Morphological description of four new species of Nyctotherus (Ciliophora: Nyctotheridae: Heterotri- chida), commensal ciliates of the digestive tract of a terrestrial Oligochaete (Megascolecidae) from the northwest region of Cameroon

Zéphyrin Fokam (1) , Paul Alain Nana (2) , Pierre Ngassam (3) , Geneviève Bricheux (4) , Philippe Bouchard (5) , Bernard Vigues (5) , Télesphore Sime-Ngando (5)

1 HTTC-UMA - Higher Teachers' Training College, University of Maroua
2 Laboratoire de Biologie Générale
3 Laboratoire de Biologie Générale
4 CMES
5 LMGE - Laboratoire Microorganismes : Génome et Environnement

The morphology and ciliature of four Nyctotherus species (Nyctotherus orthostomatus n. sp., Nyctotherus ndoumeleleensis n. sp., Nyctotherus ngassami n. sp. and Nyctotherus atunibaensis n. sp.), isolated from the mid and hindgut of a Megascolecidae annelid of the genus Eupolytoreutus from the northwest region of Cameroon, were investigated using living observation (methylene blue) and silver impregnation methods (Fernandez-Galiano, 1994). Nyctotherus orthostomatus n. sp. is recognized by a pear-shaped body (128-152 × 95-104 µm); a conspicuous buccal apparatus with the peristome and the infundibulum perpendicular to each other; about 41-46 somatic kineties covering each side of the cell; one transversally elongated massive macronucleus located in the anterior third of the cell, surmounted by a very small spherical micronucleus. Nyctotherus ndoumeleleensis n. sp. is distinguished by the combination of the following characters: ovoid body (151-163 × 87-92 µm) with rounded poles; about 52-68 somatic kineties uniformly covering the cell body; an anterior, transversal and trapezoidal macronucleus carrying laterally a small micronucleus (2-3.5 µm in diameter). Nyctotherus ngassami n. sp. can be distinguished from its congeners by the following set of features: size about 153-269 × 102-148 µm; body ovoid, with 64-86 ciliary rows covering its surface; a small and globular micronucleus hidden by a transversal macronucleus located slightly above the equatorial part of the cell. Nyctotherus atunibaensis n. sp. is characterized by size about 145-253 × 95-162 µm, ovoid cell body, 108-122 somatic kineties,a transversal and arc-shaped macronucleus hiding a small micronucleus. In the present study, new locality (northwest region of Cameroon) and new species of the genus Nyctotherus are explored.

Mots clés: N. orthostomatus n. sp; N. ndoumeleleensis n. sp; N. ngassami n. sp; N. atunibaensis n. sp; Cameroon; megascolecid earthworms; Nyctotherus; N. orthostomatus n. sp.; N. ndoumeleleensis n. sp.; N. ngassami n. sp.; N. atunibaensis n. sp.; systematics

Domaines: Sciences du Vivant [q-bio]

Zéphyrin Fokam, Paul Alain Nana, Pierre Ngassam, Geneviève Bricheux, Philippe Bouchard, et al.. Morphological description of four new species of Nyctotherus (Ciliophora: Nyctotheridae: Heterotri- chida), commensal ciliates of the digestive tract of a terrestrial Oligochaete (Megascolecidae) from the northwest region of Cameroon. Protistology, 2014, 8 (2), pp.62-70. ⟨hal-01070952⟩