Table 2 in Morphological Redescription and SSU rDNA-based Phylogeny of Two Freshwater Ciliates, Uronema nigricans and Lembadion lucens (Ciliophora, Oligohymenophorea), with Discussion on the Taxonomic Status of Uronemita sinensis

Table 2. Morphological comparison of Uronema nigricans with its congeners.
CharacteraUronema nigricans (Müller, 1786) Floren- tin, 1901Uronema marinum Dujardin, 1841Uronema elegans Maupas, 1883Uronema gallicum Pérez-Uz and Song, 1995Uronema heteromari- num Pan et al., 2010Uronema orientalis Pan et al., 2015Uronemita sinensis Pan et al., 2013Cell size in vivo20–50 × 10–25 μm25–35 × 10–15 μm30–50 × 20–30 µm20–30 × 8–11 μm25–50 × 10–25 μm40–55 × 20–30 μm25–35 × 15–20 μmSize after impregnation18–38 × 10–20 μm28–39 × 14–20 μm33–45 × 19–25 μm21–28 × 9–13 μm30–50 × 20–30 μm42–58 × 26–35 μm34–46 × 20–31 μmBody featureselongate-elliptical in outline; pellicle thin and inconspicuously notched, with ridges located longitudinally along ciliary rows; no extrusomes detected in vivoelongated elliptical in outline; pellicle smooth, without ridges; extrusomes inconspicuous, short- bar-shaped, about 2 μm longcylindrical or kidney- shaped; Pellicle thick and strongly notched on outline with con- spicuous reticulate ridges; extrusomes bar-like, about 2 µm long, densely distributedelongated, well- nourished cells often ovoid with the width almost twice of that in normal ones; pellicle thin, slightly indented. extrusomes fine and rod-like, about 2 μm longelliptical to cylindri- cal; pellicle notched with conspicuous reticulate ridges; ex- trusomes bar-shaped, about 2 μm longelongate-elliptical in outline; pellicle smooth, without ridges; extrusomes bar-shaped, about 4 μm longelongate-elliptical; anterior end truncated, with a con- spicuous apical plate; surface of the cell smooth, without ridges; extrusomes rodshaped, about 2 mm long, and tightly packed beneath cortexSomatic cilia5–7 μm long5 μm long8–10 µm long6–7 μm longabout 8 μm longabout 10 μm longabout 10 μm longCaudal ciliumsingle, 12–20 μm longsingle, ca. 15–20 μm longsingle, ca 15–18 µm longN/Asingle, ca. 10–15 μm longsingle, approximately 20 μm longsingle caudal cilium approxi- mately 15 μm longCV3–5 μm in diameter5 μm in diameterN/AN/A5 μm in diameter5 μm in diameterabout 5 μm in diameterNumber of SK10–1512–1423–26, mostly 2313–15, usually 1415–16consistently 209–10Position of posterior end of SK1SK1 is usually shorter than other SKs, ex- tending at about three fourths to four fifths of the cellSK1 is as long as other SKs, almost reaches the posterior end of the cellsame as U. marinumsame as U. marinumsame as U. marinumsame as U. marinumsame as U. marinumBuccal apparatusmembranelle 1 single- rowed with about five to seven kinetosomes, clearly separated from other membranellesmembranelle 1 single- rowed with five to sev- en kinetosomes; the gap of membranelle 1 and 2 is relatively shortmembranelle 1 short and one- or partly two- rowed, ca. 7 kineto- somes, conspicuously subapically positioned and far away from oth- er membranelles; oral cilia about 6–8 µmbuccal area large and extending about 2/3 of the cell length; mem- branelle 1 with 6–7 widely spaced kine- tosomes in a row that sometimes seems to break in the middlemembranelle 1 distinct subapically positioned and remote from other membranelles, con- sisting of ca. 4–7 basal bodiesmembranelle 1 single- rowed, divided into two partsmembranelle 1 distinct subapically positioned, separated from other mem- branelles and consisting of two or three basal bodies in a short rowDiameter of MA8–11 μm10–20 μm11–18 μmN/AN/A14–19 μm10–18 μmHabitatfresh and brackish watermarinemarinemarinemarinemarinemarineData resourceOriginal; Foissner et al. 1994; Song 1991; Thompson and Evans 1968Song et al. 2009; Pan H. et al. 2010Song et al. 2009; Song et al. 2002Pérez-Uz and Song 1995Pan H. et al. 2010Pan X. et al. 2015Pan et al. 2013
aCV, contractile vacuole; Ma, macronuclear nodule; N/A, non applicable; SK, somatic kineties.