portrait

Description:

Zosterodasys transversa (Kahl,1928) Foissner,1994. (previously known as Chilodontopsis vorax), a large nassulid ciliate. Z. transversa is elongate and dorsoventrally flattened. Both dorsal and ventral surfaces bear uniform longitudinal rows of somatic cilia. A distinctive synhymenion or hypostomial frange runs obliquely posterior to the cytostome around half the cell circumference (seen well in accompanying images). Unlike the similar Synhymenia there is no preoral suture. The cytoplasm is highly vacuolated. There are multiple contractile vacuoles. The macronucleus is ovoid. There is a very prominent anterior cytopharyngeal basket composed of stout nematodesmata. From freshwater pond near Boise, Idaho. Differential interference contrast.