Pleuronematidae

Longitude (deg): -0.7. Latitude (deg): 51.1. Longitude (deg/min): 0° 50' W. Latitude (deg/min): 51° 10' N. Vice county name: Surrey. Vice county no.: 17. Country: England. Associated species: Marchantia polymorpha. Identified by: Malcolm Storey. Comment: with Marchantia polymorpha. Category: standard photograph or close-up. Photographic equipment used: "35mm transparencies (on a variety of films, but Agfa CT18 in the 1960's to early 1980's followed by Fujichrome in the late 1980's.) Transparencies scanned with Minolta Dimage Scan Dual II AF-2820U transparency scanner.".

Logroo, La Rioja, Espaa

Talveila, Castille and Leon, Spain

Pleuronema (ploo-row-knee-ma) is a scuticociliate - a group that distinguished by a well developed undulating membrane associated with the mouth. The scuticus refers to the hook -shape of the line of cilia associated with the mouth. The scuticus is used to help capture suspended bacteria which are ingested as food. In this individual. Mostly marine. Phase contrast.

Pleuronema (ploo-row-knee-ma) is a scuticociliate - a group that distinguished by a well developed undulating membrane associated with the mouth. The scuticus refers to the hook -shape of the line of cilia associated with the mouth, and the curve of this hook can be seen as the light curving line to the left near the equator of the cell. The scuticus is used to help capture suspended bacteria which are ingested as food. In this individual, the membrane (or sail) is not extended. Mostly marine. Phase contrast.

Pleuronema (ploo-row-knee-ma) is a scuticociliate - a group that distinguished by a well developed undulating membrane associated with the mouth. The scuticus refers to the hook -shape of the line of cilia associated with the mouth. The scuticus is used to help capture suspended bacteria which are ingested as food. In this individual. Mostly marine. Phase contrast.

Cedar Swamp, Woods Hole, Massachusetts, USA. Photoed by Hwan Su Yoon.

Cedar Swamp, Woods Hole, Massachusetts, USA. Photoed by Hwan Su Yoon.

Pleuronema (ploo-row-knee-ma); a genus of very fast swimming ovoid ciliates. When feeding, the ciliates rest motionless and can be observed with care. Cells of Pleuronema coronatum, this species, measure 60 - 90 microns. There is a large prominent undulating membrane marking off the right edge of the peristome. The macronucleus is spherical and more or less centrally located. The posterior end of the cell has several long caudal cilia. The contractile vacuole is located in the posterior third of the cell. This species is found in fresh water ponds and lakes. This specimen is a resting specimen with a round macronucleus and an extended undulating membrane. 76 microns. Differential interference contrast.

Pleuronema (ploo-row-knee-ma); a genus of very fast swimming ovoid ciliates. When feeding, the ciliates rest motionless and can be observed with care. Cells of Pleuronema coronatum, this species, measure 60 - 90 microns. There is a large prominent undulating membrane marking off the right edge of the peristome. The macronucleus is spherical and more or less centrally located. The posterior end of the cell has several long caudal cilia. The contractile vacuole is located in the posterior third of the cell. This species is found in fresh water ponds and lakes. This mage emphasizes the caudal cilia. 76 microns. Differential interference contrast.

Left lateral view of the hymenostome ciliate, Pleuronema coronatum (Kent, 1881). The cell is ovoid to fusiform and slightly dorsoventrally compressed. The teardrop shaped peristome begins subapically and extends about 2/3 the cell length. There is a prominent undulating membrane on its right border. This curves around the posterior margin of the peristome forming a distinct pocket. The cytostome is in the center of this pocket. Fibrils radiate from the margin of this pocket to the cytostome. There are three adoral membranelles. . There are many longer caudal cilia. The otherwise very similar P. crassum has no tuft of longer caudal cilia. There is a fring of fusoform subcortical extrusomes (visible here at the posterior end).The spherical macronucleus is central and has 1 to 8 adjacent micronuclei. The single posterior contractile vacuole empties through a dorsal excretory pore. P. coronatum, like Histiobalantium, swims very rapidly, intermittently coming to rest. Members of the genus Pleuronema can be distinguished in vivo from the similar genus, Histiobalantium, by the absence of longer, stiff bristle-like cilia interspersed with shorter somatic cilia seen in the latter genus. Collected from a freshwater pond near Boise, Idaho March 2005. DIC.

