Bresslaua Kahl, 1931 (ref. ID; 2013, 6945, 7706)
Class Kinetofragminophora: Subclass Vestibulifera: Order Colpodida (ref. ID; 2013)
Suborder Colpodina Foissner, 1978: Family Colpodidae Ehrenberg, 1838 (ref. ID; 7706)
Family Colpodidae Ehrenberg, 1838 (ref. ID; 4692)

[ref. ID; 2013]
Occurs in 2 morphological forms depending upon nature of food supply. The smaller (microstome) form grows when micro-algae and bacteria are the food source; this transforms into the larger (macrostome) form when fed upon ciliates.
Microstome: Shape reniform to ellipsoid, plastic, dorso-ventrally compressed. Uniformly ciliated, cilia in pairs. Indentation on left side marking the entrance to the ventrally situated vestibulum. Morphology and vestibulum of microstomes similar to that of Colpoda except that in Bresslaua when viewed orally the apex of the triangular-shaped vestibular opening is directed posteriorly (in Colpoda in points anteriorly). Contractile vacuole terminal.
Macrostome: Oval in outline with rigid body, dorsally convex, ventrally flattened. Vestibulum greatly enlarged so that it occupies almost two-thirds of body. Viewed dorsally there is a cleft on the left anterior margin which marks the vestibular opening and below it lies the ventral half of the body which juts out anteriorly to the dorsal half. Macronucleus rounded. Division takes place within cysts. Resting cysts with thicker walls also formed. Contractile vacuole on dorsal side in posterior half but not terminal.
Quote; Colin R. Curds "British and other freshwater ciliated protozoa Part I Ciliophora: Kinetofragminophora" Cambridge University Press, 1982 (ref. ID; 2013)

Bresslaua vorax Kahl, 1931 (ref. ID; 4692) reported year? (ref. ID; 1618, 1622, 2099, 7600) reported author and year? (ref. ID; 191)
Description; Dimorphic; microstome form, pyriform to reniform, plastic, with a latero-ventral invagination, 35-100 um by 16-50 um; macrostome form, oval in dorsal view; rigid with convex dorsal and flattened ventral surface, up to 250 um long; the prominent cleft in the anterior quarter forms the anterior margin of vestibular opening; one macronucleus and one micronucleus; encystment. (ref. ID; 1618)
Morphology and morphogenesis. (ref. ID; 7600)