• Korean Journal of Ichthyology
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• v.22 no.1
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• pp.56-60
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• 2010

The Cobitis hankugensis-Iksookimia longicorpa complex from Korea has been presumed to be a unisexual lineage, originating from C. hankugensis and I. longicorpa and having almost all females. Recently, it was confirmed that the complex consisted of one diploid and two triploid complexes. From observation of their oocyte envelopes, three forms could be classified: a villous projection in I. longicorpa, a granular one in C. hankugensis and two triploid complexes, and a granule with villous one in the diploid complex. Even within the same granular projection, they showed specific features in length and density number from each other. These architectures are first observed in cobitid complexes and may playa role in identification of diploids and triploids.

• Korean Journal of Ichthyology
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• v.24 no.2
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• pp.94-100
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• 2012

The spine loach, Cobitis hankugensis endemic to Korea were collected at the Nokdong River, Unbong-eup, Namwon-si, Jeollabuk-do during June 2007 for study its eggs development and early life history. The eggs were obtained by injecting gonadotropin (LHRH-1) to female and were fertilized by dry method in the laboratory condition. The matured eggs were separative, demersal and light yellowish with $1.29{\pm}0.07mm$ in diameter average. Under $23{\sim}25^{\circ}C$, the eggs were hatched in 45~52 hours after fertilization, and just hatching larvae were $4.5{\pm}0.24mm$ in total length. On 5 days after hatching, they were $6.6{\pm}0.13mm$ in total length and their yolk sacs were completely absorbed. From 25 days after hatching, they became the juvenile stage with $9.0{\pm}0.49mm$ in total length. On the 100 days after hatching, their external forms and band patterns were similar to those of adults with average $27.3{\pm}2.82mm$ in total length.

• Korean Journal of Environment and Ecology
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• v.25 no.6
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• pp.878-886
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• 2011

The fish fauna and characteristic of population of Brachymystax lenok tsinlingensis at the 7 stations in the Bonghwa-gun were investigated from June 2010 to May 2011. The collected species during the survey period were 15 species belong to 7 families. Protected species by the legal were B. lenok tsinlingensis, Koreocobitis naktongensis, and Cottus koreanus. Korean endemic species were Microphy sogobio yaluensis, Coreoleuciscus splendidus, Zacco koreanus, Cobitis hankugensis, K. naktongensis, Iksookimia longicorpa, Niwaella multifasciata, Liobagrus mediadiposalis, C. koreanus, and Coreoperca herzi, which showed a ration of 66.7% in collected species. Dominant species were Z. koreanus(St. 1), B. lenok tsinlingensis(St. 3, 4, 5), and Rhynchocypris oxycephalus(St. 2, 6, 7). Length-weight relation in the population of B. lenok tsinlingensis was BW = $0.000008TL^{3.02}$, and condition factor in the population was average 0.84. Frequency analysis of total length indicated that the group 80~180 mm in total length is represented by one-year-old individuals, the group 200~300 mm by two-year-old individuals, and the group over 300 mm by three-year-old individuals. The density of population was presumed average 17 individuals per 100$m^2$ and total 4,760 individuals in the reservation for B. lenok tsinlingensis.

• Ecology and Resilient Infrastructure
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• v.4 no.1
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• pp.34-43
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• 2017

