I found Aspidiophorus bibulbosus in the Paradieswiesen in Austria. In the locations in my vicinity, I have not been able to detect this species so far.

The most striking feature of Aspidiophorus bibulbosus is the clearly dumbbell-shaped pharynx (s. fig. 1 b). The scaled skin consists, as in all species within the genus Aspidiophorus, of small, stalked scales that overlap. Kisielewski (1979) reports 23 rows of longitudinal scale rows on the dorsal side. I found exactly this number as well (s. fig. 4). Kisielewski did not specify the shape of the dorsal and ventral scales. According to my observations, the dorsal scales are ellipsoid in shape with only slightly convex lateral sides. They have a flat keel that occupies about two-thirds of the scale length (s. fig. 3 b). Laterally, I was also able to clearly see the approximately 0.5 µm high stalk of the dorsal scales (s. fig. 3 a). In the dorsal after region, there is a field with enlarged, round scales, which also have a keel, but it extends to the distal end of the scales (s. fig. 5).

Unfortunately, I could only examine the ventral scales from the dorsal side. They have obviously the same shape as the dorsal scales but are somewhat smaller (s. fig. 6). According to my count, there are 10–12 longitudinal rows of ventral scales.

More images and information on Aspidiophorus bibulbosus: Dr. Michael Müller-The small world of freshwater gastrotrichs-Aspidiophorus bibulbosus and Pillerseetreffen-Aspidiophorus bibulbosus