background: trematodes belonging to the genus schistosoma cause schistosomiasis. the relationship between schistosomes and their intermediate hosts varies among snails. this study investigated the effects of s. japonicum on its snail host, oncomelania hupensis, and cercarial release rythmicity of s. japonicum and the effects of light on it. methods: : seven groups of o. hupensis (n = 40 each) w...

1. Cyclical swimming behaviour of the cercariae of the digenetic trematode, Proterometra macrostoma, involves a highly regular alternating swim-sink sequence. During periods of swimming the cercariae are propelled upward through the water by alternating lateral contractions of the tail. Following each burst of swimming the cercariae passively drift downward. 2. Suction electrode recordings from...

The vectorial capacity of Biomphalaria pfeifferi from Ndiangue, Senegal, was investigated with an allopatric isolate of Schistosoma mansoni from Nkolbisson, Cameroon. The snail infection rate after exposure to a single miracidium per snail (MD1) was 56. 3 %, and 91.6%, for snails exposed to 5 miracidia per snail (MD5). The minimum pre-patent period was 21 days. The mean total cercarial producti...

The pond snail Lymnaea auricularia serves as an intermediate host for many digenian species. In West Azerbaijan province, northwestern Iran, the cercariae infection investigation was undertaken in L. auricularia from May to November 2010. Of 6759 collected Lymnaeid snails, 370(5.5%) L. auricularia snails were identified. Cercariae infection was found in a number of 276 (74.56 %) snails. The re...

Under natural conditions, the emergence of Opisthorchis viverrini cercariae from naturally infected Bithynia (Digoniostoma) siamensis goniomphalos showed diurnal periodicity, peaking between 8:00-10:00 AM. The cercariae did not emerge during darkness, but low-intensity light could induce a release. Cercariae shedded from each field infected B.(D.) s. goniomphalos was recorded daily. The maximum...

Centrocestus armatus is an intestinal parasite belonging to the family Heterophyidae. We developed an apparatus for recovering cercariae and clarified the infection dynamics of this parasite. To clarify the circadian rhythm of cercarial shedding in the summer season, we filtrated 30 l of river water every 2 h for 24 h. Cercariae were first detected between 06:00 and 08:00 h, increased over time...

Nghiên cứu thành phần loài ốc dựa theo đặc điểm hình thái trong ruộng lúa ở xã Tân Nhựt, huyện Bình Chánh, Thành phố Hồ Chí Minh được thực hiện vào tháng 8/2022 (mùa mưa) và 2/2023 khô). Tổng số 791 mẫu từ 9 ốc, giống, 6 họ đã thu phân loại gồm có: Pomacea canaliculata (57,4%), Bithynia siamensis (18,5%), Melanoides tuberculata (8,5%), Filopaludina sumatrensis (6,6%), Indoplanorbis exustus (3,8...

The morphology of cercariae of freshwater snails from Erawan Waterfall, Erawan National Park, Kanchanaburi Province was studied between December 2002 and August 2003. The snail samples were collected by handpicking using a counts per unit of time sampling method. The cercariae, larva stage of a trematode, were investigated using the shedding method where they were categorized into three groups ...

Over a period of about 12 years, 30 abnormal Schistosoma mattheei cercariae were found among a total of approximately 2.8 million examined. Initially seven were recovered from about 1.02 million (0.0007%), which were examined individually while being counted with the aid of a stereoscopic microscope. Subsequently, on the strength of relatively high percentages of abnormal individuals recovered ...

The effects of exogenous glucose in artificial spring water (ASW) were studied on the survival and infectivity of Schistosoma mansoni cercariae. The mean percent survival of cercariae maintained in 1% glucose in ASW for 36 and 48 hr was significantly greater than that of cercariae maintained identically in ASW. Cercariae maintained in ASW with or without glucose for 24 hr, fixed in neutral buff...