Metopidae

Collected by ATOL magnificent protist hunters at Cedar Swamp near to Woods Hole, Massachusetts, during the Protistology Workshop at MBL. October-November 2005. Isolation and art by Adrian Reyes-Prieto.

Brachonella (brack-on-ella), a heterotrich ciliate, with an adoral zone of membranelles (not well imaged here) and normal cilia on the body. The anterior end of cell is twisted. Distinguished from Metopus by its spiralling adoral zone of membranelles as opposed to the obliquely oriented but not spiralling AZM of Metopus.These cells mostly found in anoxic sites. Phase contrast. 

Brachonella (brack-on-ella), a heterotrich ciliate, with an adoral zone of membranelles (not well imaged here) and normal cilia on the body. The anterior end of cell is twisted. Distinguished from Metopus by its spiralling adoral zone of membranelles as opposed to the obliquely oriented but not spiralling AZM of Metopus.These cells mostly found in anoxic sites. Phase contrast. 

Brachonella (brack-on-ella), a heterotrich ciliate, with an adoral zone of membranelles (not well imaged here) and normal cilia on the body. The anterior end of cell is twisted. Distinguished from Metopus by its spiralling adoral zone of membranelles as opposed to the obliquely oriented but not spiralling AZM of Metopus.These cells mostly found in anoxic sites. Phase contrast. 

Brachonella (brack-on-ella), a heterotrich ciliate, with an adoral zone of membranelles (not well imaged here) and normal cilia on the body. The anterior end of cell is twisted. Distinguished from Metopus by its spiralling adoral zone of membranelles as opposed to the obliquely oriented but not spiralling AZM of Metopus.These cells mostly found in anoxic sites. Phase contrast. 

Brachonella is a ciliate. The cilia, used for movement, are arranged in rows called kineties. In addition, cilia near the back of the cell are used for feeding

The surface of Brachonella shows the numerous cilia arranged in rows.

Collected by ATOL special protist hunters at Long Pond near to Woods Hole, MS, for the Protistology Workshop at MBL, October-November 2005. Art by Adrian Reyes-Prieto.

Portrait of Metopus es, the types species of this sapropelic metopid genus of ciliates. The body is elongate with a bluntly rounded anterior twisted to the left. The posterior is narrow and truncate. The peristome slants obliquely across the ventral surface. There is a prominent adoral zone of membranelles on its left and several kineties of longer cilia along its right margin. The cytostome is at the right posterior end of the peristome. The somatic kineties are longitudinal and uniform. An orange-brown aggregate of refractile granules, typical of metopids, is present in the anterior region. The contractile vacuole is terminal posteriorly. There is an anterior ellipsoid macronucleus. From sapropelic stagnant fresh water pond near Boise, Idaho. DIC optics.

Lateral view of Metopus hasei (Sondheim, 1929).Synomnyms include Metopus fusus (Vuxanovici, 1962) and Metopus latusculisetus (Tucolesco, 1962). The cell is elongate .The anterior end is twisted to the left resulting in a rounded lip that overhangs the peristome.The spiral peristome is bordered on the left by an adoral zone of membranelles and on the right by five closely spaced kineties,the "perizonal stripe".Just to the right of the posterior termination of the AZM is a short, inconspicuous undulating membrane(usually visible only in silver-stained preparations).The The right somatic kineties parallel the peristome anteriorly and the left somatic kineties terminate at the margin of the peristome.There is a tuft of long caudal cilia (visible here). This feature distinguishes M. hasei from flask-like forms of M. palaeformis which lack long caudal cilia. The prominent ellipsoid macronucleus and adjacent micronucleus are in the anterior half. The contractile vacuole is at the posterior end.The cytoplasm contains endosymbiotic methanogenic bacilli.There is an aggregate of brown refractile granules at the anterior end (seen here)typical of the metopid ciliates.Collected from the bottom sediments of an organically enriched rain pool with abundant decaying grass contaminated by Canada goose (Branta canadensis) droppings.Boise, Idaho. January 2006. DIC.

