Abstract
Based on morphological, morphometric and infraciliature criteria, as evidenced by the ammoniacal pyridinated silver carbonate technique and 4',6-diamidino-2-phenylindole (DAPI) staining, we contribute to the knowledge of four new ciliated protozoa species from the digestive tract of earthworms (Oligochaete: Glossoscolecidae), collected on the banks of the Nkam River (Cameroon). These new species belong to the Class Armophorea, the genera Nyctotherus and Nyctotheroides. In the genus Nyctotherus, three species are described: N. nkamensis n. sp. (ovoid, 85-138 µm × 52-115 µm), N. emini n. sp. (ovoid, 66-185 µm × 50-95 µm), and N. renimorphus n. sp. (kidney form, 125-220 µm × 75-180 µm). They have in common the presence of an apical secant system on their right side. In the genus Nyctotheroides, the species N. ndogbeleensis n. sp. (elongated form, 75-120 µm × 25-40 µm) is characterized by the existence of three secant systems on both sides: an apical secant system on the right side and two secant systems (the apical and the caudal) on the left side. Contrary to known congeners, the species described in this study have a very pronounced polymorphism.