• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.126-133
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• 1999

Ultrastructure of the zona radiata and the micropyle of ripe eggs in the rainbow trout (Oncorhynchus mykiss), catfish (Silurus asotus) and loach (Misgurnus anguillicaudatus) were examined by light, scanning and transmission microscopes. The egg micropyle of rainbow trout and catfish consists of a funnel-shaped vestibule and a tapered canal transversing the zona radiata. The micropyle of rainbow trout and catfish showed the similar structure with flat pit and long canal. The micropylar wall showed the clockwise spiral structure in rainbow trout. The micropyle of the loach showed the type with a hollow pit leading into a short canal and the micropylar wall showed the counterclockwise spiral structure. There are numerous and various size pores at the surface area around the opening in every experimented fish. Interconnecting ridges were observed in the unfertilized eggs of every fish.

• Journal of fish pathology
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• v.7 no.2
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• pp.95-103
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• 1994

We have prepared cDNA libray of loach. M. mizolepis in order to isolate cDNA clone of growth hormone gene. Total RNA was isolated from pituitary of loach, and then mRNA was further purified from total RNA by oligo (dT)-coupled magnetic beads. The purified mRNA was used as substrates to prepare cDNA. The resulting cDNA was ligated into the EcoRV/Smal site of pBlueKS+. The ligation mixture have transformed E. coli JM109 strain with electroporator to obtain high yield of transformation efficiency. All the transformants was screened with DIG-labeled Tilapia growth hormone gene by high density colony hybridization. After isolating 10 putative colonies showing the positive signals, secondary colony hybridization and southern hybridization could confirm it as true clones. The nucleotide sequence of one candidate, pCGHI, was compared with 312 bp DNA fragment used as DNA probe and show 52% relative homology to Tilapia growth hormone gene.

• Korean Journal of Ichthyology
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• v.23 no.1
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• pp.70-74
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• 2011

During the winter, the rice field-dwelling muddy loach Misgurnus mizolepis is buried in burrows constructed of mud and are subjected to exposure to air at times of shortage of water. To investigate the environmental factors that lead to changes of the skin mucus cells of the muddy loach in rice fields, we carried out an experiment where we artificially exposure the fish to air, duplicating as close as possible winter conditions in nature. During the summer, a water tank containing M. mizolepis was filled with mud, and the water was allowed to evaporate. After a month of evaporation, the loach constructed burrows similar to those in a winter rice field. The epidermis in the experimental fish was mostly occupied by large elongated mucus cells, whose numbers drastically increased in all observed regions of the dorsum, lateral region, and the occiput. Such features are typically seen in fishes in wild habitats during the winter season.

• Journal of Aquaculture
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• v.8 no.3
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• pp.241-249
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• 1995

Sperm from mud loach (Misgurnus mizolepis) were electroporated in the presence of plasmid DNA, pRSV/luc or pMT/hGH over a range of field strength of 0-1,625 V/cm with capacitance from 0 to 1,000 ${\mu}F$, and the effects of electroporation on fertilization, hatching, early survival, and efficiency of gene transfer were investigated. Average fertilization rate, hatching rate and early survival rate up to yolk sac absorption of all experimental groups were not significuntly different (P>0.05). The proportion of fish carrying pRSV/luc based on the polymerase chain reaction (PCR) analysis was ranged from 0 to $20\%$, however, the values of gene transfer efficiency from the different eledctroporation conditions were not significantly different. PCR analysis of pMT/hGH transferred groups revealed that screening of pMT/hGH transferred fish by PCR was difficult because of significant nonspecific amplifications resulted from the homologous sequences in the genome of mud loach.

• Applied Microscopy
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• v.41 no.3
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• pp.179-188
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• 2011

Ultrahistology of spermatogenic cells on spermatogenesis were analyzed from triploid males of the mud loach, Misgurnus mizolepis. All the testis of triploid males were smaller in thickness and shorter in length than those of diploid males, but the testes developmental stages in triploid males were very similar to those of diploid males. And cytological characteristics were also almost identical to each other. Also Sertoli cells with high activity were recognized at intralobuli of the testis in triploid males during the period of spermiogenesis. And then a few matured spermatozoa were observed in testis of triploid, and interstitial cells also appeared high active in interlobuli. But nucleus sizes of spermatogenic cells of triploid male according to developmental stages were larger than those of diploid overall. Especially, spermatozoa of triploid showed abnormal morphology such as two or more tail flagella, significantly larger head sizes, nucleus size, and diameter of axial filaments etc. than those from diploid.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.177-183
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• 1984

