Systematics and species-specific response to pH of Oxytricha acidotolerans sp. nov. and Urosomoida sp. (Ciliophora, Hypotricha) from acid mining lakes

Abstract

We investigated the morphology, phylogeny of the 18S rDNA, and pH response of Oxytricha acidotolerans sp. nov. and Urosomoida sp. (Ciliophora, Hypotricha) isolated from two chemically similar acid mining lakes (pH ∼ 2.6) located at Langau, Austria, and in Lusatia, Germany. Oxytricha acidotolerans sp. nov. from Langau has 18 frontal-ventral-transverse cirri but a very indistinct kinety 3 fragmentation so that the assignment to Oxytricha is uncertain. The somewhat smaller species from Lusatia has a highly variable cirral pattern and the dorsal kineties arranged in the Urosomoida pattern and is, therefore, preliminary designated as Urosomoida sp. The pH response was measured as ciliate growth rates in laboratory experiments at pH ranging from 2.5 to 7.0. Our hypothesis was that the shape of the pH reaction norm would not differ between these closely related (3% difference in their SSU rDNA) species. Results revealed a broad pH niche for O. acidotolerans, with growth rates peaking at moderately acidic conditions (pH 5.2). Cyst formation was positively and linearly related to pH. Urosomoida sp. was more sensitive to pH and did not survive at circumneutral pH. Accordingly, we reject our hypothesis that similar habitats would harbour ciliate species with virtually identical pH reaction norm.

Morphology and phylogenetic analysis of two oxytrichid soil ciliates from China, Oxytricha paragranulifera n. sp. and Oxytricha granulifera Foissner and Adam, 1983 (Protista, Ciliophora, Hypotrichia)

“…sp., Oxytricha acidotolerans Weisse et al, 2013 has its paroral and endoral in the Oxytricha-pattern (vs in the Stylonychia-pattern), a lack of cortical granules (vs their presence), distinctly separated (vs confluent) marginal rows posteriorly and dorsal ciliature (dorsal kineties 1 and 2 shortened anteriorly and each comprising about 10 pairs of basal bodies (vs bipolar and each comprising about 20 pairs of basal bodies) and third dorsal kinety terminating at midline (vs 4/5) of cell length (Weisse et al, 2013).…”

A New Subspecies of Oxytricha granulifera (Hypotrichia: Oxytrichidae) from Mexico, with Notes on its Morphogenesis and Phylogenetic Position

“…Oxytricha acidotolerans Weisse, Moser, Scheffel, Stadler, Berendonk, Weithoff and Berger, could be similar to O. granulifera chiapasensis n. subsp. by having six dorsal kineties in an Oxytricha ‐pattern, a similar arrangement of transverse and pretransverse cirri, and the number of adoral membranelles, but it differs due to the undulating membranes ( Oxytricha ‐pattern vs. Stylonychia ‐pattern in O. g. chiapasensis n.…”

“…For phylogenetic analysis, the GTR + I + G model was used according to Weisse et al. () and Shao et al. ().…”

“…; Foissner , , ; Kwon and Shin , , ; Tirjaková and Bartošová ; Weisse et al. ). To our knowledge, only five species, i.e.…”

Morphology, morphogenesis and molecular phylogeny of a soil ciliate, Pseudouroleptus caudatus caudatus Hemberger, 1985 (Ciliophora, Hypotricha), from Lhalu Wetland, Tibet

“…The Hypotricha Stein, 1859 is a speciose and morphologically diverse group that inhabits a wide range of biotopes (Berger 2008;Chen et al 2013a,b;Fan et al 2014;Foissner 2012;Jiang et al 2013;Kahl 1932;Küppers and Claps 2013;Li et al 2010aLi et al ,b, 2013Liu et al 2010;Lv et al 2013 Pan et al 2012Pan et al , 2013Park et al 2013;Song et al 2009;Weisse et al 2013). The genus Pseudouroleptus was established by Hemberger (1985) with P. caudatus as the type species by original designation.…”