• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.445-445
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• 2021

대구시민의 삶의 질 향상에 크게 기여하는 신천은 홍수, 친수 및 하천환경 관리에 대한 필요성이 증가되는 상황에서 신천 복원을 위하여 하천횡단구조물 및 생태조사가 필요한 실정이다. 신천 내에 위치하고 있는 14개의 하천횡단구조물은 신천의 흐름을 가로막고 있어 수질악화 및 생물이동을 저해하고 있으며, 집중호우 등으로 인하여 구조물 주변에 대한 하천관리가 어려운 것이 현실이다. 특히 신천은 인구가 밀집해 있는 도심을 관통하는 하천으로 친수공간, 홍수 및 하천환경 관리에 대한 필요성이 증가하고 있다. 본 연구에서는 신천의 수질과 어류의 생태성의 상관관계를 확인하고 횡단구조물에 대한 해결방안을 제시하고자 한다. 현지조사 결과 총 3목 6과 10종의 어류가 관찰되었으며, 법정보호종인 멸종위기 야생생물 및 천연기념물은 관찰되지 않았으나, 고유종으로 긴몰개와 참갈겨니, 꺽지, 동사리 4종이 출현하였으며, 환경부 지정 생태계교란 생물 블루길 1종이 관찰되었다. 이러한 결과를 바탕으로 어류생물지수(FAI)를 검토하였을 때, 하류지역으로 갈수록 E등급으로 매우 나쁨의 환경상태를 나타내었다. 이는 상류에서 하류로 갈수록 비정상개체수가 증가하고 하상의 단순화 및 유기물의 축적으로 출현 종수의 감소에 따른 결과로 판단된다. 이러한 결과를 바탕으로 신천의 평균 FAI 지수는 14.71점으로 E등급의 매우 나쁨의 환경상태를 나타내는 것으로 분석되었다.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.146-159
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• 2020

The objective of our study was to analyze the distribution and composition of fish species and their community characteristics in agricultural waterways in the six water systems-Mankyung River, Seomjin River, Namhae Region, Tamjin River, Yeongsan River, and Dongjin River-during 2017-2018. Little is known about the distributions and community characteristics of the aquatic biota of agricultural waterways in Korea, even if the water bodies have important roles as spawning areas or habitats for fish. In this study, we identified 3,633 fish individuals in the waterways, belonging to 53 species, eleven families, and six orders (dominant species: Tanakia koreensis, T. lanceolate) and 7,108 fish individuals in the main rivers, belonging to 57 species, fifteen families, and nine orders. Moreover, three endangered wildlife (designated by the Ministry of Environment, Korea)-T. somjinensis, Acheilognathus majusculus and Coreoperca kawamebari-were found in the waterways. By fish guild analysis, we found that many waterways had a lower proportion of sensitive species and a higher proportion of omnivore species than those of the main rivers, which indicates a feature of a disturbed environment. In addition, by grouping with environmental variables, we found the group of waterways with high substrate complexity had a higher diversity index (Shannon index) and a lower dominance index (Simpson index) than that of simple substrate complexity. Overall, our study represents the characteristics of fish habitats in agricultural waterways and suggests the need to manage them and study further.

• Korean Journal of Environment and Ecology
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• v.38 no.1
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• pp.55-66
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• 2024

This study conducted a survey to investigate the characteristics of fish communities and the inhabiting status of endangered species in the Byekgye Stream, Korea from April to September 2020. A total of 3,415 fish of 9 families and 31 species were collected from 7 survey stations during the survey period. The dominant species was Zacco koreanus (relative abundance of 31.2%), and the subdominant species was Z. platypus (15.0%), followed by Pungtungia herzi (11.7%), Acheilognathus yamatsutae (5.4%), A. lanceolata intermedia (4.8%), Rhinogobius brunneus (4.4%), and Pseudopungtungia tenuicorpa (4.3%). Among the fish species collected, 19 (61.3%) were identified as Korean endemic species, and two cold-water fish species sensitive to climate change (Rhynchocypris kumgangensis and Cottus koreanus) were collected. Four species were designated as class II endangered wildlife by the Ministry of Environment: A. signifer, P. tenuicorpa, Rhodeus pseudosericeus, and C. koreanus. A. signifer and P. tenuicorpa mainly inhabited the mid to lower streams, R. pseudosericeus in the midstream, and R. pseudosericeus in the upstream. P. tenuicorpa inhabited in large numbers, and estimating the age by total length-frequency distribution in July, the total length of the 26-35 mm group was estimated as 0 years old, the 54-75 mm group as 1 year old, 82-97 mm group as 2 years old, 104-109 mm group as 3 years or older. The cluster analysis showed that the dominance index decreased from upstream to downstream, but the diversity, evenness, and richness index increased. The water quality of Byekgye Stream was evaluated as good overall since the river health (fish assessment index, FAI) using fish was evaluated as excellent (5 stations) and good (2 stations). Byekgye Stream has relatively well-preserved habitats, but conservation measures are required as habitats are disturbed by river repair work in some parts of the midstream and downstream areas where many endangered species inhabit.

