• 한국패류학회지
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• 제21권2호
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• pp.133-145
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• 2005

Eight species of bithyniids, Bithynia leachi, B. tentaculata, B. siamensis, B. misella, B. kiusiuensis, B. striatula, Bithynia sp. from Nepal and Gabbia australis were collected from 1957 to 1988. The samples were relaxed with pentobarbital and fixed with 70% ethyl alcohol. There was no significant difference in internal structure of soft body, except the male reproductive system. The alimentary canal of the bithyniids consisted of mouth, buccal mass, esophagus, stomach, intestine, rectum and anus. The heart consisted of an auricle and a ventricle, located at left side of the stomach in the visceral hump. The ctenidium comprised 40-70 subtriangular lamellae. Eight ganglia were located around upper esophagus. The female reproductive system comprised ovary, oviduct, spermaaheca, and albumin gland. The male reproductive system was composed of testis, seminal vesicle, prostate gland, vas deferens, penial duct, and penis in order. Male was distinguished externally from the female by a bifid penis.

• 한국패류학회지
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• 제31권1호
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• pp.49-59
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• 2015

우리나라를 비롯한 아시아, 유럽, 호주 등에서 채집한 쇠우렁이 과 패류 8종 (Bithynia striatula, B. tentaculata, B. siamensis, B. leachi, B. kiusiuensis, B. misella, Bithynia sp., Gabbia australis) 을 대상으로 주사전자현미경 (SEM) 을 이용하여 치설을 관찰한 바 다음과 같은 결과를 얻었다. 치설열의 수는 B. siamensis와 B. leachi의 경우 60-70개로 다른 종들의 치설열의 수 40-50개보다 많았다. 관찰한 8종의 패류의 치설 구조는 좌우대칭으로 한 치설열에 7개의 치아가 있었다. 즉 1개의 중치를 중심으로 좌우에 각각 1개의 측치와 2개의 외연치가 분포하였다. 따라서 기본 치설식은 2:1:1:1:2로 표시할 수 있었다. 소첨두의 수와 모양은 개체별, 종별로 차이가 있었으며 중치에만 기저돌기가 분포하였다. 중치의 중앙돌기의 구조는 B. striatula, B. tentaculata, B. siamensis 및 Bithynia sp.의 구조가 다른 종들과 차이가 있었다.

• 한국패류학회지
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• 제6권1호
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• pp.11-21
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• 1990

한국과 일본에서 채집한 Bithynia manchourica, B. misella and kiusiuensis등 3종의 Bithyniidae 과 패류의 allozyme 을 분석한 결과 B. manchourica 가 다른 2종에 비해 유전적 거리가 멀었고(0.246)B. misella와 B. kiusiuensis에서는 유전적 거리가 0.217로 나타났다. 아울러 이들 3종의 GPI주행양상은 채집지에 따른 변이가 심하지 않았고 각 종에 따른 특이한 allele을 가지고 있었다.

• 한국패류학회지
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• 제5권1호
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• pp.42-56
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• 1989

Shells and operculums of eight species of Bithyniidae, Bithynia leachi, B. tentaculata, B. siamensis, B. misella, B. kiusiuensis, Gabbia australis, B. manchourica and a Bithynia sp. collected from Nepal, were observed, There is no morphological difference between korean populations of B. misella and a Japanese popualtion of B. kiusiuensis. And the shells of these species were simialr to the other Bithynia species rather than Australian Gabbia. The coordinate of the starting point of nuclear spire of operculum(SPN)was species specific and this value had very limited range within a species. The result suggested that Korean and Japanese populations of B. misella and B. kiusiuensis are synonym and the coordinate of SPN will be a useful character in sytematics of operculated snails.

• 한국패류학회지
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• 제10권1호
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• pp.19-26
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• 1994

Eight species of the family Bithyniidae, Bithynia tentaculata, B. leachi, B. siaminsis, B manchourica, B misella, B. kiusiuensis, Gabbia australis and a Bithynia wp. collected from Nepal, were studied for their relationship between species. Total 20 characters were employed for the principal component analysis(PCA) and taxonomic distance. G. misella and B. kiusiuensis were closely related and similar to G. australis. B. manchourica, B. tentaculata and B. siamensis relatively closed group, and taxonomic distance of B. leachi was far from the other species.

• Parasites, Hosts and Diseases
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• 제51권2호
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• pp.183-189
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• 2013

The occurrence of 37-collar spined echinostome metacercariae in freshwater snails was investigated in 6 districts of Chiang Mai Province, Thailand, from October 2011 to April 2012. A total of 2,914 snails that belong to 12 species were examined, and 7 snail species (Clea helena, Eyriesia eyriesi, Bithynia funiculata, Bithynia siamensis siamensis, Filopaludina doliaris, Filopaludina sumatrensis polygramma, and Filopaludina martensi martensi) were found infected with echinostome metacercariae. The prevalence of metacercariae was the highest in Filopaludina spp. (38.5-58.7%) followed by B. funiculata (44.0%), E. eyriesi (12.5%), B. siamensis siamensis (8.2%), and C. helena (5.1%). Metacercariae were experimentally fed to hamsters and domestic chicks, and adult flukes were recovered from both hosts at days 15 and 20 post-infection. The adult flukes were identified based on morphological features, morphometrics, host-parasite relationships, and geographical distribution. They were compatible to Echinostoma revolutum or Echinostoma jurini, with only minor differences. As the adults were recovered from both hamsters and chicks, our specimens were more compatible to E. revolutum rather than E. jurini (reported only from mammals). This is the first report for metacercariae of E. revolutum in the snail host, C. helena, and also confirmed that Filopaludina spp., E. eryresi, and Bithynia spp. act as the second intermediate hosts of E. revolutum under natural conditions, which are indigenously distributed in Chiang Mai province.