Lateral view of Metopus hasei (Sondheim, 1929).Synomnyms include Metopus fusus (Vuxanovici, 1962) and Metopus latusculisetus (Tucolesco, 1962). The cell is elongate .The anterior end is twisted to the left resulting in a rounded lip that overhangs the peristome.The spiral peristome is bordered on the left by an adoral zone of membranelles and on the right by five closely spaced kineties,the "perizonal stripe".Just to the right of the posterior termination of the AZM is a short, inconspicuous undulating membrane(usually visible only in silver-stained preparations).The The right somatic kineties parallel the peristome anteriorly and the left somatic kineties terminate at the margin of the peristome.There is a tuft of long caudal cilia. This feature distinguishes M. hasei from flask-like forms of M. palaeformis which lack long caudal cilia. The prominent ellipsoid macronucleus and adjacent micronucleus are in the anterior half. The contractile vacuole is at the posterior end.The cytoplasm contains endosymbiotic methanogenic bacilli.There is an aggregate of brown refractile granules at the anterior end (seen here)typical of the metopid ciliates.Collected from the bottom sediments of an organically enriched rain pool with abundant decaying grass contaminated by Canada goose (Branta canadensis) droppings.Boise, Idaho. January 2006. DIC.

Ventral view of Metopus hasei (Sondheim, 1929).Synomnyms include Metopus fusus (Vuxanovici, 1962) and Metopus latusculisetus (Tucolesco, 1962). The cell is elongate .The anterior end is twisted to the left resulting in a rounded lip that overhangs the peristome.The spiral peristome (seen here)is bordered on the left by an adoral zone of membranelles and on the right by five closely spaced kineties,the "perizonal stripe".Just to the right of the posterior termination of the AZM is a short, inconspicuous undulating membrane(usually visible only in silver-stained preparations).The The right somatic kineties parallel the peristome anteriorly and the left somatic kineties terminate at the margin of the peristome.There is a tuft of long caudal cilia. This feature distinguishes M. hasei from flask-like forms of M. palaeformis which lack long caudal cilia. The prominent ellipsoid macronucleus and adjacent micronucleus are in the anterior half. The contractile vacuole is at the posterior end.The cytoplasm contains endosymbiotic methanogenic bacilli.There is an aggregate of brown refractile granules at the anterior end (seen here)typical of the metopid ciliates.Collected from the bottom sediments of an organically enriched rain pool with abundant decaying grass contaminated by Canada goose (Branta canadensis) droppings.Boise, Idaho. January 2006. DIC.

Right lateral view of the infraciliature of Metopus hasei (SONDHEIM,1929).The green arrowheads indicate the five rows of dikinetids comprising the "perizonal ciliary stripe" From a rewetted soil sample collected from the margin of a eutrophic freshwater pond near Boise, Idaho. Stained by the silver carbonate technique (see Foissner, W.Europ. J. Protistol.27:313-330;1991).Brightfield.

Ventral view of the infraciliature of Metopus hasei (SONDHEIM,1929).Only the anterior portion of the adoral zone of membranelles is well impregnated in this image. The dark band bordering the peristome is the perizonal ciliary stripe consisting of five rows of dikinetids.The tuft of long caudal cilia is seen here.From a rewetted soil sample collected from the margin of a eutrophic freshwater pond near Boise, Idaho. Stained by the silver carbonate technique (see Foissner, W.Europ. J. Protistol.27:313-330;1991).Brightfield.

Dorsal view of the infraciliature of Metopus hasei (SONDHEIM,1929).The tuft of long caudal cilia is seen here.From a rewetted soil sample collected from the margin of a eutrophic freshwater pond near Boise, Idaho. Stained by the silver carbonate technique (see Foissner, W.Europ. J. Protistol.27:313-330;1991).Brightfield.

Portrait of Metopus spinosus a polysaprobic ciliate (ventral view). Synonymous with Metopus caudatus. The body is elongate and slightly flattened dorsoventrally. The rounded anterior is twisted to the left and the posterior is drawn out to a tapered point. There is an anterior apical aggregate of refractile granules typical of metopids. Somatic kineties are longitudinal and uniform. The peristome slants obliquely across the ventral surface. There is a prominent adoral zone of membranelles on its left and several kineties of longer cilia along its right margin. The cytostome is at the right posterior end of the peristome. The large ellipsoid central macronucleus is not seen in this image. There is a posterior contractile vacuole.

