• The Korean Journal of Zoology
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• v.31 no.1
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• pp.56-61
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• 1988

The taxonomic status of Moroco Jagowskii and M oxycephalus a pair of sibling species inhabiting in Korean fresh waters, has been unclear up to date. Recently a sympatric area of these species was found (Kang, 1987). The purpose of this study was to clarify their specific status by analysing specimens collected from the sympatric area of these species. Isozyme analysis and morphometric comparison were performed. Among 26 loci screened 6 loci (Aco, Est-2, E-X, Gk-3, Ipo, Me) showed fixed allelic difference between them and these loci could be used as genetic markers to distinguish them. Isozyme analysis indicates that no hybridization occurs and therefore it is assumed that isolating mechanism is completed and they are distinct species. The mean number of scales above lateral line (SAL) of M Jagowskii and M oxycephalus at sympatric area was 24.93 $\pm$1.95 and 17.33$\pm$0.72 respectively, and it seems as the result of character displacement. A finer microhabitat segregation between them is noticed. M oxycephalus is found along the effluent streams whereas M lagowskii is distributed mostly in the main stream at sympatric area.

• Korean Journal of Ichthyology
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• v.20 no.2
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• pp.97-104
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• 2008

Comparative study of retinal structure in two Korean endemic freshwater fishes, Zacco koreanus and Pseudobagrus koreanus, was carried out by light and scanning electron microscopy. In the visual cell layer comprised of cone cells and rod cells, the cone cells showed a distinct difference between both species. Z. koreanus had two types of cone cells, single cone cells including a long single and short single cone cells, and double cone cells, whereas P. koreanus had only one type of single cone cells having no its short single and long single cones. Meanwhile, the cone cells of Z. koreanus were arranged in more compact-rowed pattern, but it was more loose and irregular in P. koreanus. Based on field observation, Z. koreanus is mainly a epipelagic or sometimes benthopelagic and a diurnal fish with a round and large eye, while P. koreanus is a demersal and nocturnal fish with an oval and small eye. Therefore, the difference in the retinal structure of two species seems to be closely related to their ecological habitats.

• The Korean Journal of Zoology
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• v.8 no.2
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• pp.28-32
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• 1965

It is well known that many kinds of chemical or metalic agent which were ionized or undissociated at toxified external medium and remarkable effect occurred to the fresh water fish. The effects of hydrogen ion concentration on serum protein of fresh water fish, (phycephalus argus CANTOR) had not been reported yet. In this point, authors attempted to study the changes of A/G ratio, total protein, hemoglobin, hematocrit, RBC , liver and kidney weight of snake head in the above environment. 95 snake heads were subjected to external medium with PH-4.5 and A/G ratio, hematocrit, hemoglobin, total protein, RBC, and liver & kidney weight were measured at 32.80, 15202000 and 272 hours respectively. In whole experimental period, L 1 and L2 globulin increased, on the other, albumin decreased as compare with control . Hence, the A/G ratio decreased remarkably . Though, total protein increased prominently through the whole experimental period, hematocrit, hemoglobin, RBC, increased only at 80 hours, and then decreased as compared to the control. Liver weight revealed distinctive increase at 80 hours, but no remarkable change could be seen there after. Hence, kidney weight revealed continuous rise. By these results, it may be said that as snake head were subjected to external medium with PH-4.5, this environmental factor influenced protein metabolism , blood component and organs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.612-618
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• 2012

The proximate and fatty acid compositions of the edible portion of three species of cultured freshwater fish (common eel Anguilla japonica, rainbow trout Onchorhynchus mykiss, and Israeli carp Cyprinus carpio) were compared between imports from China and domestically produced specimens. The lipid contents of cultured common eel and rainbow trout were rich in imported fishes (20.4 and 12.2%, respectively) compared with those in domestic ones (16.0 and 8.01%, respectively), while those of Israeli carp were rich only in the domestically produced specimens (8.06 and 3.07%, respectively). There was a negative correlation between the lipid and moisture contents in all fish samples (r =-0.86). The protein contents ranged from 16.6 to 21.3% in domestic fishes and 15.3 to 19.1% in imported ones. The most prominent fatty acids in the fishes were: saturated fatty acids, 16:0, 18:0 and 14:0; monounsaturated fatty acids, 18:1n-9, 16:1n-7 and 18:1n-7; and polyunsaturated fatty acids (PUFA), 18:2n-6, 22:6n-3 (docosahexaenoic acid, DHA), and 20:5n-3 (eicosapentaenoic acid, EPA). The percentage of n-3 PUFA (e.g., DHA, 22:5n-3, EPA, and 18:3n-3) was higher in domestic common eel and Israeli carp than in imported ones, but similar in domestic and imported rainbow trout, and higher in domestic wild rainbow trout than in cultured ones. On the other hand, all of the cultured freshwater fishes contained a relatively large amount of 18:2n-6, which is a characteristic fatty acid in cultured fish lipids.

