Catatropis aegyptiacus n. sp. was isolated from the large intestine of 28 out of 91 rat Rattus norvegicus. The prevalence of infection in males is 40% and 30% in females. The infection rate was (54.54%, 36.84%,26.3% and 23.8%) in winter, fall, summer and spring respectively. The study of the new species by light and scanning electron microscopy revealed that Catatropis aegyptiacus n. sp. can be distinguished from all other species of the genus in having 10 11 protruded
ventral glands that extend from the intestinal bifurcation level to the ovarian level, the triangular pointed spines cover the first anterior third of the body, the position of the genital pore and larger egg size. Also, the outer rim of oral sucker has unciliated sensory papillae and the tegument of the anterior dorsal surface covered with irregular ridges studded randomly with unciliated and ciliated domed-like papillae. Tegument of the body posterior half has branching and anastomosing
transverse striations with small unciliated sensory papillae.