Influence de l'anhydrobiose sur l'infestation de Biomphalaria glabrata par un miracidium de Schistosoma mansoni

Abstract

410 Biomphalaria glabrata (Caribbean strain of Guadeloupe) have been infected with one miracidium of Schistosoma mansoni, 110 snails, used as controls have been kept into water; the survival rate was 96.4% after 4 weeks and 25.4% produced cercariae. 300 snails were kept on wet soil, and submitted for 6 weeks to progressive desiccation. The survival rate was 23.4% but only 9 of them produced cercariae. Periodic variations of the production of male and female larvae have been shown by the weekly test of the cercariae productions. In previously desiccated snails, the production of male and female cercariae is similar while in controls the production of female larvae is more important. In experimental snails, the larval development seems to be stopped during anhydrobiosis. The production of cercariae is just delayed for the length of the dry keeping.

Effects of the desiccation on Biomphalaria tenagophila (Orbigny, 1835) (Mollusca) infected by Schistosoma mansoni Sambon, 1907

“…The desiccation, in spite of not having impeded, probably caused a pause in the development of the sporocysts I found in group V. The sporocysts I, of the group V and of the 7 days control group, were located in the anterior area of the mollusks. Experiments with desiccation in mollusks of B. glabrata, containing larvae of sporocyst I in the initial stage and of sporocyst I showing in their interior sporocysts II in formation, were accomplished by Barbosa and Coelho (1955) and Lancastre et al (1987). Theses authors also observed a pause in the development of the larvae.…”

“…Studies on the resistance to desiccation were accomplished with B. glabrata, B. straminea and B. pfeifferi by Barbosa and Dobbin (1952), Olivier andBarbosa (1955, 1956), Olivier (1956), JongBrink (1973), Pieri et al (1980), Vianey-Liaud and Lancastre (1986) and Vianey-Liaud and Dussart (1994) with healthy mollusks, and by Barbosa (1953), Barbosa andCoelho (1953, 1955), Barbosa and Barbosa (1958), Lancastre et al (1987Lancastre et al ( , 1989 and Badger and Oyerinde (1996) with mollusks infected by S. mansoni. Only one study on the resistance of B. tenagophila to desiccation is known.…”

Biomphalaria tenagophila (Orbigny, 1835) (Mollusca): adaptation to desiccation and susceptibility to infection with Schistosoma mansoni Sambon, 1907

“…Studies on the resistance to desiccation were carried out on healthy specimens of B. glabrata, B. straminea and B. pfeifferi by BARBOSA & DOBBIN (1952) 7 , OLIVIER & BARBOSA (1955,1956) 24,25 , PIERI et al (1980) 38 , VIANEY-LIAUD & LANCASTRE (1986 a and b) 50,51 , VIANEY-LIAUD & DUSSART (1994) 52 and JONG-BRINK (1973) 20 . These studies were also carried out on mollusks infected by S. mansoni by BARBOSA (1953, 1959) 2,3 , BARBOSA & COELHO (1953,1955) 5,6 , BARBOSA & BARBOSA (1958) 4 , LANCASTRE et al (1987,1989) 22,23 and BADGER & OYERINDE (1996) 1 . For B. tenagophila, only TELES & MARQUES (1989) 49 , are cited.…”