• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.413-420
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• 1986

This study was attemtped to improve the conventional processing method and to establish the basic data for evaluating the product suitabilities of dried loach. The semidressed raw material were salted in 15% NaCl solution for 15 minutes and dried to contain about 44% of water, and then heated about 10 minutes at $80^{\circ}C$ controlled by microwave (2,450 MHz). The moisture content of monolayer value for the product showed 5.34% and its water activity was 0.28. The optimum relative humidity for the storage was recognized to be from 32% to 44%. The average shelf life around the year of the Nylon-PVC-PE $(40\;{\mu})$ packed product in domestic circulation market was estimated as 207.4 days. In comparison with raw material, the contents of the major amino acids, glutamic acid, alanine and valine in the product were shown to be slightly increased, while the level of lysine, aspartic acid and methionine were slightly decreased. The contents of saturated fatty acids and oleic acid were shown to be slightly increased, while the other fatty acids tended to be slightly decreased.

• Korean Journal of Ichthyology
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• v.22 no.4
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• pp.238-248
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• 2010

We performed field investigations at six stations in Buk Stream of Goseong-gun, Gangwon-do, Korea, from May to September 2009 to understand the stream's fish fauna and community structure. In the survey, 31 species belonging to 20 families were collected. Dominant species by number was Zacoo koreanus (30.0%), and subdominant species were Pungitius kaibarae (9.4%) and Rhynchocypris steindachneri (9.3%). In biomass, the dominant species was Tribolodon hakonensis (35.5%), and subdominant species were Z. koreanus (22.5%) and Cobitis pacifica (7.5%). Eight Korean endemic fish species and two endangered species (P. kaibarae and Pungitius sinensis) were collected. In addition, four anadromous fish species (T. hakonensis, Oncorhynchus masou masou, O. keta, Gasterosteus aculeatus) and two amphidromus fish species (Plecoglossus altivelis altivelis and Gymnogobius urotaenia) were observed. Interestingly, we verified the existence of several fish species in Buk Stream where they have not lived before. Those species were previously reported to live only in rivers that run into the western and southern sea of Korea. Five of those species (Zacoo koreanus, Z. platypus, Silurus microdorsalis, Liobagrus andersoni and Coreoperca herzi) were reported in Buk Stream in the 1980s. The other species (Pungtungia herzi, Pseudorasbora parva, Squalidus multimaculatus, Misgurnus mizolepis, Koreocobitis rotundicaudata, Silurus asotus and Odontobutis interrupta) have been introduced since the 1990s.

• Journal of fish pathology
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• v.25 no.1
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• pp.1-10
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• 2012

It has been reported that various anti-oxidant substances stimulate non-specific immune responses in fishes. In this study it was examined whether N-acetylcysteine (NAC), an anti-oxidant glutathione (GSH) precursor, can modulate non-specific immune parameters in 8 different fishes. NAC was intraperitoneally administered at 10 mg/kg to catfish (Silurus asotus), loach (Misgurnus mizolepis), common carp (Cyprinus carpio), crucian carp (Carassius carassius), eel (Anguilla japonica), snakehead (Channa argus), tilapia (Oreochromis niloticus) and mullet (Mugil cephalus). Forty-eight hours later, chemiluminescence (CL) response of head-kidney leukocytes and serum lysozyme activity were assessed. In all fishes except crusian carp and loach, CL responses were amplified by NAC. Lysozyme activity was increased by NAC in all fish species but not in tilapia. This result suggests that NAC stimulates non-specific immune responses in various species, and that such effects may have beneficial significance in aquaculture for practical utilization.

• Journal of Aquaculture
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• v.8 no.3
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• pp.209-220
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• 1995

The nuclear matrix was isolated from Misgumus mizolepis liver nuclei by low salt extraction and restriction enzyme treatment. The structure was digested with proteinase K. After centrifugation, matrix attachment regions (MARs) were obtained by RNase treatment and phenol-chloroform extraction. The result leads to the appearance of smeared bands in the range of about 0.3-15 kb. pURY19 vector was constructed by inserting 2.13 kb Eco47 III fragment of the yeast uracil 3 gene into the unique Ssp I site of pUC19 plasmid vector as a selection marker. This vector is unable to be maintained in Sacrharomyces cerevisiae by itself since it cannot replicate as an extrachromosomal element. Using this system, we attempted cloning the ARS (autonomously replicating sequence) from M. mizelepis to develop an efficient expression vector for the transgenic fish. pURY19N_{l-62}$ were constructed by inserting MARs in pURY19 plasmid vector and transformation of E. coli $DH5\alpha$. Replication origins (ARS) of M. mizolepis were isolated, which enabled the vector to replicate autonomously in S. cerevisiae. The cloned DNA fragments were sequenced by Sanger's dideoxy-chain termination method. All clones were AT-rich. $pURY19N_6$, one of the clones, expecially contained ARS consensus sequence, Topoisomerase II consensus, near A-box and T-box.

