in vivo

Description :

Portrait of Balanonema dubium (penard,1922) Kahl,1931, a philasterine scuticiciliate. The body is a slightly dorsoventrally flattened cylinder both ends of which are bluntly tapered into plug-like projections. There are subapical anterior and posterior grooves at the base of the terminal projections which spiral around half the cell circumference (seen in accompanying images). The cytostome is small (about 20% of the cell length), anterior and inconspicuous (seen in accompanying image). Kineties are longitudinal and cilia are sparse in the mid body and denser at the anterior and posterior ends. The subcentral macronucleus is spherical. The contractile vacuole is also subcentral (both are seen well in this image). There is a long caudal cilium in some species. The cytoplasm of this species contains numerous small ring shaped granules similar to the glycogen granules of Dexiotricha granulosa, another philasterine scuticociliate. From sediment of slow-flowing organically enriched freshwater runoff stream near Boise, Idaho. Differential interference contrast.