• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.1
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• pp.53-61
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• 2021

Distribution of fish community depends largely on environmental disturbance such as habitat change. In this study, we evaluated the impact of environmental variables and microhabitat patch types on fish distribution in Yudeung Stream at 15 sites between early May and late June 2019. We used non-metric multidimensional scaling to examine the distribution patterns of fish in each site. Gnathopogon strigatus, Squalidus gracilis majimae, Zacco koreanus, and Zacco platypus were associated with riffle and boulder areas, whereas Iksookimia koreensis, Acheilognathus koreensis, Coreoleuciscus splendidus, Sarcocheilichthys nigripinnis morii, and Odontobutis interrupta were associated with large shallow areas. In contrast, Cyprinus carpio, Carassius auratus, Lepomis macrochirus, and Micropterus salmoides were found at downstream sites associated with large pool areas, sandy/clay-bottomed areas, and vegetated areas. On the basis of these results, we suggest that microhabitat patch types are important in determining the diversity and abundance of fish communities, since a mosaic of different microhabitats supports diverse fish species. As such, microhabitat patches are key components of freshwater stream ecosystem heterogeneity, and a suitable patch composition in stream construction or restoration schemes will support ecologically healthy food webs.

• Fisheries and Aquatic Sciences
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• v.25 no.7
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• pp.403-408
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• 2022

In April and June 2014, mortalities of goldfish occurred at Korea. The principal signs included pale gills, severely enlarged and softened spleen and kidney and red liver. Moreover, the histopathological characteristics observed mainly in hematopoietic tissues of kidney, gill lamellae and intestine. The predominant histopathological changes were severe necrosis of hematopoietic tissue. In addition, nucleus exhibiting peripherally displaced chromatin were particularly abundant in the kidney of affected fish. The histological examination led to hypothesize the implication of a virus in the mortality. The hematopoietic necrosis herpesvirus (Cyprinid herpesvirus 2, CyHV-2) DNA polymerase gene successfully detected in DNA extracted from kidney and spleen of affected fish using PCR assay and showed 100% identity with already deposited CyHV-2 DNA polymerase gene in NCBI. Artificial infection trials using affected tissues filtrates gave cumulative mortalities of 30% for virus injected goldfish. In the present study, CyHV-2 was detected and identified as the causative pathogen of the epizootic in goldfish in Korea.

• Journal of Marine Life Science
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• v.1 no.1
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• pp.41-49
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• 2016

Kisspeptin (Kiss) and its cognate receptor, kisspeptin receptor (KissR; G protein coupled receptor 54, GPR54), have recently been recognized as potent regulators of reproduction in teleosts. Additionally, leptin plays an important role in energy homeostasis and reproductive function in teleosts. The purpose of this study was to examine differences in the concentration of the hormones of the Kiss/KissR system and leptin and the expression of their underlying genes, all of which are involved in the sexual maturation of female goldfish, Carassius auratus, following treatment with Kiss. The expression levels of KissR increased after the Kiss injection. Furthermore, the peptide hormone leptin also increased after the injection (in vivo and in vitro). Additionally, the expression of GnRH and GTHs (GTHα, FSHβ, and LHβ) increased in the brain and pituitary (in vitro and in vitro). These results support the hypothesis that Kiss plays important roles in the direct regulation of the hypothalamus-pituitary-gonad axis and leptin in goldfish. Therefore, we suggest that Kiss system gene expression is correlated with energy balance and reproduction.

• Parasites, Hosts and Diseases
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• v.38 no.1
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• pp.9-15
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• 2000

A scanning electron microscopic study was performed on the surface ultrastructure of metacercariae and adults of Metagonimus takahashii. Metacercariae were collected from the scale of crucian carp (Carassius auratus) , and adult flukes were harvested 1-4 weeks after infection to rats. In excysted metacercariae. the oral sucker had type I (numerous) and type II (seven in total) sensory papillae. Tegumental spines were dense and digitated into 5-7 points on the surface anterior to the ventral sucker, but became sparse and less digitated posteriorly toward the end of the body In adults, seven type II sensory papillae were characteristically arranged around the lip of the oral sucker, and on the inner side of the lip four small and two large type I sensory papillae were symmetrically seen on each side (12 in total). Tegumental spines on anterior two-thirds of the body. were digitated with 9-12 tips ventrally and 8-13 tips dorsally. Sperms entering into the Laurer's canal were observed. The results show that the surface ultrastructure of M. takuhashii is generally similar to those of M. yokogawai and M. miyatai except for the digitation of tegumental spines.

