• Korean Journal of Ichthyology
• /
• v.28 no.3
• /
• pp.175-178
• /
• 2016

The karyotype analysis of Liobagrus somjinensis, an endemic Korean freshwater fish with restricted waters and a new species of torrent catfish was carried out from nine females and eight males of Somjingang River, Sikjeong-dong, Namwon-si, Jeollabuk-do, Korea. The diploid number of chromosomes was 42, and its karyotype was composed of 28 metacentrics and 14 submetacentrics; 84 FN (fundamental number). Polyploidy and sex dimorphism were not observed in the present species. The chromosome number of L. somjinensis was the same as its congeners, but there was a difference in karyotypes.

• Korean Journal of Ichthyology
• /
• v.30 no.1
• /
• pp.65-68
• /
• 2018

The anatomical study of the olfactory organ in Liobagrus somjinensis, being related to the habitat environment and ecological habit, was carried out using a stereomicroscopy and digital camera. The paired olfactory organs are situated at the dorsal part of the snout, and consisted of two opening (anterior and posterior nostrils) and the olfactory chamber. The tubular anterior nostril is located between the tip of upper lip and the nasal barbel. The posterior nostril flat to the surface is adjacent entirely to the basement of the nasal barbel. The olfactory chamber has a rosette structure with 22~24 lamellae of linguiform, arranged transversely and radially from the medium raphe. These results may prove that L. somjinensis is dependent on olfaction, related to the hiding, the feeding and the nocturnal lifestyle in rapids.

• Korean Journal of Ichthyology
• /
• v.27 no.4
• /
• pp.300-305
• /
• 2015

The characteristics of 11 spawning sites in the natural environment of the Korean endemic species, Liobagrus somjinensis were investigated in the Yocheon (stream) of Seomjingang (river), located in Sikjeong-dong, Namwon-si, Jeollabuk-do, Korea from May to June 2015. The spawning sites had largely two parts, the upper region close to the surface of the waters and under region at bottom: the upper part was covered with a large and flat boulder over about 256 mm in size, whereas the under part consisted mainly of pebbles and sand. The large boulder put on the upper region may be seen as a bulwark for guarding eggs laid at the under (bottom) region. All the sites under the boulder showed a similar structure having a small hollow filled with an egg mass and an individual (male). The spawning bottoms left clean having no any benthic invertebrates and detritus. The egg shape was spherical, yellow and covered with a transparent membrane and the egg size was $3.31{\pm}0.15mm$ (n=30) in diameter. The development stage of each egg mass under the boulder was almost same from morula stage to formation stage of eye lens. The average number of eggs in 11 spawning sites was $121{\pm}35.5$ (84~176) and the average number of female fecundity in ovary was $143{\pm}31.3$ (110~232).

• Korean Journal of Ichthyology
• /
• v.26 no.2
• /
• pp.118-124
• /
• 2014

As part of researching the feeding habit of Liobagrus somjinensis, the study of its stomach contents and benthic aquatic macroinvertebrates fauna at the waters the fish was collected were carried out monthly from January to December 2010 in Yo stream, Somjin River Sikjeong-dong, Namwon-si, Jeollabuk-do, Korea. In the survey of the stomach contents, the prey organisms are all aquatic insects consisting of 5 orders, 14 classes and 16 species. They fed mainly on Trichoptera and Ephemeroptera including dominant insects such as Hydropsyche kozhantschikovi (79.1%), Chironomidae spp. (48.7%), Baetiella tuberculata (34.2%) at the occurrence rate. Based the result, L. somjinensis appeared to be an aquatic insect feeder that consumes only benthic aquatic insects. The feeding rate of L. somjinensis was the highest in November, whereas it was the lowest in December to next February when they did not feed in the winter season. A survey of the benthic aquatic macroinvertebrates fauna was accompanied for prey preference at the waters. They have 7 orders, 20 classes and 27 species, and among them, two species, Hydropsyche kozhantschikovi (39.0%) and Epeorus pellucidus (18.1%), were aquatic dominant insects. Among 7 orders interestingly, Odonata and Megaloptera, known as having a larger size than other aquatic insects, were not found at the stomach contents. As a result, Liobagrus somjinensis most prefer Hydropsyche kozhantscikovi which is the most dominant species with relatively a smaller size at the waters the study was performed.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.484-484
• /
• 2022

