Fine structure of Pseudotrypanosoma giganteum of porotermes, a trichomonad with a contractile costa

Pseudotrypanosoma giganteum is a large trichomonad which shares many features with other members of the family Trichomonadidae, such as a striated costa with mesh-like structure (B pattern) and a lamella-like undulating membrane similar to that of Trichomonas vaginalis. Microtubules of the pelta have tubular reinforcements like those in the adhesive disc of the trichomonad Cochlosoma anatis. It has a contractile costa and an undulating membrane linked to the costa by microfibrils as well as two "reticular bodies" situated under the basal bodies, as seen in Trichomitopsis termopsidis; these features characterise the Trichomitopsiinae subfamily. As previously described, the costa is a very thick fibre which is contractile and truly undulates within the cytoplasm.