surface

Description :

Detail of the large nassulid ciliate Obertrumia aurea (Ehrenberg, 1833; Foissner 1987). Synonym of Nassula aurea. Obertrumia is distinguished by it's bipartite "hypostomial frange", linear arrays of ciliary tufts. A sigmoid ventrolateral frange runs anteriorly and to the left (not seen in this image) and is separated from a horizontal line of ciliary tufts on the dorsal surface (seen here). The cell appears brightly colored (orange, green or violet) due to multiple food vacuoles containing ingested cyanobacteria. Numerous small mucocysts give the cortex a roughly granular appearance. O. aurea feeds mainly on cyanobacteria. Collected from a freshwater pond near Boise, Idaho November 2003. DIC optics.