서식지적합도지수(Habitat Suitability Index, HSI)는 어류의 환경생태유량(Environmental Ecological Flow) 산정과 관련해 국내외에서 PHABSIM (Physical Habitat Simulation System)이나 River2D 모형과 같은 생태수리 모형에 적용되고 있으며, 특히 물리적서식지모의시스템은 흐름특성(유량유속, 수심 등)의 변화에 대한 하도구간 내 대표어종의 물리적 서식지 변화를 예측하여 대상 어종에 대한 가용서식지면적(어류가 살 수 있는 서식지 면적, Weighed Usable Area, WUA)유량 관계를 통해 서식에 필요한 최적 유량을 산정하는 데 목적이 있다. 물리적 서식지적합도지수 산정과 화학적 서식지적합도지수 산정방법은 WDFW (Washington Department of Fish and Wildlife, 2004)방법과 IFASG (Instream Flow and Aquatic Systems Group, 1986)의 방법으로 산정하였다. 섬진강에서 2020년에는 3개지점, 2021년에는 2020년 3개지점과 새로운 3개지점에 대하여 각각 4, 5, 6, 9, 10 및 11월에 어류 조사 및 물리적 조건 등에 대하여 현장 모니터링을 실시하였다. 2차년도 동안 모니터링 결과 섬진강에서는 줄납자루, 섬진자가사리, 참중고기, 참몰개, 잉어, 붕어, 칼납자루, 큰납지리, 누치, 모래무지, 피라미, 치리, 블루길, 배스 14종에 대하여 물리적 및 화학적 HSI를 산정하였다. 주요종의 WDFW 방법에 따른 큰줄납자루는 수심 0.3~0.6 m, 유속 0.1~0.4 m/s, 섬진자가사리는 수심 0.2~0.5 m, 유속 0.3~0.7 m/s, 참중고기는 수심 0.4~0.8 m, 유속 0.1~0.6 m/s, 피라미는 수심 0.3~0.7 m, 유속 0.1~0.5 m/s로 산정되었다. IFASG 방법으로 큰줄납자루는 섬진강에서는 수심 0.64 m에서 최대의 출현도를 보였으며, HSI는 0.46~0.83 m, 유속은 0.59 m/s에서 최대의 출현도를 보였고, HSI는 0.38~0.83 m/s, 하상기질의 선호도는 평균입경(𝚽m) -1.14(grevel)에서 최대의 출현도를 보였으며, HSI -3.35~0.65(grevel~sand)로 산정되었다. 화학적 HSI 산정결과 큰줄납자루는 BOD는 1.0 mg/L에서 최대 출현도를 보였고, HSI는 0.7~1.2 mg/L, T-N은 0.925 mg/L에서 최대 출현도를 보이며 HSI는 0.604~1.277 mg/L, T-P는 0.028 mg/L에서 최대 출현도를 보이며 HSI는 0.021~0.034 mg/L, SS는 3.6 mg/L에서 최대 출현도를 보이며, HSI는 2.1~5.2 mg/L의 범위로 산정되었다. 산정된 범위는 환경부 생활환경기준 BOD 매우좋음(Ia)~좋음(Ib), T-P 매우좋음(Ia)~좋음(Ib) 등급으로 각각 확인되었다. 본 과제는 3차년(2022년)이 아직 남아 있어 HSI에 대하여 약간 보정이 있을 것이며, 최종 HSI가 산정이 되면 향후 환경적 기능을 고려한 중장기 정부 정책의 활용성 높은 기초자료가 될 것이다.

• Korean Journal of Ichthyology
• /
• v.29 no.2
• /
• pp.89-93
• /
• 2017

For the karyotype analysis of Liobagrus hyeongsanensis, an endemic Korean torrent catfish, ten females and five males were used from Yangbuk-myeon, Gyeongju-si, Gyeongsangbukdo, Korea. The diploid number of chromosomes was 42, and its karyotype consisted of 30 metacentrics and 12 submetacentrics; 84 FN (fundamental number), with having no polyploidy and sexual dimorphism. The chromosome number was the same as other closely-related species, L. mediadiposalis and L. somjinensis, but their karyotypes showed a clear difference by species. Such result may be related to chromosomal rearrangements by Robertsonian rearrangement with geographical isolation.

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