Effect of Cystoseira barbata and Dictyota dichotoma-algae on reproduction and protein pattern of Biomphalaria alexandrina snails

Abstract

ABSTRACTControlling the snail intermediate host of schistosomiasis is one of the strategies used to reduce disease incidence. In this study screening tests were carried out on the action of dried powder of eight algal species against Biomphalaria alexandrina snails. The most effective powders were from Dictyota dichotoma and Cystoseira barbata with LC50 values of 560 and 2200 ppm, respectively. Prolonged exposure to sublethal concentrations of these two powders caused adverse effects on snails' reproduction especially at LC25. Hatchability of exposed eggs was lowest at LC25 of C. barbata, and LC15 of D. dichotoma. The most pronounced effects on the hermaphrodite gland of snails were caused by high concentrations of both algal suspensions, where ova were either degenerated or deformed and there were detrimental effects on all spermatogenesis stages. The electrophoretic separation of haemolymph proteins showed that the concentration with most effect was the LC15 for both tested algae as they resulted in more bands than the control and also an elevation in total protein content.