• The Korean Journal of Malacology
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• v.16 no.1_2
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• pp.11-16
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• 2000

The electrophoretic banding patterns of 6-phosphogluconate dehydrogenase (PGD) in the two different chromosomal ploidy groups of Gyraulus were compared. The monomeric or dimeric banding patterns or allelic variations in a locus of PGD were observed in four diploid populations (Osan, Sohre, Kimpo and Kangwha) of G. convexiusculus occurring in Korea, whereas the isozyme banding patterns encoded by at least 3 different loci were shown in the tetraploid populations of G. (Torquis) groups collected from Michigan, the U.S.A. Of 3 different tetraploid groups, G. (T.) circumstriatus group showed 3 monomorphic isozyme banding patterns, and the other 2 populations showed some allelic variations. Such results provided good evidence to differentiate tetraploid subgenus Torquis group from the diploid Gyraulus populations.

• The Korean Journal of Malacology
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• v.9 no.2
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• pp.57-67
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• 1993

A cladistic analysis for phylogenetic relationship among 3 freshwater planorbid snail species was carried out on the basis of their conchological and anatomical characteristics.The intestinal loop in the digestive systims was mainly distinguishable among 3 species of the planorbid snails. The loops in Hippeutis cantori and Segmentina hemisphaerula coiled around stomach, extended down to the distal part of the liver and finally connected with the anus, while the loop in Gyraulus convexiusculus was short and small, and connected directly to the anus after coiling around the stomach. However, the intestinal loop of Hippeutis cantori was the largest among those of 3 target snail species. In the main morpholohical differences of the riproductive systems, Gyraulus convexiusculus uniquely had a calcareous stylet in the penis sheath. Although there was no stylet in the penis sheath in the other snail species, the penis shesths connected with 1 and 2 flagella in Segmentina hemisphaerula and in Hippeutis cantori, respectively were different from each other. Two planorbid species, Hippeutis cantori and Segmintina hemisphaerula have a more recent phylogenetic ancestor out three species employed including Gyraulus convexiusculus.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.589-590
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• 2001

The genus Gyraulus is a large group of very small species of freshwater snails belonging to the pulmonate family Planorbidae. One of the these group the subgenus Torquis, contains some of the smaller members of the genus, and includes one of the most widespread and common of the North American freshwater snails, G. (Torquis) parvus. (omitted)

• The Korean Journal of Malacology
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• v.11 no.1
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• pp.51-61
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• 1995

A horizontal starch gal electrophoresis for enzyme proteins extracted from 3 species of Korean planorbid snails; Gyraulus convexiusculus, Hippeutis cantori and Segmentina hemisphaerula was carried out in order to elucidate their genetic relationships.The results from 12 enzymes employed in three different kinds of buffer systems are summarized as follows:1) Two loci from each enzyme of aldehyde oxidase, esterase, glucose phosphate isomerase. isocitrate dehydrogenase, leucine aminopeptidase, malate dehyogenase, peptidase and xanthine oxidase were detected, and only one locus was observed from each of the following four enzymes: 6-phosphogluconate dehydrogenase, glyceraldehyde-phosphate dehydrogenase, glutamate oxaloacetate transaminase and glycerol-3-phosphate dehydrogenase.2) Most of loci in 3 species of planorbid snails employed showed homozygous and monomorphic banding patterns and some of them were specifis as genetic markers among different species. However, a few of loci (EST-1. EST-2 and GPI-2)showed polymorphic banding patterns. 3)Hippeutis cantori and Segmentina hemisphaerula were more closely clustered in a dendrogram with the genetic iddentity value of 0.431, and these two species were lineated with Gyraulus convexiusculus as another cluster at the value of 0.294.In summarizing the above results, three species of Korean planorbid snails employed in this study mostly showed monomorphic enzyme protein banding patterns and genetic differences specific among 3 species.

• The Korean Journal of Malacology
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• v.10 no.1
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• pp.27-37
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• 1994

한국산 담수 또아리물달팽이과(Planorbidae)에 속하는 또아리물달팽이(Gyraulus convexiusculus),수정또아리물달팽이(Hippeutis cantori) 및 배꼽또아리물달팽이(Segmentina hemisphaerula)3종에 대한 종간 유전적 변이와 이들 상호간의 분류학적 유연 관계를 생화학적 측면에서 밝히고자 하였다. 즉, 모계유전으로 자손에 유전되고 있는 미토콘드리아 DNA(mitochondrial DNA; mt DNA)의 변이를 보기위하여 제한효소(restriction enzyme)를 처리하고 잘라진 mtDNA절편들을 상호 비교하는 restriction fragmint length polymorphism(RFLP)기법을 응용하였다. 본 실험에서 10개의 제한효소 중 CIa I, Dra I, Eco RI, Hin dIII, Kpn I및 pst I의 6개 제한효소에서 좋은 결과를 얻어 종간의 공통절편(shated fragmints)을 비교하였고, 염기분화율(nucleotide divergince rate)을 각각 측정하였다. 미토콘드리아 DNA 크기(genome size)는 또아리물달팽이가 12.08 kb, 수정또아리물달팽이가 14.4 kb, 그리고 배꼽또아리물달팽이가 12.93 kb로 관찰되었다. 염기분화율(p)는 또아리물달팽이/수정또아리물달팽이 군에서 p=12.7%, 배꼽또아리물달팽이와 상기 2종군 사이의 염기분화율은 P=56.6%여서 배꼽 또아리물달팽이류는 타 2종보다 그 분화율이 매우 높음을 알 수 있었다. 이상의 결과로 보아 분류군(taxa)의 mtDNA 변이에 의한 RELP기법이 앞으로 한국산 담수 패류 연구에 널리 응용될 수 있음이 확인되었다.