• Animal Systematics, Evolution and Diversity
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• v.9 no.2
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• pp.151-170
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• 1993

Morphometric, band-pattern and electrophoretic analysis on Cobitis taenia complex were performed to investigate the morphological and genetic differentiation and to clarify their taxonomic status. Intermediate types of band-pattern (C and D type) were more frequently expressed than that of types of C. t. taenia(type A) and C. t. lutheri (type B). Sexual dimorphism of band-pattern was observed not only in C. t. taenia(type A) and C. t. lutheri(type B). Sexual dimorphism of band-pattern was observed not only in C. t. lutheri but also in C. t. taenia and C. t. striata as well. Discriminant function analysis based on 19 morphological characters shows no significant differences among C. taenia complex. The degree of genic variation of C. t. striata was higher ( =1.48, P=31.2%, HD=0.009) than those of C. t. striata was higher( =1.48, P=31.2%, HD=0.082 and HG=0.009) than those of C. t. lutheri ( =1.37, P=2.7%, HD=0.058 and HG=0.065). The average genetic similarities between C. t. lutheri and C. t. taenia-C. t. striata were S=0.62 and S=0.66 respectively and these values indicate that C. t. tanenia has evolved specific level of differentiation. C. t. striata and C. t. lutheri show subspecifc level of close genetic similarity (S=0.82). Based on the divergent time estimate (Nei, 1975) it is assumed that C. t. tanenia was branched off from the other subspecies about two million years before present (MYBP) and C. t. striata and C. t. lutheri were differentiated about 0.6 MYBP. The use of C. sinesis an the scientific name for the Korean C. t. taenia, proposed by Kim and Lee (1988) seems incorrect since they are quite different in the structure of lamina circularis (Vladycov, 1935), the external morphology and distribution (Cheng and Zheng, 1987) and the chromosome number(Yu et al., 1989). Kim and Lee(1988) also argued that C.t. striata and C. t. lutheri should be treated as distinct species but the present study and other reports (Kim and Lee, 1984; Kim and Yang, 1993) do not support it. We conclude that C. t. taenia is a good species and C. t. striata and C. t. lutheri are subspecific status. Their scientific names should be revised in the future.

• Journal of Food Hygiene and Safety
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• v.16 no.4
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• pp.324-332
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• 2001

Foods constitute a large portion of heavy metal exposure toward general population and attract a deep concern with respect to assuring human health. This study summarized published data in Korea on the content, and dietary intake of heavy metals and assessed their risk potential in comparison with foreign data. An analysis for the yearly fluctuation of metal contents including arsenic, cadmium, mercury and lead by flood group (marine fishes, coastal shellfishes, freshwater fishes, cereal grains) exhibited a decreasing trend from the 1970s to the 1990s. When compared with domestic standards of heavy metals, their mean contents were below the limit and their maximum values seldom exceeded the limit. The data on the dietary intake of heavy metals by Koreans showed a decreasing trend from the 1980s to the 1990s. The average intakes offs and Hg were 6∼8% and those of Cd and Pb were 50∼80% of PTWI(provisional tolerable weekly intake), all of which were below the tolerance. As the extreme intakes of these metals may exceed the PTWI, a careful assessment for them may be necessary. Dietary intakes of Cd, Hg and Pb by Koreans lie in the mid-level among countries cited in the GEMS/Food monitoring data. As fishery foods are suspecious of contamination with Hg, Cd and As, and floods in general are with Pb, it is necessary to establish legal limits for these metals and monitor any progress of their contamination. Furthermore, overall assessment of exposure to heavy metals from all sources including floods, air, drinking water and occupation should be made in order to confirm the dietary risk factors and to assure the safety of food resources.

• Journal of Life Science
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• v.32 no.8
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• pp.659-665
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• 2022

Chlorella vulgaris is an important freshwater alga that is widely used as a food source by humans and animals. Recently, Chlorella has received considerable attention with regard to its potential application in aquaculture and the production of biofuels, nutrients, and therapeutic proteins. Recently, our laboratory acquired a new strain of C. vulgaris, PKVL7422, characterized by fast growth, ease of culture, and cultivability under dark conditions. However, the genes involved in its nitrogen assimilation are unknown. In this work, we identified the nitrate reductase (NR) gene of C. vulgaris PKVL7422 using rapid amplification of cDNA ends and genome walking. The NR gene of C. vulgaris PKVL7422 is approximately 8 kb long and composed of 18 introns and 19 exons, which encode 877 amino acids. An alignment analysis of the NR gene showed that it possesses the five domains and several invariant residues found in plant NRs. These results provide new insight into the molecular organization of the NR gene in algae.

