Surface topography of two trematodes parasites infecting grey heron Ardea cinerea Jouyi (Aves, Ciconiiformes) in Qena, Egypt.

Apharyngostrigea ardeolina and Echinoparyphium recurvatum are two important digenean parasites that were recovered from small intestine of grey heron with an infection rate (16.2%) and (8.8%) respectively. The surface topography of two species was redescribed by both light and scanning electron microscopy. Using SEM studies showed that the body surface of two trematodes were covered by contact receptors, several types of sensory tegumental papillae which may have useful function in orientation and feeding through increasing the surface area of absorption, could also play a role in sensation or in selection of the materials for ingestion by the fluke. The head collar of E. recurvatum is reniform in shape, bearing uninterrupted double row of 41 collar finger-like spines, a total including 4 end group ones on both ventral corners., tegumental spines were tongue-shaped without a terminal tip.