Metopus violaceus (KAHL, 1927).  Phase contrast.

Metopus violaceus (KAHL, 1927). DIC.

Infraciliature of Metopus violaceus (KAHL, 1927). Stained by the silver carbonate technique (see Foissner, W. Europ. J. Protistol., 27:313-330;1991).Brightfield

Infraciliature of Metopus violaceus  (KAHL, 1927). Stained by the silver carbonate technique (see Foissner, W. Europ. J. Protistol., 27:313-330;1991). Brightfield.

Ventral view of Metopus striatus (synonyms include M. bacillatus, M. gibbus, M. pullus and M. acuminatus among others), a colorless metopid ciliate. The body is broadly domed anteriorly. The posterior end is bluntly tapered or may terminate in a short finger-like process. The oblique peristome with its adoral zone of membranelles terminates at the oral aperture in the posterior 1/3 of the body (seen well here). The large spherical macronucleus is located in the midbody. There is one adjacent micronucleus. The sparse somatic kineties are longitudinal coursing to the left around the anterior dome. There is a longer tuft of caudal cilia. The anterior refractile granules typical of metopids are much less conspicuous in this species. There is a prominent layer of subcortical extrusomes. A single contractile vacuole is located posteriorly. Collected from polysaprobic freshwater pond near Boise, Idaho September 2003. DIC optics.

Optical section through Metopus striatus (synonyms include M. bacillatus, M. gibbus, M. pullus and M. acuminatus among others), a colorless metopid ciliate. The body is broadly domed anteriorly. The posterior end is bluntly tapered or may terminate in a short finger-like process. The oblique peristome with its adoral zone of membranelles terminates at the oral aperture in the posterior 1/3 of the body. The large spherical macronucleus is located in the midbody. There is one adjacent micronucleus. The sparse somatic kineties are longitudinal coursing to the left around the anterior dome. There is a longer tuft of caudal cilia. The anterior refractile granules typical of metopids are much less conspicuous in this species. There is a prominent layer of subcortical extrusomes. A single contractile vacuole is located posteriorly. Collected from polysaprobic freshwater pond near Boise, Idaho September 2003. DIC optics.

Portrait of Metopus striatus (synonyms include M. bacillatus, M. gibbus, M. pullus and M. acuminatus among others), a colorless metopid ciliate. The body is broadly domed anteriorly. The posterior end is bluntly tapered or may terminate in a short finger-like process. The oblique peristome with its adoral zone of membranelles terminates at the oral aperture in the posterior 1/3 of the body. The large spherical macronucleus is located in the midbody. There is one adjacent micronucleus. The sparse somatic kineties are longitudinal coursing to the left around the anterior dome (seen well here). There is a longer tuft of caudal cilia. The anterior refractile granules typical of metopids are much less conspicuous in this species. There is a prominent layer of subcortical extrusomes. A single contractile vacuole is located posteriorly. Collected from polysaprobic freshwater pond near Boise, Idaho September 2003. DIC optics.

Portrait of Metopus striatus (synonyms include M. bacillatus, M. gibbus, M. pullus and M. acuminatus among others), a colorless metopid ciliate. The body is broadly domed anteriorly. The posterior end is bluntly tapered or may terminate in a short finger-like process. The oblique peristome with its adoral zone of membranelles terminates at the oral aperture in the posterior 1/3 of the body. The large spherical macronucleus is located in the midbody. There is one adjacent micronucleus. The sparse somatic kineties are longitudinal coursing to the left around the anterior dome. There is a longer tuft of caudal cilia. The anterior refractile granules typical of metopids are much less conspicuous in this species. There is a prominent layer of subcortical extrusomes. A single contractile vacuole is located posteriorly. Collected from polysaprobic freshwater pond near Boise, Idaho September 2003. DIC optics.