Effect of the plant cupressus macro carpa [cupressacea] on some haematological and biochemical parameters of biophalaria Alexandrina snails

The dry power of the plant aerial part: cupressus macrocarpa [cupressacea] was tested Biomphalaria alexandrina. LC50 and LC90 values were 59.5 ppm, respectively. Exposure of B. alexamdrina to sublethal concentrations [LC0, LC10 and LC25] of C. macrocarpa for three weeks significantly decreased the number of circulating hemocytes. The magnitude of reduction was increased with increasing of the tested concentration. The main type of cell in the hemolymph of B. alexandrina was the granulocyte [71.8%], followed by large round sells or hualinocutes [19.0%] and small round sells or undifferentiate sells [9.2%]. The percentage of different hemocyte categories was changed in treated snails. In snails maintained at LC25, showed significantly higer percentages of small round cells than controls, 56.2% and 9.2% respectively Maintainence of B. alexandrina in sublethal concentrations for three weeks significantly reduced protein and hemoglobin content in the hemolymph. Reduction in enzyme activities occurred in the hemolymph and tissues of treated snails. The enzymes were Pyruvate kinase [PK], lactate dehydrogenase [LDH], hexokinase [HK] and phosphoenol pyruvate carboxy kinase [PEPCK] which are very important in metabolism of the protein and carbohydrate. The infectivity of Schistosoma mansoni miracidia was greatly reduced by exposure to the sublethal concentra- ions [LC0, LC10 and LC25] of Cupressus. Infection rate of B. alexandrina reached to 54.5%, 37.5% and 16.7%, respectively compared to control [81.25%]. Duration of cercarial shedding and the total periodic cercarial production/ snail showed signi-ficant reduction while the parasite incubation period was signifycantly longer [P<0.05].

Effect of ammonium chloride on Biomphalaria Alexandrina and on its infection with schistosoma mansoni and echinostoma liei miracidia

The LC50 and LC90 of ammonium chloride [NH4C1] were found to be 90 ppm and 130 ppm, respectively. Maintaining of B. alexandrina at low concentrations of NH4C1 [5, 10, 15 and 20 ppm] greatly reduced their survival rate and fecundity. The net reproductive rate was deleteriously affected. This rate was significantly reduced than that of the control snails in all tested snail groups. The reduction in Ro was 86.9%, 90.8%, 93.9% and 96.9%, respectively. The susceptibility of B. alexandrina to infection with S. mansoni and E. Liei miracidia and infectivity of these two parasites were greatly reduced. Increasing the salt concentration increased this reduction. The magnitude of reduction in infection rate was lower in case of E. Liei than that in S. mansoni indicating that E. liei was more tolerant to the effect of this salt than S. mansoni