Physiological reorganization in the hypotrich ciliate Apoamphisiella vernalis (Protista, Ciliophora, Hypotricha)

Abstract

ABSTRACT. Physiological reorganization is described for the fi rst time for the hypotrich ciliate genus Apoamphisiella Foissner, 1997, based on a population of A. vernalis (Stokes, 1887) Berger, 2006 collected from an eutrophic pond in the state of Minas Gerais, Brazil. Stomatogenesis is epiapokinetal, and the cirral pattern reorganizes from six typical fronto-ventral-transverse primordia, plus at least one short primordium located between IV and V. Primordia I and II originate from disaggregating undulating membranes and buccal cirrus, respectively; primordium III originates from left frontoventral cirrus plus a streak of basal bodies extending from the anterior end of oral primordium; primordium IV and the short extra primordia are formed from basal bodies perhaps associated to the posterior end of III plus the disaggregation of anteriormost cirri of the left ventral row. Primordia V and VI arise within the right ventral row as a single streak, splitting to form the two primordia. Marginal primordia develop initially within the pre-existent marginal rows, continuing to reorganize outside, pushing the old marginal cirri leftwards. Two dorsomarginal kineties develop associated to the right marginal row primordium. Dorsal ciliature also reorganizes from within the pre-existent dorsal kineties. The two macronuclear nodules approach each in middle reorganizers, briefl y touching each other. At least one micronucleus undergo division. The process of physiological reorganization in A. vernalis resembles that of the North American Paraurostyla weissei complex representative, and along with features of the interphase morphology, indicate that Apoamphisiella belongs or is related to the Cyrtohymena-Paraurostyla group, within the Dorsomarginalia.

Morphology of Two Eschaneustyla Species (Ciliophora, Urostylida), with Notes on Morphogenesis of Eschaneustyla lugeri

“…The hypotrichs s. l. are one of the most diverse and speciose ciliate groups with about 700 valid species de-scribed so far (Berger 1999(Berger , 2006(Berger , 2008(Berger , 2011Foissner et al 2002;Foissner 2016). Recently, much work has been carried out on the morphological and molecular diversity of hypotrichs, helping to improve the knowledge on their phylogeny, even though it remains unresolved at various levels (Shao et al 2011(Shao et al , 2013a(Shao et al , b, 2014Li et al 2013;Heber et al 2014;Paiva et al 2014Paiva et al , 2016Jo et al 2015;Luo et al 2015;Singh and Kamra 2015;Bharti et al 2016;de Castro et al 2016de Castro et al , 2017Wang et al 2016Wang et al , 2017Chen et al 2017).…”