Morphology, morphogenesis and molecular phylogeny of a novel soil ciliate, Afrokahliella paramacrostoma n. sp. (Ciliophora, Hypotrichia)

Abstract

A soil hypotrich ciliate, Afrokahliella paramacrostoma n. sp., was discovered in China. Its morphology, morphogenesis and molecular phylogeny were investigated using standard methods. The new species is characterized as follows: body about 140–180 × 60–70 μm in vivo, cortical granules absent, contractile vacuole positioned about 40% down length of body, 5–9 macronuclear nodules, 34–49 adoral membranelles, 3–5 buccal and 3–6 parabuccal cirri, usually two frontoventral rows, three or four left and two or three right marginal rows, three dorsal kineties and one dorsomarginal kinety; 1–3 and one or two caudal cirri located at the ends of dorsal kineties 1 and 2, respectively. The ontogenetic process is characterized by: (1) the marginal anlagen on each side develop in the outer right and the inner left marginal rows, respectively; (2) five frontoventral-transverse cirral anlagen, anlagen II–IV develop in secondary mode; (3) dorsal morphogenesis follows a typical Urosomoida-pattern, no parental dorsal kineties are retained; (4) caudal cirri are generated at the ends of dorsal kineties 1 and 2. Phylogenetic analyses based on SSU rDNA sequence data reveals that Afrokahliella paramacrostoma n. sp. is closely related to Parakahliella macrostoma and Hemiurosomoida longa.