I have found Bryometopus sphagni several times in moss samples from trees and rocks, which I have moistened with a little water. Penard (1922) also found the species in Sphagnum ponds.

According to Foissner (1993), Bryometopus sphagni is characterized by a high variability in size. In my population I have only found specimens below 100 µm in length. At low magnifications the specimens appear slightly kidney-shaped. The oblique mouth opening on the left, apical quarter is typical. It is oval in shape (s. fig. 2 a). The adoral zone runs in a groove diagonally across the body from left to right, where it ends in the anterior third (s. fig. 2 c). On the right side of the groove a paroral membrane is located, which is difficult to recognize.

The specimens in my population always had 2 micronuclei (s. fig. 5). The contractile vacuole was located on the border to the posterior third (s. fig. 2 c) and had a clearly visible, ventrally located excretory pore (s. fig. 3 b). The somatic ciliate consists of cilia arranged in pairs, as is typical for colpodid ciliates (s. fig. 4).