• Korean Journal of Ichthyology
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• v.32 no.3
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• pp.182-190
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• 2020

The endangered Pseudopungtungia tenuicorpa were reintroduced to the Jojongcheon Stream in the Hangang River 2011~2012 as part of the restoration project. Since then, the restoration project has been evaluated as a failure because the P. tenuicorpa were not collected from the discharge site 2014~2016. This study was conducted 2017~2019 to verify that the P. tenuicorpa restoration project failed. Six locations were selected, including the discharge site, and the fish collection method used skimming nets, cast nets, long bag set nets, and scuba diving. In the survey results, 13 individuals were collected in a 0.5 km section, including the discharge station. The P. tenuicorpa habitat was approximately at a water depth of 0.5 m to 2 m in run water flow with the boulders and rocks. The age of the collected P. tenuicorpa were 0+ to 3-years-old, and the generation alternation was occurring stably. Thus, the P. tenuicorpa restoration project was evaluated as partially-successful, as the P. tenuicorpa, re-introduced to the Jojongcheon Stream, settled in its habitat with stable generation alternation.

• Journal of Aquaculture
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• v.20 no.4
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• pp.248-254
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• 2007

Representative cDNA libraries were constructed from various tissue sources of Hemibarbus mylodon, an endangered freshwater fish species in Korea, for the mining of expressed sequence tags (ESTs). Randomized and non-normalized EST analysis was performed with 7 unidirectional cDNA libraries generated from brain, intestine, kidney, liver, muscle, ovary or testis. Of 3,383 ESTs in total, the number of singleton was 2,029, and 333 contigs containing 1,354 ESTs were assembled (percent of unigene = 70.0%). Abundantly expressed gene transcripts and broad clustering of putative gene function were tissue-specific in general, and the redundancy was also variable among those libraries. Over half of H. mylodon ESTs were matched with orthologues from other teleosts among which zebrafish gene sequences were the most frequent in those matches. This initial setting of EST libraries achieved in the present study would be a fundamental basis for the banking of gene resources from this endangered fish species.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.74-83
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• 2021

Distribution status, habitat characteristics, and extinction threat evaluation of the endangered species, Brachymystax lenok tsinlingensis were investigated in 2015 and 2019. Historical distribution reports of B. l. tsinlingensis were divided into before 1990, 1997~2006, 2000~2011, and 2010~2019. Among the 150 sampling sites investigated during the study period, number of individuals of B. l. tsinlingensis were collected 542 individuals from 67 sites. The streams inhabited of B. l. tsinlingensis were Naerincheon (11 stations), Odaecheon (11 stations), Bukcheon (10 stations), Bangtaecheon (8 stations), Songjeongricheon (4 stations), Suipcheon (3 stations), Inbukcheon (3 stations), Hyeondongcheon (3 stations) etc. The main habitat of B. l. tsinlingensis was upstream of the river with a high altitude of more than 400 m, 4~20 m water flow width, 1~2 m water depth, and high ratio (70~80%) boulder bottoms. The main reasons for the decline in population size were assumed as river works, construction of reservoirs and bridges, discharge of contaminated water into the river, the inflow of summer vacationers, and weir. Compared to our results there exists evidence that states a 20.7% reduction in occupancy within 10 years, in a small appearance range (7,732 km²) and occupancy area (268 km²), number of disconnected locations (15 locations), and a decline in habitat quality. Therefore, B. l. tsinlingensis is now considered as Near Threatened (NT) based on the results (Near meets VU A2acd, B1b(i,ii,iii)+B2b(i,ii,iii)) of IUCN Red List categories and criteria.

