Morphologic identification of a new Sarcocystis sp. in the common moorhen (Gallinula chloropus ) (Aves: Gruiformes: Rallidae) from Brolos Lake, Egypt.

Sarcocystis species are among the most common and widespread protozoan parasites of mammals and birds. The current study provides the first record of infection with Sarcocystis species in the common moorhens from Brolos Lake, KafrElsheikh province, Egypt. Morphology of the parasite cysts was described using light and transmission electron microscopy. Out of 25 examined birds, sarcocysts were found in neck, thigh, and legs muscles of two birds. The cysts were microscopic and measured 150-650 μm in length×45-185 μm in width. Histologically, the sarcocyst wall appeared striated and characterized by the presence of radial spines. Ultrastructurally, it measured 2-4.5 μm in thickness and had irregularly shaped crowded finger-like villar protrusions that measured 1.5-4 μm in length and up to 0.4-2 μm in width with the presence of dense electron ground substance of 200-750 nm thick. Several septa derived from the ground substance were present and divided the cyst into compartments containing both bradyzoites and metrocytes. The bradyzoites were banana-shaped and measured 6-12 × 1-2 μm with centrally or posteriorly located nuclei. The ultrastructural features of the cyst wall belonged to type 10 cyst wall according the classification of Dubey et al. (1989) and Dubey and Odening (2001).