• Korean Journal of Ichthyology
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• v.30 no.3
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• pp.161-166
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• 2018

The olfactory organ of Korean endemic fish Microphysogobio yaluensis are described anatomically and histologically, focused on relationship to its habitat and ecology. The paired olfactory organs are located at the dorsal snout, and externally consist of two semicircular nostrils and single nasal flap. They internally have rosette structure with 22 to 24 units of lamellae and the raphe inside the olfactory chamber. The lamella is made up of the sensory and the non-sensory epitheliums. The sensory epithelium has olfactory receptor neurons, supporting cells and basal cells whereas the nonsensory epithelium has stratified epithelial cells, ciliated non-sensory cells and mucous cells with acidic and neutral mucins. These structures might be considered that M. yaluensis has the olfactory organ which corresponds to the high sensitivity for its habitat and ecology, and is usable as a taxonomic key.

• Parasites, Hosts and Diseases
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• v.35 no.4
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• pp.223-232
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• 1997

Metagonimus miyatai n. sp. (Digenea: Heterophyidae) is described based on adult flukes collected from experimental dogs and hamsters fed with metacercariae encysted in the sweetfish, Plecoglossus altivelis, dace, Tribolodon hakonensis and T. taczanowskii, common fat-minnow. Morocco steindachneri pale chub, Zacco platypus, and dark chub, Zacco temmincki, and on those collected from naturally infected humans. The new species was morphologically compared with M. yokogawai and M. takahashii obtained from experimental animals fed with the sweetflsh and the crucian carp, Cnrossius caressius, respectively. The uterine loops of M. miyatai reached near the posterior end of the body through the space between the two testes, whereas those of M. yokogawai, occupied only the space between the acetabulum and anterior border of two testes. This uterine tubule distribution was similar to that of another closely related species, M. takahashii. However vitellaria of M. miyatai ended in front of the posterior end of the left testis, while those of M. takahcshii reached the posterior end of the left testis and ran it over. By raising M. miyatai as a new species, differentiation of M. yokogawai and M. takahashii became very clear. A key to the species of the genus Metagonimus in the Far East has been proposed.

• Korean Journal of Ichthyology
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• v.20 no.2
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• pp.97-104
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• 2008

Comparative study of retinal structure in two Korean endemic freshwater fishes, Zacco koreanus and Pseudobagrus koreanus, was carried out by light and scanning electron microscopy. In the visual cell layer comprised of cone cells and rod cells, the cone cells showed a distinct difference between both species. Z. koreanus had two types of cone cells, single cone cells including a long single and short single cone cells, and double cone cells, whereas P. koreanus had only one type of single cone cells having no its short single and long single cones. Meanwhile, the cone cells of Z. koreanus were arranged in more compact-rowed pattern, but it was more loose and irregular in P. koreanus. Based on field observation, Z. koreanus is mainly a epipelagic or sometimes benthopelagic and a diurnal fish with a round and large eye, while P. koreanus is a demersal and nocturnal fish with an oval and small eye. Therefore, the difference in the retinal structure of two species seems to be closely related to their ecological habitats.

• Korean Journal of Ichthyology
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• v.30 no.2
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• pp.92-99
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• 2018

Feeding ecology of endangered Korean endemic miho spine loach, Cobitis choii, was investigated in Jicheon Stream, Geumgang River, Korea to provide ecological characteristics and baseline data for its restoration. C. choii is active during daylight hours above sand from March to October when the water temperature exceeded $13^{\circ}C$, but tended hibernate in the stream bottoms (sand) in the winter months (November~February) when the water temperature was lower than $13^{\circ}C$. They fed (index of relative importance, IRI) mainly Diptera (69.9%), Copepoda (23.2%), Arcellidae (2.3%), Branchiopoda (2.0%) and Ploima (2.0%). And their small juvenile (age 0+) fed mainly small size, Ploima and Branchiopoda, however, they ate mainly large size, Chilonomidae, while growing to adult fish (age 2+~3+).

• Korean Journal of Ichthyology
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• v.31 no.2
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• pp.101-109
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• 2019

This study investigated the characteristics of fish communities at the Lake Yedang, in 2013 to 2014 and 2017. During the survey period, there were 29 species of 10 families collected from 3 survey stations. Of them, Cyprinidae occupied 34.5% (14 species), Bagridae, Gobiidae 10.3% (3 species), and Cobitidae, Centrachidae were 6.9% (2 species) in the number of species, respectively. Korean endemic species were 4 species (13.8%) Abbottina springeri, Cobitis nalbanti, Pseudobagrus koreanus, Odontobutis interrupta and accounted for a low rate. There were 3 species (10.3%) exotic species including Carassius cuvieri, Lepomis macrochirus, Micropterus salmoides. As a result of community analysis, dominant index was 0.45~1.00, diversity index was 0.19~2.30 and richness index was 0.41~1.94.

