Scanning and transmission electron microscopical observations on the tegument of excysted metacercariae and adults of Zygocotyle lunata.

Scanning and transmission electron microscopical observations were made on the tegument of excysted metacercariae and adults of the paramphistome, Zygocotyle lunata (Digenea: Trematoda). In accord with other paramphistomes studied, this species lacks spines and mitochondria in the tegumentary syncytium and associated cytons. The newly excysted metacercarie, which possessed relatively few tegumental papillae, were cylindrical in comparison to adults which were distinctly flat. The adults had large numbers of tegumental papillae in the region of the oral sucker and acetabulum.