• Journal of Aquaculture
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• v.9 no.4
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• pp.445-452
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• 1996

Endogeneous activities of ${\beta}-galactosidase$-like enzyme in various tissues from several finfishes and shellfishes were examined by histochemical analysis based on X-gal staining and by fluorimetric measurement using 4-methylumbelliferyl-${\beta}$-D-galactoside (4-MUG). Species used in this study were 3 freshwater fishes, mud loach (Misgurnus mizolepis), common carp (Cyprinus carpio) and tilapia (Oreochromis niloticus) ; 3 marine fishes, olive flounder (Paralichthys olivaceus), stone flounder (Kareius bicoloratus) and marbled sole (Limanda yokohamae) ; and 4 shellfishes, abalone (Haliotis discus hannai), Pacific oyster (Crassoskra gigas), pearl oyster (Pinctada fucata martensii) and ark shell (Anadara broughtonii). The activities of ${\beta}-galactosidase$-like enzyme in all finfishes examined were significantly different among species, with the wide variations between tissues in a species. In general, the tissues such as kidney, intestine and liver were ones which showed the significantly higher values in 4-MUG fluorimetry and deeper staining patterns in X-gal analysis compared to other tissues. On the other hand, serum and muscle revealed the significantly lower activities than others did, regardless of species. Shellfishes were also found to have endogenous activities of ${\beta}-galactosidase$-like enzyme which were significantly varied depending on both species and organs in a species. Hepatopancreas from all shellfishes examined showed the deepest pattern in X-gal staining and also the highest value in 4-MUG analysis, while activities of ${\beta}-galactosidase$-like enzyme in adductor muscles and mantle muscles from all shellfish species in this study except Pacific oyster were negligible : Pacific oyster had the significant activity of this enzyme in muscle tissues. Putative endogenous lacZ fragment was amplified from both finfishes and shellfishes by polymerase chain reaction (PCR). The molecular size of PCR products was about 510 bp, and there was no difference in size among species examined.

• Biomedical Science Letters
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• v.5 no.1
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• pp.109-118
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• 1999

The relationship between the intestinal histopathology and number and position of intraepithelial lymphocytes (IEL) was observed chronologically in the small intestine of rats experimentally infected with Echinostoma hortense. Sprague-Dawley rats were orally infected with 200 metacercariae obtained from Misgurnus anguillicaudatus. The rats each were sacrificed on the week 1, 2, 4, 6, 8 post-infection (PI) and samples of the intestine in the part of duodenum and jejunum were taken. The samples were stained with Hematoxylin-eosin and Giemsa. The intestinal histopathology was the severest after the week 1 PI and characterized by villous atrophy, crypt hyperplasia and decrease of villus/crypt(v/c) ratio, which continued until the week 8 Pl. The number of IEL dramatically decreased during the week 1 PI, but increased gradually thereafter with a slight decrease on the week 8 PI. In control rats, the great majority of the IEL were located at the basal region of the epithelium. During the early stage of infection, however, we found a considerable proportion of IEL to moved to the intermediate or apical regions of the epithelium. From the above results, it is sugested that the change of IEL number and position during the course of E. hortense infection should be closely related to the progression and recovery of the intestinal histopathology.

• Parasites, Hosts and Diseases
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• v.22 no.2
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• pp.181-189
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• 1984