• Parasites, Hosts and Diseases
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• v.46 no.4
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• pp.253-260
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• 2008

Freshwater fish from Vientiane Municipality and Savannakhet Province, Lao PDR were examined by the muscle compression and artificial digestion methods to know the infection status with trematode metacercariae. In the fish from Savannakhet, 2 species of metacercariae, Opisthorchis viverrini and Haplorchis taichui, were detected. O. viverrini metacercariae were found in 6 species of fish, Puntius brevis, Hampala dispar, Esomus metallicus, Mystacoleucus marginatus, Puntioplites falcifer, and Cyclocheilichthys armatus. H. taichui metacercariae were detected in 3 species of fish, P. brevis, P. falcifer, and M. marginatus. In the fish from Vientiane, 4 species of metacercariae, O. viverrini, H. taichui, Haplorchis yokogawai, and Centrocestus formosanus, were detected. Among them, O. viverrini metacercariae were found in 7 species of fish, Onychostoma elongatum, C. armatus, H. dispar, P. brevis, Cyclocheilichthys repasson, Osteochilus hasseltii, and Hypsibarbus lagleri. The metacercariae of H. taichui were detected in 6 species of fish, C. repasson, O. elongatum, C. armatus, H. dispar, Labiobarbus leptocheila, and Cirrhinus molitorella. The metacercariae of H. yokogawai were found in 9 species of fish, C. repasson, O. elongatum, C. armatus, H. dispar, Labiobarbus leptocheila, O. hasseltii. C. molitorella, Hypsibarbus wetmorei, and H. lagleri. The metacercariae of C. formosanus were detected in 4 species of fish, C. repasson, P. brevis, O. hasseltii, and C. molitorella. From these results, it is confirmed that fish borne trematode metacercariae, i.e. O. viverrini, H. taichui, H. yokogawai and C. formosanus, are prevalent in various species of freshwater fish from Savannakhet Province and Vientiane Municipality, Lao PDR.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.271-278
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• 2010

Field monitoring was conducted for fish fauna and community assessment at 7 sites from April 2008 to October 2009 in the Chogang Stream. The number of fish samples in this period were 4,669 in 36 species of 9 families. Family Cyprinidae take 66.7 (24 species), Cobitidae, Bagridae, Centropomidae and Odontobutidae occupied 5.6%(each 2 species), respectively. Twenty species (55.6%) including Acheilognathus koreensis and A. yamatsutae were found endemic out of the 36 species. The species of Pseudopungtungia nigra, Gobiobotia macrocephala and Gobiobotia brevibarba were endangered species. The most frequently found one was Zacco koreanus (34.0%, n=1,588) followed by Z. platypus (22.6%, n=1,053) and Coreoleuciscus splendidus (13.3%, n=623). The lower reach of Chogang Stream was more abundance of species, high diversity, evenness and richness, and lower dominance index than those of the upper reach. According to the dendrogram established at 0.5 level of similarity rate, sampling stations were divided into 3 groups. They were divided into upper most stream (St. 1~St. 2), upper stream (St. 3), middle and lower stream (St. 4~St. 7). Overall, it was concluded that the Chogang Stream has been relatively well protected from the anthropogenic disturbance for the legally protected species including the endemic species studied in this study.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.63-72
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• 2005

The fish fauna and community structure were investigated in the Lake Cheongpyeong, Korea, from August 2003 to April 2004. During the period, 43 species belonging 10 families were collected. There were 18 Korean endemic species 41.9%. The five dominant species numerically were A. gracilis (17.4%), Zacco platypus (14.6%), A. yamatsutae (13.2%), Hemibarbus labeo (11.9%), Rhinogobius brunneus (11.7%), and Zacco temmicki (3.0%). The five dominant species in biomass were Erythroculter erythropterus (15.07 kg), H. labeo (13.21 kg), Carassius cuvieri (6.47 kg), A. gracilis (6.05 kg), and Z. platypus (4.71 kg). Of 6 exotic fishes in the lake C. cuvieri, Lepomis macrochirus and Micropterus salmoides were originated from foreign countries but Anguilla japonica, Tridentiger brevispinis, and Chaenogobius urotaenius were introduced from other watershed in Korea.

• Korean Journal of Ichthyology
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• v.30 no.2
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• pp.119-124
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• 2018

Diversity of fish fauna and species list collected from the Imha-Dam Reservoir of the Nakdonggang River system were reviewed based on the published materials from 1992 to 2016. As a result of the present study, 46 freshwater fish species/subspecies belonging to 36 genera, 11 families, 4 orders were reported in the Imha-Dam Reservoir. Of them, Cyprinidae occupied 58.7% (27 species), Cobitidae 10.9% (5 spp.), Gobiidae 6.5% (3 spp.), and Siluridae, Centropomidae, Centrarchidae were 4.3% (2 spp.) in the number of species, respectively. The dominant species in the number of individuals was Erythroculter erythropterus (40.1%, 9,333 inds.), and the subdominant species was Opsariichthys uncirostris amurensis (9.8%, 2,281 inds.). Among 46 species/subspecies, 17 species (37.0%) were identified as endemic species to Korea. Three species were endangered fish species by the Ministry of Environment of Korea, five translocated species, and three exotic species were reported.

• Korean Journal of Ichthyology
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• v.31 no.4
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• pp.241-248
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• 2019

The freshwater fish fauna for the whole water system of Geogeumdo Island was surveyed at a total 10 sites from March 2018 to February 2019. During the surveyed period, 13 species belonging to 5 families and 4 orders were collected. Cyprinidae (68.84%) and Gobiidae (18.21%) were the dominant family, and the dominant species was Zacco temminckii (53.71%), and the subdominant species was Rhynchocypris oxycephalus (10.78%). Kichulchoia brevifasciata (1.27%) that endangered species were found in this study, but the habitat was confirmed in one site in Sinpyeongcheon compared to previous literature. Three endemic species of Korea were found in this island such as Iksookimia hugowolfeldi (5.07%), Liobagrus somjinensis (2.99%) and K. brevifasciata (1.27%). According to analysis of fish community structure based on average diversity, evenness index, dominance and richness indices in Geogeumdo Island were 1.666, 0.649, 0.645 and 1.713, respectively.