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Showing papers on "Bulinus truncatus published in 1991"


Journal ArticleDOI
TL;DR: The cercarial shedding of Schistosoma bovis and S. haematobium were studied in single and mixed infections in the snail host Bulinus truncatus and the cercaria emergence pattern is proposed as a new method to identify natural mixed infectionsin the snail intermediate hosts.
Abstract: The cercarial shedding of Schistosoma bovis and S. haematobium were studied in single and mixed infections in the snail host Bulinus truncatus. The two species displayed a distinctive diurnal cercarial emergence with an earlier shedding pattern for S. bovis than S. haematobium (the average emergence peaks were respectively at 0800 h and 1200 h). In mixed infections, each species kept its own cercarial shedding rhythm with no marked alterations. The cercarial emergence pattern is proposed as a new method to identify natural mixed infections in the snail intermediate hosts. The interactions between the two parasites are discussed.

21 citations


Journal ArticleDOI
TL;DR: Alboglossiphonia polypompholyx spends most of its life cycle endoparasitic in the mantle cavity of the snail Bulinus truncatus — possibly its only host.
Abstract: Alboglossiphonia polypompholyx spends most of its life cycle endoparasitic in the mantle cavity of the snail Bulinus truncatus — possibly its only host. Adult A. polypompholyx leaves the snail about one month before the commencement of egg-laying. Hatching occurred after about 15 d and after brooding on the venter of the parent for 7–10 d, the young briefly become free-living before entering the mantle cavity of B. truncatus. Within the mantle cavity, A. polypompholyx feeds and grows for 16–20 weeks before leaving the snail as adults. In the field and in laboratory experiments, adult leeches left the snails in August/September and January with cocoons produced in October/November and February/March, respectively. Free-living adult leeches do not feed and die 1–2 months after the cessation of brooding.

17 citations



Journal ArticleDOI
TL;DR: The results indicate that schistosomin in haemolymph ofschistosome-infected pulmonate snails, although functionally related, may differ structurally.
Abstract: In haemolymph of Lymnaea stagnalis, parasitized with the digenetic trematode parasite Trichobilharzia ocellata, a neuropeptide (schistosomin) occurs which antagonizes female gonadotropic hormones, e.g. calfluxin (CaFl). By means of an ultracytochemical hormone-assay, the CaFl assay, it was demonstrated that the occurrence of schistosomin is a general phenomenon in schistosome-infected freshwater snails. Haemolymph of the schistosomiasis-transmitting snail species Biomphalaria glabrata and B. pfeifferi, parasitized with Schistosoma mansoni, also appeared to contain an antagonizing factor, i.e. schistosomin. In contrast, in haemolymph of L. stagnalis parasitized with Diplostomum spathaceum (Diplostomatidae) no schistosomin could be found. This suggests that schistosomin may only occur in snails infected with parasites belonging to the Schistosomatidae. The effect of schistosomin is rather specific. Haemolymph of B. glabrata parasitized with S. mansoni had not the capacity to inhibit the response to CaFl in the target organs for CaFl, the albumen glands of L. stagnalis and Bulinus truncatus. The same holds true for haemolymph of infected L. stagnalis: it did not inhibit the CaFl response in glands of B. glabrata and B. truncatus and even not in those of a related species (L. ovata). Schistosomins in haemolymph of infected B. glabrata and B. pfeifferi, on the other hand, seem more related. Both appeared to inhibit the hormone response in glands of the two Biomphalaria species studied. The results indicate that schistosomin in haemolymph of schistosome-infected pulmonate snails, although functionally related, may differ structurally.

16 citations



Journal Article
TL;DR: Schistosome infection caused a marked decrease in the glycogen and protein contents in the tissue of B. arabica and B. truncatus, the snail intermediate hosts of intestinal and urinary schistosomiasis in Yemen Arab Republic.
Abstract: B. arabica and B. truncatus the snail intermediate hosts of intestinal and urinary schistosomiasis in Yemen Arab Republic, were bred in the laboratory and infected with S. mansoni and S. haematobium respectively. Schistosome infection caused a marked decrease in the glycogen and protein contents in the tissue of B. arabica and B. truncatus. The glucose content in the hemolymph of both infected snails was lower than that in the normal snails.

2 citations


Journal Article
TL;DR: Selection of progenies from infected B.alexandrina and B.truncatus snails resulted in higher infection rates, consistent when the source of micardia were from either infected human or hamsters.
Abstract: Selection of progenies from infected B.alexandrina and B.truncatus snails resulted in higher infection rates. This observation was consistent when the source of micardia were from either infected human or hamsters. Infection rate of B.alexandrina increased up to 88.2% while B.truncatus did not. Compatibility between the parasites and their intermediate hosts were also studied.

1 citations