• Development and Reproduction
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• v.22 no.1
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• pp.1-8
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• 2018

The annual reproductive cycle of the Korean endemic slender catfish, Silurus microdorsalis, was examined histologically regarding water temperature and day length of habitat, gonadosomatic index (GSI), and development characteristics of female and male gonads. The maximum GSI value was found in May, $1.23{\pm}0.33$ and $11.77{\pm}3.23$ for male and female respectively (habitat water temperature $21.5^{\circ}C/13.59hr$ day length). On the other hand, the minimal level was $0.63{\pm}0.10$ in July ($26.5^{\circ}C/14.17$) for male and $1.36{\pm}0.08$ in October ($20^{\circ}C/11.2hr$) for female. We compared and calculated the stages of testis and ovary development process in order to determine the germ cell development characteristics and the reproductive cycle. According to results, we classified the annual reproductive cycle of the slender catfish into five stages: Growing phase (December-February), Mature phase (March-April), Ripe and spawning phase / Releasing phase in male (May-June), Degenerative phase (July-August), and Resting phase (September-November).

• Korean Journal of Environment and Ecology
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• v.15 no.4
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• pp.401-407
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• 2002

Fishfauna were investigated in the Taebaeksan area streams. At the upper tributary of the Han River, 8 species of 4 families were collected and the dominant species was Rynchocypris oxycephalus. The two species, Rynchocypris kumgangensis and Silurus microdorsalis were Korean endemic species. Brachymystax lenok tsinlingensis, designated as a natural monument and vulnerable species was confirmed at the Jeongam-sa area streams At the upper streams of the Nakdong River, collected fishes were identified as 14 species of 7 families. The dominant Species was R. oxycephalus and subdominant Zacco temmincki. Korean endemic species were 8species(51.7%), Coreoleuciscus splendidus, Squalidus gracilis majimae, Microphysogobio yaluensis, Niwaella multifasciata, Silurus microdorsalis, Liobagrus mediadiposalis, Coreoperca herzi and Odontobutis platycephala. Brachymystax lenok tsinlingensis were confirmed at the Hyundong-Chon Stream and Baek-chon stream.

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.550-551
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• 2006

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.174.1-174
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• 2000

No Abstract, See Full Text

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.274-281
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• 2000

The dynamic of fish community was investigated in the Wonju stream from March 1998 to February 1999. The collected species during the surveyed period were 24 species belonging to eight families. Eight species (33%) of them were endemic species of Korea. According to relative abundance in the studied areas, Moroco oxycephalus (30.7%), Zacco platypus (29.6%), Carassius auratus (10%), Pseudogobio esocinus (9.4%) and Rhinogobius brunneus (3.6%) dominated. Hemibarbus longirostris, Pungtungia herzi, Squalidus japonicus coreanus, Zacco temmincki, Cobitis rotundicaudata, Silurus asotus, Silurus microdorsalis and Micropterus salmoides were rare to the areas, which occupied less than 0.1% in relative abundance. Dominant species was M. oxycephalus (Kumda-ri, Kwanseol-dong, Hanggu-dong, heongyang-ri), Z. platypus (Gaeun-dong) and C. auratus (Jusan-ri). It was revealed by the analysis of community that St. 3 was the most diverse among all study stations. Coreoleuciscus splendidus and Coreopera herzi have been assumed vanished in the Wonju stream. The species occurring in suddenly decreasing trend were Microphysogobio yaluensis, Liobagrus andersoni, Cottus poecilopus and R. brunneus. The species occurring in representative increasing trend were Cyprinus carpio, C. auratus, P. esocinus, M. oxycephalus, and Z. platypus.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.446-455
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• 2004

The ichthyofauna and community structure in Hongcheon river, Korea, was investigated from April to October 2002. During the surveyed period, 52 species belonging 11 families were collected. There were 23 Korean endemic species (44.23%), including Rhodeus uyekii, Acheilognathus signifer, A. yamatsutae, Coreoleuciscus splendidus, Koreocobitis rotundicaudata and Silurus microdorsalis. Dominant species were Zacco platypus (20.38%), and subdominant species were Z. temmincki (19.62%). Also, Rhynchocypris oxycephalus (8.45%), Pungtungia herzi (8.01%), C. splendidus (6.63%) were numerous. Of the 6 introduced fishes in Hongcheon river Carassius cuvieri, Lepomis macrochirus and Micropterus salmoides were originated from foreign countries but Anguilla japonica, Gymnogobius urotaenia, Rhinogobius giurinus were introduced from other native river systems. According to the fish distribution, the fish community of Hongcheon river was divided into 4 groups by principle component analysis (PCA).