• Parasites, Hosts and Diseases
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• 제51권5호
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• pp.537-544
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• 2013

The present study was performed to observe histopathological changes in tissues of Bithynia siamensis goniomphalos (Gastropoda, Bithyniidae) incubated in crude extract solutions of camellia (Camellia oleifera) seed and mangosteen (Garcinia mangostana) pericarp, and furthermore to estimate the molluscicidal effects of 2 plant substances. Substantial numbers of bithyniid snails were incubated in various concentrations of 2 plant solution for 24 hr. As the positive control, snails incubated in various concentrations of niclosamide, a chemical molluscicide, were used. The histopathological findings were observed in sectioned snail specimens of each experimental and control groups. The results showed that both camellia and mangosteen extracts had molluscicidal effects at 24 hr with 50% lethal concentration ($LC_{50}$) at concentrations of 0.003 and 0.002 g/ml, respectively, while niclosamide had $LC_{50}$ at concentrations 0.599 ppm. B. siamensis goniomphalos snail tissues (foot, gill, and digestive system) showed disruption of columnar muscle fibers of the foot, reduction of the length and number of gill cilia, numerous mucous vacuoles, and irregularly shaped of epithelial cells. Irregular apical and calciferous cells, dilatation of the digestive gland tubule, and large hemolymphatic spaces, and irregular apical surfaces, detachment of cilia, and enlargement of lysosomal vacuoles of epidermis were also shown in all groups. By the present study, it is confirmed that 2 plants, camellia and mangosteen, are keeping some substance having molluscicidal effects, and histopathological findings obtained in this study will provide some clues in further studies on their action mechanisms to use them as natural molluscicides.

• Parasites, Hosts and Diseases
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• 제58권5호
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• pp.499-511
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• 2020

Echinostome metacercariae were investigated in freshwater snails from 26 districts in 7 provinces of upper northern Thailand. The species identification was carried out based on the morphologies of the metacercariae and adult flukes harvested from experimental hamsters, and on nucleotide sequences of internal transcribed spacer 2 (ITS2) and nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad1) genes. Twenty-four out of 26 districts were found to be infected with echinostome metacercariae in freshwater snails with the prevalence of 40.4%. The metacercariae were found in all 6 species of snails, including Filopaludina martensi martensi (21.9%), Filopaludina doliaris (50.8%), F. sumatrensis polygramma (61.3%), Bithynia siamensis siamensis (14.5%), Bithynia pulchella (38.0%), and Anenthome helena (4.9%). The echinostome metacercariae found in these snails were identified as Echinostoma revolutum (37-collar-spined) and Echinostoma macrorchis (45-collar-spined) morphologically and molecularly. The 2-week-old adult flukes of E. revolutum revealed unique features of the cirrus sac extending to middle of the ventral sucker and smooth testes. E. macrorchis adults revealed the cirrus sac close to the right lateral margin of the ventral sucker and 2 large and elliptical testes with slight indentations and pointed posterior end of the posterior testis. The ITS2 and nad1 sequences confirmed the species identification of E. revolutum, and the sequences of E. macrorchis have been deposited for the first time in GenBank. The presence of the life cycle of E. macrorchis is a new record in Thailand and the snail F. doliaris as their second intermediate host seems to be new among the literature.

• Applied Microscopy
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• 제18권2호
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• pp.132-140
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• 1988

The radulae of six species of bithyniid snails, Bithynia striatula, B. tentaculate, B. siamensis, B. leachi, Gabbia misella and G. australis, were observed by SEM. The radular formula of all the bithyniids studied was 2 : 1 : 1 : 1 : 2. The all teeth were multicuspid and the central teeth had numerous basal denticles. The mesocones of the central and lateral teeth were spade or arrow-head shape. The mesocones of the central teeth and the lateral teeth of B. leachi, G. misella and G. australis were slightly larger than the other cusps in contrast of those of the other species. Number of cusp was varied by the specimen and the species.

• Parasites, Hosts and Diseases
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• 제56권3호
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• pp.247-257
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• 2018

The aim of this study was to conduct a freshwater snail survey in Mae Lao agricultural basin to assess the diversity with a focus on habitat types and their larval trematode infections. Snails were collected and examined in 14 sites of Mae Lao agricultural basin from August 2016 to October 2017. A total of 1,688 snail individuals were collected and classified into 7 families, 8 genera, and 12 species. Snail diversity and habitat types were higher in rice paddies than irrigation canals and streams. The most abundant species was Bithynia siamensis siamensis, representing 54.6% of the sample. Three species of snails act as first intermediate host were found with cercarial infections. They were Filopaludina sumatrensis polygramma, B. s. siamensis, and Melanoides tuberculata. The cercariae were categorized into 7 types; echinostome, monostome, gymnocephalous, virgulate, parapleurolophocercous, pleurolophocercous and megalurous cercariae. Parapleurolophocercous cercariae constituted the most common type of cercariae recovered, contributing 41.2% of all infections in snails. Echinostome metacercariae infections were found in 6 snail species with 7.6% prevalence. In addition, the metacercaria of avian trematode, Thapariella sp. were found in Filopaludina spp. snails and B. funiculata with a prevalence of 0.5%. This is the first report for Thapariella metacercariae in the snail host, B. funiculata, and also confirmed that viviparid and bithyniid snails act as the second intermediate hosts of this trematode. This work will provide new information on the distribution and intermediate host of trematode in this area.