Morphology, morphometry and infraciliature of four new species of Clevelandellida de Puytorac and Grain, 1976 (Ciliophora: Armophorea) from the digestive tube of hydromorphic earthworms in the Cameroonian coastal zone

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.