• Journal of Wetlands Research
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• v.16 no.2
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• pp.187-192
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• 2014

This study is on the characteristics of habitat use of Pheasant-tailed Jacana Hydrophasianus chirurgus in Upo-wetland from June to August in 2013. The purpose is population management of Pheasant-tailed Jacana. Four nests were founded which are located in $56.2{\pm}16.37m$ from the waterside. Pheasant-tailed Jacana made their nests above Euryale ferox which consists with water plants such as Salvinia natans, Spirodela polyrhiza, Ceratophyllum demersum, Hydrocharis duvia and so on. Human beings seem to be the biggest obstacle of their breeding, according to this, Pheasant-tailed Jacana moved their eggs. Only two out of four nests, they moved their eggs and the distance was 1 to 2 meters from the nests. Since plant community of Euryale ferox is extensively distributed and water level also keep stable in Upo-wetland, the number of Pheasant-tailed Jacana coming to Upo-wetland is expected to increase every year. In the past, the number of Pheasant-tailed Jacana coming to Korea was too little to include management plan, but now, we need to manage them because of their population growth and the regular advent.

• Korean Journal of Environment and Ecology
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• v.19 no.2
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• pp.177-187
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• 2005

Fish fauna of mountain streams in the Odaesan National Park area was investigated from May to October 2004. A total of 2,580 individuals were collected and classified into 26 species belonging to 9 families at the 25 sites. There were 8 Korea endemic species $(30.77\%)$, including Pseudopungtungia tenuicorpa, Silurus microdorsalis, Coreoperca herzi. Exotic species, Oncorhynchus mykiss was collected in this survey. Dominant species were Rhynchocypris kumgangensis $(37.17\%)$, and subdominant species was Rhynchocypris steindachneri$(23.02\%)$. Also Zacco platypus, Zacco temmincki, Oncorhynchus masou masou, Brachymystax lenok tsinlingensis, and Ladislavia tazanowskii were numerous. In spite of the geographical isolation by Taebaek-sanmaek, 8 species were introduced from the Han River systems to eastern water systems in Odaesan National Park.

• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.235-245
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• 2007

Toxicity of nonlyphenol (NP) one of EDCs was studied with focus on reproduction of the crucian carp, Carassius auratus. Fishes were cultured under control and nonylphnol exposure conditions for 32 weeks. Experimental group was composed of total of 4 groups, 1 control condition and 3 nonylphenol exposure condition ($18\;{\mu}g\;NP\;L^{-1},\;37\;{\mu}g\;NP\;L^{-1}\;and\;83\;{\mu}g\;NP\;L^{-1}$). Survival rate was found to be similar in control and $18\;{\mu};NP\;L^{-1}$. However, it is lower In the $37\;{\mu};NP\;L^{-1}$ and $83\;{\mu};NP\;L^{-1}$ in comparison to the control group. Deformation of gonads was the highest in the exposure condition of $18{\mu};NP\;L^{-1}$ with the female illustrating higher ratio than the male. GSI was not much different in the male but in the female, NP exposure group illustrated lower value compared to the control group. HSI and GI did not illustrate any clear differences between the control and exposure group for both male and female. Intersex was 0% in the wild group, 4.16% in the laboratory control group, and 25.67% in the NP exposure condition with female illustrating higher compared to male. Concentration of blood vitellogenin in female illustrated no clear differences between the control and NP exposure group. However, in the male, it was higher in the NP exposure group in comparison to the control group, and illustrated higher values of vitellogenin compared to the figures found in the female of same con-centration condition.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.289-300
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• 2013

In this study, two types of wetland plants, Eichhornia crassipes (a floating plant) and Ceratophyllum demersum (a submerged plant) were introduced to wetland mesocosms to understand how the water properties of wetlands such as pH, dissolved oxygen content, water temperature, oxidation reduction potential, and nutrient concentrations are affected by different types of wetland plant. The floating plant lives on the water surface and can block light penetration; it exhibited the lowest water temperature and temperature difference between lower and upper layers. After the addition of contaminants, the dissolved oxygen (DO) concentration decreased abruptly but recovered continuously in all mesocosms; especially the submerged plants, which photosynthesize in water, showed the largest increases in DO and diel periodicity DO, as well as in pH value. The oxidation-reduction potential in both water and sediment were affected by the presence of wetland plants and plant type and the results suggest that various aspects of wetland biogeochemistry are affected by the presence and type of wetland plants. The total nitrogen and phosphorous concentrations in water decreased in the following order: Water only < Water + Soil < Floating Plants < Submerged Plants. Although both floating and submerged plants can control algal concentrations, the effect was more prominent for floating plants.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.1-6
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• 1998

