portrait

Description:

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.