• Korean Journal of Ichthyology
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• v.23 no.1
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• pp.61-69
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• 2011

Gene and promoter structures of metallothionein(MT) from Miho spine loach (Cobitis choii; Cypriniformes) were characterized, and the transcriptional responses to experimental exposures to heavy metals and heat stress were examined. The C. choii metallothionein displayed well-conserved features of teleostean metallothioneins at gDNA, mRNA and amino acid levels. Bioinformatic analysis predicted that the C. choii MT regulatory region potentially possessed various motifs or elements targeted by various transcription factors associated with metal-coordinating regulation (e.g., metal transcription factor-1), immune responses (e.g., nuclear factor kappa B), and thermal modulations (e.g., heat shock factor). Acute heavy-metal exposures to 0.5 or $1.0\;{\mu}M$ of cadmium (Cd), copper (Cu), manganese (Mn), nickel (Ni) or zinc (Zn) showed that MT transcription was significantly stimulated by Cd (9.6-fold relative to non-exposed control) and Cu (10.4-fold), only moderately by Mn (2.4-fold), but hardly by Ni and Zn. Elevation of water temperature from $25^{\circ}C$ to $31^{\circ}C$ caused a rapid modulation of MT mRNAs toward upregulation to 9.5-fold; however, afterward the elevated mRNA level slightly decreased during further incubation at $31^{\circ}C$ for 6 h. Results from this study suggest that MT-based expression assay could be a useful basis for better understanding the metal- and/or heat-caused stresses in this endangered fish species.

• Korean Journal of Ichthyology
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• v.20 no.4
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• pp.279-284
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• 2008

The feeding ecology of endangered Cottus hangiongensis was studied in the Hosan stream from September 2006 to August 2007 by collecting them seasonally. The stomach contents of C. hangiongensis consisted mainly of aquatic insects and Nematoda, small fish, fish eggs, snails (Semisulcospira libertina), and small stones were also observed. The main aquatic insects in the order of relative importance were Diptera, Trichoptera, Ephemeroptera and Plecoptera. The most important prey items were Chironomidae sp.1 and Hydropsyche kozhantschikovi. Change in the main prey organisms by season were Trichoptera in the spring and the summer, Diptera in the autumn, and Plecoptera in the winter by ratio of dry weight.

• Korean Journal of Ichthyology
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• v.30 no.1
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• pp.46-54
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• 2018

The habitat characteristics and the age of endangered miho spine loach, Cobitis choii, were investigated in Ji Stream, Guem River, Korea in 2011 to provide baseline data for its restoration. The habitat of the C. choii was the downstream portion composed of sand, and the sand particle sizes was mostly 0.21~1.18 mm (88.7%). Juveniles (age 0+) preferred slower water velocity (0~25 cm/sec) and a lower water depth (5~20 cm) than did individuals who were more than 1 year old, as this group inhabited rapids with 10~25 cm/sec of water velocity and 20~50 cm of water depth. The C. choii rapidly grew during the active period from April to October and they stopped growing during the hibernating period from November to March. The estimated age of the C. choii (females) based on their total length distribution during the spawning period (June) indicated that 1-, 2-, 3- and more than 4-year-old were 40~61 mm, 64~79 mm, 80~91 mm and 92~106 mm, respectively.

• Korean Journal of Ichthyology
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• v.26 no.3
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• pp.179-184
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• 2014

A histological study on the egg envelope and oogenesis of Gobiobotia brevibarba (Pisces, Cyprinidae) was carried out by a light microscope and a scanning electron microscope. Various developmental cells appeared in the ovary caught during May 2014, spawning season. For the relative area of oocyte, the ovary consisted of mature stage (74.5%), a vitellogenic stage (yolk granule stage, 16.6% and yolk vesicle stage, 6.6%) and previtellogenic stage (perinucleolus stage 2.2%), which means its spawning season. The cytoplasm of the perinucleolus oocyte is acidic and many nucleoli are located at the inner side of the nuclear membrane. The yolk vesicles, an early vitellogenic stage, has a follicular layer and a zona radiata clearly. Numerous villi, called an egg envelope, begin to form on the zona radiata. The yolk granules, an another vitellogenic stage, proceeds and they show a strong eosinophilic nature. Such yolk granules appeared between the yolk vesicles occupying most cytoplasm, and as the stage proceeds, there are some yolk masses fused with each other. Egg envelope is covered with plenty of villi ($2{\sim}3{\mu}m$ in the length) over the entire egg surface.