An epidemiological survey was carried out to determine the first intermediate host of Clinostomum complanatum among freshwater snails in Korea. Two species of snails belonging to the family Lymnaeidae were collected in Kaum-ji (pond) , Uisong-gun, Kyongsangbuk-do. Twelve (0.9%) out of 1,273 Radiae auricularia corecna examined were found to liberate cercariae of C. complcnatum, which were identified by morphologital characteristics and experimental infections in freshwater fish, Pseunorosborc pnnjc. The cercariae were brevifurcate and clinostomatoid. They had a transparent dorsal fin, a well developed penetrating organ and a pair of eye spots. The body measured $119-147{\;}{\times}{\;}33-36{\mu\textrm{m}}$, tail stem, tailstem은 $275-370{\;}{\times}{\;}19-26{\;}{\mu\textrm{m}}$, and furcae, $72-104{\;}{\mu\textrm{m}}$. Rediae were demonstrated in the infected snail after crushing. Redia, $527-1,630{\;}{\mu\textrm{m}}$ long and 121-368${\;}{\mu\textrm{m}}$ wide, contained 10-45 germ balls and cercariae in various developmental stapes. The metacercariae recovered from fish experimentally infected with C. complanntum cercariae were morphologically identical to those from naturally infected fish.

• Parasites, Hosts and Diseases
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• v.25 no.1
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• pp.51-58
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• 1987

Tegumental ultrastructures of Echinochasmus japonicus were observed by scanning electron microscopy. The worms were recovered from albino rats which were experimentally infected with the metacercariae obtained from Pseudorasbora parva. Followings are summarized findings. 1. The worms were minute and plumpy gourdshaped with attenuated anterior and round posterior end. The tegument of whole body was wrinkled transversely and covered with cobblestone-like cytoplasmic processes. 2. Head crown was armed with 24 collar spines which were embedded in cytoplasmic pockets. The spines were arranged in a row with an interruption at dorsomedian line, however, the 2nd and the 4th spines were outstretched more than others. Oral and ventral suckers were muscular with numerous type II sensory papillae, and genital pore opened between the two suckers. 3. Tegumental spines were spade-shaped with broad base and pointed tip. They were compact in ventra-lateral tegument or dorsal surface of anterior body. They were not found between the two suckers and dorsal surface of posterior body. 4. Two types of sensory papillae, uni-ciliated (Type I) and roundly swollen sensory papillae (Type II), were observed. The type I papillae were chiefly distributed on ventral surface of tegument and type II were on the lips of suckers. Arrangement of collar spines, shape and distribution of tegumental spines or sensory papillae are regarded as characteristic features of E. japonicus.

• Parasites, Hosts and Diseases
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• v.31 no.4
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• pp.331-340
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• 1993

This study investigate the epidemiological feature of Metagonimus infection in Kangwon-do (province). The average Infection rate of the surveyed inhabitants was 7.8% (83 positives out of 1, 067 examinees) by stool examination; male, 11.4% and female, 3.2%, respectively. The egg positive rate in residents in the Som river area was 7.3%, that of the Chuchon river area 6.3%, the Pyongchang river area 12.8%, the Tong river area 3.8%, the Hongchon river area 9.8%, and the Ohsip stream area of Samchok 8.0%,respectively. The average metacercarial infection rate of genus Metagonimus in the fish was 81.0% (256 positives out of 318 fish). The infected fleshes were Zacco platypus. Zacco teminki, Opswiichthys biens, Squdidis sp., Corqssius carassius, etc. in western Kangwon-do Meanwhile, in the Ohsip stream area of Samchok-gun, eastern costal Kangwon-do, the infected fish were Plecoglossus altivelis and Tribolodon hokonensis. The rats and dogs are infected with the metcercanae obtained from Zacco platypus and Opsariichthys biens, adult worms collected were Miyata type of Metagonimus with some M. takahashii. When infected with metacercariae from Plecoglossus ltivelis, Metagonimus yokogowai was only found. M. yoogawai and Metagonimus Mlyata type were fecund together in Tribolodon hakonenis in Ohsip stream area of Samchok, in the eastern Kangwon-do. The intestinal flukes of genus Metogonimus in western Kangwon-do were Miyata type of MetQnonimuT and M. takahashii transmitting mainly by Zacco platypus and Opsariichtys bidens as a source of infection. In the eastern part of Kangwon province (Ohsip stream area of Samchok), M. yokogowai was mainly distributed by P. altivelis and T. hakonesis, but some T. hakonensis harbored the metacercariae of Miyata type of Metagonimus with those of M. yokogawai.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.308-319
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• 2016