The metacercariae of Echinostoma cineterchis (Trematoda: Echinostomatidae) were found infected in the loaches (Misgurnus anguillicaudatus) purchased from two local markets in Korea. Identification of the metacercariae was done after obtaining adult worms from experimentally infected albino rats. Brief course of worm development in rats was also observed up to 28th post-infection day. The results are as follows: 1. The metacercariae of E. cinetorchis were detected from 5 (10.9%) out of 46 loaches examined and the average metacercarial burden per infected loach was 34.4. They were always found from the posterior abdominal wall. 2. The worm recovery rate from 8 rats was 24.6% in average. It was observed that the rate decreased according to age of infection; from 40.7% after 6 days to 15.0% after 28 days. 3. The adult worms were morphologically characterized by the presence of head crown with derfally uninterrupted collar spines, 37-38 in number, and the tendency of migration or disappearance of testes. So that they were identified as Echinostoma cinetorchis Ando et Ozaki, 1923. 4. The development of worm was very rapid during 6-10 days after infection and became much slower thereafter. During the rapid worm growth the development of genital organs was more prominent than that of non-genital organs. From the results it is concluded that the loach is involved in the life cycle of E. cinetorchis in this country and may take a role for infection source to animals and man. It is also confirmed that migration or loss of testes is the distinct specific character of this echinostomatid fluke.

• Journal of Life Science
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• v.25 no.5
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• pp.533-538
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• 2015

Four sites and one site were used to analyze fish diversity at the water systems of the Sineun reservoir and the Jeonchon reservoir, respectively. The field experiments were conducted to test the density dependence that could lead to population regulation by artificial inferences and environmental changes. We examined the effects of environmental factors on fish densities using SMATR freeware. It was estimated to be reduced to the density effect at four sites in 2012. Shannon-Weaver indices of the diversity (H’) of the Sineun reservoir were similar to those of the Jeonchon reservoir. Species diversity was in a range of 0.645 to 2.105. The H’ value of the upper region was higher than those of middle and low regions were, and values of richness were lower in downstream than upstream. Using the maximum likelihood solution for the removal estimators of two low regions of the river stations, the estimated migration probabilities from the resident fish to the migrated fish for five species (Cyprinus cuvieri, Carassius auratus, Pseudorasbora parva, Misgurnus mizolepis, and Oryzias latipes) had a mean of 0.623. Especially, migration probabilities from the Jeonchon reservoir to the Sineun reservoir for five species were high (a mean of 0.681). The period of migration was suggested to be about one month because of short geographical distances (50 m). We found no significant difference between the three categories in the distribution of the other four species, indicating the species probability was similar among stations.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.3
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• pp.186-192
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• 2006

Short interspersed repetitive elements (SINEs) are dispersed throughout eukaryotic genomes. These SINEs have been shown to be excellent phylogenetic markers for the closed related species. In this report, we isolated two novel families of SINEs from the mud loach. The two SINE families, mlSINE-L and mlSINE-S, have genomic lengths of about 410bp and 270bp, respectively. 5' and 3' ends of the SINE families are well conserved and highly homologous to each of corresponding ends of RSg-1 and SmaI SINEs. Phylogenetic analysis shows that mlSINEs are unique to the mud loach. A dot blot hybridization experiment shows that mlSINE-L has an estimated copy number of $1{\times}10^3$ per $2{\times}10^9bp$ (2.8 pg) and is more frequently distributed at nuclear matrix attachment regions (MARs) than loop DNAs. The result suggests that mlSINEs may preferentially integrate in or near MARs.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.198-205
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• 2015

Impacts of climate change on aquatic ecosystems range from changes in physiological processes of aquatic organisms to species distribution. In this study, MaxEnt that has high prediction power without nonoccurrence data was used to simulate fish distribution changes in the Geum river watershed according to climate change. The fish distribution in 2050 and 2100 was predicted with RCP 8.5 climate change scenario using fish occurrence data (a total of 47 species, including 17 endemic species) from 2007 to 2009 at 134 survey points and 9 environmental variables (monthly lowest, highest and average air temperature, monthly precipitation, monthly lowest, highest and average water temperature, altitude and slope). The fitness of MaxEnt modeling was successful with the area under the relative operating characteristic curve (AUC) of 0.798, and environmental variables that showed a high level of prediction were as follows: altitude, monthly average precipitation and monthly lowest water temperature. As climate change proceeds until 2100, the probability of occurrence for Odontobutis interrupta and Acheilognathus yamatsuatea (endemic species) decreases whereas the probability of occurrence for Microphysogobio yaluensis and Lepomis macrochirus (exotic species) increases. In particular, five fish species (Gnathopogon strigatus, Misgurnus mizolepis, Erythroculter erythropterus, A. yamatsuatea and A. koreensis) were expected to become extinct in the Geum river watershed in 2100. In addition, the species rich area was expected to move to the northern part of the Geum river watershed. These findings suggest that water temperature increase caused by climate change may disturb the aquatic ecosystem of Geum river watershed significantly.