I only find Clathrostoma viminale very rarely. I have only documented two finds so far. The first is from 2006 from the Simmelried and the second in 2024 from the pond of the convent Hegne. In both cases, the specimens were found among decomposing plant material.

Clathrostoma viminale can easily be confused with Frontonia leucas at low magnifications. The body shape, position of the mouth and size are similar. Only at higher magnification can one recognize that the slit-shaped mouth opening of Clathrostoma viminale is surrounded by concentric rings of stabilizing rods, which support the entire oral apparatus (s. fig. 3 a-b). These rods reaching deep into the cytoplasm. Like Frontonia, Clathrostoma viminale has a preoral and a postoral suture above and below the mouth opening (s. fig. 4). However, these are less pronounced than in Frontonia. The pellicle is very characteristically reticulated. The macronucleus is sausage-shaped with tapered ends (s. figs. 7). It denatures quickly under coverslip pressure. In my population there were always 2 micronuclei. According to Kahl there can be up to 4. The contractile vacuole is located in the center of the body on the right side. There is an excretory porus on the ventral side (s. fig. 2). The extrusomes are scattered and irregular under the pellicle. They are spindle-shaped. According to my measurements they are 6.0–6.5 µm long (s. fig. 8).