• Journal of Ecology and Environment
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• v.35 no.1
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• pp.9-14
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• 2012

Yellow bitterns (Ixobrychus sinensis) are a small wetland bird common to Asian countries including South Korea, Japan, and China. The aim of this study is to describe diet of yellow bitterns during the breeding season in artificial wetland of northeastern South Korea between May to August 1999-2001. For the purposes of this paper, we observe the frequency of nest visiting by parents during the chick rearing period. A total of 98 boluses regurgitated by 52 chicks aged 1 day to 11 days after hatching form the sample and are shown to contain 323 food items. A bolus contained mean 3.8 items and weighs 0.2 g to 7.7 g. The most regularly occurring food items recorded are fish (63%) and insets (33%). In terms of fish, top mouth minnows (Pseudorasbora parva) and crucian carps (Carassius auratus) are frequently observed. In terms of insects, there are mosquitoes (Diptera), instars of dragonfly (Libelluidae), damselflies (Coenagrinonidae) and water bugs (Diplonychus japonicus). Yellow bitterns were also shown to feed on bull frogs (Rana catesbeiana), shrimp (Palaemonidae), and spiders (Araneae). The size of fish in a bolus ranged from 15.56 mm to 93.73 mm (mean, 37.08 mm). The amount of food can be observed to increase with the age of chicks (r = 0.279, P = 0.025, N = 64) but parents did not provide larger fish as chicks grew. Parent birds visited nests more frequently when they have a larger brood ($F_{1,21}$ = 14.529, P = 0.001). Our results suggest that fish is the most important prey during the breeding season and that age of chicks is related to amount of diet in yellow bitterns.

• The Korean Journal of Ecology
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• v.12 no.1
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• pp.51-65
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• 1989

Some aspects of limno-biology of the five dammed lakes such as Tamyang, Changsong, Kwangju, Naju, and Youngsan Lake along the Yongsan River were investigated from June 1986 to July 1988 for the comparison on the lentic ecosystems in relation to the fish fauna. Sixty four fish species representing 48 genera and 21 families of fishes were collected in these dammed areas, which included 29 species of the family Cyprinidea and 40 speaies of the primary fresh-water fishes. Among, these, 12 species such as Rhodeus Acheilognothus yamatsutae, A canathorhodeus gracilis, Sarcocheilichthys nigripinis morii, S. variegatus wakiyae, Gnathopogon strigatus, Squalidus gracilis majimae, Microphysogobio yaluensis, Cobitis longicorpus sp, Liobagrus mediadiposalis and Odontobutis platycephala are enddmic to Korea. Leiocassis nitidus and Gasterosteus aculeatus which occur in these water areas take note of the zooge rographic study of Korea. The fish species in each of the dammed lakes is in proportion of the scale of the lakes such as 32 species in Thamyang, 40 species in Changsong, 24 species in Kwangju, 35 species in Jaju, and 52 species in Yongsan Lake. The dominant fish species of the 4 upper dammed lakes of Thamyang, Changsong, Kwangju and Naju Lake are Zacco platypus and Rhodeus uyekii, while those of Youngsan Lake are Hemiculter eigenmanni and Carassius auratus. This difference of fish species of those areas suggests that the upper damed lake differ from the lower dammed lakes in the habitable condition of fishes. The migratory fish species have significantly declined and will continue to decline in both population size and number of species in the dammed lakes in near future as a result of the dam construction barriers in the river estuary. The major migratory fishes of this water area are as follows; Anguilla japonica, Plecoglossus altivelis, Hypomesus olidus, Gasterosteus aculeatus, Konosirus Punctatus, Coilia ectens, Hemirhampus sajori, Mugil cephalus. Acanthogobius flavimanus, and Takifugu ocellatus.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.173-183
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• 2005