• Korean Journal of Ichthyology
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• v.35 no.2
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• pp.91-100
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• 2023

The early life history of Silurus microdorsalis living in Jahocheon Stream was studied by observing egg and morphological development. Live fish were captured in June 2018, then reared in a circulating filtration system under a 14L : 10D photoperiod with a water temperature of 18℃. To artificially induce spawning, females were injected with 0.5 mL of Ovaprim (Syndel, Nanaimo, BC, Canada) per kg of body weight, and males were injected with 10,000 IU/kg body weight of human chorionic gonadotropin. Approximately 15 h later, eggs were artificially inseminated by the dry method. Mature eggs were light pale yellow, which separated them from immature eggs. Fertilized eggs were 2.16±0.06 mm (n=8) in diameter and fully hatched at 181 h after fertilization. The fertilization rate was 63.1±2.2%, and 10.0±3.7% of the embryos were malformed at 18℃. The rates of development were 181 h at 18℃, 109 h at 21℃, and 76 h at 24℃. The larval size immediately after hatching was 4.64±0.22 mm (n=8), and the larvae displayed negative phototaxis at 1 day after hatching. The total larval length on 7 days after hatching was 12.47±0.53 mm, with 25~30 basal anal fin rays and 14~16 basal caudal fin rays observed. The total larval length was 14.13±0.51 mm on 9 days after hatching, and approximately 90% of the black endoplasmic reticulum was deposited on the head and body. The dorsal fin had formed, and a single basal body was observed. On 15 days after hatching, the total larval length was 16.69±0.31 mm; the number of basal caudal fin rays (18 poles) was an integer because 2 dorsal fin basal rays and 60~63 anal fin basal rays were observed. The total larval length was 28.96±1.10 mm on 50 days after hatching; the numbers of caudal fins (n=18), dorsal fins (n=3), pectoral fins (n=11), and anal fin basal rays (n=67~73) were integers.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.67-76
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• 1998

The ichthyofauna and the structure of fish community were surveyed from April to November 1997 at eighteen stations in the Yonggang river which is a first tributary located at the middle reach of the Nakdong river system. During the surveyed period, 32 species belonging to ten families were collected. Of them cyprinid fish occupied 53.1% (17 species) and cobitid fish 15.6% (5 species). Thirteen species (40.6%) were known as Korean endemic species. Dominant species were Zacco temmincki (32.78%) and Moroco oxycephalus (15.10%). Zacco platypus, Pungtungia herzi. Niwaella multifasciata, and Odontobutis platycephala were common species. Rare species which occupied less than 0.1% of total individuals were Lampetra reissneri, Pseudorasbora parva, Squalidus chankaensis tsuchigae, Microphysogobio koreensis, Gobiobitia naktongensis, Cobitis rotundicaudata, Nemacheilus toni, Silurus asotus, Silurus microdorsalis, Siniperca scherzeri, and Oreochromis niloticus. A tendancy were shown in regional distribution that Moroco oxycephalus dominated in upper stream, Zacco temmincki and Moroco oxycephalus in mid - upper stream, Zacco temmincki and Niwaella multifasciata in mid - lower stream, and Zacco platypus and microphysogobioid fishes in lower stream. St. 11 which located in mid- reach of Yongam stream and St. 15 and 18 which located in main stream had the most stable and diverse community structure, but St. 1, 5, and 7 were unstable and the simplest community structure.

• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.145-152
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• 2009

The fish community was investigated from March to October 2007 in Gwangneung Arboretum. During the survey period, 22 species belonging to 9 families were collected. Among them, one species (Coitus koreanus) was classified as an endangered species in Korea, and exotic fish was Micropterus salmoides. Nine species (40.9%) were endemic species of Korea. Dominant species was R. oxycephalus (St. 1) and Z. platypus (St. 2-7). According to analysis of community based on the diversity, evenness and richness indices, fish community seems to be more stable in the St. 3. The distributions of Silurus microdorsalis, Cottus koreanus and Odontobutis platycephala were confined to the Bongseonsa Stream in the Wangsuk Stream watershed. When our data were compared with the previous data (1932), 17 species were not sampled, but 7 species could new taxa fiend its existence at the Bongseonsa Stream. We believe that Hemibarbus mylodon, Acheilognathus signifer and Zacco koreanus disappeared in the Wangsuk Stream watershed and A. signifer and Z. koreanus need to be restored at the Bongseonsa Stream.

• Korean Journal of Environment and Ecology
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• v.10 no.1
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• pp.140-150
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• 1996

The freshwater fish fauna of the Chuwangsan National Park as censused during June 1994 to December 1994 at 11 sampling sites to establish baseline data included 7 Korean endemic species and subspecies (Squalidus gracilis majimae, Squalidus multimaculatus, Cobitis longicorpus, Niwaella multifacisciata, Silurus microdorsalis, Liobagrus mediadiposalis and Odontobutks platycephala) belonging to 17 species in 6 families were collected in this region. Carassius auratus, Moroco oxycephalus, Zacco platypus, Wacco temmincdii, Misgurnus anguillicaudatus, Liobagrus mediadiposalis and Odontobutis platycephala were distributed at all of the regions on this sensus. Dominant species of thes region sere Moroco ozycephalus, Zacco temminckii and Odontobutis platyxephala.