Pleuronema Dujardin, 1836
Subclass Scuticociliatia (ref. ID; 7213)

[ref. ID; 2014]
Medium to large (80-200 um long) ovoid ciliate. A large prominent undulating membrane delineates the right edge of the peristome which dominates the cell. This membrane begins just sub-apically and travels down the right side of the body terminating in the posterior body third in the form of a pouch or pocket by winding round so it is 6-shaped. Membranelle M1 is short and occupies an anterior position, M2 is long and terminates close to the cytostome while M3 adopts a complicated shaped and is composed of two parts. The anterior part is hook-shaped and the posterior part consists of two diverging short kineties and is sometimes called the M2 extension. Somatic ciliation uniform, the kineties are bipolar and there is a short post-oral suture. There are no post-oral kineties. Caudal cilia often present. Cytoproct slit-like located just post-orally. Contractile vacuole in posterior body half. Macronucleus spherical to void more or less centrally located.
Quote; Colin R. Curds, Michael A. Gates and David McL. Roberts "British and other freshwater ciliated protozoa Part II Ciliophora: Oligohymenophora and Polyhymenophora" Cambridge University Press, 1983 (ref. ID; 2014)

Pleuronema anodontae Kahl, 1926 (ref. ID; 1622) reported year? (ref. ID; 1618)
Description; Posterior cilium about one-half the body length; in Sphaerium, Anodonta. (ref. ID; 1618)
Measurements; About 55 um long. (ref. ID; 1618)
Pleuronema coronatum Kent, 1881 (ref. ID; 1622, 1629, 1890, 1896, 2117, 3119, 4488, 4611) reported year? (ref. ID; 1618, 3342, 3690, 3771) reported author and year? (ref. ID; 7213)
Syn; Pleuronema marina Mobius, 1888 (ref. ID; 1622)
Description; Elongate ovoid; both ends equally rounded; caudal cilia long; about 40 ciliary rows; in fresh and salt water. (ref. ID; 1618)
Analysis of the internal transcribed spacer 2 (ITS2) region. (ref. ID; 7213)
Measurements; 47-75 um long. (ref. ID; 1618)
60-80 x 40-44 um. (ref. ID; 3342)
Pleuronema crassum Dujardin, 1841 (ref. ID; 1308, 1622, 1629, 3116, 4611) reported year? (ref. ID; 1618, 5462)
Syn; Paramecium chrysalis O. F. Muller, 1786 (ref. ID; 3116); Pleuronema chrysalis Perty, 1852 (ref. ID; 1622); Pleuronema crassa Dujardin, 1841 (ref. ID; 4611)
Description; Somewhat compressed. (ref. ID; 1618)
Measurements; 70-120 um long. (ref. ID; 1618)
Pleuronema glaciale Corliss & Snyder, 1986 (ref. ID; 7603 original paper)
Description; Pyriform to oblong body shape, 136 (125-168) um long 58 (42-60) um wide (n = 5). Macronucleus spherical, slightly irregular, located centrally to slightly anterior of the midline. A single micronucleus, 2.5 um in diameter, associated with the posterior portion of the macronucleus. Oral depression is located posteriorly. Fifty-two kineties (44-58). Kineties to the left of the oral area converge onto the first kinety to the right of the oral area at the anterior convergence suture. Kineties are composed of paired-kinetosome kinetids and scattered singles anterior to the cytostome, and single-kinetosome kinetids posterior to the cytostome. Six preoral kineties are found to the left of the oral area. Oral polykinetid (OPK) #1 extends anteriorly to just below the anterior convergence suture, where it is represented by a patch of kinetosomes three across, and posteriorly to one-half the length of OPK2i segment as a double file of kinetosomes. OPK2i segment is composed of a double file of kinetosomes which begins anteriorly just below the anterior end of OPK1 and extends posteriorly to just above the cytostome, ending in a left-directed hook. OPK2ii segment is a single file of kinetosomes forming a shallow "V" anterior and to the right of the cytostome. OPK3 extends from just anterior to the cytostome posteriorly and to the left as a double file to kinetosomes. The oral dikinetids (ODK) extends straight posteriorly from just posterior to the anterior terminus of OPK1 to the oral depression, which it encircles with a diameter of approximately 25 um. Two rib fields are associated with the cytostome: short ribs extend anteriorly; longer, doubled ribs extend posteriorly out toward the ODK. The characteristics of OPK1, OPK2ii, and OPK3, in particular, distinguish this species from all the (many) others in the genus (see especially Dragesco 1968, Dragesco and Small 1967). Both dinoflagellates and diatoms were found in the food vacuoles of this scuticociliate. (ref. ID; 7603)
Type locality; Samples of sea-ice pore water and sea-ice slush from the Weddell Sea, Antarctica. (ref. ID; 7603)
Pleuronema marinum Dujardin, 1841 (ref. ID; 1622, 1890, 2117, 2316, 3119) reported year? (ref. ID; 1618, 3690, 3771)
Description; Elongate ovoid; trichocysts distinct; caudal cilia medium long; about 50 ciliary rows; in salt water. (ref. ID; 1618)
Characterized by its extensive undulating membrane. P. marinum proved rather fragile after extraction. Caudal cilia clearly displayed but internal organization masked by ingested dinoflagellates. One contractile vacuole was present. (ref. ID; 2316)
Measurements; 51-126 um long. (ref. ID; 1618)
Mean length 100 um. (ref. ID; 2316)
Pleuronema setigerum Calkins, 1903 (ref. ID; 1308, 1335, 1622) reported year? (ref. ID; 1618)
Description; Ellipsoid; flattened; ventral surface slightly concave; about 25 ciliary rows; in salt water. (ref. ID; 1618)
Measurements; 38-50 um long. (ref. ID; 1618)