• Korean Journal of Ecology and Environment
• /
• v.37 no.1 s.106
• /
• pp.102-105
• /
• 2004

Larvae of two heptageniid mayflies, Iron martinus Braasch and Sold${\acute}$n and Iron longitibius sp. n., are described from Vietnam. The larva of I. martinus is distinguished by the paired spines on the abdominal segments 1-9; the larva of I. longitibius sp. n. is distinguished by the relatively long foretibiae. Their descriptions, diagnoses, line drawings of key characters, material examined, distributions, and habitat and biology data are provided.

• Animal Systematics, Evolution and Diversity
• /
• v.20 no.2
• /
• pp.215-223
• /
• 2004

Two species of the heptageniid mayfly genus Thalerosphyrus Eaton, T. vietnamensis (Dang) and T. separatus n. sp., are described from Vietnam. Thalerosphyrus separatus can be distinguished by the basally detached posterolateral expansions of pronotum in larva and by the Y -shaped penes in male adult. Their larval and adult stages are described with line-drawings of diagnostic characters. Their diagnoses, distributions, habitat and ecological data, and taxonomic remarks are provided.

• The Korean Journal of Ecology
• /
• v.20 no.6
• /
• pp.461-470
• /
• 1997

There are 7 classes, 17 orders, and 141 species of benthic macroinvertebrates at the 5 study sites from Feb, '91 to May, '92. Total species frequency number has less variations among sites than seasonal changes. Not considering seasonal changes this indicates that there are some influences from outside pollution sources. Seasonally, Ortho chadiinae sp. 2 take 21.2% share of total species. It was the dominant species in Feb. '91. With total average level Ephemeroptera take 51.3% of total species as first dominant species. Diptera 27.8% as second dominant species and Trichoptera 16.7% as third dominant species. Through these biological indexes, they appear to have unstable living environments in summer at sites 1 and 5. One can see that site 1 is more polluted than site 3 because site 1 has more pollution sources such as pastures and recreation areas.

• Animal Systematics, Evolution and Diversity
• /
• v.14 no.1
• /
• pp.1-12
• /
• 1998

Comprehensive examinations of larval and adult materials of mayfles from Korea resulted in Alainites muticus, Baetis fuscatus, B. pseudothermicus (new record), B. silvaticus (new record), B. ursinus (new record), Labiobaetis atrebatinus, and Nigrobaetis acinaciger (new record) in Baetidae. Larvae and known adults are described, figured, and photographed with SEM.

• Environmental Engineering Research
• /
• v.24 no.4
• /
• pp.638-645
• /
• 2019

This research was an evaluation of the fish fauna and the habitat for Brachymystax lenok tsinlingensis (B. lenok tsinlingensis) for 11 stations at the Bonghwa-gun sanctuary. The predominant species in this research area was Zacco koreanus. B. lenok tsinlingensis, which has been designated as an endangered freshwater fish in Korea, was found in the Bonghwa sanctuary zone, except at stations 5 and 6. The B. lenok individuals were shorter in length than 400 mm. In total, 13 endemic species were found, including Coreoleuciscus splendidus and Iksookimia longicorpus. Specimens of Koreocobitis naktongensis, a first grade endangered species, were also collected. The benthic macroinvertebrates consisted of four divisions, four classes, seven orders, 30 families, 60 species, and 10,344 individuals and were distributed among the orders Ephemeroptera (55.9%), Diptera (18.2%), Trichoptera (12.4%), Plecoptera (2.1%), and Odonata (0.3%).

• Animal Systematics, Evolution and Diversity
• /
• v.39 no.3
• /
• pp.86-91
• /
• 2023

The genus Teloganopsis Ulmer belonging to the family Ephemerellidae is only known from the species of T. punctisetae (Matsumura, 1931) in the Korean Peninsula. The members of the genus Teloganopsis are characterized by the following characteristics: head and abdominal tergites without any tubercles and complex setae; forefemur with a row of long and stout setae perpendicularly; maxilla covered with dense setae. A total of 17 species had been previously recorded in this family. Here, Teloganopsis chinoi (Gose, 1980), is newly recorded in Korea which was found under a large stone in Kyeongho river. Larval habitus, habitat, line-drawings of key characters of the species, a checklist with habitus photos of Korean Ephemerellidae, and a key to the larvae of Korean Teloganopsis are provided.