Left lateral view of the hymenostome ciliate, Pleuronema coronatum (Kent, 1881). The cell is ovoid to fusiform and slightly dorsoventrally compressed. The teardrop shaped peristome begins subapically and extends about 2/3 the cell length. There is a prominent undulating membrane on its right border. This curves around the posterior margin of the peristome forming a distinct pocket. The cytostome is in the center of this pocket. Fibrils radiate from the margin of this pocket to the cytostome. There are three adoral membranelles. . There are many longer caudal cilia. there is a fringe of fusiform subcortical extrusomes (seen well here). The otherwise very similar P. crassum has no tuft of longer caudal cilia. The spherical macronucleus is central and has 1 to 8 adjacent micronuclei. The single posterior contractile vacuole empties through a dorsal excretory pore. P. coronatum, like Histiobalantium, swims very rapidly, intermittently coming to rest. Members of the genus Pleuronema can be distinguished in vivo from the similar genus, Histiobalantium, by the absence of longer, stiff bristle-like cilia interspersed with shorter somatic cilia seen in the latter genus. Collected from a freshwater pond near Boise, Idaho March 2005. DIC.

Ventral infraciliature of the hymenostome ciliate, Pleuronema coronatum (Kent, 1881). The cell is ovoid to fusiform and slightly dorsoventrally compressed. The teardrop shaped peristome begins subapically and extends about 2/3 the cell length. There is a prominent undulating membrane on its right border. This curves around the posterior margin of the peristome forming a distinct pocket. The cytostome is in the depths of this pocket. Fibrils radiate from the margin of this pocket to the cytostome. There are three adoral membranelles. M1 begins at the anterior end of the undulating membrane and forms an acute angle with it as it extends posteriorly for a short distance. M2 is bipartite. The long anterior portion begins in the angle between M1 and the undulating membrane and extends posteriorly to the termination of the undulating membrane. At the posterior end of this part there is a sharp indentation rightward toward the peristome. This feature of M2 differentiates the "coronatum"� type oral apparatus from the "marinum" type in this genus. There is a separate V-shaped part of M2 on the right side of the peristomal pocket. Some workers describe this as M3 but Foissner includes it as part of M2 and designates the two divergent kineties to its left as M3 (Foissner W., Berger H and Kohmann F. Taxonomische und ökologische Revision der Ciliaten des Saprobiensystems- Band III: Hymenostomata, Prostomatida, Nassulida. Informationsberichte Bayer. Landesamtes für Wasserwirtschaft. 1/94: 278-284, 1994). There are approximate 35 somatic kineties with 2 to 6 preoral kineties and no postoral kineties. There is a short preoral suture and a broad postoral suture in the center of which the cytopyge is located. The anterior apex of the cell is unciliated. There are many longer caudal cilia. The otherwise very similar P. crassum has no tuft of longer caudal cilia. The spherical macronucleus is central and has 1 to 8 adjacent micronuclei. The single posterior contractile vacuole empties through a dorsal excretory pore. Stained by the silver carbonate technic (see Foissner, W. Europ. J. Protistol., 27:313-330;1991). Collected from a freshwater pond near Boise, Idaho March 2005. Brightfield.

