SURFACE-STRUCTURES OF BRACHYLAIMUS-FUSCATUS (DIGENEA, BRACHYLAIMIDAE) METACERCARIA

Brachylaimus fuscatus metacercaria develops unencysted in the terrestrial snail Ponsadenia duplocincta. For the first time in a larval stage of the genus Brachylaimus a distinctive surface structure has been observed. This structure of net-like interconnected ridges of the tegument was present on the whole body surface with the exception of the anterior part. Beside this structure scanning electron microscopy revealed five types of papillae. Three types, dome-like papillae, papillae with a finger-like process, and hollow papillae with a short cilium, were localized mainly in the suckers. Hollow papillae without a cilium were arranged in groups or singly around the ventral sucker and genital pore. Ribbed papillae were observed on the ventral body surface.