Paper Title
Clinostomum Philippinensis (Trematoda: Digenea): An Introduction of Ultrastructural Architecture of the Metacercarial Teguments

Abstract
Clinostomum is digenean fluke that commonly infected in many freshwater fish as an intermediate host. This parasite transmitted to birds as a definitive host. C. philippinensis is a member of this genus that found in fish from tropical environments. However, ultrastructure has rarely studied in this species. Here this study revealed the novel of transmission electron monograph in C. philippinensis teguments collected from Thai ricefish (Oryzias minutillus). Results revealed the surface syncytium of tegument composed three layers that apical, middle part and basal part. Apical parts covered by glycocalyx were filled with granules cells, while middle parts consisted of mitochondria and granules cells. Basal parts contained basement membrane invaginations, mitochondria, granules cells and base of spines. Spines were no texture. In layer of acetabulum, there were found many granules cells. In addition, our results also represented structures of tegument cells, associated cell bodies and other organelles from anterior to posterior part and included some structures such as musculatures, caecum, secretory cells and flame cells. Our result may be important data for supporting the knowledge of ultrastructure of Clinostomum. Keywords - C. philippinensis, metacercaria, TEM, Thailand