pleuronichthys cornutus) in the Yellow Sea of Korea. Acetylchotinesterase (AChE) activities in brain and muscle of wild flounders in the Yellow Sea were significantly lower $(20\~30\%\;and\;10\~40\%,\;respectively)$ than those of wild flounder in Pohang (control) of the last Sea. Butyrylcholinesterase (BChE) activities in brain and muscle of wild flounders in the Yellow Sea were significantly lower $(10\~30\%\;and\;35\~45\%,\;respectively)$ than those of wild flounder in Pohang of the East Sea. lactate dehydrogenase (LDH) activities in serum of wild flounders in the yellow Sea were significantly $(about\;30\%)$ lower than those of wild flounder in Pohang of the East Sea. These results suggest that AChE and BChE activities in brain and muscle of wild flounders of the Yellow Sea may be used as the most effective mean in a biochemical marker for diagnosis of pollutant effects by organophosphorus pesticides.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.608-613
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• 1997

This study was designed to investigate the biochemical pollutant marker for diagnosis of marine pollutions by changes in oxygen radicals and their scavenger enzymes of the flounder (Pleuronichthys cornutus) in the Yellow Sea of Korea Protein contents in brain and muscle of wild flounders in the Yellow Sea were remarkably lower $(15\~45\%,\;and\;35\~45\%,\;respectively)$ than those of wild flounder in Pohang (control) of the East Sea. Lipid peroxide (LPO) levels in serum of wild flounders in the Yellow Sea were Significantly higher $(30\~70\%)$ than those of wild flounder in Pohang. Hydroxyl radical formations in serum of wild flounders in the Yellow Sea were significantly high $(15\~90\%)$ than those of wild flounders in Pohang. Superoxide dismutase (SOD) activities in serum of wild flounders in the yellow Sea were significantly lower $(20\~40\%)$ than those of wild flounders in Pohang, and glutathione peroxidase (GSHPx) activities in brain of wild flounders in the Yellow Sea were also significanlty lower $(10\~60\%)$ than those of wild flounders in Pohang. These results suggest that significantly decreases of protein contents in brain and muscle, remarkable in creases of malondialdehyde (LPD) in serum and decreases of SOD and GSHPx activities in serum and brain of wild flounders of the Yellow Sea may be used as a biochemical pollutant markers for diagnosis of marine pollutions.

• Journal of fish pathology
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• v.14 no.1
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• pp.21-30
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• 2001

From March 1998 to April 2000, 4 species of marine fishes including black rockfish (Sebastes schlegeli), goby (Acanthogobius flavimannus), fine-spooted flounder (Pleuronichthys cornutus), and croaker (Nibea albiflora) were captured from the coastal area of the Gogunsan island located in the mouth of the Kum River, and greenling (Hexagrammos otakii) was sampled from the coastal areas of the Gogunsan island and the Wan-do. Trematodes from the stomach and the intestine of the fishes were detected and identified on the basis of the morphological characteristics. Four species of trematodes were detected in the stomach and the intestine of the examined fishes ; Opecoelus lobatus Ozaki, 1925 from black rockfish, fine-spotted flounder and greenling, Coitoecum glandulosum Yamaguti, 1934 from goby, Phyllodistomum sp. Braun, 1899 from croaker, and Pharyngora sp. Lebour, 1908 from greenling captured from Wan-do. This report gave morphological descriptions of O. lobatus, Pharyngora sp. and Phyllodistomum sp. from coastal marine fishes in Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.1
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• pp.34-44
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• 1990

This paper describe on the target strengths for the dorsal and the side aspects of swimbladdered fishes, Mullet Mugil cephalus, Flounder Pleuronichthys cornutus and Rock trout Hexagrammos otakii two frequencies of 50KHz and 200KHz in the experimental water tank in order to improve the biomass estimation by the scientific fish finder. The results obtained are as follows: 1. The average of maximum target strength normalized by squared total length in cm unit are almost ranging from -70.9 dB to -66.8 dB regardless of species or frequencies. 2. The average of maximum target strength normalized by two-thirds squared body weight in g unit are almost ranging from -57.1 dB to -54.1 dB regardless of species or frequencies. 3. In comparison with target strength for 50KHz and 200KHz the former is more strong than the latter.