• The Korean Journal of Zoology
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• v.33 no.4
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• pp.499-508
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• 1990

Surveys of elecirophoretic variations in isozymes and proteins encoded by 25 persumtive loci were conducted to estimate the degree of genic variation and to assess species recognition for three species of the Family Gasterosteidae (Pisces) in Korea. The average degree of genic variation of Gasterosteus aculeatus was HD = 0.086, HG = 0.084, and P =36% and it was similar to Pungitius sinensis (HD = 0.080, HG = 0.091, P = 29%). But P.kaibarae was less variable than these species (HD = 0.034; HG = 0.034, P = 13%). The average genetic similarities among the populations in each species of Gasterosteus aculeatus pungitius sinensis and P. kaibarae were S = 0.963, S = 0.953 and S = 0.800 respectively.Yongchon and Kyongiu populations of P. kaibarae were genetically remote from the rest of the conspecific populations (S = 0.690). Chae (1988) also observed morphological differences between them. The value of genetic similariiy coefficients of S = 0.606 between P. sinensis and P. kaibarae is low enough to consider as specific level of genetic difference, but moderate rate of hybridization (44%) between them at a synpatric area of Kangnung indicates that isolating mechanism is incomplete. Therefore it is concluded that P. sinensis and P. kaffarae are semispecitic status. Intergeneric genetic similarities between the genus Gasrerosteus and Pungitius were S = 0.052 and this value is the lowest estimate up to date in freshwater fishes.

• Journal of fish pathology
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• v.24 no.3
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• pp.247-254
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• 2011

The purpose of this study was to obtain reference data of parameters for hematological health diagnosis in cultured freshwater fish and also evaluate application of automatic dry-type chemistry analyzer (FUJI DRI-CHEM 3000) used to those blood tests. A blood profile of total 200 fish for rainbow trout (Onchorhynchus mykiss), israel carp (Cyprinus carpio), tilapia (Oreochromis niloticus) and eel (Anguilla japonica) cultured in Inland Fisheries Research Institute of NFRDI was determined by hemoglobin (Hb) and plasma chemistry tests: total protein (TP), albumin (ALB), alkaline phosphatase (ALP), blood urea nitrogen (BUN), lactate dehydrogenase (LDH), triglyceride (TG), total cholesterol (TCHO), creatinine (CRE), aspartate aminotransferase (AST), alanine aminotransferase (ALT), glucose (GLU). The values of ALT, TG, LDH, ALB, TCHO, AST and ALP were outside from the minimum and/or maximum of the established detectable range of the analyzer. ALT and TG were not detectable in the range of 67%~61.5%. LDH, ALB and TCHO were not detectable in the range of 36~17%. AST and ALP were not detectable in the range of 5.5~0.5%. However, the values of BUN, CRE, GLU, Hb and TP were below the detectable limits of the analyzer.

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.288-294
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• 2014

Host mussel utilization for spawning of the oily shinner, Sarcocheilichthys variegatus wakiyae (Pisces: Cyprinidae), from Korea was investigated in part of the Dalcheon (river) in Cheongcheon-myeon, Goesan-gun, Chungcheongbuk-do, Korea from April to June 2011, 2013. The non-synchronicity of mature and immature eggs obtained from females of S. v. wakiyae and the number of spawned eggs found was less than those in the mussels, suggesting that these fish may be batch spawners. Five species of freshwater mussels - Unio douglasiae sinuolatus, Lanceolaria grayana, Anodonata arcaeformis flavotincta, Lamprotula leai, Corbicula fluminea - were found at the survey area (wild conditions) but three species of freshwater mussels - A. a. flavotincta (oviposition rate, 50.0%), U. d. sinuolatus (16.2%), L. leai (11.1%) - were host of S. v. wakiyae. Spawning of S. v. wakiyae occurred mainly in the mantle cavity (wild conditions, 77.4%; experiment, 62.8%) of the mussels that were connected more to the inhalant siphon than the suprabranchial cavity (22.6%; 31.8%) that linked to the exhalant siphon. Bitterlings prefer to lay eggs in L. leai and S. v. wakiyae prefers A. a. flavotincta as a spawning host. These were considered to be the result of niche partitioning.