The Marine Gastropods Crepidula plana and Crepidula convexa Do Not Serve as First Intermediate Hosts for Larval Trematode Development

2012 ◽  
Vol 79 (1) ◽  
pp. 5-8 ◽  
Author(s):  
Jan A. Pechenik ◽  
Bernard Fried ◽  
Jeff Bolstridge
Parasitology ◽  
1927 ◽  
Vol 19 (1) ◽  
pp. 86-99 ◽  
Author(s):  
F. J. Brown

1. Crepidostomum farionis inhabits the gall bladder, as well as the intestine and pyloric caeca, of the trout and grayling.2. The life history of Crepidostomum farionis has been worked out and is based on the similarity of organisation of the cercaria, encysted larval trematode and the adult.3. The first intermediate hosts in the life history of this trematode are Pisidium amnicum (Müll.) and Sphaerium corneum (L.) though the latter is unusual.4. The second intermediate host is the larva of the mayfly, Ephemera danica (Müll.).5. There are two generations of rediae, the first gives rise to daughter rediae, which in turn produce cercariae.6. The rediae are characterised by the absence of ambulatory processes and a functional intestine.7. The cercaria (n.sp.) possesses “eye spots,” stylet and gland cells (salivary?), and the excretory vesicle is tube-shaped.8. The excretory system of the redia and the cercaria has been worked out in detail.9. The relation of the parasites to their respective hosts is discussed. On account of the need for further observations definite conclusions are held over for a later paper.


Parasitology ◽  
1998 ◽  
Vol 117 (4) ◽  
pp. 383-391 ◽  
Author(s):  
M. FERNANDEZ ◽  
D. T. J. LITTLEWOOD ◽  
A. LATORRE ◽  
J. A. RAGA ◽  
D. ROLLINSON

Traditionally, the family Campulidae has been associated either with the family Fasciolidae, parasites of ruminants, or the Acanthocolpidae, parasites of fishes, based on morphological similarities. Since morphology does not seem to resolve clearly the problem of the relationships of campulids, we have used the sequences of the 18S rRNA gene of the campulids Zalophotrema hepaticum, Campula oblonga and Nasitrema globicephalae, the fasciolid Fasciola hepatica, the acanthocolpid Stephanostomum baccatum and the outgroup Schistosoma mansoni to infer a phylogeny. Maximum parsimony and neighbour-joining methods were applied. Both methods indicated that campulids are closer to acanthocolpids than fasciolids. In order to confirm this relationship, we generated a second phylogeny using all the partial sequences of the 18S published for trematodes: Lobatostoma manteri, Echinostoma caproni, Calicophoron calicophorum, Tetracerasta blepta, Gyliauchen sp. and Opistorchis viverrini, plus those mentioned above, and Dicrocoelium dendriticum. The aspidogastrean L. manteri was used as the outgroup. Results were identical to the first analysis. According to this and the most recent Digenean phylogeny, which considers campulids and acanthocolpids as sister groups, we suggest that a common origin for these 2 groups would imply a host-switching process. The life-cycle of acanthocolpids includes marine gastropods as first intermediate hosts, and fishes as second intermediate and definitive hosts. In this context, the hypothesis would be that trematodes whose cycle ended in fishes were able to switch to mammalian hosts.


2021 ◽  
Vol 36 (1) ◽  
pp. 23-33
Author(s):  
J. Nzalawahe

Understanding of the larval trematode infections in snail intermediate hosts is essential in designing appropriate control measures. The current study was designed to determine larval trematode infection and seasonal variations in freshwater intermediate host snails Iringa and Arumeru Districts where trematode infections in cattle are endemic. A repeated cross-sectional study was adopted whereby Snails were collected three times a year (dry, early wet and mid wet). The selection of water bodies for sampling was based on random sampling and snails were collected by scooping method. The collected snails were identified based on the published morphological keys. A total of 2,016 snails were collected and 134 (6.6%) were found to be infected with trematode larvae. Six species of snails were identified that were Radix natalensis, Bulinus africanus group snails, Bulinus tropicus group snails, Bulinus forskalli group snails, Biomphalaria pfeifferi and Ceratophallous natalensis. Five morphologically different types of cercariae were identified that included gymnocephalous, amphistomes, mammalian Schistosoma, avian Schistosoma and Xiphidiocercariae. The findings on overall seasonal snail infection rates indicated low rate during the wet season while peak of infections were in the dry and early wet seasons. It is concluded that domesticated ruminants in the study areas are at high risk of getting infected with the trematodes (Fasciola and amphistomes) during dry and early wet seasons. Therefore, deworming of domesticated ruminants with an effective flukicide is recommended at the end of the wet season and followed by a treatment in mid dry season and the last treatment in early wet season.


Author(s):  
Richard S. Demaree ◽  
Donald M. Wootton

Cercariae (juvenile trematodes with tails) emerge from mollusk intermediate hosts and swim toward definitive hosts or encystment objects. The locomotor power is furnished by the tail. Upon reaching a suitable host or encystment object, the tail is cast off and the cercariae penetrate and/or encyst. Ultrastructural studies of cercariae are sparse. There is even lessUltrastructural studies of cercariae are sparse. There is even less information about the tail structure; and body-to-tail morphology has been documented only for Acanthatrium oregonense and Schistosoma japonicum.


2005 ◽  
Vol 6 (1) ◽  
pp. 93-110
Author(s):  
Faiza El-Assal ◽  
Sanaa Shanab ◽  
Amin Abou-El-Hassan ◽  
Kadria Mahmoud

2019 ◽  
Vol 15 (01) ◽  
pp. 83-84
Author(s):  
B J Thakre ◽  
Joice P Joseph ◽  
Binod Kumar ◽  
Nilima Brahmbhatt ◽  
Krishna Gamit

Taenia spp. are long, segmented, parasitic tapeworms and are relatively uncommon in canine gastrointestinal diseases compared to other tapeworms like Dipylidium caninum. These parasites have an indirect life cycle, cycling between definitive and intermediate hosts. Dogs act as definitive hosts of different species of Taenia including Taenia multiceps, Taenia serialis, Taenia crassiceps, Taenia hydatigena, Taenia pisiformis, etc. Taenia multiceps is of greatest zoonotic relevance in human. In the definitive host, it causes only mild infection. Larvae are more likely to cause disease than adult tapeworms. Taeniasis in pets should be cautiously handled because of its zoonotic importance. This communication reports a case of 3 months old pup suffering from Taenia infection that was successfully managed with a combination of praziquantel and fenbendazole.


2020 ◽  
Author(s):  
Carlie Pietsch ◽  
◽  
Brendan M. Anderson ◽  
Lauren M. Maistros ◽  
Ethan C. Padalino ◽  
...  

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