Biological and physiological parameters of <i>Bulinus truncatus</i> snails exposed to methanol extract of the plant <i>Sesbania sesban</i> plant

Abstract

The effects of sublethal concentrations of methanol extract of sesbania sesban plant on survival rate, egg laying of Bulinus truncatus snails, hatchability of their eggs, infection rate with Schistosoma haemato- bium miracidia, cercarial production and certain physiological parameters of treated snails were stu- died. The sublethal concentrations of the tested plant extract (LC0, LC10 and LC25) caused considerable reduction in survival rates; egg production of B. runcates snails; hatchability of eggs as well as in the infectivity of Schistosoma haematobium miracidia to the snail. Also, the tested concentrations reduced the cercarial production per snail and the period of cer-carial shedding. The glucose level in haemolymph of exposed snails was elevated while the glycogen, pro-tein content and the activities of hexokinase (HK), pyruvatekinase (PK) and lactate dehydrogenase (LDH) showed a decrease in soft tissues when compared with the control group. It was concluded that the app lication of sublethal concentration of methanol ex- tracts of Sesania sesban may be helpful in snail con- trol as it interferes with the snails’ biology and phy- siology.