Reproductive activity alterations on the Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex

Abstract

The reproductive activity of Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex was evaluated. Parameters related to fecundity and fertility were observed. The snails were exposed to the LD 50 (1 mg/l) of crude latex. At the first week post exposure (p.e.) (Magalhães & Lucca 1971, Kawazoe 1977.The physiological stress factors, as temperature variations (Pimentel-Souza et al. 1990), lightness (Barbosa et al. 1987), starvation (Livingstone & Zwaan 1983), and parasitism by larval trematodes (Looker & Etges 1979, Sullivan et al. 1985, Cooper et al. 1994, Cousin et al. 1995 have been pointed as able to influence the reproductive biology of the snails.There are few studies on the interference of plants that exhibit moluscicide action with the reproductive activity of the snails, intermediate host of helminthes. The reproductive capacity of B. alexandrina is reduced when it was exposed to Allium sativum, A. cepa, and Atriplex halimus (Mantawy 2001, Tanatawy 2002.Many molluscicide have been used to schistosomiasis control, and one of the most promising and widely studied in Brazil, is the crude latex of Euphorbia splendens var. hislopii. The latex obtained from this plant, under laboratory and field conditions, showed that it attends to queries needed to be used as a natural molluscicide (Schall et al. 2001, Vasconcelllos & Amorim 2003.The lethal effects on the embryos in the egg masses were obtained using elevated concentrations of the latex (870 a 1500 mg/l) (Schall et al. 1998), but, until the moment, there were no studies focusing the latex effects on the reproductive biology of B. glabrata.The objective of this study was evaluating the influence of sub lethal dose (LD 50 ) of latex of E. splendens var. hislopii on reproductive parameters of B. glabrata. MATERIALS AND METHODSCollection of E. splendens var. hislopii latex -Samples of E. splendens var. hislopii latex were collected in the autumn from plants cultivated in plots near Departamento de Biologia, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brazil. The latex was collected as described by Vasconcellos and Amorim (2003a), on the same day of tests conduction.Rearing of B. glabrata in the laboratory -Specimens of B. glabrata (Belo Horizonte, BH lineage) were reared at the Laboratório de Esquistossomose Experimental, Instituto Oswaldo Cruz-Fiocruz, RJ, Brazil. The snails were placed in 30 l polyethylene aquaria, with dechlorinated water. The average water temperature was 28 ± 1 o C and relative humidity varied from 70 to 78% throughout the experiment.Three times a week the aquaria were cleaned and the snails were fed ad libitum with lettuce leaves (Lactuca sativa L.). All the specimens of B. glabrata used in the experiments had shell diameters between 8-10 mm and exhibit ovipository activity.Determination of sublethal concentrations of latex of E. splendens var. hislopii -The determination of LD 50 were made according to Vasconcellos and Amorim (2003a), in accordance to WHO recommendations (WHO 1983) and Mott (1987) Reproductive ...

Behavioral response of Biomphalaria glabrataexposed to a sublethal concentration of Euphorbia miliivar. hislopii latex

“…hislopii latex on B. glabrata egg masses, showing a lethal effect on the eggs from 870 mg/L, eight times more than recommended by the WHO as the lethal concentration for mollusks. Mello-Silva et al (2007) studied the action of this same product in sublethal concentrations (LC 50 ) on B. glabrata exposed for 24 hours. In the present study, we observed a temporary reduction in egg laying in B. glabrata caused by latex exposure in the first week after exposure in accordance to Mello-Silva et al (2007) which also reported the reduction of the egg laying in the first week after exposure to the E. milii var.…”

“…Environmental conditions directly influence the reproductive potential of B. glabrata. Several factors may alter the reproductive biology of snails such as parasitic infection, starvation, and exposure to toxic products, since these factors may influence carbohydrate reserve, hemolymphatic glucose alteration, glycogen levels, and mobilization of galactogen reserves (Mello-Silva et al 2007, Augusto et al 2015, Faro et al 2013. However, the snails can restore the population rapidly, from only one specimen, when the environmental conditions become favorable (Barbosa & Barbosa 1994).…”

“…The two physiological stress processes, latex action of E. milii var. hislopii and parasitism by S. mansoni, reduce the snails' energy reserves (glucose and galactose) and temporarily prevent egg laying (Mello-Silva et al 2007, 2011, Faro et al 2013, Augusto et al, 2015. Regarding changes in the energy reserves, El-Ansay & Al Daihan (2006) observed that a metabolic decrease can influence locomotor parameters.…”

Molluscicidal activity of some marine substances against the snail Biomphalaria glabrata (Mollusca, Planorbidae)

“…Studies on the molluscicidal activity of natural products have been stimulated due to the high cost of synthetic molluscicides and recurrent resistance of snails to these (Bakry 2009;Bezerra et al 2002;Luna et al 2005;Mello-Silva et al 2007;Rapado et al 2011;Silva et al 2006).…”

Changes in the reproductive biology of Biomphalara glabrata infected with different doses of Echinostoma paraensei miracidia

“…These initial phases are essential for the trematode to multiply. For this reason, studies to control the diseases caused by digenetic trematodes focus on combating the host snails (Lustrino et al, 2008;Mello-Silva et al, 2006, 2007. However, the larval development can cause changes in the host snail's reproductive activity and interfere in the parasite's life cycle Amato, 1994, 1995).…”