The Naeseong Stream as a tributary of Nakdong River has conserved the unique structure and function of a typical sand-bed stream ecosystem. However, it is expected to change the stream bed environments and then the fish fauna in the downstream of the dam after the operation of the Yeongju Dam from 2016. We collected fishes and investigated their habitat environments from 2014 to 2016 in the downstream of the Yeongju Dam under construction in order to monitor changes in habitat environment, fauna and community structure of fishes in the Naeseong Stream. The size of the bed materials increased immediately downstream of the Yeongju Dam under construction. Before the operation of the Yeongju Dam, Zacco platypus was dominated and Opsarichthys uncirostris amurensis, Coreoleuciscus splendidus, Hemibarbus longirostris and Pseudogobio esocinus were sub-dominated according to the different sampling sites. Hemibarbus labeo, H. longirostris, Pseudogobio esocinus, Gobiobotia nakdongensis, Cobitis hankugensis and Leiocassis ussuriensis were found as a psammophilous fish specific to sand stream in the Naeseong Stream. At the downstream of the dam, the fish community was classified into a group of gravel-bed fishes such as Microphysogobio yaluensis, Coreoleuciscus splendidus and Coreoperca herzi and a group of sand-bed fishes such as Hemibarbus labeo, Cobitis hankugensis and Gobiobotia nakdongensis. These fish communities gradually tended to change from sand-bed fish community to gravel-bed fish community during the construction of the Yeongju Dam. Therefore, it is necessary to collect the baseline data for the stream ecosystem conservation in the sandy stream by continuously monitoring changes in the environment and fish in the downstream of the Youngju Dam.

• Korean Journal of Environmental Biology
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• v.28 no.3
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• pp.143-149
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• 2010

The pathogens and community structure of the fishes in Taehwa river were investigated from March 2007 to January 2009. During the study period, 3,504 individuals belonging to 35 species, 17 families and 9 orders were collected. The numerically dominant and subdominat species were Opsarichthys uncirostris (relative abundance 39.7%) and Hemibarbus labeo (relative abundance 30.9%). There were five Korean endemic species (20.8%) including Squalidus chankaensis tsuchigae, Zacco koreanus, Cobitis hankugensis, Coreoperca herzi, Odontobutis platycephala. The large fishes like Hemibarbus labeo or Opsarichthys uncirostris were gathered around the Samho bridge, sampling site 2 according to a season. The reaction to which two kinds of fish pathogenic virus is all negative and no fish pathogenic bacteria was isolated from 220 individuals. The fish pathogenic parasite not present variously with 7 species. Especially, Trichodina sp. was detected monthly and the infective density was high. But it is cosidered that temporary overcrowding of fish is not influenced mass mortality causing diseases in the specific site of river.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.874-887
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• 2016

We surveyed bimonthly from April to October 2015 to understand the fish fauna and community structure in Wangpicheon. The collected species during the survey period were 40 species belonging to 15 families. Dominant species by number were Zacco koreanus (31.3%) and Rhynchocypris oxycephalus (14.7%). In biomass, the dominant species were Z. koreanus (29.2%) and Coreoperca herzi (8.6%). Also, nine endemic species (22.5%) including Squalidus multimaculatus and two endangered species (Lethenteron reissneri, Cottus koreanus) were identified. It was identified one introduced species (Oncorhynchus mykiss) from foreign countries for aquaculture. Compared with previous data, nine species were newly identified including L. reissneri, S. gracilis majimae, Pseudobagrus fulvidraco, O. mykiss, Chelon haematocheilus, Siniperca scherzeri, Acanthogobius lactipes, Luciogobius guttatus and Channa argus. Seven species (Rhodeus ocellatus, S. gracilis majimae, Hemibarbus longirostris, Pseudogobio esocinus, Microphysogobio yaluensis, Hemiculter eigenmanni and Cobitis hankugensis) introduced from other native waters in Korea were estimated. According to the analysis of the habitat characteristics of major migratory species (Tribolodon hakonensis, O. keta and Plecoglossus altivelis), O. keta was observed at station 11 and T. hakonensis at station 7, 10 and 11. These fishes have been mainly identified in the downstream. However P. altivelis was widely distributed from station 3 to 11. In the comparison of average standard length of P. altivelis at each station during the same period, populations collected from station 3 and 5 which are mid-upper area of the stream were $125.8{\pm}34.2mm$. Their growth was good compared with those collected from station 8 and 11 (mid-lower area): $80.2{\pm}16.6mm$. This difference in length comes from the artificial structures including weir, thus it is necessary to create a fishway that enables P. altivelis to pass around barriers for free movement and resource management.