• Korean Journal of Ichthyology
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• v.18 no.2
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• pp.112-118
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• 2006

The ichthyofauna and fish community structure were investigated at eleven stations in Namdae stream, Yangyang during April, 2004 and March 2005 monthly. During the surveyed period thirty five species belonging to fifteen families were collected. Dominant species in number was Triboblodon hakonensis (relative abundance : 27.9%) and subdominant was Zacco koreanus (15.0%). There were five Korean endemic species including Rhynchocypris kumgangensis. Eleven species including Pungtungia herzi are first recorded in this study. There are stabilized fish community structure with dominant species R. kumgangensis in upstream, Z. koreanus and Z. platypus in midstream and T. hakonensis in downstream respectively. But, it is very worried the change of ichthyofauna in foreseeable future because of pumped storage power station construction in midstream.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.4
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• pp.267-271
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• 2008

We experimentally determined the physico-chemical properties of seminal plasma as well as the sperm cryopreservation techniques of masou salmon, Oncorhynchus masou masou. Seminal plasma contained $18{\pm}1mmol/L$ potassium, $144{\pm}4mmol/L$ sodium, $116{\pm}3mmol/L$ chloride, $83.2{\pm}3.1mg/L$ calcium, $14.8{\pm}0.7mg/L$ magnesium, $45{\pm}9mg/L$ glucose, and $1.0{\pm}0.0g/L$ total protein. The osmolality and pH of seminal plasma were $287{\pm}7\;and\;7.7{\pm}0.1mmol/kg$, respectively, and the spermatocrit was $28{\pm}2$. The rate of embryonic survival at the eyed-stage and the hatching rate were highest in 10% methanol with 300 mM glucose. Compared to DMSO or glycerol, methanol served as a better cryoprotectant of masou salmon sperm.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.383-384
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• 2001

The tonguefish, Cynoglossus robustus and C. abbreviatus (Order Pleuronectiformes, Family Cynoglossidae), inhabits on soft and sand mud bottoms at depth of 20∼85 m around Korea, China and Japan(Nakabo, 1993; Okamura et al., 1970). The tonguefishes are economically important species and are relatively abundant among the fishes found in the Seto Inland Sea(Inaba, 1963: Inaba, 1988). (omitted)

• Korean Journal of Ichthyology
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• v.31 no.2
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• pp.90-100
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• 2019

This study was carried out from March to November, 2013 to investigate the fish community structure and distribution characteristics of Phoxinus phoxinus and Rhynchocypris kumgangensis appearing in Gihwacheon Stream, Pyeongchang. A total of 6 families and 19 species of fish emerged during the survey period. The dominant species were R. kumgangensis (Individuals 44.7%, Biomass 30.2%) and P. phoxinus (Individuals 27.7%, Biomass 15.9%). Endemic species were 10 species including Pseudopungtungia tenuicorpus, Coreoleuciscus splendidus, Hemibarbus mylodon, Gobiobotia brevibarba, Microphysogobio longidorsalis, R. kumgangensis, Zacco koreanus, Korecobitis rotundicaudata, Iksookimis koreensis and Coreoperca herzi. Endogenous species were P. tenuicorpus, G. brevibarba and P. phoxinus. Hemibarbus mylodon was a natural monument. Oncherhynchus mykiss was exotic species and translocated species was Oncorhynchus masou masou. The dominant species, R. kumgangensis, appeared at all survey sites. Except for St.6, the b value was more than 3.0 and the slope of K value showed positive correlation. P. phoxinus appeared in St. 3~St. 6 and St. 3 and St. 4 only showed stable populations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.4
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• pp.338-343
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• 2006

Histological observations of the barbels of torrent catfish (Amblycipitidae) in Korea are reported. The bullhead torrent catfish (Liobagrus andersoni) and Korean torrent catfish (L. obesus) have eight obvious barbels in two pairs each on the maxilla and mandible. Each barbel is composed of an epidermis, dermis, and central cartilagerod. The epidermis of the maxillary and mandibular barbels of the bullhead torrent catfish is thicker than that of the Korean torrent catfish (P<0.05) and is formed of stratified epithelium that contains many cutaneous taste buds and a few small club cells. There are many taste buds on the upper part of each barbel. The dermis consists of loose connective tissue fibers that enclose blood vessels and bundles of nerve fibers. The barbels of these fish can be categorized into stiff and flexible types and are accessory, feeding, and sensory structures. Our results validate the barbels as gustatory receptor organs for these fishes.

• Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.89-92
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• 2011

We investigated the antioxidant and cholinesterase inhibitory activities of the aqueous extract of rainbow trout Oncorhynchus mykiss. The antioxidant activity of O. mykiss aqueous extract was determined by in vitro peroxynitrite scavenging activity and reducing power assays. The aqueous extract of O. mykiss showed potent peroxynitrite radical scavenging activity ($IC_{50}=0.12{\pm}0.001\;mg/mL$) and reducing power (absorbance=$0.47{\pm}0.001$) at the concentration of 1 mg/mL. The in vitro cholinesterase inhibitory activity of O. mykiss aqueous extract was examined using spectrophotometric analyses of acetyl- and butyrylcholinesterase. The aqueous extract of O. mykiss showed acetylcholinesterase inhibitory activity ($IC_{50}=1.61{\pm}0.13\;mg/mL$), but did not exhibit inhibitory activity against butyrylcholinesterase. These results suggest that O. mykiss possesses antioxidant and acetylcholinesterase inhibitory activities and provide scientific evidence for the health benefits of O. mykiss aqueous extract.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.3
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• pp.182-187
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• 2008

Nine biochemical characteristics of female Oncorhynchus keta subpopulations that migrate to three streams (Namdaechun, Myeongpachun, Oshipchun) in Gangwon, Korea, were evaluated during November 2006: aspartate aminotransferase, alanine aminotransferase, creatine kinase, triglyceride, cholesterol, glucose, hemoglobin, and urea in the blood and RNA/DNA in muscle. The three subpopulations were identical morphologically, but differed in their biochemical characteristics. The RNA/DNA ratio could be useful for distinguishing the subpopulations. RNA/DNA ratios of the Namdaechun and the Myeongpachun and Oshipchun subpopulations were $3.52{\pm}0.7$ and $2.9{\pm}0.7$ and $2.4{\pm}0.8$, respectively. The difference was statistically significant (P<0.05). By contrast, the blood parameters were somewhat ambiguous.

• The Korean Journal of Malacology
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• v.31 no.3
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• pp.171-178
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• 2015

The reproductive ecology of freshwater bivalve, Unio douglasiae in Lake Uiam were examined from March 2014 to February 2015. The gonads distributed in reticular connective tissue, the dioecious clams take an internal fertilization and fertilized eggs are stored in the foster-sack in the gills, then the hatched juveniles are released outside after an ovoviviparous process. The gonad index (GI) began to increase in April, reached the maximum value in July and to decrease in August. The reproductive cycle of U. douglasiae can be divided into five successive stages: multiplicative stage (November to January), growing stage (February to March), mature stage (February to May), spawning stage (April to September), recovery stage (August to December). The spawning periods were from April to September, and the main spawning occurred between April and July. The shell length at 50% group maturity was estimated to be 29.4 mm.

• Korean Journal of Ichthyology
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• v.17 no.4
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• pp.264-270
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• 2005

The ichthyofauna and fish community structure were investigated at three areas in Lake Chungju from April to October 2004. During the surveyed period,32 two species belonging to 12 families were collected. Dominant species in number was hemibarbus labeo (relative abundance : 23.2%) and subdominant was Erythroculter erythropterus (12.1%). Siniperca scherzeri (9.2%), and Pseudogobio esocinus (8.6%) were also numerous. There were nine Korean endemic species belonging to six families including Acheilognathus yamatsutae. The number of fish species collected was 28 in Danyang, 17 in Jecheon, and 15 in Chungju. Highest dominant index calculated was 0.670 in Chungju, and highest diversity index calculated was 2.442 in the Danyang area. We need closer observation of population fluctuation of some species, including H. labeo, the dominant species by biomass in Lake Chungju.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.198-209
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• 2008

During studies of the fish fauna and communities of Mankyeong River, which flows to the Yellow Sea, 14 families in 44 genera and 63 species of freshwater fishes were caught. Zacco platypus (27.7%) was the dominant species and Z. koreanus (11.3%) the subdominant species in this river. Twenty-three species of Korean endemic fishes appeared, and two of these, Pseudopungtungia nigra and Liobagrus obesus, represented endangered Korea species. Community structure of each branch stream was stable, showing appropriate dominant species: Z. koreanus in Jeonju Stream, Z. platypus in Kosan and Soyang Streams, and Carassius auratus in Mankyeong main stream. Three introduced species appeared: C. cuvieri, Micropterus salmoides, and Lepomis macrochirus. Among these introduced species, M. salmoides expanded its territory from midstream to downstream because of its strong carnivorous tendency and it favoring of lentic waters. This distribution of M. salmoides affected the number and distribution of small native freshwater fishes, especially those in the subfamily Acheilognathinae.