1. 1Department of Medical Malacology, Theodor Bilharz Research Institute, Giza, Egypt
2. 2Department of Zoology and Entomology, Faculty of Science, Helwan University, Egypt
3. 3Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
4. 4Department of Pathology, Theodor Bilharz Research Institute, Giza, Egypt