Genus: Body blunt at rear; kineties spiralled when body contracts (Illustrated Guide, 1985).
1-3 mm long (without expansion or attenuation);
peristome 2/3 body length; macronucleus moniliform;
size and the length of the peristome separate this species from S. intermedium
(600 μm long , peristome1/2 the body length)
(Carey, 1992).
50 μm
100 μm
150 μm; x 400 :
31 μm
63 μm
94 μm; x 640
Spirostomum ambiguum, x 100, x 200, x 400?, Uruguay Nov. 1999, photo by Yuuji Tsukii