Detail of oral infraciliature of the hymenostome ciliate, Pleuronema coronatum (Kent, 1881). The cell is ovoid to fusiform and slightly dorsoventrally compressed. The teardrop shaped peristome begins subapically and extends about 2/3 the cell length. There is a prominent undulating membrane on its right border. This curves around the posterior margin of the peristome forming a distinct pocket. The cytostome is in the depths of this pocket. Fibrils radiate from the margin of this pocket to the cytostome. There are three adoral membranelles. M1 begins at the anterior end of the undulating membrane and forms an acute angle with it as it extends posteriorly for a short distance. M2 is bipartite. The long anterior portion begins in the angle between M1 and the undulating membrane and extends posteriorly to the termination of the undulating membrane. At the posterior end of this part there is a sharp indentation rightward toward the peristome. This feature of M2 differentiates the "coronatum"� type oral apparatus from the "marinum" type in this genus. There is a separate V-shaped part of M2 on the right side of the peristomal pocket. Some workers describe this as M3 but Foissner includes it as part of M2 and designates the two divergent kineties to its left as M3 (Foissner W., Berger H and Kohmann F. Taxonomische und ökologische Revision der Ciliaten des Saprobiensystems- Band III: Hymenostomata, Prostomatida, Nassulida. Informationsberichte Bayer. Landesamtes für Wasserwirtschaft. 1/94: 278-284, 1994). There are approximate 35 somatic kineties with 2 to 6 preoral kineties and no postoral kineties. There is a short preoral suture and a broad postoral suture in the center of which the cytopyge is located. The anterior apex of the cell is unciliated. There are many longer caudal cilia. The otherwise very similar P. crassum has no tuft of longer caudal cilia. The spherical macronucleus is central and has 1 to 8 adjacent micronuclei. The single posterior contractile vacuole empties through a dorsal excretory pore. Stained by the silver carbonate technic (see Foissner, W. Europ. J. Protistol., 27:313-330;1991). Collected from a freshwater pond near Boise, Idaho March 2005.

Oral infraciliature of the hymenostome ciliate, Pleuronema coronatum (Kent, 1881). The cell is ovoid to fusiform and slightly dorsoventrally compressed. The teardrop shaped peristome begins subapically and extends about 2/3 the cell length. There is a prominent undulating membrane on its right border. This curves around the posterior margin of the peristome forming a distinct pocket. The cytostome is in the depths of this pocket. Fibrils radiate from the margin of this pocket to the cytostome. There are three adoral membranelles. M1 begins at the anterior end of the undulating membrane and forms an acute angle with it as it extends posteriorly for a short distance. M2 is bipartite. The long anterior portion begins in the angle between M1 and the undulating membrane and extends posteriorly to the termination of the undulating membrane. At the posterior end of this part there is a sharp indentation rightward toward the peristome. This feature of M2 differentiates the "coronatum"� type oral apparatus from the "marinum" type in this genus. There is a separate V-shaped part of M2 on the right side of the peristomal pocket. Some workers describe this as M3 but Foissner includes it as part of M2 and designates the two divergent kineties to its left as M3 (Foissner W., Berger H and Kohmann F. Taxonomische und ökologische Revision der Ciliaten des Saprobiensystems- Band III: Hymenostomata, Prostomatida, Nassulida. Informationsberichte Bayer. Landesamtes für Wasserwirtschaft. 1/94: 278-284, 1994). There are approximate 35 somatic kineties with 2 to 6 preoral kineties and no postoral kineties. There is a short preoral suture and a broad postoral suture in the center of which the cytopyge is located. The anterior apex of the cell is unciliated. There are many longer caudal cilia. The otherwise very similar P. crassum has no tuft of longer caudal cilia. The spherical macronucleus is central and has 1 to 8 adjacent micronuclei. The single posterior contractile vacuole empties through a dorsal excretory pore. Stained by the Protargol technic (Wilbert modification) (see Foissner, W. Europ. J. Protistol., 27:313-330;1991). Collected from a freshwater pond near Boise, Idaho.Brightfield

Originally described by Ehrenberg under the name Paramecium chrysalis.

Originally described by Ehrenberg under the name Paramecium chrysalis.