The ichthyofauna and community structure in the Chuncheon Reservoir, Korea, were investigated from August 2003 to April 2004. The total number of fish caught from the period was 10,821 fish representing 41 species and 13 families. There were 16 Korean endemic species, including Hemibarbus mylodon, Acheilognathus yamatsutae and Odontobutis platycephala. Dominant species was Hypomesus olidus $(30.69\%) $ and subdominant species was Hemibarbus labeo $(14.70\%)$. Also, Zacco platypus $(10.57\%)$, Zacco temminckii $(9.66\%)$, Micropterus salmoides$(4.81\%)$, Rhinogobeus brunneus $(4.28\%)$ and Microphysogobio yaluensis $(3.10\%)$ were numerous. The biomass of collected fishes were Hemibarbus labeo (34.63 kg), Hypomesus olidus (19.01 kg), Cyprinus carpio (12.77 kg), Opsariichthys uncirostris amurensis (11.28 kg), Zacco platypus (8.04 kg). Among the 7 introduced fishes in Chuncheon Reservoir Carassius cuvieri, Hypophthalmichthys molitrix and Micropterus salmoides were originated from foreign countries, and others (Anguilla japonica, Hypomesus olidus, Oncorhynchus masou mason and Chaenogobius urotaenius) were introduced from other native river systems.

• Parasites, Hosts and Diseases
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• v.56 no.5
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• pp.509-513
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• 2018

Present study was performed to survey infection status of digenetic trematode metacercariae in 2 alien fish species, Micropterus salmoides (largemouth bass) and Lepomis macrochirus (bluegill), in 2 rivers draining Chungcheongbuk-do, Republic of Korea. A total of 107 largemouth bass and 244 bluegills were caught in Daecheong-ho (ho=lake) and Musim-cheon (a branch of Geum-gang), in Chungcheongbuk-do April-July 2015. Additionally, 68 native fish of 5 species, i.e., Zacco platypus, Hemibarbus longirostris, Carassius auratus, Pseudogobio esocinus and Puntungia herzi, were caught from the same water bodies. All of the fish collected were examined by artificial digestion method. The metacercariae of Centrocestus armatus, Clinostomum complanatum, Metagonimus sp. and Diplostomum spp. were detected from 4 out of 5 native fish species in Daecheong-ho. However, any metacercariae were not found from 87 M. salmoides and 177 L. macrochirus in Daecheong-ho. In Musim-cheon, metacercariae of Exorchis oviformis and Metacercaria hasegawai were detected from 78% Z. platypus and 34% L. macrochirus, but any metacercariae not found in M. salmoides. We report here that the 2 alien fish species were less infected with the metacercariae than the native ones. Surveys on the metacercariae in the alien fish species in geographically various rivers should be undertaken for better understanding on the role of alien fish species in the trematode infections in Republic of Korea.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.934-942
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• 2010

Bentic macroinvertebrate and fish fauna were investigated from September 2008 to October 2009 in the middle reach of the Suyoung river in Busan. During the survey period benthic macroinvertebrates were collected total 35 species at the three sites (Hanmul-gyo, Dongcheon-gyo, Seokdae Jct.) of Suyoung river. At that sites, species diversity index was 1.9, 1.5, 1.6, dominance index was 0.75, 0.81, 0.86 and Korean Saprobic Index (KSI) was 1.8(B), 4.4(D), 4.4(D) on average, respectively. Dominant species was Caenis Kua, Chironomidae sp., at Hanmul-gyo site and Limnodrilus gotoi, Chironomidae sp., at Dongcheon-gyo and Seokdae Jct. sites. Fish fauna was also investigated at the two sites (Hanmul-gyo and Seokdae Jct.) of Suyoung river. Total caught fishes were 10 species 32 individuals in the first survey and 6 species 26 individuals in the second survey. Dominant species was Carassius auratus in the both surveys. Index of Biological Integrity (IBI) value was C grade at the Hanmul-gyo and D grade at the Seokdae Jct.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.225-230
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• 1989

Infectious Pancreatic Necrosis Virus (IPNV) is one of the most important pathogens for inland fish farming and had been first reported in Korea from returning adult chum salmon (Oncorhynchus keta) at hatcheries on the east coast. During the past years, several viruses identified as IPNV were isolated not only from chum salmon, but also from gold fish (Carassius auratus), eel(Anguilla japonica), and rainbow trout (Salmo gairdneri). An isolate, coded DRT, from fingerlings of pan-cultured rainbow trout in Daechung Dam showed different serotype from three known reference serogroups of IPNV such as VR-299, Sp, and Ab. Antisera to three of these serotypes, however, partially neutralized the infectivity of this isolate. Anti-Sp type was rather effective than either anti-VR-299 or anti-Ab, implying DRT could be more closely related to Sp. DRT has been purified and its RNA genome segments were compated showing that the isolate does not belong to any of known serogroups even with some common antigenicity.