• Korean Journal of Ichthyology
• /
• v.25 no.2
• /
• pp.90-105
• /
• 2013

This study was performed to find out stomach contents of cold water fish such as Manchurian trout (Brachymystax lenok tsinlingensis) and River salmon (Oncorhynchus masou masou) in the Odae mountain area. Field survey was carried out 3 times by each season from May to October 2012 along the Gyebang stream and the Yangyang-Namdae stream at north-west mountain slope and north-east mountain slope of the Odae mountain area respectively. The result of digestive track analysis showed that food species of Manchurian trout were total individuals of 645 including 5 orders, 23 families, 39 species of benthic macroinvertebrates and 11 taxa of terrestial insects. And each IRI (Index of Relative Importance, %) value of food species by Manchurian trout was terrestial insects 37.0%, Trichoptera 36.4%, Ephemeroptera 20.0%, Diptera 3.9%, Plecoptera 2.7%, and Gordea <0.1%. While the River salmon fed on 1,186 individuals covering 4 orders, 20 families, 33 species of benthic macroinvertebrates and 6 taxa of terrestial insects including arachnid. Also IRI values by River salmon were terrestial insects including arachnid 2.7%, Ephemeroptera 52.9%, Trichoptera 27.9%, Diptera 9.4%, and Plecoptera 7.0% respectively. With these results, we might say that both Manchurian trout and River salmon is carnivorous fish which display the feeding preference to terrestial insects and benthic macroinvertebrates. As a results we could find out that the two kinds of cold water fish preferred similar habitat types and liked same order of food species in same season, however the compositions of food species for Manchurian trout and River salmon were considerably different.

• Korean Journal of Ichthyology
• /
• v.30 no.1
• /
• pp.27-35
• /
• 2018

The activity period and feeding ecology of the Iksookimia yongdokensis were investigated to obtain baseline data for its ecological characteristics in the Chuksan Stream and Gokgang Stream, Gyeongsangbuk-do, Korea from 2015 to 2016. I. yongdokensis were active on cobble, pebble and sand bottom from March to November when the water temperature exceeded $10^{\circ}C$, but tended to overwinter in cobble and pebble during the winter months (December~February) when the water temperature was lower than $10^{\circ}C$. During the day from 9 am to 15 pm, individuals of I. yongdokensis were highly active with a high rate of food consumption. I. yongdokensis activley fed on the surface of stone, pebble and sand as a filter feeder. Their main food sources analyzed with an index of relative importance (IRI) include Chironomidae (54.7%), Branchiopoda (10.1%), Rotatoria (8.7%), Arcellidae (8.6%), Chlorophyceae (6.5%) and Bacillariophyceae (5.1%). Juveniles of I. yongdokensis (total length 20~39 mm) fed on small-sized preys such as Rotatoria, Branchiopoda and Arcellidae, but they exhibited a transition in their prey-size markedly dominated by large-sized preys such as Chironomidae and Ephemeroptera as they grow.

• Korean Journal of Ecology and Environment
• /
• v.36 no.1 s.102
• /
• pp.29-37
• /
• 2003

Benthic macro-invertebrates were seasonally collected in the Onchen Stream in Pusan, from July 2001 to March 2002. Generally 4 phylum 5 class 10 order 19 family 23 species were observed in the study sites. Ephemeroptera, Plecoptera and various species appeared in headwater stream while Oligochaeta and Chironomidae were dominated in downstream sites. Community abundance patterns, especially the dominant taxa, Oligochaeta and Chironomidae, appeared to be different depending upon the sampling months. Oligochaeta was usually observed in July, December and March while Chironomidae was appeared in September. The biological indices, TBI(Trent Biotic Index), BS (Biotic Score), BMWP (Biological Monitoring Working Party)were calculated with the appeared communities of the sampling sites through the survey months. TBI showed 1 to 8, BMWP was 1 to 93 and CBI appeared 9 to 387 in the different sites. The biological indices decreased from headstream to downstream sites, We implemented the unsupervised Kohonen network for patterning of community abundance of the sampling sites. The patterning map by the Kohonen network was well represented community abundance of the sampling sites. Also, we conducted RTRN (Real Time Recurrent Neural Network) for predicting of the biological indices in the different sites. The results appeared that the predicting values by RTRN were well matched field data (correlation coefficient of TBI, BMWP and CBI were 0.957, 0.979 and 0.967, respectively).

• Korean Journal of Ecology and Environment
• /
• v.33 no.3 s.91
• /
• pp.230-243
• /
• 2000

A large-scale community data were patterned by utilizing an unsupervised learning algorithm in artificial neural networks. Data for benthic macroinvertebrates in streams of South Korea reported in publications for 12 years from 1984 to 1995 were provided as inputs for training with the Kohonen network. Taxa included for the training were 5 phylum, 10 class, 26 order, 108 family and 571 species in 27 streams. Abundant groups were Diptera, Ephemeroptera, Trichoptera, Plecoptera, Coleoptera, Odonata, Oligochaeta, and Physidae. A wide spectrum of community compositions was observed: a few tolerant taxa were collected at polluted sites while a high species richness was observed at relatively clean sites. The trained mapping by the Kohonen network effectively showed patterns of communities from different river systems, followed by patterns of communities from different environmental disturbances. The training by the proposed artificial neural network could be an alternative for organizing community data in a large-scale ecological survey.