• Parasites, Hosts and Diseases
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• v.21 no.1
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• pp.118-124
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• 1983

The distribution, external morphology, radula, chromosome numbers of Planorbidae snails were studied. 1. The specimens were collected at four stations in Nonsangun, Kongjugun, and Daedukgun which are located around Geum river. Three genera and three species of Planorbidae, Hippeutis cantorir Segmentina hemisphaerula and Gyraulus cenvexiusculus, were collected. H. cantori was the most abundant species among the three species. G. convexiusculus was the least abundant one. 2. Each species could be identified on the basis of its external characteristic, since the periphery of each species has a peculiar shape. H. cantori was the largest one among the three species. 3. The radula formula of each species was very similar to other species. The size of radula was proportional to the size of shell. The radula formulae of H. cantori, S. hemisphaerula, and G. convexiusculus were 29 : 1 : 29, 23 : 1 : 23, and 16 : 1 : 16 respectively. The difference of radula formula could be found in the total numbers of laternal and marginal teeth. 4. The haploid chromosome number of H. cantori was eighteen (n=18), S. hemisphaerula and G. convesiusculus were assumed to be same in their chromosome numbers (n: 18).

• Journal of Environmental Science International
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• v.25 no.4
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• pp.459-472
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• 2016

We assessed the distribution of benthic macroinvertebrate at four surveying sites in Upo Wetland, a Ramsar site and the largest wetland in Korea, from February 2006 to November 2013. A long-term ecological monitoring was done monthly by using quantitative sampling method with dip net for analyzing the community change and correlation between the biodiversity and the environmental factors because environmental factors have a decisive effect on the community structure of the benthic macroinvertebrates. Total samples from the Upo Wetland area were classified into 3 phyla, 6 classes, 17 orders, 68 families, 176 species, and 25,720 individuals. Among the 176 species, 62 of the species had not been previously reported in this area. Asellus sp., Diplonychus esakii, and Gyraulus chinensis were the most common species in Upo Wetland. The change patterns of annual species diversity and species richness were calculated by using the average number of monthly occurring species and individuals. Diversity index increased from March to May and decreased after that showing lower diversity indices in July and August. It increased again in September and in October. Richness index showed similar tendency and fell around February and July, followed by a rising tendency around May and October. Correlation and regression analyses were performed with the change of biodiversity and each environmental factor. We found that water temperature have very significant positive correlation with species diversity in spring, and have significant indices in autumn and winter. On the other hand, precipitation showed a significantly negative correlation value in summer and autumn suggesting it has an effect on the community structure of benthic macroinvertebrates.

• The Korean Journal of Malacology
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• v.19 no.1
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• pp.53-70
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• 2003

In order to understand freshwater molluscan fauna in Asan area, a survey was conducted on the watersheds of this area during the period of October 1999 to August 2000. For the purpose of easy overlook of the molluscan fauna in Asan area, present survey was undertaken on a total of 101 sampling sites of 4 major watersheds connected along Onyang River, Gokgyo River, Sapgyo Lake, and Asan Lake. The collected freshwater mollusks were analysed based on the environment of their habitats. The freshwater mollusks collected through out the present survey were 27 species, 12 families, 5 orders, and 2 classes. Of these, gastropods were 18 species, 10 families, 3 orders; and bivalves were 9 species, 2 families, and 2 orders. The dominant gastropods in this area were Radix auricularia coreana, Cipangopaludina chinensis malleata, Hippeutis cantori, Physa acuta, Gyraulus convexiusculus and Austropeplea ollula and the dominant bivalves were Anodonta arcaeformis, Anodonta arcaeformis flavotincta, and Anodonta woodiana. Dominant species in rice fields were Fossaria truncatula, Segmentina hemisphaerula and Physa acuta, dominant species in rivers were Radix auricularia coreana, Physa acuta, and Hippeutis cantori. Dominant species in reservoirs were Cipangopaludina chinensis malleata, Radix auricularia coreana, Austropeplea ollula, and Fossaria truncatula. Dominant species collected in lakes were Cipangopaludina chinensis malleata, Hippeutis cantori, Cipangopaludina japonica, and Radix auricularia coreana. Radix auricularia coreana, Cipangopaludina chinensis malleata, and Austropeplea ollula were dominantly inhabiting on the muddy bottoms. Anodonta woodiana, Cipangopaludina japonica, and Corbicula fluminea occurred mainly in the gravel areas. Radix auricularia coreana, Cipangopaludina chinensis malleata, and Hippeutis cantori were dominant in the muddy rock areas. Rock-dominant species were Radix auricularia coreana, Semisulcospira forticosta and Koreanomelania paucicincta. Sand-dominant species were Physa acuta, Radix auricularia coreana, and Hippeutis cantori. Sand gravel-dominant species were Physa acuta, Radix auricularia coreana, and oreanomelania paucicincta. Hippeutis cantori, Cipangopaludina chinensis malleata, and Gyraulus convexiusculus occurred in the sand-muddy areas. Cristaria plicata, appointed as an endangered species from the "Natural Environmental Conservation Law", was collected from 5 sampling sites (site Nos. 45, 47, 48, and 52). For the endangered species found in this survey should be make appropriate protection.