This study aims to find the taste compounds of wild loach, Misgurnis mizolepis, which is important fresh-water fish in this country. In order to elucidate the origin of the taste of wild loach meat, free amino acids, organic bases, nucleotides and their related compounds, organic acids, sugars and minerals were analyzed, and then followed by organoleptic test of synthetic extract prepared on the basis of the analytical data. Sensory evaluations of synthetic extracts prepared by omitting each extractive components were carried out by a triangle difference test, and changes in taste profile were assessed. In free amino acid composition, histidine, threonine, glycine, lysine, alanine were abundant. IMP and AMP were dominant in the wild loach in content. Total creatinine and butyric acid were abundant. As for the minerals, $Na^+,\;K^+,\;Cl^-\;and\;PO_4^{3-}$ were found to be the major ions. From the results of omission test of synthetic extracts the major components which contribute to produce the taste were arginine, glutamic acid, valine, aspartic acid, IMP, succinic acid, $Na^+,\;K^+,\;Ca^{2+}\;Mg^{2+}\;Cl^-\;and\;PO_4^{3-}$.

• Korean Journal of Ichthyology
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• v.18 no.2
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• pp.65-77
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• 2006

Gene transcripts potentially responsive to the heat stress were surveyed by cDNA microarray analysis in mud loach (Misgurnus mizolepis). Transcriptional profiles of hepatic tissue in the fish exposed to either $23^{\circ}C$ or $32^{\circ}C$ for 4 weeks were compared each other by 3 replicated hybridization assays using 1,124 unigene clones selected from mud loach liver expressed sequence tags (ESTs). A total of 93 clones showed the substantially increased mRNA levels (>2-fold) in $32^{\circ}C$-exposed group when compared in $23^{\circ}C$control group. It includes various enzymes and proteins involved in energy pathway, protease/protein metabolisms, immune/antioxidant functions, cytoskeleton/cell structure, transport and/or signal transduction. Maximum level of increase was up to 15-fold relative to $23^{\circ}C$ treatment. Heat exposure also resulted in the significant decrease (less than 50% relative to $23^{\circ}C$-exposed fish) of the transcriptional activities in 85 genes. Besides the above categories, yolk protein (vitellogenin) and ribosomal proteins were notably down regulated in the fish exposed to heat stress. A number of novel gene transcripts were also detected in both up-regulated and down-regulated groups.

• Korean Journal of Ichthyology
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• v.7 no.2
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• pp.187-194
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• 1995

This study was carried out to obtain fundamental data on the metabolism of hibernant fish loach, Misgurnus mizolepis. Main focus was on the compositon of muscle components and its changes in fresh - water loach before and after spawning season and before and after hibernation. Distributional changes of carbohydrate, protein and lipid in the muscle tissues were also investigated. Change patterns of miosture and crude protein, and moisture and crude lipid were in inversely proportional, i.e. : moisture amount showed the lowest value after spawnig season, the highest just after hibernation, but crude protein and crude lipid were the highest values after spawning season, and the lowest just after hibernation. Carbohydrate showed the highest value just before hibernation and tended to decrease thereafter. Muco layer of epidermis and muscle cell of hypodermis layer in loach were remarkable in its PAS dyeing degree after sapwning season, and it was presumed to include high percentage of protein or carbohydrate. Dermis layer became thinner before spawning hibernation. Lipid component in female tended to distribute relatively widely in the muscle cell layer before spawning season, but in case of male mainly in muco layer and epidermis layer. It appeared that lipid was spreaded mainly in epidermis and hypodermis tissue after spawning season, while it prevailed in almost all tissues but tended to decrease after hibernation.

• 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.

• Korean Journal of Ichthyology
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• v.32 no.4
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• pp.232-238
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• 2020

The objective of the present study was to investigate fish farm and growth performances of Chinese muddy loach (Misgurnus mizolepis) under indoor and outdoor aquaculture conditions for the domestic loach aquaculture industry. The investigation was conducted from August 2017 to October 2019 at one indoor farm (D-site) and two outdoor farms (P1-site and P2-site). Results showed that WG (weight gain), DWG (daily weight gain), and SWG (specific weight gain) based on growth measurements were 175.27±36.2%, 7.98±3.3%, and 0.94±0.2% at D-site, 320±34%, 4.07±0.6%, and 0.55±0.1% at P1-site, and 295.9±53%, 4.15±0.5%, and 0.62±0.1% at P2-site, respectively. WG was higher in outdoor farms (P1-site and P2-site), while DWG and SWG were higher in the indoor farm (D-site). Such differences of the present study might be due to differences in growth, water quality, plant and sale frequency depending on aquaculture types. In particular, outdoor farms takes more than a year to have sales whereas indoor farms can have sales three times in a year.