In order to evaluate the role of macrophytes as refuge of zooplankton on physical distribution (i.e. summer rainfall), we investigated the environmental factors, macrophytes, and zooplankton in waterside zones (macrophytes zones) and open water zones of 17 wetlands from May and August, 2011. In this study, a total of 51 zooplankton species were identified, and Polyarthra sp. and Diaphanosoma brachyurum were found to be the most dominant species. Waterside area of each wetland were occupied by a total of 10 macrophyte species, species composition and biomass (dry weight) were different in the survey sites. Zooplankton was more abundant in waterside zone than open water zones lacking macrophytes (One-way ANOVA, df=2, F=27.1, P<0.05), in particular, waterside zone of 1, 8, 9, 10, and 11 wetland were supported by high zooplankton density after summer rainfall. This wetlands were developed by various macrophyte species than other wetland, and submerged plant commonly presented. Waterside zones with various macrophyte species provides complexity to the habitat structure, should be utilized as refuge to avoid disturbance such as summer rainfall. The results indicate that macrophytes are the key components to enhance bio-diversity include zooplankton, and the inclusion of diverse plant species in wetland construction or restoration schemes will result in ecologically healthy food webs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.466-469
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• 1999

Cladocera are important food organism for seed production of finfishes. freshwater cladocera such as Daphnia and Moina are well known food organisms for the larval rearing of freshwater fishes and are easy for mass culture. However, mass culture technique for marine cladocera are not yet developed, The only mass produced food organisms available these days for the larval production of marine finfishes are rotifer and Artemia. An estuarine cladoceran, Diaphanosoma celebensis, has a high possibility of being used as a food organism for the larval rearing of marine finfishes because this species is much easier to mass culture than marine ones. Therefore many studies are needed for this species. In this study, the effects of the volumes of culture container, 40, 1,500 and 15,000 ml, on the stable production of this species were tested and results are as follow: The maximum densities of this species in each of the culture volumes were reached after 14 days in 40 ml, 12 days in 1,500 ml, and 21 days in 15,000 ml with values of 3.4 $\pm$ 0.4, 14.2 $\pm$ 2.1 and 2.5 $\pm$ 1.6 per ml, respectively. The relative population growth index (RPGI) was stable in the culture volume of 1,500 ml. Moreover, possible harvesting number(individual/ml/day) was much higher in the 1,500 ml container than the other culture volumes. Therefore, optimum culture volume among the tested volumes for mass production of this species was 1,500 ml.

• Journal of Marine Life Science
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• v.4 no.2
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• pp.70-80
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• 2019

Ichthyofauna and community structure of fish were studied for two fisheries resource reserves, Chuncheon reservoir and Andong reservoir from 2017 to 2018. Fish were sampled 8 times at each reservoir. In Chuncheon reservoir, total number of fish sampled was 1,197 representing 34 species and 13 families. Dominant species and sub-dominant species were Lepomis macrochirus (23.2%) and Zacco platypus (17.4%), respectively. In Andong reservoir, total number of fish sampled was 1,393 representing 24 species and 9 families. Dominant species and sub-dominant species were L. macrochirus (15.7%) and Carassius carassius (15.2%), respectively. The diversity index of two sampling site increased compared to previous investigation. The evenness index was not changed much in Andong reservoir but increased in Chuncheon reservoir. Ichthyofauna and community structure of fish at sampling sites in both reservoirs maintained stable except high proportion of exotics species with needed to be reduced by consistent effort. For better fish population in these communities, however, various efforts such as seed stocking and installment of artificial spawning ground should be provided to these reservoirs.