Morphology, morphogenesis, and molecular phylogeny of Pleurotricha oligocirrata nov spec. (Ciliophora: Spirotrichea: Stylonychinae)

Pleurotricha oligocirrata nov. spec. was discovered in samples collected from a freshwater wetland in Korea and is described here based on its morphology, morphogenesis, and the nucleotide sequence of its nuclear small subunit ribosomal rRNA (SSU rRNA) gene. In its genus, P oligocirrata is the only species that possesses one right marginal cirral row. The morphology of P. oligocirrata is as follows: body size 98-148 x 47-72 mu m in protargol preparations, colourless and rigid body; contractile vacuole anterior of mid-body near left margin; cortical granules lacking; two macronuclear nodules with two micronuclei; undulating membranes in Oxytricha pattern; 50-62 adoral membranelles, 23-27 frontal-ventral-transverse cirri, one left and one right marginal cirral row; six or seven dorsal kineties, including dorsomarginal rows, with three caudal cirri. The genetic distances between P oligocirrata and its congeners P curdsi and P. lanceolata were 0.257%-0.386% (4-6 nt difference) and 0.064% (1 nt difference), respectively. (C) 2017 Elsevier GmbH. All rights reserved.