• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.34-44
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• 2015

Fish fauna, difference of stable isotope ratio between freshwater and seawater, and trophic guilds of freshwater fishes were investigated in the lower Geum River. The study was conducted in 2011, and total study area was about 30 km of 20 km upstream and 10 km downstream from the Geum River estuary barrage. Only freshwater fishes were used for analyzing trophic guilds, and discriminant function analysis (DFA) was utilized to reclassify trophic guilds based on stable isotope ratio. Fish fauna in freshwater and seawater areas were entirely different each other, but small number of migratory species such as Coilia nasus and Chelon haematocheilus occurred both areas. Other species were not collected in the different areas because they did not have physiological ability to adapt different salinity concentrations. Stable isotope ration of two areas were different considerably due to food sources. Estuary and seawater fishes uptake food sources originated from marine, and freshwater fishes were from freshwater and terrestrial. Some migratory species showed reverse stable isotope ratio. Even though they collected in freshwater, they showed stable isotope ratio of seawater. This is because ecological characteristics of each species. Trophic guilds of freshwater fishes were reclassified by DFA, and showed slight difference with literatures. However, because this result is related with ontogenetic shift of species, more studies are needed to explain exact and correct trophic guilds. Stable isotope ratio can be changed among regions, seasons and ontogenetic stage, thus we always consider these aspects when analyzing results to get a right answer.

• Journal of the korean veterinary medical association
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• v.49 no.12
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• pp.759-762
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• 2013

• Journal of the korean veterinary medical association
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• v.49 no.11
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• pp.705-709
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• 2013

• Journal of the korean veterinary medical association
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• v.49 no.11
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• pp.689-703
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• 2013

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.394-403
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• 2009

The fish fauna and community structures were investigated at 15 stations in the midupper region of the Seomjin River watershed from August in 2008 to April in 2009. During the studying period, 42 species belonging to 11 families were collected. Dominant family in the all sites was Cyprinidae (28 species, relative abundance: 66.7%) during the study. Total of 42 species (primary freshwater: 40 species, peripheral freshwater: 2 species) were found with the primary freshwater fishes being the highest. Dominant species was Zacco platypus (22.3%), and subdominant species was Coreoferea herzi (10.8%). Also, Pseudogobio esocinus (9.0%) and Carassius auratus (5.8%) were numerous. There were 17 Korean endemic species (40.5%), including Rhodeus ocellatus, Acheilgnathus koreensis, A. somjinensis, Coreoleuciscus splendidus and Sarcocheillichthys variegatus wakiyae. Among them, Acheilgnathus somjinensis was identified for designation required to protect under a wildlife category. In conclusion, we could define that the Seomjin River watershed has a very good water conditions as habitat of fish.

• 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.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.210-219
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• 2008

Monthly variation in species composition of upstream-migrating fish in the Cheonjeyeon Estuary was determined by analyzing fish data collected January~September 2004 and January~August 2007. Fish migrating from the sea to freshwater through the channels were collected by a rectangular net with a mesh size of 2 mm during the day and at night in the new moon. Of 14 species collected, ayu (Plecoglossus altivelis altivelis) and mullet (Mugil cephalus) predominated in abundance. Glass eels (Anguilla japonica) occurred mainly during the night from February to May. Other fishes collected included brackish-water gobiids (Gymnogobius urotaenia, Rhinogobius giurinus, Tridentiger obscurus, and Sicyopterus japonicus), freshwater fishes (Misgurnus anguillicaudatus and Rhynchocypris oxycephalus), and coastal marine fishes (Engraulis japonicus, Pempheris japonica, Plotosus lineatus, Takifugu niphobles, and Terapon jarbua). Ayu occurred during almost all sampling periods. They ranged principally from 55 to 100 mm total length (TL), with some fish larger than 100 mm TL collected after April. Mullet also occurred during almost all sampling periods. They ranged principally 25~58 mm TL, with some larger fish of 103~240 mm TL collected in February and April. That only a few freshwater and brackish-water fishes occurred in the study area is probably related to the freshwater systems having long been isolated from the continental systems and to the poorly developed estuaries in Jeju Island reflecting limited river discharge.

• Korean Journal of Ichthyology
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• v.24 no.3
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• pp.201-219
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• 2012

The estuaries bank of Nakdong River, Korea, was constructed in 1987 and many arguments have been under discussion on the subject of ecological impact on ecosystem during 20 years. In this context, however, it was not focused on the role of fish-way and the way of improvement to promote fish movement to complete its life history. This paper was the result of investigation on fish fauna of upper and lower part of the bank and the analysis of comparison of the fishes with those using fish-way which were installed in each side of bank as ladder type and fish gate. The authors discussed the importance of fish gate and its management base on the result. The number of fishes collected in this study for upper part of estuaries bank was 31 species, among them 71% was the pure freshwater residents indicating the characteristics of the area as a freshwater ecosystem. It was observed that 9 species of coastal fishes were found in this region including Coilia ectens and Neosalanx sp. which is anadromous to spawn. Excluding 6 freshwater fishes, 30 fish species collected in lower part of estuaries bank were coastal fishes indicating that former brackish ecosystem was changed into marine one. The freshwater fishes found in this region were restricted the appearance only in the season of discharging freshwater into the sea. The number of fishes found in fish-way was 39 species, more than that of river and coast. But only 19 species founded in fish ladder was comparable with the result of investigation on fish gate including 32 species. It was considered that the fish gate has more important role as a fish passage from the fact that only it allowed to movement of numerous number of fry of Neosalanx sp. and Engraulis japonicus. These results indicates that two-way movement system is more efficient than downward only one in estuaries bank for fish migration.

• Animal Systematics, Evolution and Diversity
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• v.30 no.1
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• pp.22-25
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• 2014

Two species of small gobiid fishes genus Luciogobius, i.e., L. elongatus, L. platycephalus were described as the first records from Korea based on specimens collected from gravel beaches of Gijang-gun, Busan-si, Korea. Luciogobius elongatus is distinguished from congeners by very elongated and naked body, 42-44 vertebrae, 6-7 dorsal soft rays, and no free rays on pectoral fin, and L. platycephalus is characterized by having very depressed head, naked body, 40-41 vertebrae, 10-11 dorsal soft rays, and pectoral fin with only upper 2-4 free rays. We propose the new Korean name "Ga-neun-mi-kkeun-mang-dug", "Nab-jak-mi-kkeun-mang-dug" for L. elongatus and L. platycephalus, respectively.

• Korean Journal of Ichthyology
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• v.21 no.sup1
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• pp.63-72
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• 2009

The taxonomic research based on extensive investigations and specimen collections throughout all varieties of freshwater and marine habitats of Chinese waters, including mainland China, Hong Kong and Taiwan, which involved accounting the vast number of collected specimens, data and literature (both within and outside China) were carried out over the last 40 years. There are totally 361 recorded species of gobioid fishes belonging to 113 genera, 5 subfamilies, and 9 families. This gobioid fauna of China comprises 16.2% of 2211 known living gobioid species of the world. This report represents a summary of previous researches on the suborder Gobioidei. A recently diagnosed subfamily, Polyspondylogobiinae, were assigned from the type genus and type species: Polyspondylogobius sinensis Kimura & Wu, 1994 which collected around the Pearl River Delta with high extremity of vertebral count up to 52-54. The undated comprehensive checklist of gobioid fishes in China will be provided in this paper.